My 35mm tires measure 32mm when mounted.... Do I need wider rims to increase width?
 

I'm running Sun Venus rims that apparently have a 19.4mm width.

I mounted Continental Cyclocross Race Clincher tires that are 700 x 35c and when mounted, my calipers show that the tire is 31-32mm wide. Is this due to rim width not being wide enough? Or is the actual tire width really that far off? Thanks for any info. This is my first season with a cross bike!

http://i.imgur.com/gGwb4Z9.jpg

http://i.imgur.com/UdxRN7w.jpg

The size listed on many tires is often incorrect.

It would probably come out wider on a wider rim, but that kind of difference isn't unusual.

Continental has often produced a smaller tire than labeled. They can advertise a lighter tire than a correctly sized competitor.

your happiness depend on that extra 3mm ?

:p

I went with a wider rim, Velocity A23, and it got my 35mm Happy Medium and Speedmax up to about 34.5mm. On my old wheelset they were about 32.5mm. So I agree that a wider rim, may widen the tire.

Basic geometry says that a 3mm increase in rim width will get you about a 1mm increase in tire width if the tire's mounted cross-section is roughly circular.

*thinks for a second* OK I'll buy that.

This. More often than not, tires are narrower than their advertised width. Some, however, are actually wider. Jack Brown 33s and Vittoria Rando Hyper 32s both measure close to 35 mm on my wheels, which are Mavic Open Pros.

Some of my Vittoria tires are oversized and others are undersized. Hypers are larger than labeled, my 700x28 Rubino Pro Tech II ate narrower and the 700x25 Corsa CX are correct. My 700x27 Challenge Parigi Roubaix are more than 29mm wide. I use 23mm wide rims with all these rims.

I have heard people mention that you can let tires set around for a few days aired up to the maximum listed psi in a warm environment. After doing so, the tire will grow in volume, then reduce the pressure to your desired ride quality. I plan to test this theory after I unwrap my new tires and wheelset for Christmas. :)

Have fun...