Your Tires Could Be Costing You Minutes. Tire Rolling Resistance with Josh Poertner
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- เผยแพร่เมื่อ 22 ธ.ค. 2024
- What tire and tire pressure you choose can have a huge impact on your speed. In this video I sit down with Josh Poertner of Silca to discuss how to determine the optimal tire pressure, what makes a tire fast or slow, and whether or not tire inserts increase rolling resistance.
Find your optimal tire pressure with the Silca Professional Tire Pressure Calculator:
silca.cc/pages...
Find out which tires are faster or slower with BicycleRollingResistance.com:
www.bicyclerol...
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If wider tires have lower rolling resistance and assuming this does not apply to bicycle tires only, then that means putting wider tires in cars can actually improve efficiency?
Oooooooooooooooo
@@sepg5084 oooooooooooooooo ooooooooooooooooooooooooooooooooooooooooooooooooopoooopooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooopp
@@sepg5084 as it was said in the video, there is a limit in both directions. As far as i know, car tyres are already very very wide as the are optimised for grip, not for rolling efficiency. Look at the electric car tyres where efficiency (= range) is critical, the are much thinner :)
This is great. I love hearing people who know what they're talking about address issues that we usually don't have any good data on
There's lots of good data out there and has been for the last couple of decades. Guys like Tom Anhalt have been testing tires for the longest time...
Id say the big guys are actually working for the rubber producing companies like maxxis but for sure its great insight although i would have loved context on especific tire recomends and pressures for different types of riding?
Hard choice when there is 490,000 tire options
Let me know if you liked this style of video and if I should include more guests in the future. There is a lot more from this conversation that I plan on releasing.
Find your optimal tire pressure with the Silca Professional Tire Pressure Calculator:
silca.cc/pages/sppc-form
Find out which tires are faster or slower with BicycleRollingResistance.com:
www.bicyclerollingresistance.com/
Great content. Thanks. I am going out to lower my psi. lol
Great information and insight into tire/tube air pressures. Very interesting and educational. Thanks for this excellent material...
Hi Dylan, I very much enjoyed this style of video. I was hoping Josh/you would get into discussing the pros/cons of various tread types & tire manufacturers. I've been on nothing but Rene Herse tires for years -> Barlow Pass 38mm slicks which actually measure 43mm on my FSE 27mm internal width wheels... However, I've had my eye on some Vittoria tires as well. Thanks again for the great content!!
Your normal videos are better.
Bro you left me hanging! I wanna hear the second part
I got a new bike! I ran 25mm tires at 120 psi on my old bikes for many years. My new bike came with 32mm tires. I used a tire pressure calculator and I currently run them at 55/60. I don't think these tires roll faster, but they are much more comfortable on the chip seal road surfaces I ride around here. I'm old, so comfort is a priority.
Thanks Dylan I am one of those guys that ran as much pressure in my tire as I good back in the day. (1980) Know that I am a bit older (68) I can use every bit of help I can get. LOL I've been running lower pressure for years and it helps make the ride more enjoyable and at the same time faster. Good tires at the right air pressure, the best chain you can afford, best chain rings and cassette, then bearings and a frame that allows the peddle stroke to move the bike forward with no energy loss. With that in place we have NO Exceuses. Ride hard and with passion. Rick
I hear ya, I’m 68 also, raced bikes in 76, and mountain bikes in the 90’s. I always used 110 in my sew ups for races on the road. Now I use 100 lbs. in the rear, and 90 lbs in the front (700x25 clinchers) for rides. My mountain bike I use tubeless tires at 35 to 40 lbs. hard tail with 110mm Fox front shock. I still love to ride regularly.
This was so useful. Used the linked calculator and found I was about 10 psi too high. Let the excess air out and sure enough the bike feels much better and no noticeable change in speed over the last 3 weeks. Thanks Dylan + Josh 😃
Josh is amazing and definitely knows all the details and has all the experience working with cycling teams and testing products. I buy Silca products because of his insight.
