As one who constantly alternates between hard and full squish, this makes total sense and aligns with what I’ve felt over the years. Great video and content!
Damn i wish you made this 8 months ago. Cause it now make so much sense why my hardtail feels bigger than my full squish rig even though the geo numbers are the same.
Yup, with the sport's marketing focus on West Coast riding there is a growing gap in reality for East Coast riders. It's being filled by smaller brands, though they're still a bit expensive for average joe.
Great description of the movement of the full-suspension bike! Regarding hardtails, it is impossible for a hardtail to lengthen when the fork is compressed (using a standard telescoping fork). The lengthening as demonstrated is an illusion. Here is why: the front hub moves toward the rear hub as the fork compresses. In doing so, the headtube angle gets steeper. This pitches the handlebar forward as the wheelbase shortens which makes it appear that the bike is getting longer but the handlebars are on a different plane than the hubs. In order to truly lengthen a hardtail, the headtube angle would have to slacken and the front hub would have to move forward, or away from the rear hub. This happens when you wheelie or manual. So in reality, both hardtails and full suspension bikes shorten as the suspensions are compressed. Thanks for the great vids!
I had the same initial reaction as yourself regarding the hard tail. In order to do a proof of the "science", I crunched the numbers using my bikes geometry and it turns out that the reach does lengthen. Bear in mind that when the fork compresses, everything you say happens, and in addition then, the reach measurement takes place at a different plane because of the steepened head tube angle and shortened stack height as a result. Reach being measured at a line that intersects at a horizontal line from the headset to a vertical line at 90 degrees from the bottom bracket. See my separate post regarding actual numbers. This can all be calculated using some trig calcs.
Great food for thought in this video. Must admit, being a logic and data driven personality, I did a double take after seeing the assertion that the hard tail reach increases when dropping into the forks. A quick logic check didn't make sense for me. My initial reaction was that the drawing on the board represented a drop onto the forks shortening the length of the wheelbase and that reach actually also decreased. To prove or disprove my logic, I of course went into the maths. I used my bikes geometry as a starting point. It is a full suspension bike but I assumed in the calculations it was a hard tail. I crunched the numbers and, in summary , they verify that the reach does indeed increase when using the fork travel. Must admit, I had to delve deep into my memory to extract the high school maths knowledge from almost 4 decades ago. The basic numbers used as a starting point for the calcs were: Reach 500mm Wheelbase 1245 mm BB Drop 35mm (ignored this for parts of the calcs to keep it simple) Chainstay 434mm Fork Offset 48mm Fork Travel 130mm Fork plus headtube length 660mm Head Tube angle 66.5 The end result was that, assuming using full fork travel of 130mm, Reach increased from 500 to 555mm, Stack decreased from 605 to 505mm (excl BB drop), Wheelbase decreased from 1245 to 1199mm, and head tube angle steepened to 72.2 degrees.
THat's awesome! Someone commented earlier about the same thing, they thought I meant the entire bike grew but like you pointed out it's really just the reach, the wheelbase shrinks.
This explains why I feel comfortable on a full squish. I’m a small guy 5.5ft almost always ride S in a hardtail. Few months ago I went all out & got Supercaliber in M since I couldn’t find one in S (at least at my price point). But out of surprise the bike fit was perfect even though geometry numbers were waaay out of my reach.
Jeff is such an asset to the sport. Decades of experience behind these insights. It’d be interesting to see a similar analysis for wheelbase (tall guys know about wheelbase) and the relationship between front center and chainstay length.
as a dedicated hardtail rider, I appreciate the explanation of he difference. I would have a hard time making a modern bike fit me with the "compact" fit I prefer.
Jeff, I'm sure I'm not the only one whom has been saved by this video from choosing a frame size too large (especially when going from full suspension to hardtail). Thanks!!
Man. Love your videos. Much appreciated! I am 46. 6’1 with 35” inseam, and prefer to ride size Large frames. Recently watched Lee’s RAD measurement video. As soon as I was done watching, ran to a park nearby, and did a bench test to see if my bike fits. It is SPOT ON. 😁
I love riding hardtails, and currently only ride a HT. Never thought of this take on sizing. Great video. And I love their vids on RAD sizing and pretty much everything else they do. I've made fit changes to my bike from watching those vids and has helped me progress past a plateau I think I've been stuck at for a while.
Just like joy of bike and Lee, another video telling me i need a shorter stem for my hard tail. My RAD is at least 3 cm shorter than my current bike set up. Thank you for the HT / FS comparison: haven't seen that before.
Got to know the things no body talk and even explains for a beginner like me. Most of the videos are more technical. But thanks to you I am now more clearer about right size bike. And also thanks for the link of the RAD video.
The minute you referred your viewers to Bogusky’s RAD measurement videos I knew you were trustworthy 😉 Their videos make so much sense and O completely buy into that methodology. Great vid man
Thanks! I love their channel but it’s funny that I’ve been riding PRO for 25 years and THEY make me trustworthy. Lol. I’m hoping to ride with those dudes in a couple weeks.
@@JeffLenoskyTrailBoss You seem slightly annoyed by my compliment? Upper case words and the lot 🤣 I should have worded it differently then...“The fact that you do not simply promote longer/slacker/longer makes you trustworthy”. Take it easy...PRO
just bought (and sold )a hardtail, witch had "modern geometrie", the reach was 20mm longer then my full sus(witch also falls within the RAD) , with a shorter stem my cockpit length was almost the same as my full sus, but it felt way longer...and now i know why! it was quite stable, when i changed to my fuel ex , that thing felt nervous, but the hardtail was good for straight lines, but not for hopping or jumping . (cornering wasnt even that bad)...seeing this vid strengthens me in my believe i made the right choice selling the bike again, an that i can buy a shorter hardtail. i will try some bikes first, but this was really helpfull! so tnx!
Excellent and easily understood explanations and "experiments", Trail Boss! Can't wait to see you, Lee, and Alex getting together to talk MTBs and ride! Some charismatic chemistry ... You'll be a terrific trio!
Great news. I've accidentally got 2 bikes that are exactly the right size for me. My Giant Reign is right on R.A.D measurement and my Nukeproof Scout is about 40mm R.A.D minus according to Lee and Alex's formula. They've also got a video out with bar sizing, and "bang", I'm spot on with my sizing there too. Wow, that stuff never happens to me! I'd normally be the exact opposite of what I should be.
Thanks for addressing this issue. I am one of those riders who at 5’5” 29 “ inseam is sought of in between S and M frames depending on cockpit dimensions. I always have to test ride a bike. Currently my full suspension is a M size Santa Cruz Tallboy 29 that fits perfect. It’s my understanding that SC bikes run a little tighter so size up is common. Thinking of getting a Giant Trance X 29 and reading that they run a little longer. Will definitely have to test ride. This can be challenging with the supply chain delays and emphasis to order and ship to the bike shop.
I definitely would have made the mistake of buying a hard tail with the same measurements as my full squish. Knowing that I can go smaller gives me some hope that I can actually a find a hard tail that fits me. Thanks for the video and helpful experiments!
Great informative video! The only thing I’d like to add is definitely get a size that compliments the area you ride in. Not all West Coast areas are wide open trails, we got a lot of twisties and tech stuff out here too!
I change bike every 6 mos so I buy bikes 2x / yr. What I'm doing is I place my elbow at the back of steerer tube/stem and my fist towards the saddle. My fist should touch or at least have 1-1.5 cm allowance to the tip of the saddle. That's the perfect fit for me and it never fails. If there's too much room, adjust the saddle to safe mark. If there's too much room still, bike is too big for me. By the way, it only works if you have 35mm or shorter stem length. For FS, same technique but need help from someone that will push the saddle down according to your weight and PSI settings.
Great explanation. I like the "East Coaster" comment. I am in central CT, riding dynamics are from really twisty to really gnarly. The variety is awesome!
