Sounds like none of you guys have been in Belgium... Here in Belgium instead of repairing the potholes they place permanent roadsigns that say 'wegdek in slechte staat' or translated 'road in bad condition'... Why you think so many belgian riders won 'Paris-Roubaix' if you look back in history :D
I’m 65....and I testify right now....to the UA-cam crowd.....that I am an idiot! This video is exceptional! Old dogs CAN learn new tricks! I think I recentlyruined a brand new custom STANs wheel.....by inflating my tire to the marked tire pressure. Idiot that I am......the tire was fully 30% HIGHER than the rim’s high pressure. When it blew, (I’m retired military and law enforcement), I swear, I went to my knees and reached for my right hip! Thank you, again.....great educational video!
I just spent 30 minutes listening to why I like wider tires with lower pressures. Didn’t think I would ever say that! Very interesting and very informative, nice!
Smart. I do similar things according to temperature. When it's warm I raise pressure. The tire is more supple when it's warm so it gets squishy when pressures are too low. When it's cold I lower temperature maybe down 5 or even ten psi because the compounds suffer greatly when cold. Tires lose grip when they are cold. This effects grip when power is applied due to deflection and lack of grip when cornering due to the hardness/deflection ratio. Cold over pressured tires can be deceptively dangerous when taking a corner where you are used to one cornering speed on a known path when warm and then grip is significantly less cold. Think race cars wherein they do a setup lap getting tires up to temperature before they do a timed lap or the danger of becoming passed due to a lack of cornering speed because their tires where cold coming out of the pits. Same principle, different application of that science.
Great interview. From a tech perspective I think it was your best, at least for me. Josh is fantastic and thanks for allowing him to go on about a topic. Many interviewers would have cut for time. I really appreciate that.
Josh is a great interview. It’s rare someone can talk so much about the same subject and keep it interesting. The “negative space in the smooth road” explanation was enlightening. His knife cutting a mop analogy was particularly good at explaining sidewall cuts.
I've recently started to prioritize smoothness and comfortable riding over speed, or the perception of speed, since I found this channel. I'm never looking back #supplelife
I just got a Midnight Special that weighs 38% more then my Giant TCX with exact same gearing. The TCX had 38mm and 60 psig and the Surly has 650b 47mm tires at 42 psig and multiple trips on my 15 mile test loop is 8% slower! Supple life AND speed, thanks @pathlesspedaled
@RollinRat I like the summary you've given this presentation. The point I'd contest might be unloaded weight off the seat for general duration riding. Obviously, off the saddle during high intensity transitions is a very good thing. Yet, people are speaking more (in endurance and touring) of the reduction in muscular load when the rider is not constantly tensing against vibration and increasing tenseness in lifting their entire upper mass off the saddle. So, just a bit more to consider as we define our approach to efficient riding. Cheers!
Great informative talk. I just dropped the PSI on my Gravel bike ( tubed) down to 60 psi from 80 and felt no difference in speed but a smoother ride. Certainly felt the slight wander at the rear on cornering so may go up a couple of PSI, I ride mostly road but our roads have lots of voids due to rocky pavement. Love your channel and really dig the non competitive gravel culture that you espouse. Keep up the good content.
Wow! What an excellent video. Every single assertion that Josh makes is born out by what I know of engineering and years of personal road and mountain bike riding. Take his words to heart! And, Thanks
I'm a newbie in biking. I only commute. I got 2 tubes that I pinched since July, for 1600km of riding. So I decided to inflate them at max PSI... And NOW, you all make me dive into this new rabbit hole of tire pressure... I'm gonna ghetto-tape my wheels for a tubeless setup.
Great interview. Have to love it when someone who has extreme depth of understanding in a field is able to communicate the principles to those who don't. Thanks.
When I got my first road bike, the guy who ran the shop was all about tire pressure. He said to always run the max pressure that was on the sidewalls. He also always recommended one tire: The Vredestein Fortezza. The max pressure on the Vredestein Fortezza is 175psi. Riding chip seal pavement on that bike I thought I was going to lose teeth.
85-100psi seems fine for less than ideal road conditions on a 23-28c tire. Higher the pressure the less rolling resistance. Less rolling resistance = faster speeds. Larger volume tires can handle less psi. Smaller volume tires require more.
@@SugmaDLigmaNutz 28c is the ideal rolling tire usually anyway. might depend a bit on specific tires but i think that the consensus was 28 was best with 32 slightly behind by like 0.5W but much more comfort. 65 front and 75 rear is just fine.
Thanks for letting us know about the Silca tire pressure app. The feel I get following its recommendation on my road bikes is incredible. It is transformative for me. This is one of those rare cycling videos that has been not just interesting, but which provided practical info that iimmediately changed my cycling. I thought I ran relatively low pressures before but they still weren't low enough.
Great interview! Love information like this. I have a feeling the people who downvote are all like "I RUN MY TIRES AT 150psi AND NO ONE CAN TELL ME DIFFERENT!!!"
I've long been a convert to smooth is fast, but I did learn something new in this video about pressure, case tension and risk of sidewall cuts. Thanks Josh, thanks Russ.
