FSA Gossamer non-drive crank query

evil_breakfast Posts: 446
edited November 2018 in Workshop
Slight duplication of :


Whilst prepping for a ride earlier, I noticed that the screw-in cap/bolt was MIA. :shock:
Ordered the part
from LBS, who STRONGLY advised against riding without it, claiming I run the risk of severe crank spline failure.
This was reinforced by a quick visit to a 2nd LBS, to see if they had 1 in stock. (No dice there either.)
On reflection, and after a bit of googling that found the above BR topic, the cap can't be all that 'important', based on its torque rating?
But they have succeeded in giving me the vapours over this.
Can I ride? Or should I play it safe and turbo until the part arrives?
You're the light wiping out my batteries; You're the cream in my airport coffee's.


  • imposter2.0
    imposter2.0 Posts: 12,028
    The cap is there to torque/preload the BB bearings in much the same way as a headset cap is, so technically you could ride without it providing the crank arm is correctly tightened onto the crank spindle. Also, technically, if the crank arm and the end cap were both fitted correctly, then the cap should not have come off in the first place, as the crank arm - once tightened - should 'pinch' it and hold it in situ.
  • lesfirth
    lesfirth Posts: 1,382
    IMHO both LBS are talking nonsense. I would ride the bike without the cap .
  • keef66
    keef66 Posts: 13,123
    I'm not familiar with your cranks so I'm not dispensing any advice.

    Is that bolt with the suspiciously low torque numbers on it the only thing that's holding the crank onto the spindle?

    Or is it like the Shimano system and that bolt preloads the bearings then the pinch bolts actually clamp the crank onto the spindle.

    Some of the anecdotes I've read suggest the former, which sounds a bit scary to me :shock: