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Actual diameter of 700c rims?(9 posts)

Actual diameter of 700c rims?Humma Hah
Jul 12, 2002 9:15 AM
I'm sitting here fighting with a 700c tire and a vintage Campy front wheel. The wheel was represented as being a 700c clincher, and my LBS took one look at it and agreed. However, a 700c tire seems WAY too tight on it, and I'm disinclined to force it. I have a sneaky suspicion this vintage 36-spoke wheel is actually a 28".

Anyone got a tape measure?
622mmSteveO
Jul 12, 2002 9:20 AM
perhaps you have a 27 inch (630) rim?
The flange OD is about 641 mm (25.25") ...Humma Hah
Jul 12, 2002 9:29 AM
... the bead seat is about 622 mm.
The flange OD is about 641 mm (25.25") ...SteveO
Jul 12, 2002 9:43 AM
Any 622 seat should fit a 700c tire (cant figure why it wouldnt). A 28 inch rim has a larger seat (635mm if i recall).

Unless someone has any data to the contrary, i say force away, once seated, it should fit (?)
re: Actual diameter of 700c rims?brider
Jul 12, 2002 9:23 AM
Chances are that it is indeed 700c. The industry has settled on one standard for 700c rims and tires, and you can actually see it molded into any tire sidewall. You'll see a number that looks like 571-23, which means a bead-seat diameter of 571mm and a round cross-section diameter of 23mm. (BTW, if memory serves, 571 mm is the standard for 650 wheels. Don't remember the number for 700s)
re: Actual diameter of 700c rims?Akirasho
Jul 12, 2002 9:47 AM
http://www.sheldonbrown.com/tire_sizing.html

We abide.

Remain In Light.
re: Actual diameter of 700c rims?curlybike
Jul 12, 2002 9:49 AM
Campy rims were always very tite mounting some tires. I do not believe they ever made a 27" 630 bead seat diameter. Make sure that your rim tape is very thin and that the tire bead is as close to the center depression of the rim as possible. Keep pushing the bead to the center all the way around, make sure that the tube is not between the bead and rim as you can cut the tube when forcing the bead over the rim with irons.
Tape was thick but ...Humma Hah
Jul 12, 2002 10:28 AM
... I was not using a correct rim tape for this trial fitting, just friction tape. I removed it completely, soaped up the tire.

The last time I had this much trouble with a tire, I was trying to put a 26 x 1.75 tire on a 26 x 1 3/4" rim. They said it couldn't be done, but I did it. It was lumpy, cause the bead was running down in the spoke area in places.

... irons, huh! Maybe that's the problem, I'm working the tire with PLASTIC tire tools. Maybe I oughta dig out that old steel Schwinn tool.
I think that you are doomed.Spoke Wrench
Jul 12, 2002 11:15 AM
If you have a tire and rim combination that's that tight, you KNOW you're going to puncture the first time you get farther away than you want to walk back.