johnsmittysmitt

I am trying to change the tire and tube on a 1994 front wheel. I have changed many bike tires and changed this one years ago.

Today it was very hard to get the old tire off the wheel. I cannot get the new tire to go over the rim either.

Is it possible for wheels to stretch over time.... any ideas of why it is so hard now?

Thank you,
John

Jeff Wills

No, wheels do not stretch.

You need to tell us what kind of bike you have, what size the old tire was, what size the new tire is, how long the old tire has been there, etc. etc. Details matter.

techsensei

Wheels can't stretch, but a wheel that has lost all its spoke tension would be larger. That scenario is unlikely, but possible.

Some tires just fit tighter than others. Not sure why there is such a variance in manufacturing; it doesn't necessarily correlate to the tire width or pressure rating.

FBinNY 

Wheels do not stretch, and I'm pretty sure you know that. Nor do tire bead diameters shrink, though some multi-strand beads might stretch very slightly over time.

The key to mounting or removing a tire lies in finesse not strength, or the ability to stretch a non-stretchable bead. Rims have center wells deep enough that the tire can be shifted over to make enough slack to fit over the rim. Unfortunately, many modern rims' center wells aren't that deep so the amount of slack you can produce is very limited.

Also the valve keeps the tire from moving the the center which is where the rim is deepest, so when mounting it's best to finish at the valve. Likewise when removing, start just to either side of the valve. It also helps to use metal tire levers because they're thinner, and easier to slip under a tight tire.

Lastly, rims vary in depth, so consider the design when buying or building wheels, and tires vary slightly in size so avoid tires with a reputation for being hard to mount.

davidad

I have one of these for the Schwalabe I haven't worn out yet. I don't know if the hand strength I used to have would have made a difference, but I doubt it. This tool makes mounting any tire easy(except the #@%&* Marathon, it's still tough).

prathmann

Rims don't stretch, but the rubber around the tire bead can harden and make it just a bit more difficult to get over the edge of the rim. In addition to getting the already mounted part of the bead as deep as possible into the center of the rim channel it can also help to lubricate the edge of the rim with a bit of soapy water where you're working to get the last bit of the bead in place.

FBinNY 

Building on this, old tires can be bonded to the rim and not move to the center well on their own. When removing an old tire, where I see that the tire is stuck to the rim, I start by pushing the tire away on both sides all the way around. Sometimes I can free the tire faster by slipping a tire lever between the tire and rim, and sliding it all the way around.

However you do it, unsticking an old tire is a prerequisite to moving it to center and getting some working room.

Kimmo

We should start a list!

Michelin PRO3 Race
Schwalbe Marathon

Looigi

Lube bead with soapy water or talc. Helps immensely.