I found this so fascinating, thank you for doing this interview. I used to ride a much heavier bike than I do now for mountain biking. And back in the day I would run the biggest tire I could fit which at the time was 2.8 and no one could understand why I did so. They all thought that it was totally unnecessary and that I was just running big tires to run big tires. But for riding here in the Northeast with all the rocks and roots it made sense and I use to tweak the air pressure all the time depending on the terrain. I was, without really knowing it, looking for the smooth feeling. I feel so justified right now.
This was a great re-enforcement for me. I met a fellow in Oakland at a cycling event and he was going on about tire pressure and contact patches. He sent me some data and I have to admit it took me aback. Hard tires = fast was just accepted...I'm stubborn, but not too proud to admit I've been converted. Great video!
That was a fantastic interview. Really nice work. You do a great job talking with interesting, knowledgeable people to help dispel some long standing myths. Particularly, for the non racing folk which, as Josh mentioned us pretty much all of us! Thanks again! Keep up the great work!
This has been a great video, hit on topics that I have been preaching for years. I am glad that an engineer finally validated what I have been talking about. I cannot say how many people made fun of me 25 years ago when I would show up on 32c tires stuffed into my road bike. I also loved the talk on aero vs tire pressure and tire pressure vs ceramic bearings.
I first came across it in windsurfing. When you just lean back, relax and enjoy a magic carpet ride, you're most likely fast. When everything rattles, you're slow.
I strongly believed this too, until I had the opportunity to take a few hotlaps in a car driven by ex F1 driver Roberto Guerrero. I considered the laps violent. They were incredibly faster than any of the local "pros". They are able to redefine a standard quite different of where the ragged edge actually is.
Many years ago I saw a telecast of the DH Worlds. John Tomac was one of the last riders, and set the fastest time up to that point, but looked really ragged, on the verge of crashing for the whole run. The last rider was Nicolas Vouilloz who was super smooth the whole way, with little or no visible sliding. He absolutely nailed his run, easily setting the fastest time, while looking in total control the whole way. Smooth is good, and easier on gear too.
Great video, so many people run too much pressure and it is great to see someone validating what I have been saying for years. Keeping track / notes are key.
What I like about Josh's approach is that it is useful for recreational riders (like me) just the same. Optimizing riding comfort to get you as far as possible without killing you, thats the point. I made the experience of equaling or even outlasting stronger riders on touristic rides just because I always care a lot for a comfortable ride and position.
Great interview. Great content. Even though Josh is race-focused, there’s lots of good stuff here for enthusiasts. It was especially interesting to learn about the advantage of wider rims - that the tire can deform more easily because it’s not as dependent on the flex of a perpendicular sidewall. One thing I wanted was some discussion of tubes vs. tubeless. Josh told how inefficient butyl tubes are. Latex is faster, but needs a daily refill (which tells me that it won’t be consistent on long rides.) Tubular is fine if a support vehicle follows you, but us mortals don’t get that luxury. That leads us to tubeless. I’d love to get his take on the topic. Lots to ponder!
RollinRat -Thanks for the wealth of information based on real-world experience! Tubulars really do make sense for racers with lighter rims, lighter, more supple tires, and the safety factor and ability to ride on with a glued tire. That said, some time trialists on the tour now use tubeless fronts. As disc wheels start supporting tubeless, I expect that we’ll see them on the rears now soon. I’m guessing that this is just for flat stages. And maybe they’re being adopted for budget/workload reasons. Road tubeless has been flawless for me. I run 25s at 70-75 psi and 28s at 60-65 psi for for rough, Southern Oregon roads. I weigh 180ish. When the weather improves and I get some time, I’ll grab a notebook and optimize things. Your post removed any last inkling of me using tubulars. Even with perfect reliability, the cost and maintenance seem painful! Thanks again for your awesome post!
RollinRat Could be an expensive test ride, lol. I risk tubular addiction! I’ve been riding 25 and 28c tires on 19mm internal rims. I’m getting an ENVE 4.5 AR Disc wheelset with 25mm internal width. I’m hoping that will provide a more supple ride with the ease of a tubeless setup.
RollinRat I’m going with Schwalbe Pro One TLE 28mm tires. I’d try the Conti GP5000 tubeless, but ENVE doesn’t recommend them on these rims. And yes, I check my pressure and lube the chain before most every ride. Maintaining tires and drivetrain is easy money!
I think it's the opposite isn't it? i.e. that the tire can deform more easily on a narrower rim, not a wider rim. On a wider ID rim, the sidewall becomes more vertical. Jan Heine's article on rim ID says what I just did - that's where I got it.
I think of it this way. A tire on a wider rim becomes an effectively wider tire, so it’s got a larger effective radius from sidewall to contact patch to sidewall. That means that more of the tire is close to the angle of the road. Anyway, it makes sense to me and aligns with the interview info.
What a fantastic explaination of tyre losses. I have watched a bunch of videos on this subject and this guy has nailed explaining losses. He didn't even need a power point or fancy graphics!
Fascinating. I've been a low pressure fan for years. His way of explaining the why is the best I've heard. Thanks so much for putting this together, I thoroughly enjoyed it!
Very pleasantly surprised. I wasn't so sure what I would find with that title from you. Good choice to have Josh. Very cool that he agreed to share his insights with you and us. Thank you.