I am completely sold on the RAD measurement for my next bike purchase. I have a 2016 Process 134 Medium, that I thought was too short in the reach dept. (435mm, also I was 5'10", I shrunk to 5'9", 33" inseam). Based on some demos of large frames, I thought I needed a large frame for my next bike. Like you said the perceived stability downhill was great (I'm a plowing, wheels on the ground kinda guy). What I now understand is that longer reach would actually compromise the row/anti-row we use for bunny hops, jumps etc.. So, I measured the RAD on my old process (BB ctr to pt. between grips), and low and behold it's right at the recommended RAD neutral position, maybe a bit RAD+. Knowing this, your info above, and living on the east coast (VT) I'd probably stick with a Medium frame (450mm reach), not Large (475mm+) to keep that manueverability. I also played around a lot with anglesets, overforked my 140mm fork to 160, and changed the HTA from 68 to 65 in combo with a -2 works angleset. That alone was a huge confidence booster in steeps. So before when I thought I needed a longer reach, really all I needed was a more slacked out fork to help rip the trails I ride. Overall, the last couple years have shredded my perspective on bike sizing. Now if I could just go back in time and buy the right bike in the first place... :P
Im getting into MTB coming from Dirtbiking and BMX when I was younger. Im 5'9.5" with a 30" inseam. My APE is 1:1. Im looking at IBIS RIpmo and their chart says Large. The medium reach is 460mm, stack 619mm, seat tube angle 77'. I have no clue what im looking at lol. The large reach is 475mm. IBIS said they recommend me on the large. I wish I could sit on these bikes to confirm I want the medium and not make a huge mistake w/ a large
@@2Tsmoke I am very close to that but I think you have a longer torso so you might be more comfy on a large, reach wise. However - the only issue will be the seat tube length, with your shorter inseam the longer seat tube will limit your dropper length and the jump can sometimes be significant from Med-Large (30mm or more!). So scout out the geo charts and if it’s too much of a risk I’d stick with a medium. If your riding is techy and slower, you might be better off with a shorter wheelbase anyway. If you do more jumps, higher speeds (20mph+) or bike park a large frame may suit your style more. Good luck! EDIT: I’m seeing the large frame has a 432mm seat tube which is actually shorter than most (sometimes 450+). The medium is 406mm.. You might get away with the large, but do consider the terrain you’re riding, as well.
@@rpiian thanks for the reply - this gives me some things to consider. I'm swaying more towards the medium for my local terrain but I will also be going to bike parks on rare occasions. I'm in the Midwest so we have some gnarly rooty single track but it requires lots of pedaling up and then down. Appreciate the response!
@@2Tsmoke For sure! I’m no expert but that’s been my experience as a 5’9” dude. Can always run a longer stem on a medium. Not ideal but I’ve done it in the past to stretch out an older geo medium (430 reach). Bonus is added front wheel traction. I’m pretty comfy at 450-460 currently.
thank you so much for this. Looking at moving to a full suspension from a 10 year old hard tail. they all feel too big. All the bike shops want me to move to a XL, my hard tail is a L frame. I'm 6'2" 34" inseam. This video help me understand fit better than any bike store.
I ride L size frame with 27.5 and usually M size with 29. I like a little more nimble bike for my tight trails in OH. Not many real extended downs where the length is needed for stability here. I'm a tweener @ 5'10" with a longer torso than legs... hard to find the right fit. I have to monkey with stem lengths and saddle positions to get it right. Great explanation and keeping it simple.
das habe ich früher auch immer gemacht - ganz schlechte entscheidung! immer wenn ich anfing die sattel position(vor oder zurück) zu verändern kam ich mit denm bike nie mehr wirklich zurecht. vor allem dann nicht wenn man auch entsprechend uphill unterwegs ein möchte. beide aktionen (sattelposition -und vorbau länge veränderungen sind nicht gut. genau diese beiden werte sollen passen. bei meinem vorigen HT hab ich den sattel nach hinten geschoben um gefühlt mehr platz zu bekommen, die folge waren rückenschmerzen, nackenschwmerzen und sitzknochen beschwerden. beim neuen rad ist alles in ordnung - weil eben die geo für mich passt - sobald der reach wirklich passt, sind alle sorgen weg.
Great video! At 5' 10" with average proportions I can often switch between L and M frames. After trying both, I decided on a L Megatower and Spot Ryve, but went with a M Chameleon for my hardtail. Part of that decision was simply wanting different riding plans for the bikes. The MT is my "park" bike where I want it long and stable. The Chameleon is more for jibbing at playing. Granted, I bought the two Santa Cruz frames back in early 2019, so it was as much a case of blind luck as anything else.
I think a lot of this left coast stuff influences the bike industry, even though it's not practical for a lot of areas. If I was doing nothing but 5000 ft. of climbing on steep fire roads only to descend again with my seat fully down, a 76+ degree seat tube angle (and 8' wheel base) might make sense. But if you are spending half your time on relatively flat trails or quick up and downs, that steep seat tube angle is only efficient with a 200 mm negative rise stem and pursuit bars.
i am riding a xs surly ICT for trails and trials i am 5'5" everyone always say i should ride a 17"/16" frame, i am so glad this videos on here it proves my point for the smaller frame
Truth. Unless youre going full speed down hill, a smaller bike will always be more fun, more agile, lighter, and easier to maneuver. Yes, its slower downhill, that is totally ok by me. I like my uphills to be short and easy, and my downhills to be long and challenging. Its why i bought a XC bike!
@@RC-DC Yup. Modern fat tires turn any full suspension bike into a better down hiller than dedicated down hill bikes from the 1990s. I used to ride 1.5 inch wide cross tires on my mountain bike. It was astoundingly agile and sharp on pavement, yet had enough width for dry hard SoCal dirt trails. But modern 2.6 tires are absurd. You can roll over mud sand snow and rocks. They are suspension all by themselves! My next xc bike is getting 2.4 tires, minimum. I don't know if you're familiar with this site, but you may want to look around it. www.bicyclerollingresistance.com/mtb-reviews Especially this tire. 2.2 wide and 497 grams. Crazy light. Want. www.bicyclerollingresistance.com/mtb-reviews/continental-race-king-racesport-2014
Wish you had made this video 3.5 years ago :-) would have saved me some "learning" opportunities and expenses. Really appreciate the info and I have shared with others. Never have found good resources that really talk about what aspects of geometry are important for what. Each person's arm/torso/leg lengths (and maybe even neck plays a part) are rather unique and it took me some time to figure out what parts of the geometry I need to look for to have a good fit/balance/confidence when riding. I usually need a longer reach with full suspension bikes. head tube angle is what I look for with the type of riding I do, which is a mix of everything, so 67 and above a little too steep, but 64 and below a little too slack. Seat tube angle has been important for how well the bike pedals when on flat/uphills, steeper usually being better. Seat tube length and standover height I'm still working out for me, but I know that for rear wheel scoops for less dialed jumps and rowdy terrain I want a lot of space between my bum and my saddle, moving the bike around is harder when I don't have that. wheel base and chainstay lengths are important but I don't know exactly why or what would be important for me...reach and head tube angle are usually what I look for to have a fun, balanced ride. By really fitting myself for my current bike, I've been able to learn a ton with confidence, and now I can adapt pretty easily to other bikes with different geometries (ie I travel a lot and rent a lot of bikes). I have learned to have a good bit of fun doing what the bike I have rented is really good at that is different on my bike at home. So much depends on a person's unique body composition and the riding they want to do.
Thankfully, the Jamis i bought is sized perfectly. I have another hard tail that feels a bit too long and your explanation confirms what i have experienced. Btw, i like twist turns more than speed through the trails. I ride my road bike off i wanted speed. Lol
My man Glad I came across your video Just ordered the new. 2023 ibis dv9 frame. (It’s a hardtail). I’m between lg-xl I went with my gut chose the Large. I’ve been second guessing, and after watching your video, I’m comfortable with my choice actually pretty happy. I’m an Midwest rider we have narrower more technical trails with awesome dirt
At 6'6" it has been pretty hard to find bikes to fit. When I first started riding mountain bikes in the mid 90's 26" wheels and a 22" frame bikes always seemed small. Fast forward to today I'm riding Specialized Fuses XXL with 29" wheels and a Trek Fuel EX8 XXL 29" wheels. It amazing how much more comfortable the bikes feel. Still hard to find bikes that fit, but it is easier.
I am 5.9 and thus often between sizes. I choose to go with a size M over a L (Trek soft tail bike, or optional M/L) because in the end you can always make a smaller bike bigger, but you are limited the other way around.
This was interesting to see! I dilly dallied when purchasing my hardtail last year, so all the large frames were sold out. I ended up with an XL frame. It works, but it has been very hard learning manuals, etc. on it compared to an old large full squish bike. I can get the old bike to the balance point, but not the new one.
Joy of Bike are a great channel! The RAD approach makes slot of sence, yet factor in your riding type XC will benefit from a longer RAD measurement dependant on terrain. Short bikes feel unstable to me, as I ride XC/trail and flowy fast trails are preferred over dabbing, big bunny hops etc Factor your ride style and terrain and get another bike if you want b to venture into something different.
Wow...RAD was great and I was using it before, but you illustrated to me why my 480mm Reach Torrent HT in Large, feels so much longer than my 480mm Reach, Siskiu T in Large, on the trail...