I've been buying Silca products LONG LONG before Josh took over (I have an orange Silca Pista floor pump, and an ancient Silca Impero frame pump from over 52 YEARS AGO, when I first started racing on tubulars, both still fully functional!!).
But yeah, this man most definitely knows his subject matter, and then some!
(He might even be able to change my old school, died in the wool
Needs an interviewer who knows what he's talking about. Let Backwards Hat Dylan take the next one.
Seriously though, great video!
I remember when Vredestein sold road tires with their advertisement that you can pump them up to 150 psi for decreased rolling resistance. It is interesting how things have changed.
Track Riders 150 to 200 psi
I always Ride @ 120 - 125 psi Clinchers Specialized Training Tyres
@@Robert-mn8gc too much
@@Robert-mn8gcwell, Dygert just won the pursuit at worlds running tubeless 25mm tires that were probably under 90psi
@@veganpottertheveganuh...no. 150+ psi more likely
@lunam7249 no, the beads would blow on the tires they used at 150psi sitting still. No way could they handle the force of the banks on the track
Love love love this content. This channel is all about getting faster in a practical data based way. Give us more!
This style of video is a nice change of pace from the regular "what do the studies say" videos. I like both styles.
This is a must podcast ! Can’t wait for the rest of this conversation.
Definitely think you doing a podcast is the way forward !!
Great content. Great guest. Love the MG podcast. Please consider a conversation with Jan Heine, Rene Herse. If I recall correctly, Josh has hinted on the MG podcast that he may disagree with some of Jan's findings/testing/data on wider tires not being slower. If you could get a full length panel discussion with both of those guys - THAT would be gold. Keep up the good work, Dylan.
I definitely agree. It's hard to have a conversation about low tire pressure and rolling resistance without mentioning the huge contribution of Jan Heine!
Really enjoyed this. So many interviewers love to jump in and take the show. But this was an interesting dude and you kept the convo moving forward. Loved it.
I like the discussion. Remember years ago, seeing a set of roll down tests of different tires and pressures, and a 'quick and dirty' correlation between how easy it was to deflect the UNINFLATED tire on say the sales rack and the rolling resistance; the easier to deflect, the easier to roll. Goes along with the hysteresis losses examined in the vid. Not foolproof and lots of qualifications but workable.
Excellent! Your guest was very knowledgable and articulate
Right on! We ALL have left countless watts on the course because of this. I found the insert discussion especially valuable! A deeper dive on this would be great! 👊🏻💥
I was drawn to tire inserts (Vittoria Airliner) for a 28mm road bike rim. I don't compete, but I was looking for added confidence that my tubeless setup would not leave me stranded in a rural area - - where I live. At the time I was running Continental GP 5k (TL), and they were notoriously hard to acquire, and even harder to mount. The Airliner just made it impossible for me.
I never tried the insert with the Pirellis that I used to replace the GP5K's, but these are much easier to mount. In the end, with this new ease of installation, I have abandoned the inserts for the road bike, in favor of carrying a few patches, a boot, and an innter tube.
Glad you asked insert question. I’ve been curious
Damn, that was just straight up excellent. So robustly and concretely communicated.
After looking into the TIRE PRESSURE CALCULATOR and seeing how low the suggested tire pressure should be, I'm very enthusiastic to try it out! It's pretty sweet tool. Thank you for the insight!
u will regret it when u hit a pothole at high speed. Bye bye to ur carbon rim.
@@ighfirlee If I were to worry about damaging my bike, I would ride slow, flat, boring tail trails... However, I can't worry about that! I would rather have the traction to make the turn and grip to dirt accordingly! Plus, my ENVE carbon rims have a lifetime warranty :) Ride On!
Can you address mismatched tire width pressures such as 25 mm front and 28 mm rear?
I run that and would like to learn more about the consequences.
Thats illegal
Just Measure it two times, one for front one for rear
Very interesting! As a downhill/enduro bro, I actively look for a tyre with high hysterisis to keep grip on trails. Michelin tyres are a great example; very low durometer, very slow rebound. Those characteristics keep the tyre from feeling bouncy or "pingy" when riding through fast, chunky sections.
