Can 700x28c wheels and tires fit in my MTB frame?
An old MTB will have used 26&quot; wheels (559mm rims), you want to put 700c (662mm) rims on it with smaller tires.
We can work out wheel approximate diameters. Assuming tire height above the rim is about the same as its nominal width and the MTB frame will take a 50mm tire.
559/2 + 50 = 329mm
622/2 + 28 = 339mm (+10mm)
The 700c tire might fit but bear in mind you are also raising your bottom bracket 10mm, which will raise your position on the bike and affect handling to some extent. The larger diameter wheel will also effectively increase the gear ratios.
Note that a 27.5&quot; / 650b (584mm rim) with a 32mm tire comes out to the same diameter as the 559 with a 50mm tire.
584/2 + 32 = 320mm
Finding 27.5&quot; wheels with rims narrow enough to take a 32mm tire make be tricky though.