Thank you Russ, this was an excellent interview and presentation. I am more times than not telling some of my riding buddies that thy're running too high a pressure. We have really crappy chip seal roads that have lots of negative space as your guest called it. I'm about 170 - 178 lbs. and I normally run 80 front 85 in the rear with a 25 mm tire that actually measures about 30 mm on my Easton R90SL rims. Keep it supple my friends, smooth is speed.
Thank You for this wonderfully informative interview! GCN went from saying supporting the skinny tire / high pressure line of thought for a while and then seemingly switched to the newer argument for slightly wider tires (as supposedly faster). But they never really explained the science behind it! This video was awesome. Just so incredibly helpful to better undertstand a complexi topic.
Great video - and totally familiar to the situation - have been asking/convincing people their air pressure is too high (most of times). Impressive how many people over-inflate their tires, and still believe they are right - too much air means less comfort, less traction, more flats AND less speed. Learning your right tire pressure is quite a game changer.
My eyes were glazing over in the beginning, but glad I hung on as it was very interesting and informative. Good explanation of why tubeless is better than tubes.
Man, this is why I love this channel and am a patreon supporter. You do great, great work Russ and your interviews are top notch. Your videos range from relaxing fun to uplifting to technie nerd out extremely informative and helpful. Thank you! I truly enjoy your channel.
Excellent conversation, I was fascinated!!! I'm only into fat bikes at the moment (5 to 20 psi) and never had a "roadie" bike. But I totally understood what Josh was on about, as I've spent a few years as a tire fitter in the car/commercial/plant/implement(farm) sectors. I know that pressure differences can seem to be more generous as tires get bigger/wider and weight of vehicle increases. But if you want 10, or 20, or 30,000 miles or more out of a set of car (36psi) or truck tires (100psi), pressures are very important. Even as little as 2 psi gains or loses a load of miles. Equally, if you want your tractor to return to the farm instead of getting bogged down somewhere, pressures are equally important. Oh, and for race tires? 1psi can mean hundredths of a second per lap.
This is a fantastic video - great content - and the enthusiasm of the expert is infectious. Thanks so much for sharing this information - it is going to change the way I ride!
Your video is causing me to question my own nerd credibility. I can't believe that I never knew what the tire pressure range on the sidewall meant!! OMG. Looking forward to more.
Russ, loved to see a convo like this with the creator of the catalyst pedal (pedaling innovations). The science and laymen understanding to how pedals vary and what is actually optimal vs what the industry has simply just been reusing for decades/centuries. Great info and vid as always, regret missing you at Philly Bike Expo.
I’ve been easing down the supple path for awhile... I finally went all in and got some Compass 700x55s, am just back from my first 20 mile ride on them and wondering how to dial in the pressure... happened to pull up your channel while I eat lunch and can’t believe how much information was in this, and it’s exactly what I need!
Awesome, I love going techie on tires. If you had edited that to be twice as long, I still would have loved it. (and a great edit too with the prologue snippets and the camera view changes) Heck, watching it a second time now. If you liked this, I would recommend finding a couple episodes of the FloCycling podcast that also had a couple great interviews with Josh Poertner regarding tire pressure and tubeless tire setups. I'm running Rene Herse 38s on my fast recumbent and have a helluva time convincing my local club riders to go wider and softer. Will have to share this video to the club page.
Since I come from an MTB background I’ve never really followed the numbers on the side. Running in the region of 21-25psi depending on what Ive been eating and what I’m riding and the size of the tier. Not to mention most tubeless rims don’t like to be inflated over 40psi. Never understood why the road crowd seemed so reluctant to drop the pressure. Even if you don’t fully understand the reasons why it offers more grip that much is obvious and is way more comfortable. A day of high frequency vibrations does not feel fast at all in my mind. It bloody hurts
@vibratingstring same , but I ride tube tires, if I go that low, they'll puncture, I leave it at 40. That's also why we don't want to lower our pressures on road bikes. My road bike has it at 115.
I think that last bit he says 34:18 is key here. A lot of PLP fans are quick to write off roadies but "saving watts" simply means "better comfort, less fatigue" in a many cases--particularly as it pertains to "slower" aka normal human speeds--which is something ALL riders, not just roadies and racers can appreciate.
rang of air pump into tire. 3 factors. One is inner tire range Maximum PSI Two is outer tire range Maximum PSI three is total your weight on bike(yourself and bag&stuff)
I have 3 follow up questions: You explained the origin of the maximum recommended pressure number. What is the origin of the minimum recommended pressure? Should there be a difference in front versus rear tire pressure? If so, how much? Based upon your experience, Is there a typical tire pressure in the pro peloton by tire type?
Super cool stuff. I saw the length of the video and thought, "no way!" But it was really cool, super cool, way cool in fact. :) Sort of matches up with what I learned when I went to tubeless tires on my bikes ~15 years ago. I was running about 85-90psi in my 23c road tires and about 25-28psi in my 2.0 MTB tires. I was about 215-220lbs and a lot faster back then. The average 150lb xc racer was running low 20's back then and few guys dipped lower. I'm a good bit heavier/slower these days and still only run 50psi in my 32c slicks on my road wheels. I runabout 40psi in my 40c gravel tires, and I think I need to go lower, but I'm fairly new to gravel. Every once in a while I'll miss a little on the low side. I get the bouncy rear tire and I feel like I'm riding in wet grass.
