Mountain Bike Fork Offset Explained | What Is Fork Offset and How Does It Make Your Bike Feel?
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- Опубліковано 8 вер 2024
- Mountain Bike manufacturers have recently started playing around with fork offset, creating shorter offset forks and shouting about them on the spec sheets! Suddenly talk of offset is everywhere and we see more manufacturers speccing stock builds with shorter offset forks. But what exactly is it, and more importantly, how does it change the feel of the bike?
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Some very good info about fork offset and how it affects the bike , But if the fork offset does not matter to much to a rider like Neil then I think I will not worry to much about it
Good vid! 🙏🏻
This was *THE* opportunity to shine a light on the ever returning question _"Can i mount a longer travel fork?!"_ thoroughly. All the facts were right there and you even touched that topic. Hope the community watching makes the connection! 🤞🏻
I put on a 44 offset on my 2018 intense carbine 29.. it was 51 offset.. now at 44offsett i feel more stable and comfortable.. 44 offset rocks 🔥
I'm thinking of doing the same thing
Surely that would make the bike looser on DH trails etc but only more stable in the straights
The videos Henry has been making lately have been very informative and answered lots of my questions about bikes.
Loving it
🤦♂️🤦♂️🤦♂️
I agree 👍🏻
30 years ago when i first bought my bike color, scheme and sizing are the only thing that i worry about. Nowadays you add numbers, angles and the whole bike chart etc. -- stressful :D
A nice try at explaining this topic What I'm getting is : More fork offset = less trail, ie: less self correcting /faster (twitchy?) steering. Slacker head angle or less fork offset= more trail (more self correcting and slower steering) Shorter stem can increase direct feeling with steering, in effect counteracting a shorter offset/slacker hta with more trail.
On thing you people missed and literally ever video has missed is how increased offset slackens the effective HTA. So if 2 bike have the same HTA and one with a longer offset it will behave slacker at least in a straight line. It lengthens the wheel base and puts the axle further in front of your hands.
This guy may have been a good mechanic but he doesn't know anything about physics or engineering. #uselessinfo
Switching to a shorter offset fork brought an immediate difference in front wheel grip in turns. A strong improvement that I’m not keen to go backwards on
I actualy dont care how mi bike feels i am sellfish.
Keep it up and one day your bike will leave you.
When I went from a 50mm stem to a 30 I crashed twice. But my 50 back on and feel fine 🤣
Could be some other factors sometimes you have to raise or lower the stem if you reduce or extend the length. When you went to the 30 mm you could have put some spacers underneath the raise it up if you hadn't done that. That could have provided a bit more stability also the length of your bars would be a factor shorter stem with a little bit wider bar would provide some stability. Conversely longer stems with shorter bars work better
Flying Lap Productions 780mm bars didn’t change anything else has the 50 back on since June and been fine.
Andy Sintes could be geometry of bike I have a really slack 180mm enduro bike more aimed at free ride
@@jackbeames7643 Same here. I tried a 35mm and it didn't feel as good as the 50mm. When you have a really slack head angle (64 on my Patrol) a super short stem doesn't put enough weight on the front wheel.
RideMTB_SF yea I have a cube fritzz 180mm really slack probably same reason as you tbh
fork offset is far less about increasing length and weight distribution than it is about reducing trail to keep the bike from feeling "over stable" and steering like a freight train,. And on a road bike, more weight on the front wheel isn't the cause for the stability,, it's more that you're leaning forward against it, effectively pushing the bars forward., and because you're applying the pressure ahead of the steering axis, it pushes them towards being straight forward. If anything, the extra weight on the front wheel actually makes the bike handle more twitchy.
The thing about fork offset is that it was kind of chosen to what worked well with the bike geometries at the time that they first started making them, and then when 29" got popular they increased the offset to maintain the same trail with the bigger wheels, but geometries are changing, and those old numbers probably aren't optimal anymore.
This is all second nature to those in the custom motorcycle world, yes there is a sweet spot, get it right you have a safe and stable bike at all speeds and environments, get it wrong and you've created a monster that will kill you without warning if you can't read the signs 😉
good clear video. I wouldn't call the caster effect mysterious though...ever looked at shopping trolley wheels? It makes them track in a straight line. Also car front wheels have a set caster angle so that the front wheels will straighten up on their own when you release the steering wheel after a turn - try it.
