Question about how wide a size range a particular rim will fit. For instance, a typical road bike rim will take at least 23,25,and 28mm tires (approx). So a touring bike for example, that comes with factory 40mm tires, and can handle up to a 2" tire for gravel, will it likely be able to take a 32mm (1 1/4") road tire?

I'm just not sure how much size latitude would fit a particular rim, and yes, I realize I'm probably generalizing here as it would be specific to each particular size rim.

Personally, I'd just try it and see for myself whether it works or not. But as frequent as this question comes up.........................

Try this.... https://www.google.com/search?q=reco...w=1257&bih=922 but remember they are just recommended and probably conservative as they are generalizing about a range of tire manufacturer's, quality, and design standards. As well they are making assumptions about the rider weight and riding style.

The 32 mm tire should work fine. I used to have an older Trek MTB that came with 26x2.0 (559-50) semi-knobby tires. When I "streetified" it I switched to 26x1.25 (559-32) street tires and they fit the rims perfectly and rode and handled well. Your proposed size change isn't even that extreme.

I don't like to have tires mounted that are only as wide as the rim's outside width is. Tires with a slight curve to the sidewall (between the rim and tread cap) ride nicer IMO. But too much curve (or overhang) and the tire bead will more easily come un seated in extreme side loading, the side wall can wear more right at the rim's top edge and the handling tends to be a bit more "wallowy".


But their are no black and whites in this discussion, only shades of gray and opinions. this is why we often suggest experimenting and finding out your real results.


When going to a wider tire be aware of tire/frame/fork/caliper/fender/rack clearances. When going to a narrower tire pay attention to pedal/ground strike increase. Andy

Sheldon Brown offers some guidance on rim/tire size fit in this article. It is in a table pretty far down the page so scroll down to find it.

Tire Sizing Systems

Okay thanks for the info. I have some 32's ordered so I guess I'll know for sure when I mount them.

We did the same to my son's old Schwinn Sierra, a rigid fork Mtn bike. It's an absolute kick to ride with the narrow tires. Had to buy narrow tubes as well.

Limit may be the frame clearance, & brake clearance. usually so..

Not a problem for going DOWN in tire size.