25mm to 28mm road tire
#26
Senior Member
Not sure I understand how Enve, as a performance-based marketer, derives their charts though. Eg. looking at an SES 3.4 chart.. 25mm tire, 150lb rider, inflation of 60psi. Ok, but how do you reconcile this with eg. data from BicycleRollingResistance, which will show better performance at higher PSIs than 60. Scroll about halfway down: Conti 5kTL
With respect to the Enve charts, I don't know where they get them either but I've been using them and they seem to work well for me in terms of both perceived rolling resistance/power output and comfort. Basically, I think they do a better job accounting for rim width in the pressure calculation than others.
The relatively recent focus on inflation, tire size, rim width etc... is fairly new. I got into it when I had a bike that was just horrible to ride in terms of ride compliance when I mounted it with 23 or 25mm tires inflated to 100psi. I changed forks, seat posts, etc... but still hated the bike. When I went to 30mm tubeless tires an started experimenting with inflation I was pretty shocked to see my average speeds stay the same as on my 16lb road bike and yet the ride was just super plush at a pressure of about 75psi. I've subsequently lowered that to around 65 with equal speed and better comfort. This, on a route that I have ridden more than 800 times over many years on several bikes all with archived data. So I was pretty sure what I was seeing and feeling was true and that the speed data was consistent with what I was experiencing on the bike.
I don't know if that works for everyone, but that's what's worked well for me and it is a definitely an improvement in both speed and comfort.
It's also worthy to note, that I took Poertner's guidance on pump gauge accuracy. I picked one pump (happened to be Silca) and used that as my standard. I then compared my 3 pumps (different brands) and the variance was all over the place when I compared them to the actual pressure in the tire and the Silca gauge. 10psi is a significant difference and eliminating that variance was important.
J.
#27
Senior Member
Not sure I understand how Enve, as a performance-based marketer, derives their charts though. Eg. looking at an SES 3.4 chart.. 25mm tire, 150lb rider, inflation of 60psi. Ok, but how do you reconcile this with eg. data from BicycleRollingResistance, which will show better performance at higher PSIs than 60. Scroll about halfway down: Conti 5kTL
#28
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Not sure I understand how Enve, as a performance-based marketer, derives their charts though. Eg. looking at an SES 3.4 chart.. 25mm tire, 150lb rider, inflation of 60psi. Ok, but how do you reconcile this with eg. data from BicycleRollingResistance, which will show better performance at higher PSIs than 60. Scroll about halfway down: Conti 5kTL
#29
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BicycleRollingResistance holds the tire rigidly against a drum, the data isn't accounting for the tire's behavior as suspension. Pumping a tire stiffer will always make it deform less against a rolling surface, but in the real world, you tend to get better performance if the tire is deforming around irregularities rather than transmitting deflections to the bike and rider. Comfort is speed; the energy spent making you uncomfortable when tires are pumped too stiff is energy being stolen from your forward momentum. The lighter the rider, and the rougher the surface, the squishier the tires need to be pumped to do their job properly.
Not sure this isn't another way of saying that if you want to have performance gains thru higher pressure (meaning above 60psi), a hookless rim isn't a good idea.
#30
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If I'm tracking all of your negations correctly, we agree on that. Hooked rims are harder to make in carbon, so companies are selling hookless rims and coming up with ex post facto justifications for them. Apparently it didn't take long to forget why hooks were a good idea.
#31
Senior Member
BRR isn't trying to quantify suspension effects, as they vary by bike and rider and road. BRR is just trying to compare hysteresis between tires.
And the drum has some sorta texture.. no idea what kinda road the drum's texture might emulate though.
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