Back in the day a few cross country bikes had less offset; Zinn, the Cannondales with their integral suspension fork, and the first Fisher 29ers. They were steadier downhill and wandered excessively climbing out of the saddle. I had all these bikes and the steering felt a little lifeless to me. Gary Fisher thought so too and increased offset to 50+ to reduce the trail the 29er wheels and slacker head angles added. Recently adding 40mm of travel slackened my 29er Inbred head angle and using 52 offset brought the steering back to feeling the same. I remember Brant realising that putting a 52 offset 100mm fork on a 29er inbred he ended up almost exactly the same geometry as a steel Niner. The point I'm making is that having watched several vids on offset not one comment has been made as to how/if it affects out of saddle pedaling or indeed slow speed seated pedaling. And I'd like to know before buying a fork. Bikes are so different now that I can't depend on my experiences a decade or two ago.
I love the explanation with using standing on your feet as an example 👍
Neil is always damn fast. Must be so happy he can finally go all out with a downhill bike again.
Brilliantly illustrated explanation at 6:00!
So for the oldies amongst us it’s basically fork rake in a modern mtb guise. We’ll explained though 😊
going to have to watch this a few times to get my head around it 😂 but love watching henry he is so good at explaining things because he doesn’t assume people should know something wish he was my teacher at school 😂
🙄🙄🙄
give us the bloopers after every video lol hopefully with some henry dancing
Nice video simplifying what manufacturers make complicated. Good for good trail talk and uneducated advise we like to dish out :). I would like to know how to setup your bike so it behaves more balanced/drifty like Neil mentioned - perhaps starting with a HT so it's dead easy and then on to FS. The outtakes will be especially entertaining no diggety.
*I have a 2012 Trek Cobia hardtail 29er. The 51mm stock offset lengthened my handlebar reach, which hurt my back and felt uncomfortable. To make matters worse, the fork was cut low before I bought the bike. To compensate, I am trying a shorter stem and swapping with a higher-rise handlebar. Seat moved forward.*
Mostly incorrect about stem length. So basically, everything the front wheel hits, rolls over, etc, makes the wheel want to turn around the head tube axis. That’s mostly because of the caster, or offset that forks have. It’s like an office chair wheel. The longer the stem, the less force is needed to resist the front wheel wanting to pivot around the head tube axis. Because of increased leverage. Increased bar length does the same. Now, a shorter offset fork WILL increase weight over the front but that weight isn’t what speeds up or slows down the turning feel.
The longer the stem, the wider the steering arc becomes and the 'longer' it takes to make the radii turn. The increased axis makes it harder to turn quickly requiring more 'force' on the bar or,if you will just an increase of speed of the physical input to the bars. That is why a shorter stem/axis results in quicker steering, than longer stems.
Close, but to get a bit more technical, the amount of energy, or work, needed to turn the front wheel around it's axis never changes no matter the stem or bar length. What's happening though is that you're trading force for distance. Longer stem or bar requires less force to turn, but must travel a further distance to make that turn. Energy spent is the same. This is why a longer stem makes a bike more stable.
After re reading your comment, I think we're saying the same thing. Sorry about that.
I'm glad someone else pointed out that most of this video is mis-information; saves me having to waste time doing so. If you want to know how something works, ask an engineer!
@@11leonidas11 No worries mate.
The Rider is always the most significant variable. A good rider who understands this can focus his efforts on adapting to practically anything. We see this more broadly in the motorcycle road racing curriculum where the competitor, overly concerned with setup, often gets lost in the minutiae of adjustability. Casey Stoner famously won the MOTOGP title on the most un-ridable bike in the paddock. He’s an evangelist for this very philosophy.
Nice video, why not to show also how the geometry changed between the tests?
And...a video about the mtb geometry evolution???🤩
So I upgraded to a Raceface 15mm stem. This video answers my question. I’m going to go with a 51mm offset to offset my shorter stem.
that double crown 36 looks amazing
You blowin' my mind Henry! Very informative video. Keep it coming
You should have timed all 3 runs. Something can feel better and yet be worse, and vice versa. Having the time data broken up over a few segments would paint a better picture on the pros and cons of each set up.
I think I finally understood some of those words! Thank you :)
Does anyone else think that the anonymous rider looks a bit like Neil?
Henry should have a nerd-off about this with MBUKs Seb Stott. Seems like they have VERY different persecutions about fork offset :P Stott claims that it is diminishing returns to reduce offset on a slack bike and trail/xc (=steeper ha) bikes might benefit more with a reduction in offset
But I really did enjoy this as this is something that some companies are "building their bikes around".
