Psychocycles

Hello, I recently swapped GXP BB for BB86 Shimano for Shimano 105 crankset (BB was done by LBS). I installed the crankset & noticed this gap on the non drive side. There is no wiggle or play if I yank on the arm. Does this require a spacer? Or is it good to go as is?

Also, I had to use a rubber mallet to get the crank to seat as it was a pretty tight fit and when I turn the pedals backwards it feels a bit tight & does not spin freely. LBS told me this is normal per Shimano & should loosen up within a few weeks. Is that normal? My GXP crank did not feel this tight even immediately after a BB swap.

Thanks!

oldbobcat

The reason the axle isn't wiggling when you yank a crank arm is is the same reason the crank feels stiff or binding. Something is not right. either a bearing is not set in the frame straight, or there's an incorrect shim between the bearing and the axle. It's hard to say for sure without seeing the bike. Anyway, what keeps the axle from sliding sideways is a little bit of side load from the cranks. Loosen the pinch bolts on that left crank and see if you can bring the crank right up against the bearing face with the crank nut. If the nut bottoms out, then you need a shim. Somewhere.

tomtomtom123

Shimano road BB are 91mm overall width to the end caps, on a shell of 68mm . If it's not 91mm a little over or under may be ok , but if it's under by a lot and causing the spindle splines to bottom out on the left arm, then you need to shim either the BB cups or the spindle. The innermost surface of the crank should touch the end cap, not counting the o-ring which is supposed to compress. If it's not touching because of bottoming out, then check shimming as above. You're supposed to tighten the compression bolt on the left arm to something like 2Nm, you can check the Shimano instructions for the exact value. You do this while the 2 clamping bolts are loose. After you have the compression bolt set, then tighten the 2 clamping bolts. Follow the torque instructions.

Psychocycles

Thanks for the responses, guys. I'll probably take it back to the LBS and ask them to take another look at it.

am8117

Could it be that the LBS accidentally installed MTB BB into road frame? No experience with BB86, but both threaded and pressfit Shimano standard BB cups are slightly differently sized for road and MTB. If used without spacers under cups, the MTB BB with road crankset in 68mm produces similar result as pictured.

am8117

The need for a mallet to get the crank in is not suspicious, but the "does not spin freely" is very odd, almost sounds like axial misalignment between the bearings - have those been pressed in properly?

Psychocycles

So I took it back to the LBS to get a second mechanic's look at it, he agreed that the left crank needed a shim & installed one. What the first mechanic said seems to be true, as I rode for about an hour on it it spins much more freely than it did when I first installed it, although it won't spin forever it does feel much more free than before. Thanks for the responses, guys, glad I took it back and am sure that everything is ok!