marcag wrote:
Cajer wrote:
I'm curious if you've ever done testing between wider/thinner tires at the same casing tension (lower pressures with wider tires) or more simply the optimal pressures for that width to see if wider tires are actually any faster. I'm curious as I've never seen that data, and all the data people cite for wider tires being faster is with the same pressure used for both the narrower and wider tires.
We were more interested in optimal pressure for a given wheel/tire/ride/surface. Each test set was 10 runs at 5 different pressures. The only thing that varied run to run was pressure. Each test set (10 runs) was a different combination of tire width/inner width, rider weight, surface.
There were two test sets where the only thing that changed was tire width. Optimal for 28 was slightly different than optimal for 30 but they tested very close at their optimal pressure. This is a combination of rr and aero. I am not sure just those 2 tests (of 10 runs each) is enough to make a conclusion
GCN did this, although I am not sure how precise it is. They corrected pressure for different widths using Silca.
In theory we could take our "optimal" tire pressure results and use them to feed a fastest tire width test.
Thanks for the answer. To close the loop on if wider is at all better on decent roads. It would be really interesting to see the optimal setup for the same model of 25/28/30mm tires on the same wheel compared (combination of rr and aero) on decent road surfaces with pictures of the road surface. I'm very skeptical that 28mm is going to be faster than 25mm, and I assume 30mm will be the slowest.
Then add an accelerometer glued to the seat post also, and we can get data on comfort and hysteresis loss in the rider to some extent. If you need help analyzing the vibration data, I can help as I do some of that at work.
marcag wrote:
Slowman wrote:
marcag wrote:
why do they not go wider than 25 when they do the hour record? They certainly could have.It's interesting "oh, the aero penalty is measured and so small it can be ignored". "We didn't measure the RR gain, but trust us, it's worth it"
I think this is the crux of the matter, the manufactures claim that wider is faster but refuse to share any data making their claims look suspicious. If they had the data and it was as clear cut as they make it seem, why don't they release it. It would help to convince everyone especially hold outs like me to switch to wider tires/wheels. The fact that they haven't implies: the data isn't as clear cut as they make it seem, they haven't collected any or it's very noisy, or they've tested it and wider isn't faster so it's just marketing speak to convince people to buy new equipment. I hope it's not the last scenario. But with their handling of hookless to help their bottom line, I wouldn't be suprised.