Gosh! A lot of information there. Josh certainly is passionate about what matters to him. Great interview Russ but it looked like you were mesmerised too.
Very useful and insightful interview. This is what I have been trying to convince the riders around me for a long time based on instinct-engineering (if there is such a thing). They usually stare at me like I have three heads though. :) Thank you both for this.
Thank you for explaining what the physics of why running 150%max side wall psi(60max ran 90-95psi), in my 2.20"x 26" semi-slick on my Trek Anelope 800 back in the late 90's. The extreme pressure limmits the carcass hysteresis to an absolute min almost 0, making the tread hysteresis the primary factor. At 30-47mph they had a hell of a hum on the back country roads of Merced County( Turlock Road, Oakdale Road, Looney Road, the stair step Hill section I don't recall the name of five laps was a 125 MI race that I saw growing up out there.) 3/4-1 1/2" rock cheep ruff asphalt . The ride from my high school to the course, one lap oh, and the ride home was 51 miles 3x /week. I couldn't afford a real road bike willingness work outside the box and walk the pressure in as you describe . 110 rule 2.20 was the smallest tire the loacal bike shop had for my 25mm mountain bike wheels and could support 250lbs with book bag. I love hearing the technical aspects but how it works
Been playing with pressure on my CO-motion tandem. Running ReneHerse 650b X 48 total weight 405 lbs. running 48lbs. The ReneHerse tre pressure calculator suggest 57lbs. Truefully tires feel great at both pressures. On pavement.
Much good info in this video. Best I've ever seen on this topic. It hadnt occurred to me that cutting vs pinching would have different risk vs pressure. But it should have been obvious. That comment about smooth = fast maybe one of the most important things I've seen in a bike video for quite awhile.
It would be interesting to know what the optimum inner rim width to actual tyre width should be, as well as tyre pressure, to give the best handling for the supple life.
Personally I run my tyres just above squidgy (technical term) and rely on the repeatability of my thumb. I do know a few people who I will direct to this video though.
“Squidgy”, eh? When are you guys gonna crawl out of the Dark Ages and go metric? The term you are looking for is “hectopinch”. As in: “Lose me a few hectopinches, Alfred, as I intend to take the scenic route this morning.”
@@albertbatfinder5240 "hectopinch" is too precise and you'll have to get your inflation devise out every couple of yards (1828.8mm) to adjust for changing grit size. Rule of thumb every time for me ;-)
I live in the North of England. Some of the negative spaces in our asphalt is 2 or 3 feet across.
Ha.
We can top that here. Some of the ones here drop you to the center of the earth.
Some "pothole gardening" are started, in fact, in UK.
_Weather_ is key word.
Everything is bigger in America, even the pot holes ;-) ... (my first impression at a visit)
Sounds like none of you guys have been in Belgium... Here in Belgium instead of repairing the potholes they place permanent roadsigns that say 'wegdek in slechte staat' or translated 'road in bad condition'... Why you think so many belgian riders won 'Paris-Roubaix' if you look back in history :D
I’m 65....and I testify right now....to the UA-cam crowd.....that I am an idiot! This video is exceptional! Old dogs CAN learn new tricks! I think I recentlyruined a brand new custom STANs wheel.....by inflating my tire to the marked tire pressure. Idiot that I am......the tire was fully 30% HIGHER than the rim’s high pressure. When it blew, (I’m retired military and law enforcement), I swear, I went to my knees and reached for my right hip! Thank you, again.....great educational video!
I just spent 30 minutes listening to why I like wider tires with lower pressures. Didn’t think I would ever say that! Very interesting and very informative, nice!
I think it’s important to raise my tire pressure 2-3% in January to support December’s holiday eating.
Thomas Benenati I like to work on eating in 2-3% more in Dec to prevent the need to let the air out of over inflated tires! 😂
#supplelife
Smart. I do similar things according to temperature. When it's warm I raise pressure. The tire is more supple when it's warm so it gets squishy when pressures are too low. When it's cold I lower temperature maybe down 5 or even ten psi because the compounds suffer greatly when cold. Tires lose grip when they are cold. This effects grip when power is applied due to deflection and lack of grip when cornering due to the hardness/deflection ratio. Cold over pressured tires can be deceptively dangerous when taking a corner where you are used to one cornering speed on a known path when warm and then grip is significantly less cold. Think race cars wherein they do a setup lap getting tires up to temperature before they do a timed lap or the danger of becoming passed due to a lack of cornering speed because their tires where cold coming out of the pits. Same principle, different application of that science.
This is the kind of podcast I will listen to 2-3 times. Your guest was as good as they get.! Thanks again!
Great interview. From a tech perspective I think it was your best, at least for me. Josh is fantastic and thanks for allowing him to go on about a topic. Many interviewers would have cut for time. I really appreciate that.
He's like the Quentin Tarantino of tyres.
Dean Herde yes but, blissfully, with fewer potty words.
"Did you see a sign in front of my house that said.... "
If the word "right" was a pebble, this conversation would be a gravel road.
