What PSI do you use with your 25mm tires?
03-11-08, 08:00 AM
#26
feros ferio
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Too many tires are embossed with an inappropriately rigid "one size fits all" pressure recommendation. Sheldon had a good article about tire pressure, which should be a function not only of tire model and size, but also of rim type (hooked vs. straight-walled), rider weight, and position (5-10 PSI lower for the front than the rear, as noted several times in this thread).
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Capo: 1959 Modell Campagnolo, S/N 40324; 1960 Sieger (2), S/N 42624, 42597
Carlton: 1962 Franco Suisse, S/N K7911
Peugeot: 1970 UO-8, S/N 0010468
Bianchi: 1982 Campione d'Italia, S/N 1.M9914
Schwinn: 1988 Project KOM-10, S/N F804069
"Far and away the best prize that life offers is the chance to work hard at work worth doing." --Theodore Roosevelt
Capo: 1959 Modell Campagnolo, S/N 40324; 1960 Sieger (2), S/N 42624, 42597
Carlton: 1962 Franco Suisse, S/N K7911
Peugeot: 1970 UO-8, S/N 0010468
Bianchi: 1982 Campione d'Italia, S/N 1.M9914
Schwinn: 1988 Project KOM-10, S/N F804069
03-11-08, 09:12 AM
#27
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We seem to use a lot higher pressure than most -- 135 on 25mm Vredestein Tri-Comps. We're about 300 lbs on a tandem. Comfort seems to be fine. Guess our roads are relatively smooth.
03-12-08, 09:44 PM
#28
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More of the same: Conti GP4000's (fine tire) 25's......95rear, 90front-- I weigh mid 160's. Higher inflations and I get too much "boing" on rougher roads.
03-12-08, 10:34 PM
#29
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You gotta take the rim/tire and pump it up until it breaks the rim or blows off the tire. Note the pressure. Then from then on you inflate to 1 psi less. Simple.
Back in the day I rolled on 18s. I can't find 'em any more and am stuck with big fat 23s...But I keep 'em rock hard because I hate rolling resistance more than a rough ride. And it shows how cool I am. As a bonus, when I get a rare blowout it is really impressive.
Back in the day I rolled on 18s. I can't find 'em any more and am stuck with big fat 23s...But I keep 'em rock hard because I hate rolling resistance more than a rough ride. And it shows how cool I am. As a bonus, when I get a rare blowout it is really impressive.
03-12-08, 10:47 PM
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I have this pet theory that any energy saved by "less rolling resistance" is expended as your body absorbs the shocks of hard tires. It's like trampolining...amazing what an aerobic workout it can be as your body tenses every time it comes down into the tramp. Same with bumping around skiing moguls. Or marriage...absorbing all the mini shocks sort of wears you out over the years (lame joke!).
03-13-08, 12:08 AM
#31
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I have this pet theory that any energy saved by "less rolling resistance" is expended as your body absorbs the shocks of hard tires. It's like trampolining...amazing what an aerobic workout it can be as your body tenses every time it comes down into the tramp. Same with bumping around skiing moguls. Or marriage...absorbing all the mini shocks sort of wears you out over the years (lame joke!).
Seriously though, on my commuter with larger tires and lower pressures I work a lot harder to go a lot slower than I do on my road bike with rock hard tires.
It may be placebo, but I swear I can feel the difference between 100 and 120 on the road bike. Yet the lower pressure never feels much smoother or less painful, just slower. YMMV
03-13-08, 08:56 AM
#32
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Too many tires are embossed with an inappropriately rigid "one size fits all" pressure recommendation. Sheldon had a good article about tire pressure, which should be a function not only of tire model and size, but also of rim type (hooked vs. straight-walled), rider weight, and position (5-10 PSI lower for the front than the rear, as noted several times in this thread).
I am not saying doing more research is a bad thing, merely that using the recommended pressure is not bad either.
03-13-08, 01:28 PM
#33
Do I use too many commas?
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110 psi front and rear. Bontrager Hardcase tires. I don't have any comfort issues. I also have a steel fork and frame.
