Originally Posted by
Moisture
mstateglfr sorry for the confusion. Allow me to re iterate.
I see lots of options out there with 700c x 45 as well as 650b x 45 . Im trying to understand why one would make more sense over another?
Also, I see 700c gravel bikes out there which claim to also fit a 650b wheelset without offering enough tire clearance to fully compensate in diameter. Would such a change not throw off geometry figures enough to avoid doing so?
Correct. As a generalization, its gonna screw up the handling to do that on the same frame. You can't make that big a difference without affecting stability, trail, bottom bracket height, etc.
So, when going to a smaller wheel you should always use a larger tire to keep the overall diameter the same.
In my experience, increasing the diameter adds more stability, more ground clearance and makes the bike better off road. Smaller diameter can make the bike more agile, less stable, increase pedal strike, and reduce toe overlap.
But again, the goal is to keep the diameter the same.
I'm not sure what you are getting at.
AFAIK, the only OEMs that make a 650x45 and 700x45 wheel options on the same bike do that on different frames. They use 650b wheels on their smaller frames so that they can keep the angles, geometry, and handling the same as their larger frames. Toe overlap is also an issue with 700c & with a short wheelbase agile bike in a small frame size. Maybe this is what you were referring to - doing this on different frames?