I just purchased a used Ordu with a BB86-compatible frame. It came with an existing FSA bottom bracket installed which the previous owner used with a power-meter 105 (5800) crankset that didn’t some with the purchase. I installed my own new 5800 last night and there is a small gap between the crank arm and BB, enough that I can feel the play along the spindle axis.
I thought all BB86 bottom brackets and cranks were compatible. Is that not the case? Do I need a Shimano BB86 bottom bracket? Is a spacer required?
Things I have made sure of:
The plastic threaded screw on the end is fully engaged
The 2 crank arm screws are not yet tightened
The “key” tab on the crank arm is not in the way (it’s still “open”)
If you can see the bearings you’re missing the covers.
If covers are on you need a spacer. Some BBs come with a pack in order to make up for component variances
You are right. No clue then why you still have play. Maybe the dust covers are missing?
Dust covers are there. I’m thinking there is a compatibility issue with using an FSA bb and Shimano crank, at least in a carbon frame for some reason.
Your frame is 86.5mm wide ± some tolerance
Your crank shaft is 90.5mm face to face with a tolerance that is less than that on the frame
Your BB is supposed to take up that 4mm, but the tolerances (of frame particularly) can have it fall short.
Usually the issue with Shimano and FSA is that Shimano do the axle as 24- tolerance and FSA 24+ tolerance so you can get play one way or not fitting the other.
As for which side the shim should go on - welcome to the world of putting the crank together then measuring left/right symmetry and mucking around with spacers for ages to get smooth. Or find a 24mm ID wave washer to take up the slack without compressing the bearing too much.
I have this bike and did the exact same thing, took the FSA crankset off and replaced with a 105 crankset (now moved onto a quarq).
The FSA crankset used a wave spring between the NDS crank arm and the the BB, if you still have this use on the 105. Should give you enough to get some light pre-load and remove any play.
I have this bike and did the exact same thing, took the FSA crankset off and replaced with a 105 crankset (now moved onto a quarq).
The FSA crankset used a wave spring between the NDS crank arm and the the BB, if you still have this use on the 105. Should give you enough to get some light pre-load and remove any play.
And there it is. Thank you so much for taking the time to reply!
Bite the bullet and put a Shimano BB in that shell. Seems they stack tolerances in opposite directions, with Shimano spec’ing a 24mm ID bearing, and ever-so-slightly undersizing the spindle to fit in, while FSA spec’s a 24mm spindle and ever-so-slightly over-bored ID bearing for fit. Cyclists who try to put 24mm FSA cranks in a Shimano BB often have a helluva time getting the spindle through the bearings, sometimes even having to resort to hammering the crank in or sanding down the spindles. Going the opposite way (Shimano crank in FSA BB), the crank will go in easy, but there maybe too much gap between the bearing ID and the spindle. Not so much that it won’t work, but it’s not ideal for longevity, especially in a threadless shell.
Put a Shimano BB in that shell. Seems they stack tolerances in opposite directions, with Shimano spec’ing a 24mm ID bearing, and slightly undersizing the spindle to fit in, and FSA spec’ing a 24mm spindle and a slightly over-bored ID bearing for fit. Cyclists who try to put 24mm FSA cranks often have a helluva time getting the spindle through the bearings, sometimes even having to resort to hammering the crank in or sanding down the spindles. Going the opposite way (Shimano crank in FSA BB), the crank will go in easy, but there’s maybe too much gap between the bearings and the spindle. Not so much that it won’t work, but it’s not ideal for longevity, especially in a threadless shell.
Yep that’s the plan. Have a Shimano bb86 on the way.