Explanations were very understandable and made sense. This content and others that you have shown have helped shift my perspective. That's been very helpful and have provided for a more enjoyable experience on and off the road. Thanks.
Great video. Post up the entire conversation. I would listen to the whole thing!
Yes please release more of this conversation. The insight offered is great and I lost track of time listening to it.
Super interesting discussion. I felt like we could have kept going with the topic. I think it’s nice you’ve brought in industry experts and pioneers to discuss a subject. Would love to see more. Maybe you have podcasts in your future?
Love the bike on the stand back there. Huge Lemond fan here growing up. I'm very intrigued by all this lower pressure stuff. I remember putting 140 psi in my 18mm Conti GP4000's back in the day, and I had that Silca Track Pump too, haha.
Same ... back in the day (30 years ago - heck!!!) I was running 18mm Conti GP's at 120psi, on my Mavic Open Pro rims ... boy did they sound lovely on my local 10 mile TT - was doing 21 minute 10's back then (not now 😔) ... god knows what I would have done on one of todays aero bikes ...
Absolutely outstanding video; your contributor Josh was excellent and informative - the perfect mix of technology, application and real-world knowledge.
Just the little intro clip with the pressure calculator was new to me. Thank for that .
My experience is that the more expensive lightweight high-performance racing tires seem to be more prone to punctures . They usually have thiner sidewalls and less rubber overall in their construction.
It is. Cheaper tires are always more puncture resistance, at the cost of rolling resistance, comfort (higher TPI) and weight.
They last less too the more expensive they are .
Of course, but it isn't a 1 to 1 correspondence. The Continental 5000S variants for instance are very fast and pretty durable. As you go to tires much faster than that, you need to consider the course, and replace them sooner.
Awesome video! Dylan you lead the way with science based cycling content! Really an eye opener when it comes to tires and pressure.
So you are confirming something I've been observing for a while but never really checked deeply.
I've been thinking about this loss of energy when going with high pressure on road with loose gravels
So glad you asked about inserts. Was thinking just that when he was explaining hysteresis 👍🏼 super interesting info, thanks for sharing!
Yes, please do more in this style! And definitely let us hear the immediate follow-on from this one. I'm on Tubolight in two different wheelsets per your recommendation and I'm convinced they (insterts in general rather than tubolight specifically) are the most underrated tech in gravel/cx at the moment. It was really fascinating to hear more of the science behind how and why they work and what sets different types apart from one another!
Great content, Dylan I would be a non-stop listener if you had a podcast.
You’ll be a great curator interviewer of this type of content it’s a great complement to your other work
Excellent, having two people talking makes it more entertaining. Very informative!
I have 25mm section. Running 6bars front, 6.5 bars rear.
Hi Dylan your my go to guy for everything cycling racing related, your very specific in you videos and all the stuff is 100% related to my cycling,, keep it up, don’t change a thing, your by far the most informative
Engineer here, the reason low pressure is faster is down to idea gasses being perfectly elastic, meaning that compressing air is much more efficient than compressing your tire will ever be, making the tire lower pressure puts a lot more of the burden of deforming on the air rather than the tire. That's the real reason it's faster to run lower pressure
Define “lower” pressure.
@@traderstatusquo a gauge pressure lower than the expectation that most people have (70psi being faster than 110 psi for a 150lb rider)
Mmmm, I would push back on that. (Pun unintentional but I'll roll with it). Ideal gas which behaves adiabatically is a valid first order assumption, but that would mean that it's not absorbing any of the energy. Thus, if we limit the control volume to the tire and air, the losses are due to inelastic deformation of the tire.
However, I suspect that if we expand the control volume to include the entire bike & rider system, the power required to vibrate the mass of the system is a function of both tire pressure (neglecting sidewall stiffness), and surface roughness of the road. Thus, I would expect for perfectly smooth surfaces maximum tire pressure to be fastest. I would speculate based on the observed trend that an optimal tire pressure exists for a given roughness, that what I am assuming are vibratory losses scale as a function of pressure faster than tire deformation. (At least in the local space of sane tire pressures.)
