Different tire and rim widths front and back - Why? Should I replace one?

Question

I just bought a Trek 7.2 hybrid bike on Ebay and got the surprise (didn't read the listing closely!) that the front and back tires and rims are different widths. I am wondering if I should give it a try or spend some money on making the front wheel be the same width of the back. Why would someone have different wheels? Here's the configuration I have:

Rims: (Front) Alexrims DA22, (Rear) Matrix 750, Tires: (Front) Vittoria Zaffiro 700 X 25C, (Rear) Bontrager Select Invert 700 X 35.

Any thoughts on this would be appreciated.

Answer 1

• It is ok to have different width of tires on front and rear wheels, I have a thinner tire on rear wheel as the clearance is low and I wanted to fit a full fender.

• Why would someone have different wheels? -

  It is quite uncommon for new bikes to have different width of tires but used bikes can(as your's is). Perhaps, if the wheel was damaged/stolen the previous owner may have replaced with what is available/cheap.

• If you plan to change the tire size, ensure that the rim can securely hold whatever width of tire you are about to install and has enough clearance for fenders/frame.

• If you bring your bike into local bike shop, they should be able to tell you if a certain width will fit your wheel.

• Just a tip for comfort - 35mm tires will ride a lot smoother as the pressure on 35mm will be approximately half of what 25mm tires requires.

Answer 2

Wheels don't need to match and neither do tires, unless you're really picky about that sort of thing. Sometimes the wheel is damaged (out of true, bent, cracked, etc) and needs to be replaced. Other times it's changed to meet a specific need such as wanting a rim that supports a wider tire or a stronger rim if you're riding over tougher terrain.

Personally, I ride (mountain bike) with a wider rear tire to run a larger tire for more grip. Fortunately, I bought a wheelset so mine match, but I could just as easily have run my previous front wheel and had a mismatching set.

You could also get really granular and look at what spokes, nipples, hubs, and rim strips are the wheels, but having differences in these between front in back won't make the bike un-ridable, it will simply change the way each wheel works.

Answer 3

As others have mentioned, there's no problem having different wheels or tires. There are actually some very good reasons to have a larger tire in the back than in the front.

Larger tires allow you to run the tire at a lower pressure and gives you a cushier feel. Slimmer tires are lighter, reduce rolling resistance and aerodynamic drag, and give the bike a more nimble feel.

Since rear wheel supports more weight, it makes more sense to put a larger tire in the rear. A larger tire. This isn't as much of a concern with the front wheel since it's supporting less weight. Also, your arms absorb an unexpected bump a bit more easily than your butt does. That being the case, you can put a smaller tire up front to make the steering more nimble and reduce weight, rolling resistance, and drag.

For all the same reasons mentioned above, it's also relatively common to see rear wheels more stoutly built than their front counterparts. This is most apparent on high-end race bikes, which can have almost twice as many spokes on the rear wheel as they do on the front. The rear wheel spokes are also crossed to give them greater strength while the front are often laced radially without any spokes crossing the others.

Answer 4

Unless you have a problem with it, it doesn't make a huge difference to the bike. A narrower front wheel gives more agility in steering, a wider rear wheel more traction in slippery conditions, so it's even a clever combination. The wheels are the same diameter, so it's possible the same tires will fit on both. Width is fiddly, though, so your narrow front and wide back might require different tires, though it is not necessarily the case, as it would be if, say, the front was 26", 650B, or 650A, and the back was a 700C. You can use the same tubes for both.

I'd say go with it, and try it out for a while. If you find you really dislike the difference, a replacement wheel shouldn't be too hard to find.