Looking at getting a gravel bike, but then wondered whether I could just buy a disc specific road bike and put 29er mtb wheels on it with narrow tyres. My theory is that the smaller diameter wheels will remove the clearance issue and provide the ability to run a wider tyre than the stock 25c one you would use with road wheels. My current road bike has about 4mm of clearance on the back tyre to frame when running a 25cc tyre.
Eh?
You know that a 29r wheel is the same rim diameter as a normal road bike?
Hub widths may differ too but fundamentally a 29r wheel is not smaller than a 700c road wheel.
Aren't 29er wheels the same size as 700c road wheels?
Oh yeah. I thought they were smaller. What about a 650b wheel. Would that be too small?
If you are buying a new bike why buy one without clearance and then try to bodge clearance in afterward?
Plenty of people trying 650 conversions though, but usually for a bit more volume, and it only works if you have room as its tyre width that's the restricting factor.
Fair point, but there are many more deals to be hand on disc specific road bikes and there are very few adventure / gravel bikes on the market.If you are buying a new bike why buy one without clearance and then try to bodge clearance in afterward?
650B might work.
You'd want some fairly large tyres on it to get the overall diameter up to close to what a 700/25 would be. Then you need to check side clearances as well.
You'd need to check the hub widths too. Road and MTB are historically different.
Note also 700C is not the diameter of the rim (that's 622mm). NOt sure what the equivalent is for 650b but i'm sure google would find it for you.