I am not sure if this is a stupid question or not. Finding compatible parts is not so easy for MTB, after quite a search I found my bottom bracket shell is not so standard, PF107.
I bought a Rotor raptor bundle, this includes a supposedly-30mm external-diameter spindle axle that should fit the Rotor bottom bracket 4130, which supposedly has 30mm internal-width. I did not buy the wrong parts, they are mentioned in the manufacturer website, even the BB says it is compatible with the axle.
However, there is no way I can put the axle through the bottom bracket, at least with my hands. They both have 30mm exactly, I would say either of them should have a slightly different measure, so that the axle can slide into the bottom bracket.
I am new to fitting MTB parts, but my road bike doesn't have this issue, the spindle goes through the bottom bracket effortlessly.
Hence the main question is: Should the axle fit by force into the bottom bracket? (I would need to apply quite some pressure, probably just like fitting the bottom bracket to the frame).
If not, would I have the same problem with other 30mm bottom brackets?
I am wondering if this is a design mistake on the bottom bracket or on the axle. If most 30mm bottom brackets have slightly more than 30mm internal diameter, then a 30mm diameter spindle can fit, and I can just return the BB-4130, go and buy another BB107 for 30mm and solve the problem.
Otherwise, if the axle is too wide (so, most 30mm spindles are slightly less than 30mm and this one is not), then it is pointless trying to fit this crankset and I should return all the products right away.
I do not have another 30mm crankset or BB to know what's the issue, my road bike uses 24mm.
Any help is much appreciated. Thanks!