hazben1

My bike came with 23s but I upgraded to GP4000s 25s which I love. However, there is very little clearance between the frame and tire. This weekend I hit a few fairly solid bumps and 10-15 miles later I stopped and noticed my tire was contacting the frame a small amount. My question is how much will this hurt the frame? My other question is would it be a good idea to carry an old 23 with me in case I break a spoke and cant' true it enough to stop it rubbing on the frame? I do carry a spoke wrench with me.

dstrong 

Where was the tire rubbing? Chain stay? Seat stay?

StanSeven

Just replace the 25s with 23s. The same tire in 23 is a great tire. Think about what your wide tire is doing - probably causing some harm to the frame long term and you'll wear the sidewall of the tire. You may end up with a blowout.

hazben1

Chain stay.

hazben1

I previously had the GP4000s 23s on the bike but I am a heavier rider and got several pinch flats. The ride on the 25s feel so much better. The rubbing is only if it gets knocked out of true. Something I hope does not happen too much. I actually had the 25s on a different set of rims and it was less of an issue. I am guessing these new rims must be a slightly different width.

FLvector

Release the skewer and make sure that the tire is properly seated. Then spin the rear tire and check carefully to see how much clearance you have. If the tire is contacting the chain stay due to tire or frame flex, I'd just go back to the 23's. Its not worth the risk.

hazben1

I did check to make sure the wheel was properly seated and it was. I have only had the new rims a month or less I may try to get some rims a tiny bit narrower. I guess this would make the tire a tiny bit narrower. Again, it is only if the tire is out of true. I am going to go to the LBS and have them detension the spokes and retrue the wheel to see if it will do a better job of staying true. How much clearance do you'll think I should have between the tire and the rim?

PaulRivers

I was going to say, personally I suspect that your wheel was knocked out of true. I'd get a retrued - the bump might have affected the wheel enough that even the 23c's would rub.

If you have rim brakes and your wheel rubs against your brake in any way whatsoever, it will significantly slow you down. This is not caused by tire size, but by the wheel not being in true, so if you pick up the back of the bike, spin the wheel, and the wheel rubs against the brake in any way at all you need to get it trued regardless of tire size.

Edit: Guess you posted while I was composing a response, I see you're going to get the wheel trued. Good luck.

dtrain

Doesn't sound like it's quite enough clearance, but will probably work okay when true. A narrower rim will compromise comfort just like returning to a 23 tire.