Great video. I never looked at the difference between hardtail and full suspension reach numbers like that. Makes sense to me. I am looking at getting a hardtail in the future and will definitely use this info to make sure I get the right size. Thanks Jeff.
Feel like a similar effect happens when you setup your front and rear suspension hard or soft. I demo’d a remedy with suspension pumped to the moon and it felt insanely good. Bought one and tailored the pressure to my weight to be supple / correct and it feels slightly small. Have a HT with longish top tube and shortish WB and it feels like the bars are a mile away. This definitely speaks to me. Nice video. Crazy!
I found this video and I watched half of your rad from a month ago. Thx for the info. I'm looking at a 2021 Schwinn Axum DP Dropper Post MTB. I'm on a budget and weekend rider from time to time.
What you're referring to is really pitch and yaw. More Pitch though regarding the perceived lengthening and shortening of the bike. Obviously a hardtail will pitch less, meaning there will be less weight transfer (energy or kinematics) from rear to front under braking and virtually no pitch from the front to the rear under acceleration (pedaling) Physics dictates that a bike wants to rotate around its 3 CoG intersecting axes. Full suspension bikes have much more weight transfer both fore & aft. Much more on a motorcycle because of the engine torque; acceleration & deceleration + the braking forces.
That's super interesting but I feel like weight transfer is exaggerated on the hardtail since it all pivots from the rear axle into the fork... I definitely run my front suspension stiffer on my hardtail vs full sus because of that.. you're making me ponder it more!
@@JeffLenoskyTrailBoss I think that's interesting that you feel like the load (weight) transfer is more prevalent on the hardtail. I understand what you mean as I have switched over to a hardtail this year. I do feel like the weight or load shift from rear to front feels a bit harsher with a quicker front 'dive' response. I believe this is just a perception rather than an actuality of the load forces. At least for me I believe it's a perception. One of the reasons could be that because of the rigid rear, it's a more abrupt transfer. On a FS, even if the rear suspension is not compressing very much or is set a bit on the stiffer side, it is still transferring load during it's travel. The bike tends to be more in balance under braking or hard pedaling where as the hardtail exhibits fairly the same characteristics. The only 'suspension' would be the rear tire and wheel. Which could result in some variations depending on the width of the tire and the air pressure. Another factor in load transfer would be the length of the wheelbase. Also CoM & total bike weight would be contributing factors as well. I tell you two wheeled Vehicle Dynamics or any vehicle dynamics are enough to hurt your head! 😄 I mean I only scratch the surface & I'm still learning but the physics behind what's happening when we ride bikes is just mind-blowing!
I wouldn't have thought that hardtails were so different to full-sus bikes so that was interesting. I need way more explanation though to understand what you mean by long or short bikes. Intuitively a short bike would mean shorter wheelbase which would make it better for slower speed riding.
Very interesting. That marker test is pretty clever! I read Mr. McCormack's book, Dialed, and bravely ordered a short-travel Sqweeb V3 in a size medium this January. It has the same reach as the "XL" XC hardtail my local Specialized dealer put my 6'1" body on now. That bike feels a bit too big, even after swapping the 70mm(!) stem for a 40mm one. But that Steering Hands Offset is almost perfect with the shorter stem
@@josephfarrugia2350 The Sqweeb is the nicest bike I've ever had, so I don't have much to compare it with, besides what my friends have upgraded to over the years. It's an insanely well-built machine that is whisper quiet and feels sturdy--something I'll have for many, many years. I've done a few foolish things on it, but the bike's bare-metal finish shrugged the resulting tumbles off. 🤘 The fit on the medium ended up fine, even if there's still some seat post sticking out of the frame in addition to the 200mm Oneup dropper. Now that I've spent a year on the medium, I don't think a large frame would have been too clunky, but I really enjoy the snappiness of the medium with the 40mm stem it shipped with. It definitely handles turns more easily than the XL Rockhopper, despite the Sqweeb's longer wheelbase.
Geometry is a tricky thing when suspension is involved. Your demonstration is very useful but just note; the bottom bracket, particularly on a hardtail, is also moving forward/downward through the fork stroke. So your total observed change in length at the handle bar is more than the actual change in reach length. A hard tail is pivoting from the rear axle not the bottom bracket. Still agree that the reach should be slightly less on a HT than a full suss but not by too much. I have played a lot with my HT (which is what i prefer to ride most of the time on moderately aggressive terrain) to achieve minus, neutral and plus R.A.D.; and for me neutral feels best.
That's actually false. The bb moves back as the fork compresses. The bb is always lower than your axels on a mtb, so if you take the line segment from the rear axel to the bb and rotate it downwards around the rear axel, because it's already below horizontal, it can only move backwards.
Apparently I'm a genius because my hardtail has a 425 reach and the squishy bike has a 460! the problem is my RAD is way too long @460, but I'll stick with it for now.
I just figured I need a shorter HT for a more playful ride, so super useful video. Thanx and I pushed 'subscribe'. out of curiosity, what is your length?
The full suspension doesn't become shorter it just goes "backwards" for the first part of the rear suspension travel because of the position of pivoting point. When you immobilize the rear wheel the only way the pivoting will occur is by pulling the part of the bike that will allow that movement. So at most if a hardtail will become "longer", a full suspension will remain "neutral" when constraints are removed.
Hmmmm. If you immobilize the rear wheel a hard tail will remain the same pulling back and grow as the handlebars rotate around the axis of the rear axle. On a suspension bike the bottom bracket drops Down which makes the reach shorten.
@@JeffLenoskyTrailBoss yes.. it goes down but so does the fork. So, if you ask me the reach become longer because of the front suspension and in the same time shorter because of the rear suspension. This is why I said that when are no constraints the full suspension will stay "neutral". But until we measure things we can not be 100% sure
@@JeffLenoskyTrailBoss I get what you are saying, but if the bb is dropping, so are you. If you stand, the bottom bracket is dropping, the pedals are attached to the bb and you to the pedals, so you are dropping. The reach doesn't change. Basically everything just moves backwards including you.
I am 6'5" lcan ride a trance L 29er Its a lot of fun So if i could find a hard tail, that is a similar size. It might be a lot of fun probably be a lot of fun
To clarify, a longer reach does NOT put more weight on the front axle. Yes a longer reach drags your hands farther out in front of your body, putting you in a more aggressive body position, but a longer reach is pushing the front axle farther away from the bottom bracket and your center mass. The only time a more aggressive riding position puts more weight on the front axle, is for a given reach and wheelbase, then lengthening the stem, pulling your body position further over the front axle. If you have a 430mm chainstay and 470mm reach with a 40mm stem, going to XC 90mm stem puts more weight over the front axle by pulling your body forward into a more aggressive position. If you have 430mm chainstay and 510mm reach with a 40mm stem, you will have less weight on the front axle than on the 470mm reach example. Think of it as chainstay vs front center. The higher the ratio, the more unbalanced the bike/weight distribution will be. The higher the ratio, the less weight will be on the front axle. You can get an idea by reach ÷ chainstay(if head angle and other metrics remain the same). 470/430 = 1.093 _ lower ratio more weight on front axle 510/430 = 1.186 _ higher ratio less weight on front axle
Makes sense, thanks! I think what I was trying to convey is that it puts more weight on your hands (but doesn't necessarily transfer to front wheel like you said) which isn't necessarily good for tech riding. Thanks for some good insight though, definitely helpful.
@@JeffLenoskyTrailBoss I know exactly what you were trying to say. I agree, I was just clarifying for your viewers who do not have your extensive knowledge/experience. Respect, Jeff!
Totally agree! Super informative! The terrain here in Finland is also super rocky, rooty and technical, and fast straight descends just is not a common thing here. Ive also shunned away of this new long trend and like my bike a bit shorter :) So I think Finland is also this east coast category that u keep talking about xD
In the MBTR forums there are 5'2" -5'6" geniuses who are on 450mm-460mm bikes....they have no idea or method how to calculate fit, yet they suggest larger & larger frames to other riders; & crap on Le McCormack & consequently Jeff Lenosky.
