So this has been a bit of a while ain’t it? Bought me-self a new cyclocross frame. I’m looking at it as a bit of a testing mule. See I h e always known what I have been preaching as a matter of theory, that what I said was always correct, that what I said was always logical, but WOAHHHH!!!!! I ain’t never felt this in practice like this before!
Ok, I hear ya, you been telling me all this stuff and you never knew it to be applicable? To a degree yes, I did. I have always been a road fiend. Alway had ridden the faster bikes and tires. Never have complained. I love steel, but I’ve ridden the rest. I prefer tubulars but I’ve ridden some amazing clinchers. I’ve ridden some mighty old frames with more clearance and larger tires and they were the best.
See some of this is just plain math. A 23mm tire holds ehhhhhh 637,671,468mm(2)
I’ll have to check my measurements….
A 32mm tire holds 666,309,409mm(2)
That’s a hugely high number it’s not double, but it’s somewhere in the area of thirty million millimeters(2) more? Can that be right? That’s a massively large amount of air.
I gotta check that math.
We’re talking a lot of displacement.
I can’t even get to the point of calculating psi but what it comes down to is this. You can run half the pressure of a 23 in a 32 and still be protected by air volume.
That’s the theory.
Now, I’m a big dude. 278lbs of lovin and joy as the great Howlin Wolf said it. Now, to ride a 23 with out pinch flats the tire would need 140-175 psi. 175 for Tubulars… 140 on some Bontrager clinchers.
That means I’d need some 70 to 90psi in 32mm tires.
None of this applies to rolling resistance. Flexing tires are slow right?
The tire I have on this new cyclocross steed are 38mm. I went out on my first ride. Felt some sag, felt some squish and thought “hell, I’ll top em off at my buddy’s.” Didn’t feel any sluggishness on the bike though. It rolled plenty fast. I’d say no loss in speed at all.
Then I rolled over two setts of train tracks. They are pretty rough over here on the south side of Chicago. No pinch. Just smoothly glided over. Real cushy like. I got to my buddy’s house and went to top em off. My gauge read 40 psi.
Now I know that racers are riding their cross tires at 22psi but they are little thin weenies. 140-160 lb lightweights. My feed bag weighs more than that. 40 psi to hold me up? That’s amazing. I can’t wait till I throw some nice tires on here. This bike is screaming for paselas.
Oh and hey, I told myself screw the cold. I’m riding now.
It’s my first day of commuting. So here is the steed on the train as proof.