KaslTrek

I have a Trek 750 Multi Track(women's) -- says 21"; purchased in 1990s, occasional rider i.e. several times a year but not weekly/dail but I still love it and am planning a 2+ day longer ride with one of the R-to Trail trips so want it in good shape. Very comfortable etc. When I check tire sizes I seem to have 2 different: Front 700-35 C Back: 700-38-C Spec for bike of 1997 seems to be 700-35. Would there be a reason for the 2 sizes? Thanks.

FBinNY 

If they're original it might have been based on the logic that rear tires bear higher loads. OTOH, if one is a replacement, it might have been a matter of the nearest match available at the time, a planned segue from one width to the other, or an intentional mis-match based on the logic of higher loads in the back.

Regardless, it's a non issue and you're free to use either size, or something wider or narrower next time around.

molsen

700-35 means that the diameter of the wheel is 700, so both wheels have the same size. The 35 is the thickness of the tire. You can get thicker or thinner tires depending on your preferences or simply what is available. The "C" actually goes with the 700 as in 700C. So you would say you have 700C rims and want some 35 wide tires for it, if that makes sense...

When shopping for tires you may also see notation like 35-622 (notice the smaller number is in front) which is the ETRTO notation. This means that the little lip (called a bead) that holds the tire inside the rim has a diameter of 622 mm. That is the size that fits on 700C rims. A third way of writing these things on tires is using inches for example "28 x 1 3/8" which is again the same size.

The highlight is that tires saying 700C-mm, mm-622 or 28 x nn (nn being inches) will all fit your bike so you can look at them and pick the ones you like.

I just wanted to clarify those measures a bit, as I remember my total confusion first time I went tire shopping.

Michael

10 Wheels

Suggest you have New Tires installed before the trip.

Your tires could be 10+ years old.

lopek77

Tire size shouldn't be any issue, but as 10 Wheels noted, these may be very old ones, and with the old tubes inside.

I suggest to visit your local bike store for some safety check and tune up. The last thing you want is to be stranded on your ride. Trust me...it's way more fun to keep riding, than to keep walking

KaslTrek

Thanks to all for the tips, suggestions. Very helpful and will be sure to do a full tune up and tire check before taking the trip.

nfmisso

I suggest even a larger mis-match front to rear; like 28-622 on the front and 35-622 on the rear - FOR pavement only. Thus lines up better with the load on the tires.

If you are going gravel, my recommendation is different - and in line with Sheldon's - wider more treaded tire up front, maybe even a 40-622 with a 35-622 on the rear.

The Trek 750 is a great bike. I am presently build one up as a loaner with drop bars for when a friend visits from the east coast. I wish I could find one in my size for a reasonable price.

dsbrantjr

Check the clearance if you decide to go bigger in front. The smaller tire may be there for that reason.

altondavis2

Hey Newbie, Nothing wrong with a fresh set of 700x32 tires.
If that size fits on the front, no doubt it should fit on the rear.

kwcahart

If I were going on a ride like that, I would definitely want new tires and tubes. New tires and tubes give you a secure feeling on a long ride. Be sure to get a patch kit and extra tubes to take along.