Could you do a episode on aftermarket damper/spring upgrades? :D
So if I go from a 150mm fork with a 51 offset, and I put on a 160mm fork (slackens head tube angle) and have the 160mm fork be a 44mm offset, did I do it right?
What about fork offset on cross country bikes? or is it the same across the bord.
Thank you, Henry. Very well explained.
Great vid. Thanks. Could you test the different offsets in technical terrains (like rock gardens) and even with climbing? The test trail looked like it was mostly descent. Thanks!
Amazingly clear and informative👏👏👏👏
These guys need to get someone in who actually understands bicycle stabilty and geometry to explain it. I would be interested to hear that.
Would it be better to do the test on a long distance run? I bet the results would be quite interesting. I bet the enduro guys love tinkering. 😀
Hoping to see more enduro bikes with dual crown forks...imho this is the future
Who is this guy? He was really easy to listen to and understand.
Did you just tell me to fork off??!! 😒😡
I’ll be offset if you did.
Very informative, I learnt some stuff I wasn’t too aware of.
Do you think bike manufacturers, put the length stem that they believe best suits the geometry of the bike and you have to be careful messing with that ?
For example I’ve got the new Nukeproof mega , it comes with a 45 or 50 mm stem , I was thinking of trying a 35 , out of curiosity more than anything,, a lot of guys seem to be running 35 mm stems, now after watching this , I’m thinking why mess with something that is working fine . I could unweight the front wheel and it could be a negative more than a positive.
easy use
Hi Henri, could you mention by how much you guys changed the offset or trail. Thant would help to better quantify the effects felt. Cheers Andy
Great video. Very informative. What is that awesome fender on that front wheel?
The moustache Henry gave to Neil. Wasn't from the same field where Steve Jones got his fake moustache in on of the EMBN videos is it.
I have to ask. When you guys flopped the forks around, did you also change the front ride height to compensate for the front end going higher from the ground? This would be a factor.
Great explanation! I'd been wondering about offset recently. That key lime looks AMAZING!
Those stem bolts were not tightened correctly might be smart to fix that with the carbon bar
Love these super geeky videos super interesting
Which are offset is better for corner grip on loose gravel?
I've just bought fork with 51mm offset. What did I do? 🤦♂️I was only thinking about increasing wheels base.
That’s no problem. Just get a 50mm stem and the steering feel will be good, plus you’ll be leaning a little further forward allowing more weight on the front end. Short offset forks are kind of unnecessary.
Namaste Henry lad... Namaste 🙏🏼
11:50 nice :D
I am running a 51mm 160mm offset fork on a 27.5 and it's just fine 😂
Does this bike come with reflectors?
Really interested in these tech experiments. You guys can change and record the difference as you have amazing access to bikes and components so the average mtber can never get close to testing.
I have a question about the frame and fork combo, I was told by canyon I can't fit a downhill fork on my torque as it's not designed to be used with one. You fitted it to a strive. What are the differences between an Enduro frame and downhill frame that stop you from using whatever fork you want? Obviously travel and geometry, but are they reinforced/strengthened more for stresses of double crown over single crown?
I think it's down to personal preference....
27.5plus/29er Hardtail Fat Chance yo Eddy 2.2. 68.5 head angle 50mm stem & 429mm chain stay. Fox factory 130mm 29in fork. How do I choose offset 44 vs 51mm? Any info appreciated. Thx!
27.5 use 44mm, for 29er use a 51mm
It went together easily in less than an hour. ua-cam.com/users/postUgkxHL1v1R3NE5x4KiYfyt8dnQmyNYz7qi5L Make sure the front fork is forward or the pedals will hit the front tire. Tires are both a little soft so it needs air before I ride it. The rear wheel didn't come with a clamp regular bolts hold it on. The front had the clamp. No scratches out of box. Rims are a little off with a slight wobble. They could have spent more time with the spoke tool fixing the run out. So far out of the box I'm happy with it. I did replace the pedals with a nice aftermarket set. After riding it a bit my A$$ is a bit sore so I ordered another seat. Overall I'm nearly 60 and didn't ride a bike in 30 years. I like my new 29" Schwinn. It will be used for casual rides with my friend.
