Originally Posted by
Podagrower
2012 Giant Defy Composite needs a new rear wheel. The factory wheel is 22mm outside width, and I am running 25mm tires. I have a few mm clearance on the sides, but only about 2mm clearance to the seatpost. One of the rims I am looking at is 25mm wide, which in my mind will result in a slightly wider and slightly less tall wheel.
Hi Podagrower,
I agree with the previous responses that you probably won't see a significant decrease in tire height with the larger 25 mm wide rims.
Here's something else to consider: For best aerodynamics it is best to use a tire that is slightly wider than the rim. A 25 mm tire would be ideal for a rim whose outside width is 22 mm. Since your frame won't accommodate a larger tire, I would hesitate to go to a 25 mm rim---I would stay close to the 22 mm rim width. Unfortunately for those of us with older frames, the current trend is toward wider rims and larger tire widths. There are some good advantages to this. Unfortunately, there are many, many road frames in use (like yours and ours) that don't have the clearance for the bigger tires. This may limit your rim selection if you are looking for the "latest and greatest" on the market.
My Team Fuji and my wife's Specialized Ruby frames (both carbon frames) max out at a 25 mm tire size. So we're in a similar boat as you. Where we ride, wind is frequently a major factor and crosswinds are very common. For training, we've been running Shimano Ultegra wheels (WH-6800 and WH-6700). Their outside width is 21.4 mm. I'm running 25 mm wide tires and she's running 23 mm wide tires.
Kind regards, RoadLight