I am riding the wrong bike, because I found bikes at the bike shops to be beyond my reasonable reach - in the non-tech meaning of the word. I know that to support our latest crusade, the Fed and Treasury have printed more dollars which cheapens each one in my pocket and troubled savings bank. My mom taught me frugality, something our war mongers in Washington DC have never learned! I found a mountain bike sold by Walmart for less than $100. It was a small size, but I am only 5'-6" and I thought I could work with it. The ad said for people my height and less. I found I had to raise the seat in order to get the recommended leg extension. That had me riding in an aggressive crouch - not for touring comfort. I raised the handlebar 2" with an extension of the stem. I was still riding in a crouch. I saw an ad for a "swallow" handlebar. Installing it gave me another 6". That was much better: 8" or more up! I had also to do some cable work for the elevated bar. I was becoming a bike mechanic! Riding the bike in west-central Florida, where there are only man-made mountain, ramps would be a better description, I realized that 21 speeds were hardly necessary. Futher, I found that the front derailleur was not well positioned. Shifting into third gear required re-routing the left shift-cable. I decided that 7 speeds were more than enough. I removed the shifter and the front derailleur. The bike functions very well on the rear derailleur. To solve the short ETT problem of my small, highly modified mountain bike, I bought a setback seattube. I finally achieved an effective frame that suited all my 5'-6" extensions! I celebrated by buying plastic fenders, an alloy rear carrier and a modestly comfortable seat. I think I have spent about $250. altogether. I now have a 7-speed touring or commuter bike with an alloy frame, a front suspension, fenders, a rear carrier, and a decent seat for a long ride. I don't think any bike shop could beat that price. Also, at a very reasonable price, I found an addition that converts my bike to an exercise bike for the winter months. I confess I still have the knobby tires. The frame is still short, which gives a smaller turning ratio; so I have to be careful.
Awesome video, i was hesitant to buy a new bike 29" wheels with frame size M (im 6.2" tall) but now i think im gonna give it a try and see how it feels for a couple of days; thanks man.
Hey man! Thanks, I found tis video very useful, and I also watched the Joy of Bike video on RAD last week. Based on this, I think I should size down from L to M for my new Hardtail bike....if it's ever back in stock anywhere! Subb'ed and Notifications Enabled !
as a 5'7"ish dude (170cm) do you think the Mondraker Raze in size S would be a good fit for me? (it has some kind of forward geometry and other fancy stuff that I can't understand at all 😂) It has a 450mm reach but there's no smaller size than that for it... 30mm stem on it. Thank you!
It depends on how you want to ride it. For tech stuff it might be a little long but for downhill not quite as much. Are you committed to the Mondraker?
@@JeffLenoskyTrailBossthanks for answering! I like how the bike looks but it’s not set in stone 😊 I want a bike that can “do it all”. I like the stumpjumper too and the trek fuel ex 7 gen 6. With trek I hate the fact that it’s a creaky bike for a top price. 😢 What bike would you recommend? I have about 75-76 inseam if it helps with anything, average length for arms. Thank you!
I pick a bike geo that allows me to ride pain free if that makes sense . Shorter reach bikes end up aggravating the lower back hip area for me , it doesn’t happen first ride , it’s an accumulative thing , a couple of months in I start to feel it . But those bikes can be fun to ride . There is a sweet spot of a 475 reach for me with the right stack height and it doesn’t happen .
Lol. What channels? For a suspension bike it might make sense but I wouldn’t advise for a Hardtail. At the end of the day some of it is personal preference.
I would like to see this demonstration done with mullets, 24/26, 26/27, 27/29, 26/29. Hard tail vs. full squish. I would guess the numbers will be exaggerated or compressed in some way shape or form.
This is really a great video. I've been struggling with all the talk about the "new" geometries. My first ever eMTB is a medium large, and I've been freaked out over the talk of RAD, as a measurement of the correct size bike for me. My new bike according to the RAD philosophy is way too big. I have not seen much in this discussion about RAD, however, concerning full suspension eMTB's. Given the information in this video, perhaps it's not such a big problem. The only thing I don't like about it, when I compare to my wife's small frame, same model bike, is I feel like I have more weight on my wrists and hands on my long reach over RAD eMTB.
I am 168 Cm height, and i am riding XC hardtail bike.. i choose M size.. I am ever riding my friend bike, and the bike size is L size.. that big bike for me more stable on rough descend but kind a hard to turn and bunny hop..
You not even know how value this clip was for me since 5:00.... Gosh I am now stuguling to fit for new FS bike where Effective TT is same as in my HT Bike 596mm. In FS size M have 595 but L 610. Current 595 is at my limit and less whould be make me pain at bike, and now i see that ! In real world my new M size FS bike would be just too short with pouting too much waight over front tire and ruine fun of decount. Conclusion is: with my 595mm Effective TT HT Bike i need to buy size L FS Bike with TT 610mm. I know you say about Reach in clip but I am more that convinced that this parametr would be not suitable for me in FS Bike in M size.
I don't do 360 and don't think I can learn to do it, i change from a full,suspension enduro bike from 2015 , 445 reach to a new agresive hardtail 470 reach very long bike and love the feel of the hardtail already sold the full suspension
Thanks mate mates sense i,m 6 2 with gorilla arms your numbers i think are spot on. Oh one thing you didnt mention regarding steep sa ie 76 or more is they are not that good on flatter pedally trails i think it needs to be super steep to justify anything more tha 74 what are your thoughts cheers yoda
Sizing can be difficult when your between sizes according to manufacturers. This is typically what keeps me from buying online, as I can’t test fit before I buy.
I recently bought a Canyon Spectral size XL online. I'm right on the line between their L and XL. They only had XL in stock so I gave it a try. Knew as soon as I sat on it that it was one size too big. They've got a 30 day return period so I just sent it back. They refunded shipping charges as well. Worth a try if they have something you like.
I ride a size medium full suspension commencal clash enduro bike. Size Is perfect. I used to ride a diamondback hard tail size large. And it felt a little too big.
As one who constantly alternates between hard and full squish, this makes total sense and aligns with what I’ve felt over the years. Great video and content!
Damn i wish you made this 8 months ago. Cause it now make so much sense why my hardtail feels bigger than my full squish rig even though the geo numbers are the same.
Man, I have never seen it explained this way before. Especially where I could understand it. Thanks or the video Jeff.
Thanks Charlie! Share it!
Yup, with the sport's marketing focus on West Coast riding there is a growing gap in reality for East Coast riders. It's being filled by smaller brands, though they're still a bit expensive for average joe.
Can we have a video on Reeb bikes sometime? Like a inside look and maybe an origin story.
For those of us interested in the industry it's pure gold
I can do that!
Great description of the movement of the full-suspension bike!
Regarding hardtails, it is impossible for a hardtail to lengthen when the fork is compressed (using a standard telescoping fork). The lengthening as demonstrated is an illusion. Here is why: the front hub moves toward the rear hub as the fork compresses. In doing so, the headtube angle gets steeper. This pitches the handlebar forward as the wheelbase shortens which makes it appear that the bike is getting longer but the handlebars are on a different plane than the hubs. In order to truly lengthen a hardtail, the headtube angle would have to slacken and the front hub would have to move forward, or away from the rear hub. This happens when you wheelie or manual. So in reality, both hardtails and full suspension bikes shorten as the suspensions are compressed.
Thanks for the great vids!
You’re 100 right. I was replying to reach or cockpit not wheelbase. Thanks for clearing that up.
I had the same initial reaction as yourself regarding the hard tail. In order to do a proof of the "science", I crunched the numbers using my bikes geometry and it turns out that the reach does lengthen. Bear in mind that when the fork compresses, everything you say happens, and in addition then, the reach measurement takes place at a different plane because of the steepened head tube angle and shortened stack height as a result. Reach being measured at a line that intersects at a horizontal line from the headset to a vertical line at 90 degrees from the bottom bracket. See my separate post regarding actual numbers. This can all be calculated using some trig calcs.
Great food for thought in this video. Must admit, being a logic and data driven personality, I did a double take after seeing the assertion that the hard tail reach increases when dropping into the forks. A quick logic check didn't make sense for me. My initial reaction was that the drawing on the board represented a drop onto the forks shortening the length of the wheelbase and that reach actually also decreased. To prove or disprove my logic, I of course went into the maths.
I used my bikes geometry as a starting point. It is a full suspension bike but I assumed in the calculations it was a hard tail. I crunched the numbers and, in summary , they verify that the reach does indeed increase when using the fork travel. Must admit, I had to delve deep into my memory to extract the high school maths knowledge from almost 4 decades ago.
The basic numbers used as a starting point for the calcs were:
Reach 500mm
Wheelbase 1245 mm
BB Drop 35mm (ignored this for parts of the calcs to keep it simple)
Chainstay 434mm
Fork Offset 48mm
Fork Travel 130mm
Fork plus headtube length 660mm
Head Tube angle 66.5
The end result was that, assuming using full fork travel of 130mm, Reach increased from 500 to 555mm, Stack decreased from 605 to 505mm (excl BB drop), Wheelbase decreased from 1245 to 1199mm, and head tube angle steepened to 72.2 degrees.