I suppose at the limit one gets either train wheels, or that one time JPL made 20 foot tall experimental rover tires made of parachute nylon inflated to something like 0.5psi, which were super efficient when going over giant boulders
This’s only true on rough surfaces. The smoother the surface, the higher the pressure, the lower the rolling resistance.
@@traderstatusquo jordan peterson is that you?
I'm a big fan of Josh Poertner! Thanks for having him on the show! 🙌🏻
Great conversation,Dylan. On a side note, while understanding this was a completely different setup, the audio of your voice was significantly better sounding than recording in your (assuming) garage. Was much easier to listen to.
Yes, this was a helpful video and my tire pressure was too high 10 PSI in the front and 20 PSI in the back.
If you are on a track having high pressure and thin tires is the way to go. However, on the road with thin tires may be fast but if you get flats your gain is not worth much. I went on a bike ride and I saw other riders getting flats left and right and I did not get any flats. I think due to poor tire selection that many riders were getting flats and it took them out of the ride for a chunk of time.
The rheology of tires and the rubber compounds used to make them is so interesting. The balance between elasticity and energy dissipation in polymer systems especially in the context of real world performance is very fascinating to study.
Great video. Great guest and information. Format is good and only adds to the content you provide!
I watch this video every season. Idk why but the third time watching still fascinates me.
Yes,more like this please Dylan.
This was the excellent, please keep providing this type of content. Thanks!
Fascinating would love to hear more about tire inserts.
Great vid. Look forward to the rest of that conversation!
Nice talking. It make me think that FMB try to make his tires thiner and softer. Many Paris-Roubaix were win with them from 2008 to almost 2015 I think ! I love the way your talking about de foam that is being push and don't have the time to reform so you just "hit the rigid". More you have a tire which filter the vibration of the road, less you loss watt
Unreal stuff. Way too much info that I have been looking at, from the silica wax vs one I'm using, to the vittoria foam inserts added resistance. That man is a wealth of info.
Thank you for this video. The knowledge about the tires really helped me.
Fascinating discussion. Thanks. It was surprisingly informative and interesting even though I no longer race.
This guy is awesome. Just straight shooting without any garbage P/R words.
Wow, amazing video, very well explained. Would be interesting to make a video about different tyre puncture protection and their cost in watts (for road if possible) and if it's worth it, for example vittoria cinturato velo tlr, as i found on bicyclerollingresistance those tyres are the most puncture proff yet not the lowest rolling resistance as they were expected at that puncture score.
Dylan, Really good video. Your training videos are the best but introducing other topics/styles such as this is really interesting. Great to learn from experts.
I'm so glad you asked about the inserts. (I was not surprised you did though!) I don't think I've ever heard authoritative, objective information on them before.
This video actually got better as it went along. Thumbs up!
Adding some diversity to the channel format is good. We all enjoy your scientific format, but branching out can be good, and I found this chat interesting.
Maybe once the race calendar starts you might want to do a video with some of the new teammates. Unbound pre or post race video with The jukebox crew.
So the days of two people putting as much force into their pumps to get 150 lb into 23 mm tyres have gone .I m thankful for seeing this vid.Used the Silka tool and lowered my 25 mm s to 80 lb and I m not only more comfy I ve already beat my 30 mile time on my usual course plus I m too bothered about bad gritty roads now .Handlebar buzz also nearly all gone
As a track rider I put 16 bars pressure, on the road i put only between 5.5 and 6.5 😅
Very interesting video,
However I would like to add two other consideration for tire pressure.
1. Higher pressure makes descending more stable\
2. Higher pressure is more puncture resistant when biking on more marginal roads, that have potholes.
To me that is a big consideration not be stranded with a flat tire on a remote road
One of the best and most tecnical videos about tires I have ever seen. And from my experience I agree 100%. On the Silca link I miss the rim width variable and afew more details like disc or rim brake, comfort average or performance and also dry, mixed or wet surface, that in the old “my mavic” app were. But still very sweet link
To be fair, it asks for "measured width" of the tire, which takes into account the effects of rim internal width (i.e. how it affects the width of a particular tire when mounted). Brake type doesn't have any appreciable effect on the pressure requirements either.
