Tire sizes

[flirty1]

I have a Schwinn 26 inch mountain bike from big box mart LOL the rear tire the tread is wearing out from braking. The current tire size is 26x2.0 Do i have to use this size or whats the biggest width I can go with? Also do they sell 26 inch wheels with the 7 gear cassette thingy already attached? I have worn out 6th and 7th gear in the rear and its not a year old.

[Bud9051]

Hi Flirty, sorry to be late.
The rear tire size has to match the rim and there is generally some flexibility, but most of the time they already have the widest tire on there. See if there is any size stamped into the rim, between the spokes. The sprockets come in many varieties, but in most cases you would need to replace the entire group of 7 sprockets. Again, there will be a name on the sprocket, but it would take a bike shop to spin off just the outer two even if they were replaceable.

If the cluster is in trouble in 6th and 7th, then you are using the high gears too much and need to kick it down and increase your pedal rate. I know, I can't do that either, but that is what wears out the high gears. The bad news is that it also wears out the chain. Measure 12 inches of chain and each link should fall on a 1/2" mark. If at the 12" mark the chain is 1/16 of an inch longer than it should be, it needs to be replaced. At 1/8th inch of stretch it will not function long on a new sprocket and will quickly wear it out. Chains and sprockets are usually replaced in pairs.

If you stop into a bike shop with the rear wheel to ask about the sprocket and tire they can quote you a price for removing the sprocket if needed.

Bud