THat's awesome! Someone commented earlier about the same thing, they thought I meant the entire bike grew but like you pointed out it's really just the reach, the wheelbase shrinks.
This explains why I feel comfortable on a full squish. I’m a small guy 5.5ft almost always ride S in a hardtail. Few months ago I went all out & got Supercaliber in M since I couldn’t find one in S (at least at my price point). But out of surprise the bike fit was perfect even though geometry numbers were waaay out of my reach.
Nice!
Jeff is such an asset to the sport. Decades of experience behind these insights. It’d be interesting to see a similar analysis for wheelbase (tall guys know about wheelbase) and the relationship between front center and chainstay length.
Thank you and that’s a great idea!
as a dedicated hardtail rider, I appreciate the explanation of he difference. I would have a hard time making a modern bike fit me with the "compact" fit I prefer.
Jeff, I'm sure I'm not the only one whom has been saved by this video from choosing a frame size too large (especially when going from full suspension to hardtail). Thanks!!
this is the most informative, most down to earth and easy to understand video on the topic out there. thank you.
Thank you!
Man. Love your videos. Much appreciated!
I am 46. 6’1 with 35” inseam, and prefer to ride size Large frames. Recently watched Lee’s RAD measurement video. As soon as I was done watching, ran to a park nearby, and did a bench test to see if my bike fits. It is SPOT ON. 😁
I love riding hardtails, and currently only ride a HT. Never thought of this take on sizing. Great video. And I love their vids on RAD sizing and pretty much everything else they do. I've made fit changes to my bike from watching those vids and has helped me progress past a plateau I think I've been stuck at for a while.
This is super interesting! I would have never thought HT vs FS behave so differently. Very thoughtful video!
See?? Now you know why I incessantly blabber when we ride about everything feeling different. I finally figured it out.
I always felt like there is something different, but never thought why is that, now I know :)
@@piciu256 Część Piotruś ja też jestem Piotrek.
They don't!
Just like joy of bike and Lee, another video telling me i need a shorter stem for my hard tail. My RAD is at least 3 cm shorter than my current bike set up. Thank you for the HT / FS comparison: haven't seen that before.
Hey! We can't all be wrong... lol
Got to know the things no body talk and even explains for a beginner like me. Most of the videos are more technical. But thanks to you I am now more clearer about right size bike. And also thanks for the link of the RAD video.
Im glad you found it useful
The minute you referred your viewers to Bogusky’s RAD measurement videos I knew you were trustworthy 😉 Their videos make so much sense and O completely buy into that methodology. Great vid man
Thanks! I love their channel but it’s funny that I’ve been riding PRO for 25 years and THEY make me trustworthy. Lol. I’m hoping to ride with those dudes in a couple weeks.
@@JeffLenoskyTrailBoss You seem slightly annoyed by my compliment? Upper case words and the lot 🤣 I should have worded it differently then...“The fact that you do not simply promote longer/slacker/longer makes you trustworthy”. Take it easy...PRO
@@johnlaw5762 Jeff was just commenting on the irony your statement, being that he is one of the OG's of technical and trials MTB'ing.
just bought (and sold )a hardtail, witch had "modern geometrie", the reach was 20mm longer then my full sus(witch also falls within the RAD) , with a shorter stem my cockpit length was almost the same as my full sus, but it felt way longer...and now i know why! it was quite stable, when i changed to my fuel ex , that thing felt nervous, but the hardtail was good for straight lines, but not for hopping or jumping . (cornering wasnt even that bad)...seeing this vid strengthens me in my believe i made the right choice selling the bike again, an that i can buy a shorter hardtail. i will try some bikes first, but this was really helpfull! so tnx!
Awesome, i'm glad it helped
Excellent and easily understood explanations and "experiments", Trail Boss! Can't wait to see you, Lee, and Alex getting together to talk MTBs and ride! Some charismatic chemistry ... You'll be a terrific trio!
We plan to do some riding when Jeff is in CO.
Great news. I've accidentally got 2 bikes that are exactly the right size for me. My Giant Reign is right on R.A.D measurement and my Nukeproof Scout is about 40mm R.A.D minus according to Lee and Alex's formula. They've also got a video out with bar sizing, and "bang", I'm spot on with my sizing there too. Wow, that stuff never happens to me! I'd normally be the exact opposite of what I should be.
Awesome!
Thanks for addressing this issue. I am one of those riders who at 5’5” 29 “ inseam is sought of in between S and M frames depending on cockpit dimensions. I always have to test ride a bike. Currently my full suspension is a M size Santa Cruz Tallboy 29 that fits perfect. It’s my understanding that SC bikes run a little tighter so size up is common. Thinking of getting a Giant Trance X 29 and reading that they run a little longer. Will definitely have to test ride. This can be challenging with the supply chain delays and emphasis to order and ship to the bike shop.
Same here im 5'5 i use now Medium more comfortable rather than small
I definitely would have made the mistake of buying a hard tail with the same measurements as my full squish. Knowing that I can go smaller gives me some hope that I can actually a find a hard tail that fits me. Thanks for the video and helpful experiments!
Thanks for watching.
Great informative video! The only thing I’d like to add is definitely get a size that compliments the area you ride in. Not all West Coast areas are wide open trails, we got a lot of twisties and tech stuff out here too!
I change bike every 6 mos so I buy bikes 2x / yr.
What I'm doing is I place my elbow at the back of steerer tube/stem and my fist towards the saddle. My fist should touch or at least have 1-1.5 cm allowance to the tip of the saddle. That's the perfect fit for me and it never fails. If there's too much room, adjust the saddle to safe mark. If there's too much room still, bike is too big for me. By the way, it only works if you have 35mm or shorter stem length.
For FS, same technique but need help from someone that will push the saddle down according to your weight and PSI settings.
I learned a lot from your video, Super!!, I'm using HT and working in the Bicycle. New supporter from Philippines
Yessss
@@JeffLenoskyTrailBoss 😱😱❤️
thanks for the info, I just got back into riding bought a bike that feels way too big. wish i had seen this before my purchase!
I'm 6' and love my medium hardtail. RAD measurement is closer then manufacturer recommendations for sure.
Great explanation. I like the "East Coaster" comment. I am in central CT, riding dynamics are from really twisty to really gnarly. The variety is awesome!
I am completely sold on the RAD measurement for my next bike purchase. I have a 2016 Process 134 Medium, that I thought was too short in the reach dept. (435mm, also I was 5'10", I shrunk to 5'9", 33" inseam). Based on some demos of large frames, I thought I needed a large frame for my next bike. Like you said the perceived stability downhill was great (I'm a plowing, wheels on the ground kinda guy). What I now understand is that longer reach would actually compromise the row/anti-row we use for bunny hops, jumps etc.. So, I measured the RAD on my old process (BB ctr to pt. between grips), and low and behold it's right at the recommended RAD neutral position, maybe a bit RAD+. Knowing this, your info above, and living on the east coast (VT) I'd probably stick with a Medium frame (450mm reach), not Large (475mm+) to keep that manueverability.
I also played around a lot with anglesets, overforked my 140mm fork to 160, and changed the HTA from 68 to 65 in combo with a -2 works angleset. That alone was a huge confidence booster in steeps. So before when I thought I needed a longer reach, really all I needed was a more slacked out fork to help rip the trails I ride.
Overall, the last couple years have shredded my perspective on bike sizing. Now if I could just go back in time and buy the right bike in the first place... :P
Im getting into MTB coming from Dirtbiking and BMX when I was younger. Im 5'9.5" with a 30" inseam. My APE is 1:1. Im looking at IBIS RIpmo and their chart says Large. The medium reach is 460mm, stack 619mm, seat tube angle 77'. I have no clue what im looking at lol. The large reach is 475mm. IBIS said they recommend me on the large. I wish I could sit on these bikes to confirm I want the medium and not make a huge mistake w/ a large
@@2Tsmoke I am very close to that but I think you have a longer torso so you might be more comfy on a large, reach wise. However - the only issue will be the seat tube length, with your shorter inseam the longer seat tube will limit your dropper length and the jump can sometimes be significant from Med-Large (30mm or more!). So scout out the geo charts and if it’s too much of a risk I’d stick with a medium. If your riding is techy and slower, you might be better off with a shorter wheelbase anyway. If you do more jumps, higher speeds (20mph+) or bike park a large frame may suit your style more. Good luck!
EDIT: I’m seeing the large frame has a 432mm seat tube which is actually shorter than most (sometimes 450+). The medium is 406mm.. You might get away with the large, but do consider the terrain you’re riding, as well.