Yes. He is a happy genius. A rare creature indeed.
No mention of foot fetishes
Josh is a great interview. It’s rare someone can talk so much about the same subject and keep it interesting.
The “negative space in the smooth road” explanation was enlightening. His knife cutting a mop analogy was particularly good at explaining sidewall cuts.
I've recently started to prioritize smoothness and comfortable riding over speed, or the perception of speed, since I found this channel. I'm never looking back #supplelife
I just got a Midnight Special that weighs 38% more then my Giant TCX with exact same gearing. The TCX had 38mm and 60 psig and the Surly has 650b 47mm tires at 42 psig and multiple trips on my 15 mile test loop is 8% slower! Supple life AND speed, thanks @pathlesspedaled
@RollinRat I like the summary you've given this presentation. The point I'd contest might be unloaded weight off the seat for general duration riding. Obviously, off the saddle during high intensity transitions is a very good thing. Yet, people are speaking more (in endurance and touring) of the reduction in muscular load when the rider is not constantly tensing against vibration and increasing tenseness in lifting their entire upper mass off the saddle. So, just a bit more to consider as we define our approach to efficient riding. Cheers!
Great informative talk. I just dropped the PSI on my Gravel bike ( tubed) down to 60 psi from 80 and felt no difference in speed but a smoother ride. Certainly felt the slight wander at the rear on cornering so may go up a couple of PSI, I ride mostly road but our roads have lots of voids due to rocky pavement. Love your channel and really dig the non competitive gravel culture that you espouse. Keep up the good content.
Wow! What an excellent video. Every single assertion that Josh makes is born out by what I know of engineering and years of personal road and mountain bike riding. Take his words to heart! And, Thanks
This was really great - bringing us all further out of the biking dark ages one talk at a time.
I'm a newbie in biking. I only commute. I got 2 tubes that I pinched since July, for 1600km of riding. So I decided to inflate them at max PSI...
And NOW, you all make me dive into this new rabbit hole of tire pressure...
I'm gonna ghetto-tape my wheels for a tubeless setup.
Great interview. Have to love it when someone who has extreme depth of understanding in a field is able to communicate the principles to those who don't. Thanks.
I could listen to Josh for hours. Thanks Russ for those bike-nerdy guests
When I got my first road bike, the guy who ran the shop was all about tire pressure. He said to always run the max pressure that was on the sidewalls.
He also always recommended one tire: The Vredestein Fortezza.
The max pressure on the Vredestein Fortezza is 175psi.
Riding chip seal pavement on that bike I thought I was going to lose teeth.
85-100psi seems fine for less than ideal road conditions on a 23-28c tire. Higher the pressure the less rolling resistance. Less rolling resistance = faster speeds. Larger volume tires can handle less psi. Smaller volume tires require more.
@@SugmaDLigmaNutz 28c is the ideal rolling tire usually anyway. might depend a bit on specific tires but i think that the consensus was 28 was best with 32 slightly behind by like 0.5W but much more comfort. 65 front and 75 rear is just fine.
?
Never thought I’d find myself watching through a video on tire pressure, but this was really good! Great information!
Discovering this interesting episode in 2023. Awesome subject matter expert, l learned quite a lot...thank you!
Thanks for letting us know about the Silca tire pressure app. The feel I get following its recommendation on my road bikes is incredible. It is transformative for me. This is one of those rare cycling videos that has been not just interesting, but which provided practical info that iimmediately changed my cycling. I thought I ran relatively low pressures before but they still weren't low enough.
Great interview! Love information like this.
I have a feeling the people who downvote are all like "I RUN MY TIRES AT 150psi AND NO ONE CAN TELL ME DIFFERENT!!!"
I've long been a convert to smooth is fast, but I did learn something new in this video about pressure, case tension and risk of sidewall cuts. Thanks Josh, thanks Russ.
I found this so fascinating, thank you for doing this interview. I used to ride a much heavier bike than I do now for mountain biking. And back in the day I would run the biggest tire I could fit which at the time was 2.8 and no one could understand why I did so. They all thought that it was totally unnecessary and that I was just running big tires to run big tires. But for riding here in the Northeast with all the rocks and roots it made sense and I use to tweak the air pressure all the time depending on the terrain. I was, without really knowing it, looking for the smooth feeling. I feel so justified right now.
My 25 year old niece just walked past me and heard me listening to this and gave me a WTH look!! Hahahaha
This was a great re-enforcement for me. I met a fellow in Oakland at a cycling event and he was going on about tire pressure and contact patches. He sent me some data and I have to admit it took me aback. Hard tires = fast was just accepted...I'm stubborn, but not too proud to admit I've been converted.
Great video!
Top three best content series from Russ in no particular order 1) nerdy interviews like this 2) PLP Talks 3) Cave of bad ideas.
That was a fantastic interview. Really nice work. You do a great job talking with interesting, knowledgeable people to help dispel some long standing myths. Particularly, for the non racing folk which, as Josh mentioned us pretty much all of us! Thanks again! Keep up the great work!
This has been a great video, hit on topics that I have been preaching for years. I am glad that an engineer finally validated what I have been talking about. I cannot say how many people made fun of me 25 years ago when I would show up on 32c tires stuffed into my road bike. I also loved the talk on aero vs tire pressure and tire pressure vs ceramic bearings.
