's Forum Archives - General

Archive Home >> General(1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 )

Query re mixing tire sizes.(5 posts)

Query re mixing tire sizes.LAIrish
Jul 16, 2001 10:53 AM
I can't find the answer to this on sheldon brown, bicycling mag, etc. so I thought I'd check here.

My (like me, newbie) riding buddy recently screwed up one of his 700 x 23 tires trying to change a flat. So we went to find a replacement. He bought some on sale, but got 700 x 20 instead of 700 x 23 because he wanted the beige sidewall instead of black. He plans to replace both tires and keep the remaining good 700 x 23 as a spare.

When he ineveitably screws up one of the 700 x 20's, he intends to ride with one 700 x 20 and one 700 x 23. Now, this just seems to be like it would be a bad idea, but I really can't articulate why. (Maybe my natural conservatism.) He says that maybe he would notice a 3 mm difference if he was Lance Amstrong, but he's sure it won't make a difference to him.

Any insights?
re: Query re mixing tire sizes.Lardog
Jul 16, 2001 11:31 AM
I don't see a problem with it. I've used two tires that had the same number printed on them, but were definitely different. A Michelin Axial Pro 700x20 is definitely a touch narrower than a Conti 3000GP 700x20, im my opinion.
re: Query re mixing tire sizes.LC
Jul 16, 2001 2:04 PM
I have seen racers that actually put a wider tire on the front for better cornering.
re: Query re mixing tire sizes.Jim Burton
Jul 16, 2001 9:36 PM
I ran a 23 in back and a 20 in front for about eight months on my old bike because the local bike shop was out of 20s when I exposed some threads on my old tire. I had no problems with this setup. Some Time Trial bikes have a 700cc wheel in back with a 650cc wheel up front. Surely, if that doesn't cause any problems, three millimeters won't cause a problem.
Shouldn't be a problemjw25
Jul 17, 2001 8:26 AM
Once you account for tire spread, varying pressures, rim width, and any other factors, a few mm's shouldn't matter much. Given a choice, I'd run the wider one up front, as the front tire angles more during cornering, and a widertire up front should corner better, but I doubt it'd be very noticeable.