@@rpiian thanks for the reply - this gives me some things to consider. I'm swaying more towards the medium for my local terrain but I will also be going to bike parks on rare occasions. I'm in the Midwest so we have some gnarly rooty single track but it requires lots of pedaling up and then down. Appreciate the response!
@@2Tsmoke For sure! I’m no expert but that’s been my experience as a 5’9” dude. Can always run a longer stem on a medium. Not ideal but I’ve done it in the past to stretch out an older geo medium (430 reach). Bonus is added front wheel traction. I’m pretty comfy at 450-460 currently.
thank you so much for this. Looking at moving to a full suspension from a 10 year old hard tail. they all feel too big. All the bike shops want me to move to a XL, my hard tail is a L frame. I'm 6'2" 34" inseam. This video help me understand fit better than any bike store.
I ride L size frame with 27.5 and usually M size with 29. I like a little more nimble bike for my tight trails in OH. Not many real extended downs where the length is needed for stability here. I'm a tweener @ 5'10" with a longer torso than legs... hard to find the right fit. I have to monkey with stem lengths and saddle positions to get it right. Great explanation and keeping it simple.
das habe ich früher auch immer gemacht - ganz schlechte entscheidung! immer wenn ich anfing die sattel position(vor oder zurück) zu verändern kam ich mit denm bike nie mehr wirklich zurecht. vor allem dann nicht wenn man auch entsprechend uphill unterwegs ein möchte. beide aktionen (sattelposition -und vorbau länge veränderungen sind nicht gut. genau diese beiden werte sollen passen. bei meinem vorigen HT hab ich den sattel nach hinten geschoben um gefühlt mehr platz zu bekommen, die folge waren rückenschmerzen, nackenschwmerzen und sitzknochen beschwerden. beim neuen rad ist alles in ordnung - weil eben die geo für mich passt - sobald der reach wirklich passt, sind alle sorgen weg.
Great video! At 5' 10" with average proportions I can often switch between L and M frames. After trying both, I decided on a L Megatower and Spot Ryve, but went with a M Chameleon for my hardtail. Part of that decision was simply wanting different riding plans for the bikes. The MT is my "park" bike where I want it long and stable. The Chameleon is more for jibbing at playing. Granted, I bought the two Santa Cruz frames back in early 2019, so it was as much a case of blind luck as anything else.
sick! sounds like a solid choice to me!
My friend his height 5'8 but he use large frame trek sometimes its personal preference
dude - the way you hit those stepups and bunnyhops is nuts! Nice skills. I need me a cup o' that!
Thank you!
I think a lot of this left coast stuff influences the bike industry, even though it's not practical for a lot of areas. If I was doing nothing but 5000 ft. of climbing on steep fire roads only to descend again with my seat fully down, a 76+ degree seat tube angle (and 8' wheel base) might make sense. But if you are spending half your time on relatively flat trails or quick up and downs, that steep seat tube angle is only efficient with a 200 mm negative rise stem and pursuit bars.
I love the small clip of Alafia in there at the end when talking about east coast trails. North Creek is awesome! Especially Gwazi berm!
This explains why my XC HT felt longer than it was! Good thing I bought a L size HT when I'd usually choose an XL. Thank you for the insight. 👍👍
This has helped me to choose a L fat bike over an XL, which I am riding for my trail/all mountain bike. Cheers!
Great!!
i am riding a xs surly ICT for trails and trials i am 5'5" everyone always say i should ride a 17"/16" frame, i am so glad this videos on here it proves my point for the smaller frame
Truth.
Unless youre going full speed down hill, a smaller bike will always be more fun, more agile, lighter, and easier to maneuver. Yes, its slower downhill, that is totally ok by me. I like my uphills to be short and easy, and my downhills to be long and challenging. Its why i bought a XC bike!
Better still is a the fact that it's got huge soft tyres means it's great at high speed over rough terrain too.
@@RC-DC Yup. Modern fat tires turn any full suspension bike into a better down hiller than dedicated down hill bikes from the 1990s.
I used to ride 1.5 inch wide cross tires on my mountain bike. It was astoundingly agile and sharp on pavement, yet had enough width for dry hard SoCal dirt trails.
But modern 2.6 tires are absurd. You can roll over mud sand snow and rocks. They are suspension all by themselves!
My next xc bike is getting 2.4 tires, minimum. I don't know if you're familiar with this site, but you may want to look around it.
www.bicyclerollingresistance.com/mtb-reviews
Especially this tire. 2.2 wide and 497 grams. Crazy light. Want.
www.bicyclerollingresistance.com/mtb-reviews/continental-race-king-racesport-2014
For sure. I'm 5'8 and all my HT and FS are size S. Why? Because my FS have more reach than my FS
Wish you had made this video 3.5 years ago :-) would have saved me some "learning" opportunities and expenses. Really appreciate the info and I have shared with others. Never have found good resources that really talk about what aspects of geometry are important for what. Each person's arm/torso/leg lengths (and maybe even neck plays a part) are rather unique and it took me some time to figure out what parts of the geometry I need to look for to have a good fit/balance/confidence when riding. I usually need a longer reach with full suspension bikes. head tube angle is what I look for with the type of riding I do, which is a mix of everything, so 67 and above a little too steep, but 64 and below a little too slack. Seat tube angle has been important for how well the bike pedals when on flat/uphills, steeper usually being better. Seat tube length and standover height I'm still working out for me, but I know that for rear wheel scoops for less dialed jumps and rowdy terrain I want a lot of space between my bum and my saddle, moving the bike around is harder when I don't have that. wheel base and chainstay lengths are important but I don't know exactly why or what would be important for me...reach and head tube angle are usually what I look for to have a fun, balanced ride. By really fitting myself for my current bike, I've been able to learn a ton with confidence, and now I can adapt pretty easily to other bikes with different geometries (ie I travel a lot and rent a lot of bikes). I have learned to have a good bit of fun doing what the bike I have rented is really good at that is different on my bike at home. So much depends on a person's unique body composition and the riding they want to do.
Thanks for checking out the video, I'm glad you seem to put as much thought into geometry as I do!
Thankfully, the Jamis i bought is sized perfectly. I have another hard tail that feels a bit too long and your explanation confirms what i have experienced. Btw, i like twist turns more than speed through the trails. I ride my road bike off i wanted speed. Lol
My man Glad I came across your video
Just ordered the new. 2023 ibis dv9 frame.
(It’s a hardtail). I’m between lg-xl
I went with my gut chose the Large.
I’ve been second guessing, and after watching your video, I’m comfortable with my choice actually pretty happy.
I’m an Midwest rider we have narrower more technical trails with awesome dirt
At 6'6" it has been pretty hard to find bikes to fit. When I first started riding mountain bikes in the mid 90's 26" wheels and a 22" frame bikes always seemed small. Fast forward to today I'm riding Specialized Fuses XXL with 29" wheels and a Trek Fuel EX8 XXL 29" wheels. It amazing how much more comfortable the bikes feel. Still hard to find bikes that fit, but it is easier.
tell me about it...Im 6'5" riding 23" frame with 29.. seems good to me
Thanks for the video. Makes total sense. Glad I saw this before purchasing a large hardtail. Now I'll go with the medium. Thanks again TB
Good info homie! It’s always nice to have a better understanding of geometry. A hand full of MM can make all the difference. 👍
Thanks for checking it out!
I am 5.9 and thus often between sizes. I choose to go with a size M over a L (Trek soft tail bike, or optional M/L) because in the end you can always make a smaller bike bigger, but you are limited the other way around.
This was interesting to see! I dilly dallied when purchasing my hardtail last year, so all the large frames were sold out. I ended up with an XL frame. It works, but it has been very hard learning manuals, etc. on it compared to an old large full squish bike. I can get the old bike to the balance point, but not the new one.
Great info! I'm totally new to all this stuff so this will help a lot. Off to the RAD video.
This had me 🤯. Off I go to grab poster board and sharpies (and a scale) to measure my bikes!
I would say super simple measures but surprisingly sophisticated results and impact to bike size perception 👍
Joy of Bike are a great channel!
The RAD approach makes slot of sence, yet factor in your riding type XC will benefit from a longer RAD measurement dependant on terrain.
Short bikes feel unstable to me, as I ride XC/trail and flowy fast trails are preferred over dabbing, big bunny hops etc
Factor your ride style and terrain and get another bike if you want b to venture into something different.
Good call.
Wow...RAD was great and I was using it before, but you illustrated to me why my 480mm Reach Torrent HT in Large, feels so much longer than my 480mm Reach, Siskiu T in Large, on the trail...
Amen! I ride a small Vertex (XC), medium Instinct (trail) and large Blizzard (snow). Horses for corses!