If it “feels fast” it probably isn’t. Smooth is fast. I’ve heard this in automotive racing all the time too.
I first came across it in windsurfing. When you just lean back, relax and enjoy a magic carpet ride, you're most likely fast. When everything rattles, you're slow.
This is the mantra for me from now on.
I strongly believed this too, until I had the opportunity to take a few hotlaps in a car driven by ex F1 driver Roberto Guerrero. I considered the laps violent. They were incredibly faster than any of the local "pros". They are able to redefine a standard quite different of where the ragged edge actually is.
Many years ago I saw a telecast of the DH Worlds. John Tomac was one of the last riders, and set the fastest time up to that point, but looked really ragged, on the verge of crashing for the whole run. The last rider was Nicolas Vouilloz who was super smooth the whole way, with little or no visible sliding. He absolutely nailed his run, easily setting the fastest time, while looking in total control the whole way. Smooth is good, and easier on gear too.
Great interview. He is a great teacher the way he presented the concepts.
Terrific interview, Russ
Thanks Russ, this was very nerdy but satisfyingly Supple
Great video, so many people run too much pressure and it is great to see someone validating what I have been saying for years. Keeping track / notes are key.
We put more negative space in our roads depending on the need for wet weather grip.
What I like about Josh's approach is that it is useful for recreational riders (like me) just the same. Optimizing riding comfort to get you as far as possible without killing you, thats the point. I made the experience of equaling or even outlasting stronger riders on touristic rides just because I always care a lot for a comfortable ride and position.
Great interview. Great content. Even though Josh is race-focused, there’s lots of good stuff here for enthusiasts.
It was especially interesting to learn about the advantage of wider rims - that the tire can deform more easily because it’s not as dependent on the flex of a perpendicular sidewall.
One thing I wanted was some discussion of tubes vs. tubeless. Josh told how inefficient butyl tubes are. Latex is faster, but needs a daily refill (which tells me that it won’t be consistent on long rides.) Tubular is fine if a support vehicle follows you, but us mortals don’t get that luxury. That leads us to tubeless. I’d love to get his take on the topic.
Lots to ponder!
RollinRat -Thanks for the wealth of information based on real-world experience! Tubulars really do make sense for racers with lighter rims, lighter, more supple tires, and the safety factor and ability to ride on with a glued tire. That said, some time trialists on the tour now use tubeless fronts. As disc wheels start supporting tubeless, I expect that we’ll see them on the rears now soon. I’m guessing that this is just for flat stages. And maybe they’re being adopted for budget/workload reasons.
Road tubeless has been flawless for me. I run 25s at 70-75 psi and 28s at 60-65 psi for for rough, Southern Oregon roads. I weigh 180ish. When the weather improves and I get some time, I’ll grab a notebook and optimize things. Your post removed any last inkling of me using tubulars. Even with perfect reliability, the cost and maintenance seem painful!
Thanks again for your awesome post!
RollinRat Could be an expensive test ride, lol. I risk tubular addiction!
I’ve been riding 25 and 28c tires on 19mm internal rims. I’m getting an ENVE 4.5 AR Disc wheelset with 25mm internal width. I’m hoping that will provide a more supple ride with the ease of a tubeless setup.
RollinRat I’m going with Schwalbe Pro One TLE 28mm tires. I’d try the Conti GP5000 tubeless, but ENVE doesn’t recommend them on these rims.
And yes, I check my pressure and lube the chain before most every ride. Maintaining tires and drivetrain is easy money!
I think it's the opposite isn't it? i.e. that the tire can deform more easily on a narrower rim, not a wider rim. On a wider ID rim, the sidewall becomes more vertical. Jan Heine's article on rim ID says what I just did - that's where I got it.
I think of it this way. A tire on a wider rim becomes an effectively wider tire, so it’s got a larger effective radius from sidewall to contact patch to sidewall. That means that more of the tire is close to the angle of the road.
Anyway, it makes sense to me and aligns with the interview info.
What a fantastic explaination of tyre losses. I have watched a bunch of videos on this subject and this guy has nailed explaining losses.
He didn't even need a power point or fancy graphics!
Fascinating. I've been a low pressure fan for years. His way of explaining the why is the best I've heard. Thanks so much for putting this together, I thoroughly enjoyed it!
Wow
I never thought I would enjoy a 35 minute video about the science of tires.
Really cool, amazingly knowledgeable guest.
👊
Every time I re-watch this, I pick up on some new detail or concept. There's just so much information in here. Amazing interview.
Very interesting interview, Russ. I've been trying to convince my friend that his pressures are too high, I'm going to send him this video.
Very pleasantly surprised. I wasn't so sure what I would find with that title from you. Good choice to have Josh. Very cool that he agreed to share his insights with you and us. Thank you.
Thank you Russ, this was an excellent interview and presentation. I am more times than not telling some of my riding buddies that thy're running too high a pressure. We have really crappy chip seal roads that have lots of negative space as your guest called it. I'm about 170 - 178 lbs. and I normally run 80 front 85 in the rear with a 25 mm tire that actually measures about 30 mm on my Easton R90SL rims. Keep it supple my friends, smooth is speed.
