BB386EVO Crank install opinions sought

[mick over there]

Hello, all.
I am trying to install a new FSA SL-K Light crank in my wife's bike, BSA external cups for BB386EVO. While doing a preliminary out-of-the-bb assembly, the photos show that the left arm does not want to go all the way down on the spindle at final assembly torque. Seems like about 3mm to spare. I used only the assembly grease that was already in place. The self-extracting crank bolt pulls them apart with no drama, but you can see where the rub marks end on the spindle in the other (lousy) photo. Rubber mallet time? Do you think it is a defective? It looks wrong in the bb, too.

I haven't dealt with BB386EVO before, but several others without such difficulties.
Never tried posting a pic before. Please excuse me if I screw this up!

Thanks for any insight.

[Mark McM]

30mm cranks (BB30, BB386, etc.) usually aren't designed to go all the way up the splines. Instead, they are are designed so that the crank bottoms out at the end of the spindle, and the spline has only enough taper for a light press fit. When tightening the crank bolts, you'll typically find that the torque slowly builds as the crank gets pressed onto the spline tapers, and then ramp up rapidly as the crank bottoms out on the end of the spindle. The amount of the splines showing in your photo isn't unusual, depending on crank model.

[alexihnen]

Originally Posted by Mark McM

30mm cranks (BB30, BB386, etc.) usually aren't designed to go all the way up the splines. Instead, they are are designed so that the crank bottoms out at the end of the spindle, and the spline has only enough taper for a light press fit. When tightening the crank bolts, you'll typically find that the torque slowly builds as the crank gets pressed onto the spline tapers, and then ramp up rapidly as the crank bottoms out on the end of the spindle. The amount of the splines showing in your photo isn't unusual, depending on crank model.

I concur. FWIW

[mick over there]

Thanks. Very helpful. I just needed to know that this is a thing. You saved me from doing something rash! I now see stacks of BB30 shims are also a thing. I probably have to get some if I have a prayer of the front derailleur staying in alignment with the crank.

peace

mick