Nice. I have something to think about now before I build a new bike.
Great video. I never looked at the difference between hardtail and full suspension reach numbers like that. Makes sense to me. I am looking at getting a hardtail in the future and will definitely use this info to make sure I get the right size. Thanks Jeff.
Awesome!!!
Feel like a similar effect happens when you setup your front and rear suspension hard or soft. I demo’d a remedy with suspension pumped to the moon and it felt insanely good. Bought one and tailored the pressure to my weight to be supple / correct and it feels slightly small. Have a HT with longish top tube and shortish WB and it feels like the bars are a mile away. This definitely speaks to me. Nice video. Crazy!
I found this video and I watched half of your rad from a month ago. Thx for the info. I'm looking at a 2021 Schwinn Axum DP Dropper Post MTB. I'm on a budget and weekend rider from time to time.
I hope it helped you out! Good luck out on the trail, have fun!
What you're referring to is really pitch and yaw. More Pitch though regarding the perceived lengthening and shortening of the bike. Obviously a hardtail will pitch less, meaning there will be less weight transfer (energy or kinematics) from rear to front under braking and virtually no pitch from the front to the rear under acceleration (pedaling)
Physics dictates that a bike wants to rotate around its 3 CoG intersecting axes. Full suspension bikes have much more weight transfer both fore & aft. Much more on a motorcycle because of the engine torque; acceleration & deceleration + the braking forces.
That's super interesting but I feel like weight transfer is exaggerated on the hardtail since it all pivots from the rear axle into the fork... I definitely run my front suspension stiffer on my hardtail vs full sus because of that.. you're making me ponder it more!
@@JeffLenoskyTrailBoss I think that's interesting that you feel like the load (weight) transfer is more prevalent on the hardtail. I understand what you mean as I have switched over to a hardtail this year. I do feel like the weight or load shift from rear to front feels a bit harsher with a quicker front 'dive' response. I believe this is just a perception rather than an actuality of the load forces. At least for me I believe it's a perception. One of the reasons could be that because of the rigid rear, it's a more abrupt transfer. On a FS, even if the rear suspension is not compressing very much or is set a bit on the stiffer side, it is still transferring load during it's travel. The bike tends to be more in balance under braking or hard pedaling where as the hardtail exhibits fairly the same characteristics. The only 'suspension' would be the rear tire and wheel. Which could result in some variations depending on the width of the tire and the air pressure.
Another factor in load transfer would be the length of the wheelbase. Also CoM & total bike weight would be contributing factors as well. I tell you two wheeled Vehicle Dynamics or any vehicle dynamics are enough to hurt your head! 😄 I mean I only scratch the surface & I'm still learning but the physics behind what's happening when we ride bikes is just mind-blowing!
@@archetypex65 I love trying to figure out the physics
@@JeffLenoskyTrailBoss Yup, me too! 👍
Great video, really drives home the point that you need to go with the “Feel” of a bike over what a chart says you need. Super helpful!!!
Thanks For checking it out dude!
I wouldn't have thought that hardtails were so different to full-sus bikes so that was interesting. I need way more explanation though to understand what you mean by long or short bikes. Intuitively a short bike would mean shorter wheelbase which would make it better for slower speed riding.
Very interesting. That marker test is pretty clever! I read Mr. McCormack's book, Dialed, and bravely ordered a short-travel Sqweeb V3 in a size medium this January. It has the same reach as the "XL" XC hardtail my local Specialized dealer put my 6'1" body on now. That bike feels a bit too big, even after swapping the 70mm(!) stem for a 40mm one. But that Steering Hands Offset is almost perfect with the shorter stem
That's great! You're gonna love it! Update us on how you like it.
Any updates Eric? Please do share your thoughts, insights & experiences.
@@josephfarrugia2350 The Sqweeb is the nicest bike I've ever had, so I don't have much to compare it with, besides what my friends have upgraded to over the years. It's an insanely well-built machine that is whisper quiet and feels sturdy--something I'll have for many, many years. I've done a few foolish things on it, but the bike's bare-metal finish shrugged the resulting tumbles off. 🤘
The fit on the medium ended up fine, even if there's still some seat post sticking out of the frame in addition to the 200mm Oneup dropper. Now that I've spent a year on the medium, I don't think a large frame would have been too clunky, but I really enjoy the snappiness of the medium with the 40mm stem it shipped with. It definitely handles turns more easily than the XL Rockhopper, despite the Sqweeb's longer wheelbase.
Thanks for heads up, I would have matched up my 485 reach, what you said makes sense when you draw it out.
This makes total sense! I wish I would have figured this out before I bought my latest hardtail frame.
do you feel like it's too long?
@@JeffLenoskyTrailBoss especially when trying new maneuvers.
Geometry is a tricky thing when suspension is involved. Your demonstration is very useful but just note; the bottom bracket, particularly on a hardtail, is also moving forward/downward through the fork stroke. So your total observed change in length at the handle bar is more than the actual change in reach length. A hard tail is pivoting from the rear axle not the bottom bracket. Still agree that the reach should be slightly less on a HT than a full suss but not by too much. I have played a lot with my HT (which is what i prefer to ride most of the time on moderately aggressive terrain) to achieve minus, neutral and plus R.A.D.; and for me neutral feels best.
That’s interesting! Thanks for watching.
That's actually false. The bb moves back as the fork compresses. The bb is always lower than your axels on a mtb, so if you take the line segment from the rear axel to the bb and rotate it downwards around the rear axel, because it's already below horizontal, it can only move backwards.
Great video. Given how expensive bikes are these days I think it's especially important to consider how well the bike fits you to maximize enjoyment.
Great info ! Thanks for taking the time to make this video .
Thanks, Share it!
i like this old school frame, like mine too , its really hard for me to bunnyhop and mannual, .but im inspired by your tutorials ,thanks jeff....
Apparently I'm a genius because my hardtail has a 425 reach and the squishy bike has a 460! the problem is my RAD is way too long @460, but I'll stick with it for now.
Nice!
I just figured I need a shorter HT for a more playful ride, so super useful video. Thanx and I pushed 'subscribe'. out of curiosity, what is your length?
Thanks for the sub! The bike I’m riding now is a 465 reach and I’m 6’4”
The full suspension doesn't become shorter it just goes "backwards" for the first part of the rear suspension travel because of the position of pivoting point. When you immobilize the rear wheel the only way the pivoting will occur is by pulling the part of the bike that will allow that movement. So at most if a hardtail will become "longer", a full suspension will remain "neutral" when constraints are removed.
Hmmmm. If you immobilize the rear wheel a hard tail will remain the same pulling back and grow as the handlebars rotate around the axis of the rear axle. On a suspension bike the bottom bracket drops
Down which makes the reach shorten.
@@JeffLenoskyTrailBoss yes.. it goes down but so does the fork. So, if you ask me the reach become longer because of the front suspension and in the same time shorter because of the rear suspension. This is why I said that when are no constraints the full suspension will stay "neutral". But until we measure things we can not be 100% sure
@@JeffLenoskyTrailBoss I get what you are saying, but if the bb is dropping, so are you. If you stand, the bottom bracket is dropping, the pedals are attached to the bb and you to the pedals, so you are dropping. The reach doesn't change. Basically everything just moves backwards including you.
Jeff, this was simply incredible 🤘🤘🤘♥️
thank you Raheem!
I am 6'5" lcan ride a trance L 29er
Its a lot of fun
So if i could find a hard tail, that is a similar size.
It might be a lot of fun probably be a lot of fun
What a great video that will help a lot of people unlock bike sizing.
thanks for checking out the vid Kevin!
@@JeffLenoskyTrailBoss never miss them
To clarify, a longer reach does NOT put more weight on the front axle. Yes a longer reach drags your hands farther out in front of your body, putting you in a more aggressive body position, but a longer reach is pushing the front axle farther away from the bottom bracket and your center mass.
The only time a more aggressive riding position puts more weight on the front axle, is for a given reach and wheelbase, then lengthening the stem, pulling your body position further over the front axle.
If you have a 430mm chainstay and 470mm reach with a 40mm stem, going to XC 90mm stem puts more weight over the front axle by pulling your body forward into a more aggressive position.
If you have 430mm chainstay and 510mm reach with a 40mm stem, you will have less weight on the front axle than on the 470mm reach example.
Think of it as chainstay vs front center. The higher the ratio, the more unbalanced the bike/weight distribution will be. The higher the ratio, the less weight will be on the front axle.
You can get an idea by reach ÷ chainstay(if head angle and other metrics remain the same).