Spread the word brother, you could even save them from a fall one day.
Thank You for this wonderfully informative interview! GCN went from saying supporting the skinny tire / high pressure line of thought for a while and then seemingly switched to the newer argument for slightly wider tires (as supposedly faster). But they never really explained the science behind it! This video was awesome. Just so incredibly helpful to better undertstand a complexi topic.
My wrists determine my front tire pressure. Usually 10 psi less than the rear.
vibratingstring ...Actually it's the base of my thumbs. Some arthritis from decades of twisting wire nuts. 👌
Man this channel keeps getting better the more i look into it. this is so interesting!
Wow this is the most interesting and educational discussion I have heard in a long time! I so enjoyed this and will have a play with those pressures.
Great video - and totally familiar to the situation - have been asking/convincing people their air pressure is too high (most of times). Impressive how many people over-inflate their tires, and still believe they are right - too much air means less comfort, less traction, more flats AND less speed. Learning your right tire pressure is quite a game changer.
Absolutely loved his vivid way of explaining
My eyes were glazing over in the beginning, but glad I hung on as it was very interesting and informative. Good explanation of why tubeless is better than tubes.
Man, this is why I love this channel and am a patreon supporter. You do great, great work Russ and your interviews are top notch. Your videos range from relaxing fun to uplifting to technie nerd out extremely informative and helpful. Thank you! I truly enjoy your channel.
Exceptional discussion and highly valued information! Thank you.
What an informative interview! Such a wealth of information from Josh.
Excellent conversation, I was fascinated!!!
I'm only into fat bikes at the moment (5 to 20 psi) and never had a "roadie" bike. But I totally understood what Josh was on about, as I've spent a few years as a tire fitter in the car/commercial/plant/implement(farm) sectors. I know that pressure differences can seem to be more generous as tires get bigger/wider and weight of vehicle increases. But if you want 10, or 20, or 30,000 miles or more out of a set of car (36psi) or truck tires (100psi), pressures are very important. Even as little as 2 psi gains or loses a load of miles. Equally, if you want your tractor to return to the farm instead of getting bogged down somewhere, pressures are equally important.
Oh, and for race tires? 1psi can mean hundredths of a second per lap.
Fenomenal. Thank you - proud to be helping you guys on Patreon
This is a fantastic video - great content - and the enthusiasm of the expert is infectious. Thanks so much for sharing this information - it is going to change the way I ride!
Thanks for this video. I just got my tires down to comfortable a pressure and it really improved my ride!
Wow, I didn’t know that there was so much physics behind the term “supple”!
Your video is causing me to question my own nerd credibility. I can't believe that I never knew what the tire pressure range on the sidewall meant!! OMG. Looking forward to more.
I pump the tire and after i sit on the bike i say: "that's good enough"!
Russ, loved to see a convo like this with the creator of the catalyst pedal (pedaling innovations). The science and laymen understanding to how pedals vary and what is actually optimal vs what the industry has simply just been reusing for decades/centuries. Great info and vid as always, regret missing you at Philly Bike Expo.
This is a really insightful video about tyre pressure, great job!
This was awesome, great find for an interview- Thanks, y'all!
Great interview. You let your guest talk and asked good questions.
I’ve been easing down the supple path for awhile... I finally went all in and got some Compass 700x55s, am just back from my first 20 mile ride on them and wondering how to dial in the pressure... happened to pull up your channel while I eat lunch and can’t believe how much information was in this, and it’s exactly what I need!
No product hype, just solid science. I liked that.
This was such a great interview/video. I am learning so much; I will probably have to watch it over and over again to process everything!
Awesome, I love going techie on tires. If you had edited that to be twice as long, I still would have loved it. (and a great edit too with the prologue snippets and the camera view changes) Heck, watching it a second time now.
If you liked this, I would recommend finding a couple episodes of the FloCycling podcast that also had a couple great interviews with Josh Poertner regarding tire pressure and tubeless tire setups.
I'm running Rene Herse 38s on my fast recumbent and have a helluva time convincing my local club riders to go wider and softer. Will have to share this video to the club page.
Puncture protection is what keeps most gravel riders away from extra light (ExtraLight) tyres, tubeless or not.
This was your best video! Could listen to him for hours. Very informatic and perfectly explained.
Pump up to 55, press with thumb, “close enough”, ride.
Watching this was like taking a masterclass in bicycle tires!
Since I come from an MTB background I’ve never really followed the numbers on the side. Running in the region of 21-25psi depending on what Ive been eating and what I’m riding and the size of the tier. Not to mention most tubeless rims don’t like to be inflated over 40psi. Never understood why the road crowd seemed so reluctant to drop the pressure. Even if you don’t fully understand the reasons why it offers more grip that much is obvious and is way more comfortable. A day of high frequency vibrations does not feel fast at all in my mind. It bloody hurts
@vibratingstring same , but I ride tube tires, if I go that low, they'll puncture, I leave it at 40.
That's also why we don't want to lower our pressures on road bikes. My road bike has it at 115.
I love this content. It's like that interview with the merriam-webster guy.
