On the road I notice tires get faster as they wear. Putting on new tires is always a bit disappointing because you slow down. Low pressures make cornering and descending more uncertain. Pinch flats a big reason to run high pressure.. Very high pressure quite nice during the night if you are slow, seems to be less fatiguing, and will be the right pressure in the morning (latex tubes). Weight I suppose another factor.. cost too if you run super thin tubulars.. its a very big topic, thanks for sharing your views.
It is sad that only the BicycleRollingResistance website publishes tire testing results so openly, because while informative, these results should be taken with a grain of salt. Bikeradar published testing results for 8 road bike tires based on tests performed at the Silverstone Sports Engineering and the tire ranking was somewhat different (the one difference that struck me was that the Pro One performed somewhat better than the GP 5000 S TR). I'm usually skeptic towards what Jan Heine says or publishes, but maybe he's right when he says small diameter drums tend to give somewhat inaccurate results.
I guess private teams and companies have nothing to gain publishing their data, but can gain by keeping it private. Testing is really resource intensive too, so I like to support BRR with memberships from time to time. The Bike Radar Silverstone data adds a nice second perspective, but their protocol seems limited versus the battery of BRR tests. Still, I would prefer to use cheap Pro One TLE under the illusion of equal performance, so I may 'believe' the Silverstone data for budget's sake. I also am skeptical any time B.Q. publishes any technical information. The Rene Herse calculator uses only 2 variables, but I included it as many US randonneurs like the brand.
I agree entirely - and I also pay for the BRR pro view subscription plan. I have seen academic evidence that roller size had an impact on rolling resistance testing, although SILCA claims that ranking is conserved anyway, but doesn’t back up that claim with evidence. This is my main and only issue with BRR : their testing apparatus has limitations that may affect test results somewhat, although aside from that they tend to at least have somewhat rigorous methodology and provide an abundance of data. And yeah, B.Q./R.H./Jan Heine make a lot of unsubstantiated claims.
@@SilveryK-v8q I believe some company promoting small wheel sizes doubly ran into that problem. Small wheel plus small drum doped their results. Lab-only testing couldn't account for attack angle of the smaller wheel either, so real world experience was about as far from lab results as you could get. I forget if it was Greenspeed Recumbents or Moulton. BRR does okay communicating their limitations and methodological choices at least. General audiences have a tough time with limitations though. I recall a cycling podcast host calling a study 'a crap study' because a study methodology didn't match his particular application. Private firms do have the real world data. Here's an interesting video from Ineos/Continental on tire testing. According to the comments section, I better get my accelerometer + tire pressure/width experiments done quickly before Peak Torque beats me to the punch. Shame I had surgery this weekend. I'll be delayed. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-DBuFqrjVydI.html
I think the primary point Jan makes with his research & products, is that wider tires, inflated to the proper psi, are no slower than narrower tires at their proper psi. Is there an aero penalty pedaling a wider tire into the wind on longer rando/ultra distances? No doubt. However, having turned 60 yrs old recently, I myself am firmly in the, "comfortable is fast", camp.
@@JosephDowski You may like my video 'Comfort = Improved Endurance Performance?" I hope to publish accelerometer testing for tire and suspension stem/seatpost systems soon (teased in this video), but I have to recover from surgery first to finish the tests. Jan was influential in expediting the move across cycling to wider tires on the road, and for that I give my appreciation. I was on 33c Rivendell Jack Brown Green tires back in 2015, partly influenced by Jan (and by sore hands and bum). These days, I teach academic reading/writing to graduate students at a science and technical institute, among other tasks. I spend my days reading and talking about expectations of scientific work and guiding students to create work that meets a particular standard. I love it. My issue, and the issue many seem to have with Jan/BQ/RH, is a long history of presenting bad science with biased interpretation as actual science and truth, all while ignoring/denying evidence that opposes desired outcomes. Quite postmodern of him, which plays well with a subset of the Pacific Northwest crowd. It's popularity has poisoned the well a bit for discourse on technical topics in randonneuring, which is an area I care about. Creating this channel is, in part, a response to that issue. That said, I expect to reach several of the same conclusions along the way.
What tires have you been running at what psi? At 185lbs I run a 30mm tire on my steel road bike and a 32mm tire on my titanium rando bike. My psi is never over 70 but on centuries and longer fatigue of the body is what I’m trying to prevent. Great video; no one ever discusses hoop stress, and i think a lot of information gets looked over because of generalized statements regarding tires, in a way that is end all be all when to many factors need to be considered. Safe riding!
Hi Ian, thank you for the kind words. At 200lbs I am currently on 30c GP5000 STR at ~60 PSI. They balloon to 32.5mm on 25mm inner width rims (tubeless). I use suspension stem and seatpost as well. They seem to handle mid sized and larger bumps better than tires. Very curious what my testing will find when comparing tires widths, pressures, and suspension add-ons.
Tire inserts might help mitigate some of those compromises - at least for gravel riding and MTB. At low pressures on gravel an insert can help the tire feel more stable and less squirmy plus make tubeless much easier to reinflate on the roadside by holding the bead out against the rim. They also should (some types) help attenuate rim impacts.
Have them (Vittoria) in my 25mm tubeless GPs. Was afraid to take them to the PBP because you can't change to tube when there's an insert in there... Plugs&sealant would maybe be enough, but I'm still not great at working with them. Btw, getting those road inserts into your tires (and getting them out!) is an effort!
I have the gravel Vittoria inserts on wide 30mm internal rims. These might be easier to work with than the road version! So far its been ok just to press firmly on the sidewall against the insert and insert a tire lever. The bead then pops off ok with the lever (not by hand) and the insert can be pulled out as needed. Trust the PBP went ok. @@bb3lo
Great video, thanks for calling put the equalized pressure nonsense. I feel like short, faster rides call for zippy feeling 28s, but I'd roll with some comfy 38s on a randonneuring trip. 38s are slower, but not by much, and less flickable, but you're not darting around on a rando trip. Much more comfort and grip though.
Cheers, researching for this video was frustrating to say the least. It's technical on an unfamiliar axis to cycling journos, so even earnest reporting on the topic is often filled with misinformation or misinterpretation. Putting aside low quality data and shoddy experiments populating some corners of the cycling media space, some in positions of authority on the topic can and do mislead with how they share good data. They have used 'equalized pressure' stats to do it. I hope my interpretation, while imperfect, was clear and insightful. I've only ridden very narrow tires a few times in the past 6 years, but the clip at the end was testing 24mm wide GP5000s. They handle so spritely, even though the wheel/tire weighs significantly more than my usual 30 or 32mm set up. Super fun, but not ideal for rando.
I think once you get high quality tires in the same range than the GP5000, the difference in rolling resistance between brands is very marginal. Good tires of the right width for your needs, the right pressure and you are good to go. I used to check BRR but I don't find that their data reflects the reality.
It really isn't much in it once you get to the high end. The differences are well under an amount we can perceive, but calories saved over 20 hours of cycling is pretty valuable. I generally regard BRR as more robust than other testing like Aerocoach or Bike Radar/Silverstone. Still, all those tests find general agreement. That said, there seem to be some tires that perform way worse than would be expected given their construction. Knowing to avoid them is as valuable as knowing which 5-6 models fit the bill. Another valuable nugget for me is knowing which tires are thick enough to trust. GP5000 STR are thinner than I would normally trust, but I am trying them out anyway. If their life is short (I am heavy) I'll be moving back to cheaper Pro Ones.