470/430 = 1.093 _ lower ratio more weight on front axle
510/430 = 1.186 _ higher ratio less weight on front axle
Makes sense, thanks! I think what I was trying to convey is that it puts more weight on your hands (but doesn't necessarily transfer to front wheel like you said) which isn't necessarily good for tech riding. Thanks for some good insight though, definitely helpful.
@@JeffLenoskyTrailBoss I know exactly what you were trying to say. I agree, I was just clarifying for your viewers who do not have your extensive knowledge/experience.
Respect, Jeff!
Totally agree! Super informative! The terrain here in Finland is also super rocky, rooty and technical, and fast straight descends just is not a common thing here. Ive also shunned away of this new long trend and like my bike a bit shorter :) So I think Finland is also this east coast category that u keep talking about xD
Hyva!
In the MBTR forums there are 5'2" -5'6" geniuses who are on 450mm-460mm bikes....they have no idea or method how to calculate fit, yet they suggest larger & larger frames to other riders; & crap on Le McCormack & consequently Jeff Lenosky.
I am riding the wrong bike, because I found bikes at the bike shops to be beyond my reasonable reach - in the non-tech meaning of the word. I know that to support our latest crusade, the Fed and Treasury have printed more dollars which cheapens each one in my pocket and troubled savings bank. My mom taught me frugality, something our war mongers in Washington DC have never learned!
I found a mountain bike sold by Walmart for less than $100. It was a small size, but I am only 5'-6" and I thought I could work with it. The ad said for people my height and less. I found I had to raise the seat in order to get the recommended leg extension. That had me riding in an aggressive crouch - not for touring comfort. I raised the handlebar 2" with an extension of the stem. I was still riding in a crouch. I saw an ad for a "swallow" handlebar. Installing it gave me another 6". That was much better: 8" or more up! I had also to do some cable work for the elevated bar. I was becoming a bike mechanic! Riding the bike in west-central Florida, where there are only man-made mountain, ramps would be a better description, I realized that 21 speeds were hardly necessary. Futher, I found that the front derailleur was not well positioned. Shifting into third gear required re-routing the left shift-cable. I decided that 7 speeds were more than enough. I removed the shifter and the front derailleur. The bike functions very well on the rear derailleur. To solve the short ETT problem of my small, highly modified mountain bike, I bought a setback seattube. I finally achieved an effective frame that suited all my 5'-6" extensions! I celebrated by buying plastic fenders, an alloy rear carrier and a modestly comfortable seat.
I think I have spent about $250. altogether. I now have a 7-speed touring or commuter bike with an alloy frame, a front suspension, fenders, a rear carrier, and a decent seat for a long ride. I don't think any bike shop could beat that price. Also, at a very reasonable price, I found an addition that converts my bike to an exercise bike for the winter months. I confess I still have the knobby tires. The frame is still short, which gives a smaller turning ratio; so I have to be careful.
Awesome video, i was hesitant to buy a new bike 29" wheels with frame size M (im 6.2" tall) but now i think im gonna give it a try and see how it feels for a couple of days; thanks man.
Dude..that was super enlightening 🤘🏼 explains why my size small hardtail feels like my size medium full sus 🤔🤘🏼
DOOD! Thanks for checking it out. Hope to ride with you soon!
Hey man! Thanks, I found tis video very useful, and I also watched the Joy of Bike video on RAD last week. Based on this, I think I should size down from L to M for my new Hardtail bike....if it's ever back in stock anywhere! Subb'ed and Notifications Enabled !
AWESOME! Thank you Ricardo! What kinda bike are you gonna get?
@@JeffLenoskyTrailBoss I'm thinking of a Nukeproof Scout 275
as a 5'7"ish dude (170cm) do you think the Mondraker Raze in size S would be a good fit for me? (it has some kind of forward geometry and other fancy stuff that I can't understand at all 😂)
It has a 450mm reach but there's no smaller size than that for it...
30mm stem on it.
Thank you!
It depends on how you want to ride it. For tech stuff it might be a little long but for downhill not quite as much. Are you committed to the Mondraker?
@@JeffLenoskyTrailBossthanks for answering! I like how the bike looks but it’s not set in stone 😊 I want a bike that can “do it all”. I like the stumpjumper too and the trek fuel ex 7 gen 6. With trek I hate the fact that it’s a creaky bike for a top price. 😢 What bike would you recommend? I have about 75-76 inseam if it helps with anything, average length for arms. Thank you!
Great analysis of full and front suspension MTB sizing. Where do you think a non suspension bike would fit?
When your handle bar comes down (5.00), does your crank move as well, or not ? if yes, does the reach of your FS bike really reduce so much ?
Thank you someone mentioned this 🤦♂️🤔🙌
No, the BB does.t move so much on a HT bike.
So yes, the effective Reach does increase.
I pick a bike geo that allows me to ride pain free if that makes sense .
Shorter reach bikes end up aggravating the lower back hip area for me , it doesn’t happen first ride , it’s an accumulative thing , a couple of months in I start to feel it . But those bikes can be fun to ride .
There is a sweet spot of a 475 reach for me with the right stack height and it doesn’t happen .
Great video but it goes against what other channels advise to go bigger and have more stability. I was confused before but now my head is fried. 🤣🚲
Lol. What channels? For a suspension bike it might make sense but I wouldn’t advise for a Hardtail. At the end of the day some of it is personal preference.
I would like to see this demonstration done with mullets, 24/26, 26/27, 27/29, 26/29. Hard tail vs. full squish. I would guess the numbers will be exaggerated or compressed in some way shape or form.
This is really a great video. I've been struggling with all the talk about the "new" geometries. My first ever eMTB is a medium large, and I've been freaked out over the talk of RAD, as a measurement of the correct size bike for me. My new bike according to the RAD philosophy is way too big. I have not seen much in this discussion about RAD, however, concerning full suspension eMTB's. Given the information in this video, perhaps it's not such a big problem. The only thing I don't like about it, when I compare to my wife's small frame, same model bike, is I feel like I have more weight on my wrists and hands on my long reach over RAD eMTB.
I am 168 Cm height, and i am riding XC hardtail bike.. i choose M size..
I am ever riding my friend bike, and the bike size is L size.. that big bike for me more stable on rough descend but kind a hard to turn and bunny hop..
Crystal! Keep it up.. God bless. Stay safe brother..
I'm 5.9 but I really like the fit and control I get with my 2021 XL giant talon 1 gives me.
Awesome video helps demystify this new geometry stuff.. i’m lookin for 18” frames 😂
You not even know how value this clip was for me since 5:00.... Gosh I am now stuguling to fit for new FS bike where Effective TT is same as in my HT Bike 596mm. In FS size M have 595 but L 610. Current 595 is at my limit and less whould be make me pain at bike, and now i see that ! In real world my new M size FS bike would be just too short with pouting too much waight over front tire and ruine fun of decount. Conclusion is: with my 595mm Effective TT HT Bike i need to buy size L FS Bike with TT 610mm. I know you say about Reach in clip but I am more that convinced that this parametr would be not suitable for me in FS Bike in M size.
I don't do 360 and don't think I can learn to do it, i change from a full,suspension enduro bike from 2015 , 445 reach to a new agresive hardtail 470 reach very long bike and love the feel of the hardtail already sold the full suspension
Nice! Like i said, everyone rides different and like different stuff, stoked you're on a hardtail though!
Those experiments were pretty cool! And I agree about the tradeoffs of a long reach bike 😅
Thanks for checking it out Matt!
Hey Jeff great video to true how tall are you buy the way .
I'm 6'4"
Thanks mate mates sense i,m 6 2 with gorilla arms your numbers i think are spot on.
Oh one thing you didnt mention regarding steep sa ie 76 or more is they are not that good on flatter pedally trails i think it needs to be super steep to justify anything more tha 74 what are your thoughts cheers yoda
It would be interesting to see what happens to the bottom bracket horizontal position when a full suspension bike sags.
It drops quite a bit
Sizing can be difficult when your between sizes according to manufacturers. This is typically what keeps me from buying online, as I can’t test fit before I buy.
that's definitely challenging!
I couldn't agree more!
I recently bought a Canyon Spectral size XL online. I'm right on the line between their L and XL. They only had XL in stock so I gave it a try. Knew as soon as I sat on it that it was one size too big. They've got a 30 day return period so I just sent it back. They refunded shipping charges as well. Worth a try if they have something you like.
@@phatbob72 How big are you?
This is going to be the most popular upload I bet!
Great info thanks for taking the time to share.
I ride a size medium full suspension commencal clash enduro bike. Size Is perfect. I used to ride a diamondback hard tail size large. And it felt a little too big.