Good Stuff, I just bought one of these Vittoria inserts to try on the gravel setup here soon. So glad to hear he gave some real world info on it.
Great Video. I enjoy that you vary the style of your videos. The scientific-paper ones are nice, but interviews and alternative approaches to topics really spice up your channel. I like it. Also: Great topic here
Interesting different format/directions for a video on your channel. Personally my take on this specific question is that I used to worry about tyre selection and tyre weight and tyre pressure in terms of maximising my speed… until I realised that it was all pointless and the one thing that cost me the most time was simply avoiding punctures. Now I just run as bulletproof a setup as I can get and cover ground both faster overall and with less annoying stoppages/mechanicals. Perhaps marginal gains in rolling resistance matter more to pros who have a team car and can simply swap wheels/bikes if they puncture but for the rest of us it does seem to make more sense to simply aim for avoiding mechanicals and all other considerations really are secondary or irrelevant
So whats your pick?
@@romelagz Schwalbe Marathon Plus SmartGuard? :)
Tubeless solved the puncture problem years back.
I've ridden 28mm road tyres on brutal MTB type terrain and not exactly tentatively either, sometimes it's chasing KOMs.
Though I swapped to light 33mm CX tyres after realizing they were just as fast on road, and obviously faster/more comfortable on rougher stuff.
This is what I like the science and engineering part on how to be more efficient and faster . In this case it's about rolling resistance and how to maximize that to a riders advantage . That's why constant tinkering can help to improve performance . It can be 30 percent or more of your overall effort figuring things out . If not your wasting your brain power and just focusing on athleticism . Now some ( not many ) can rely on that but most of the rest will have to find an advantage to keep up .
Great video. Please do one solely focused on mountain bike tires! Thank you!
Definitely enjoyed this style of video and came away with some good takeaways.
I ordered latex inner tubes yesterday can't wait to try them out.
This was awesome. I really learned a lot of things from this discussion that I don't really hear anywhere else. Thanks for sharing. And I'm definitely going to check out that podcast.
Hi Guys, I like your talk about tires and tire pressure. Because of it I tell you what are three players which influence RRC on the smooth drum: hysteresis, deformatin and volume of material
Those tree players have in paralel impact to: wet grip, robustness, footprint, stiffness - > effect: grip, durability handling &comfort.
Good balance of tire design or selection is key to success 😊
Jan Heine from Rene Herse Cycles was describing this 15 to 20 years ago and got a lot of flack for it. He did a lot of test with power meters and also with different tire width to prove his findings. Still today there are riders who still believe in maxing out their tire pressures and has still yet to figure it out. Great video, I have heard Josh Poertner talk about this in the past and together with Jan Heine.
Why would publicists take any interest in the arcane intricacies of bicycle tyres?
Ive put conti 5000 on my bikes. I love the feel on long rides and mixed surfaces plus rhey give a lot of confidence on long fast alpine descents. Im 181 and 72kg on a 7.5kg s works. Calculator tells me to inflate 6.3 but i tend to underinflate to about 5.5. Subjecrive to accuracy of my pump meter. 25mm wide
That was very interesting Dylan excellent job.
Sometimes, I only increase pressure to avoid pinch flats on the metal manhole covers I encounter on my road bike... with my commuter bike, with Schwalbe Marathons, (and a bigger carcass anyway) I have much lower pressures. I'm a heavy guy (100kg) and always had the idea that more pressure was a compensation for my weight so as to not deform the tyre too much... I know that higher pressures on my indoor trainer (driven off the tyre, not via the cassette) is a better thing, I notice the difference in my numbers, but that is a very controlled environment...
This video raises some interesting points, and like you do with your other subjects, uses actual science stuff to make the case... BHD might reconsider running those solid silicone tyres he uses for chasing KoM's...
Great video. Would have liked to hear what preasures were used and what was to high and what was to low on specific tires just to get a ballpark number.
Thanks for the great videos
Loved hearing Josh talk tires!