I've got blown away
..cuz of dis vid😊😊😆
#AskGMBNTech
Hi gmbn team,
I am having troubles finding a rear shock for my bike, a specialized camber 2017 with 29”. Due to the fixed specialized mounting hardware, I can’t seem to find an upgrade for my bike. Currently running a x-fusion pro 02 rl - which i am slowly outgrowing, needs a replacement. After looking into a possibility of a bike yoke but not sure of the effects of travel and available shocks I seem to be stuck. I was wondering if you could find a few options for me to use and what would work out. I am a very obnoxious rider so jumps and drops will be on the list and also commute on the same bike. I really hope you can help out.
All the best, Matt cleverley
what stem is that?
What frond fender is that?
interesting
ta
Why isn't the "trail" of a bike called the Caster like it is on cars?
Your brakes are loud in every video! Lots of awesome info tho
5:45 how to clear the woodland of children 😂
1:40 - 1:49 I’m the only who thought that something went wrong with the speaker
It's the Sennheiser wireless units they're using, not the best. And to the untrained ear they can put it down to brushing the microphone, when what it is is actually RF noise
Way to ignore tiler effect. which is really important when talking about how twitchy the steering feels.
Offset is all about trail/flop and "none" about weight distribution. Why they decided to waste several minutes talking about something irrelevant is concerning. If you take real offset differences and calculate weight distributions on modern wheelbases, you will see it is of no consequence.
Professional riders testing offset differences have said they can feel a difference but quickly forget about it since the effect is minor. This is a fabricated issue of no consequence. Offsets have increased as head tube angles have slackened, and for good reason. Recently that has changed but not for good reason but instead because people in the industry don't understand as well as they should.
Also, the claim at the end that offset has a greater effect on trail with slacker head angles is exactly wrong. Offset has a constant effect on trail regardless of head angle and therefore has.a greater proportional effect with steep HTAs.
It's sad how poor this video is technically. I like Henry but this is a big miss.
16:32
1st comment good video keep the good work up
built in auto centering... where do you want that to occur when for what ever the reasons are for no hands... while in the air or on the ground? or maybe the gyroscoptic effect overules all that? I should've been an engineer. no I'll just ride! and watch gmbns
I'm even more confused now lol
Wish you would have done the test on a trail/enduro bike. Change offset on a downhill bike I think isn’t felt as much because even a longer offset still gives a big tire patch because the dh bike is so slack. When you get a small enough trail with a longer offset on a less slacking bike you really start to notice that smaller footpatch loosen up the steering and flop over/dig in much easier on steeper terrain.
This is an enduro bike the canyon strive it just has a dual crown fork on to change fork offset
But with the dual crown fork slackens out the bike much more correct?
More slacker the bike still has a bigger tire patch/trail than a normal fork correct?
Shanerr J I think it will be the same travel fork as what comes stock on the bike so shouldn’t affect things too much 👍
Ok thanks
Jeez just ride your bikes folks
so this is why i can barely ride no-hands - stem too short.
No.
@@archetypex65 what then, low trail? he mentioned stem and trail causing more or less stability.
welp nevermind i looked into it and it can be a few things
@@dinobot_maximize Hahaha, how on Earth would stem length affect riding without hands? You're not using your hands to steer, so it has no impact.
@@dinobot_maximize More to do with body position and CoM of the rider. Less to do with stem length.Of course if you're running a 70mm or 25mm way outside the designed range, than it will have more of an effect.
Toss your dining fork out of the picture frame and is off the set
Just another way to keep the money coming in by over confusing joe public
Yes and no.
Whats the pants are you wearing?!?
"the onset of offset" who writes this? lmao
2:08 nice joke
fork off.........set
Not that big of a deal. Go ride your bike
Internet Police extra information is always good
@@rudySTi #stfu 😃👍
@@rudySTi go ride your bike
Flying Lap Productions fuck off mate if you don’t like the video don’t watch it give over been so negative about everyone
Sounds like he did not change the offset but rather he changed the streaming axis angle which is really changing the effective head tune angle. I don’t think this guy really understands offset, HT angle and trail.
Did he even explain what fork offset was? Terrible audio as usual from Henry... 😣
Mr Neil Donoghue saying Henry's chat of offsets was boring him .... that was just rude Mr Donoghue. Shame on you.
God I yawned alot at this one 🙄
Exactly. This guy's a dopey muppet
Great vid. Thanks. Could you test the different offsets in technical terrains (like rock gardens) and even with climbing? The test trail looked like it was mostly descent. Thanks!