I think that last bit he says 34:18 is key here. A lot of PLP fans are quick to write off roadies but "saving watts" simply means "better comfort, less fatigue" in a many cases--particularly as it pertains to "slower" aka normal human speeds--which is something ALL riders, not just roadies and racers can appreciate.
Even tho I understood most of that, I thoroughly enjoyed it. Thanks for having him on to speak to us.
rang of air pump into tire.
3 factors.
One is inner tire range Maximum PSI
Two is outer tire range Maximum PSI
three is total your weight on bike(yourself and bag&stuff)
Learned more about bike tires in 35 minutes than I knew from over 60 years of riding!
I have 3 follow up questions:
You explained the origin of the maximum recommended pressure number. What is the origin of the minimum recommended pressure?
Should there be a difference in front versus rear tire pressure? If so, how much?
Based upon your experience, Is there a typical tire pressure in the pro peloton by tire type?
Super cool stuff. I saw the length of the video and thought, "no way!" But it was really cool, super cool, way cool in fact. :)
Sort of matches up with what I learned when I went to tubeless tires on my bikes ~15 years ago. I was running about 85-90psi in my 23c road tires and about 25-28psi in my 2.0 MTB tires. I was about 215-220lbs and a lot faster back then. The average 150lb xc racer was running low 20's back then and few guys dipped lower.
I'm a good bit heavier/slower these days and still only run 50psi in my 32c slicks on my road wheels. I runabout 40psi in my 40c gravel tires, and I think I need to go lower, but I'm fairly new to gravel. Every once in a while I'll miss a little on the low side. I get the bouncy rear tire and I feel like I'm riding in wet grass.
What a sharp guy. Those were great explanations! Thanks for the interview, Russ!
This was such a great and informative video!! Just getting into gravel bike riding and really enjoying all the videos on your channel.
Omg!!!! Your vids are only getting better! Thank you for putting out this content.
Gosh! A lot of information there. Josh certainly is passionate about what matters to him. Great interview Russ but it looked like you were mesmerised too.
A good host knows how to shut up.
This is an excellent discussion on the matter of tire pressure. Thank you very much for sharing it!
Josh did an awesome job of explaining the physics of this and I really enjoyed it!
Great information, really enjoyed every minute, thanks to you for helping us become a better cyclist.
Finally a comprehensive explanation on what has been my stance for a while: less pressure is more most of the time.
Very useful and insightful interview. This is what I have been trying to convince the riders around me for a long time based on instinct-engineering (if there is such a thing). They usually stare at me like I have three heads though. :) Thank you both for this.
Thank you for explaining what the physics of why running 150%max side wall psi(60max ran 90-95psi), in my 2.20"x 26" semi-slick on my Trek Anelope 800 back in the late 90's.
The extreme pressure limmits the carcass hysteresis to an absolute min almost 0, making the tread hysteresis the primary factor. At 30-47mph they had a hell of a hum on the back country roads of Merced County( Turlock Road, Oakdale Road, Looney Road, the stair step Hill section I don't recall the name of five laps was a 125 MI race that I saw growing up out there.) 3/4-1 1/2" rock cheep ruff asphalt . The ride from my high school to the course, one lap oh, and the ride home was 51 miles 3x /week. I couldn't afford a real road bike willingness work outside the box and walk the pressure in as you describe .
110 rule 2.20 was the smallest tire the loacal bike shop had for my 25mm mountain bike wheels and could support 250lbs with book bag.
I love hearing the technical aspects but how it works
Been playing with pressure on my CO-motion tandem. Running ReneHerse 650b X 48 total weight 405 lbs. running 48lbs. The ReneHerse tre pressure calculator suggest 57lbs. Truefully tires feel great at both pressures. On pavement.
Great interview! I really enjoyed this one!
Much good info in this video. Best I've ever seen on this topic. It hadnt occurred to me that cutting vs pinching would have different risk vs pressure. But it should have been obvious. That comment about smooth = fast maybe one of the most important things I've seen in a bike video for quite awhile.
Thank for sharing, Russ. Thank Josh for this interview.
Thanks Russ, this is absolutely the most enjoyable and informative UA-cam video on cycling I have watched. Brilliant work. 👍🏼👍🏼
As a mountain biker, I always wondered where the heck those psi ratings come from on the sidewall. I'm generally around half of the supposed minimum.
Great interview. Super helpful for dialing in my commute over rough roads...
This video has been so helpful and gave me a lot of food for thought. Thank you very much 👍
It would be interesting to know what the optimum inner rim width to actual tyre width should be, as well as tyre pressure, to give the best handling for the supple life.
Personally I run my tyres just above squidgy (technical term) and rely on the repeatability of my thumb.
I do know a few people who I will direct to this video though.
“Squidgy”, eh? When are you guys gonna crawl out of the Dark Ages and go metric? The term you are looking for is “hectopinch”.
As in: “Lose me a few hectopinches, Alfred, as I intend to take the scenic route this morning.”
@@albertbatfinder5240 "hectopinch" is too precise and you'll have to get your inflation devise out every couple of yards (1828.8mm) to adjust for changing grit size.
Rule of thumb every time for me ;-)
This gets so nerdy on tires, but I absolutely love it. Thanks for this.
Amazing contribution, thanks!