This kind of detail will save a lot of tears and guess work. Great stuff👍
Thanks Dylan for sharing. Quite fascinating. We were debating this issue recently in our cycling club. I shared your video with our members. We may all be faster next weekend LOL
Extremely cool video and great info! But at 13:57 Josh says that "high hysteresis tires don't hold road as well", this is very controversial thing to say, because high hysteresis rubber compounds are known for the better grip, rubber conforms to the bumps and holds shape, not bouncing back. you can check this article for example (google "racecar-engineering tyre-grip"). Or did Josh mean something else?
Never heard about inserts although I still run latex tubes. No tubeless here yet I am just used to replacing tubes if I get a flat. Although I will say since I started running lower pressure I haven't had a flat knock on wood.
Super interesting! Back when I was working in a shop it was all about the highest psi possible. If you ran lower, it was just for comfort.
This was great. I listened to the entire session. Please share the rest of it.
Your video helped me to understand the 'why' behind the what better than others have. I knew that a 'more supple' sidewall helped reduce resistance. Now I have a better sense for why. That's cool and thank you.
Interesting format. I‘d love to see more, especially on the MTB side. I plan to race XCM again this years after a long break and on a 5 or more hour race a few watts saved make a difference.
Hey Dylan. First of all, great result at Unbound this year! I have been following you for years and have been rooting for you watching Lifetime GP events. I have a tire pressure question for you. I will be racing the 2024 Dirt Diggler (long course) in your backyard in a few weeks in the Men's 50+. I pre-rode the course last weekend on 45mm F and 40mm R tires (26psi F / 28psi R). Was not fun except the road section. When I came home, I purchased a set of Conti Race King 2.0's. My SC Stigmata will fit 2.1's so I thought why not, Dylan does it. So, to my question: With Road, GLV 2, and GLV 3/4 on that course, what tire pressure do I run? Silca tire pressure recommendations range from 21psi to 31psi (front tire) based on surface conditions described. Thoughts?
Awesome video! Great to hear an expert talking tech
I definitely would love to see more of this kind of videos!
Great video. As someone obsessed with gravel tires, this was very insightful.
This was awesome, he was talking to us and not "at" us, very clear and super interesting
This was really interesting! I had wondered if the Vittoria inserts were worth the cost, and now I think they might actually be.
Proceed with caution.. haven't experience myself, but word is that these inserts are great functionally.. but make removal of tire almost impossible... reports that teams that used them literally cut tires off to remove rather than trying to pry them off with levers 😳
I've had no issues with my Vittoria gravel insert. I only installed one on my rear wheel since I didn't want to spend for both wheels. They were really easy to install. Basically just like an inner tube. They give me that extra piece of mind when I do rougher trails and small jumps on the gravel bike. I'd say it's worth for the rear wheel. 😊
I do have issues with the Silca rolling resistance calculator for off road. I did a recent gravel ride, and even selected a fairly smooth surface. On the rough sections, I smacked rims repeatedly. If I have had actually selected that surface, it would have recommended an even lower number.
For my mtb, it suggested 12 psi in my 2.4” tires! I’m 175 lbs, so that would mean I couldn’t corner, and would pinch flat on every pebble!
Brillant video. A lot of very interesting discussion providing much food for thought with the next time I need to either make a tyre purchase or go out for a road or gravel ride
Talking Vittoria insert......I installed a set on my aluminum gravel wheels and don't "notice them", which is good, but I really doubt I could ride them without air. The Vittorio foam is very easy to compress, so I'm pretty sure you would be riding on the rims. Other inserts may be more dense and resistant.
Great video especially about the foam insert. I'll have to look up Vittoria
Great content and info. Really good to know I’ve been heading in the right (lower) pressure direction, especially on my crappy Tucson roads…impedance is stupid here!
Hi! I have a question, that might be interesting for a future video.
Can HRV (and smart watches) be a good solution to avoid overtraining, or even adjust our daily training plans according to those measurements?
He actually has one that answers that last question. Check out his video on whoop (they are mainly HRV based)
Pushing the limits of nerdy content. Love it 😁