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new tire size for a retro-grouch?(9 posts)

new tire size for a retro-grouch?MLCrisis
Sep 15, 2003 11:40 AM
I ride a heavy old steel Raleigh built like a tank with very steep frame geometry - quite a stiff ride. Here in Michigan, the roads are also not the smoothest. I am in my 40s and strictly a recreational rider, but looking to get the best possible efficiency out of my feeble power output. I'm also looking for decent tire life. The bike has got 27" clincher rims with 17mm internal dimension. I've always ridden 27x1-1/4 tires on it. According to a graph on Sheldon Brown's tire size article, I could safely choose 1" wide rubber. If you were me, would you follow old patterns (choose traditional 1-1/4" tires), go for possibly reduced rolling resistance along with the greater risk of pinch flats (1" wide) or split the difference and go with 27x1-1/8"?
Personally, I'm a fat-tire guycory
Sep 15, 2003 11:57 AM
I'm a Clydesdale, so this may not apply if you weigh 140 or so, but I'd stick with the big tires. I don't think you'll notice much difference in rolling resistance, and if you do, it wouldn't be worth the tradeoff in comfort, at least to me.
My main ride is an Atlantis, and I swap around among tires between 28 and 38mm. Best all-around compromise for me, on our semi-bad roads, is 700x35 at about 80psi.
What are your favorite fat tires? nmlancezneighbor
Sep 15, 2003 8:38 PM
re: new tire size for a retro-grouch?Fredrico
Sep 15, 2003 12:10 PM
A 1" wide tire aired to the same pressure as the wider tires, wouldn't have significantly less rolling resistance, but would offer a harsh ride, and increase chances of pinch flats and broken spokes. 27 x 1 1/8th would be fine, if aired up to 100-110 psi, and ridden unloaded.
Now there's some completely backwards informationKerry Irons
Sep 15, 2003 5:11 PM
At the same pressure, the NARROWER tire has more rolling resistance, not the wider one. You've got it completely backwards. At the same pressure, you'd be hard pressed to tell the difference in ride feel between two different widths of the same brand/model tire. Also remember that 1" is a 25mm tire (if it really is 1") and that is generally considered a wide tire - especially for someone under 200 lb. The old 1 & 1/4 standard is a 32 by today's measure, and you usually only see those on tandems.
Not a lot of rolling resistance difference ...Humma Hah
Sep 15, 2003 1:17 PM
I tried 1 1/4 on the Paramount's front 27", but couldn't use it because it rubbed the top of the fork. Otherwise, that's what I would be running instead of 1 1/8.

I checked out photos of Letourner's Paramount, ridden to a 108 mph speed record in 1941, drafting a midget racer. The tires on that bike look to be at least 1 1/4", maybe 1 3/8. My cruiser, running 1.95" slicks, routinely out-dives roadbikes in downhill coasting situations. I don't think you sacrifice enough energy to measure using fatter tires.

Reports are that Letourner's tires actually melted and fused to the rims as a result of that ride.
Sep 15, 2003 3:06 PM
I can say, with some degree odf certainty, that those tires were the old-fashioned "wide" tubulars, rarely seen today, outside of a few cyclocross applications.

Now, the reason why your cuiser is faster downhill is simple: it is more massive. Back in the 1920's, bobsled teams often hired 2 fat guys to sit in the center, just to give the vehicle more weight. The faster the sled got up to terminal velocity, the quicker the run. As a result, the olympic commitee passed a rule reating a maximum weight allowed.

BTW, I doubt you pass many uphill....
And your point is ...Humma Hah
Sep 16, 2003 6:11 AM
... Yeah, tubulars on wooden rims. But pretty fat for a >100 mph speed record attempt by modern ways of thinking. The point being that he could have chosen track tubulars, but didn't see any need to.

The real reason the cruiser is so fast downhill is the weight to drag ratio is favorable. That's not just because the bike and rider are heavy, it is also because the bike's geometry allows me to achieve an uncommonly tight aerodynamic tuck. But the fact remains that my outrageously fat tires basically don't even figure into the drag equation ... tire width is virtually a non-issue.

As for passing riders uphill ... it is highly dubious I could pass anyone it this forum. However, on a typical day on a typical bike ride, I not only can, but frequently do, pass folks in full roadie kit on some very nice roadbikes on hills. And the key to THAT is that climbing fast on a heavy singlespeed shortens the duration of the suffering, compared to typical casual roadbike riders who drop to granny and take it easy.
27x 1 1/4 are what you wantContinental
Sep 16, 2003 7:25 AM
27 X 1 1/4 will give smoother ride, longer life, nearly equal rolling resistance, fewer flats, and will be better on loose gravel and rough roads. The 20-25 mm tires are for racers, wannabes, and posers. Lower weight, lower wind resistance, and selection of quality tires are the only benefits, and those don't matter unless gaining 1 minute or less on a 2 hour ride is important to you.