trail wrote:
Cajer wrote:
As said above if you don't make pressure adjustments (lower the correct amount) for wider tires, then yes wider will be faster and more comfortable. But there hasn't been any data showing that when you do, wider tires are faster on decent surfaces. If you know of any please share it with me.
I'm not quite following. Yes, a tire of any width should have a pressure consistent with that width, the road surface, and system weight. Don't think that's in dispute.
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The same applies to comfort, and that's harder to measure especially with how powerful the placebo effect is.
It *is* hard to measure! But often we have bias towards things that are easy to measure. (Cue my frustrations with engineering managment trends where managers fixate on narrow metrics at the cost of the big picture) And just because the placebo effect exists does not mean a real effect doesn't exist to maybe find.
Anecdotally speaking, of all the people I know who've gone from 23m to 28mm road bike tires, not one has gone back the other way. It's one hell of a mass delusion if it's a delusion. Most recently a 55 y.o. grizzled veteran masters racer I know who used to give me side eye about my 30mm road tires. He was recently forced to replace his ~2015 Tarmac with a 2024 Tarmac. To say he's in love with it, and the tires it came with (28mm Specialized 2Bliss), is an understatement.
I think you must be in the 11% in the poll to the right. Optimize the #'s we can optimize at all costs. Everything else is namby-pampy stuff. I'm in the 68% on this one, despite being somewhat of an # optimizing zealot in most cycling contexts.
Thank you. That's a better of putting it. Reframed more clearly, I believe that lowest achievable rolling resistance for a given tire model on decent roads is not lower for a wider tire than a narrower tire. All the data I've seen has not put any effort into finding the optimal pressures for the two widths and instead tests them at the same pressure.
I definitely care about comfort even if it's harder to measure as discomfort leads to fatigue which leads to lower performance from the rider. I just don't agree that wider tires are more comfortable on non-bad surfaces.
In the case of comfort, if we should assume that on good roads different tires show minimal differences in comfort due and we should focus on rougher roads. On these rougher roads I believe that a faster (lower rolling resistance we will disregard aero here) tire when tested with a rider on the intended surface should be more comfortable. Due to reduced transfered vibrations and therefore hysteresis losses in the soft deformable body that is the rider.
I recently had to switch from a 23 to 28mm gp5000 in the rear due to the shop now having a 23 or 25mm in stock after a bad flat, and I didn't notice any differnece in comfort despite running much lower pressures on the 28mm. However I am also riding on very nice roads, if one on riding on poor quality (cracks and potholes) or chipseal there is likely to be a difference.