Checking new bottom bracket/chain set install

new2br
new2br Posts: 57
edited January 2015 in Workshop
Hi,

Just looking some advice on my new bb/chain set which was installed by LBS.

Its a new ultegra 11 speed chain set and hollowtech II bb (in bb30 to English sleeve adapter). Anyway when I got bike home I just happened to notice crank arm in horizontal position (no chain or pedals attached). When I rotate crank it turns smoothly but sticks at any position when I stop applying force, ie they don't freely spin and the resistance I feel when turning manually is small but significant. Anything I've seen online is the crank should free spin for many revolutions if flicked even lightly when no chain attached.

So I'm suspecting the new bb cups/bearings are at fault or if possibly something has been overtightened on installation. So before I contact supplier/LBS was just wondering if anyone can say categorically that the crank resistance I'm experiencing is not normal and should definitely spin freely and not down to some bedding in time needed for new bearing grease to be distributed (I have turned the cranks by hand many times which hasn't made any difference).

Any advice much appreciated...

Comments

  • keef66
    keef66 Posts: 13,123
    Sounds normal to me. It's the bearing seals that create the drag. If you install HT2 cups then try to rotate the inner part by hand you can feel it.

    Makes no difference to your pedalling efficiency

    Well sealed bearings last a lot longer if you ride in the wet.
  • wishitwasallflat
    wishitwasallflat Posts: 2,927
    IME with HTII they can be stiffer when new cause they are full of lube. I just fitted new Ultegra one two weeks ago and it didn't spin much beyond a rev a first but now after 100 or so miles its freer. Spinning by hand won't make a diff personally as long as it's smooth and not binding or grinding I would ride it and expect it to loosen up soon. You could check the bearing pre load yourself just in case that is too tight though, thats easy done.
  • keezx
    keezx Posts: 1,323
    new2br wrote:
    Hi,

    Any advice much appreciated...

    Remove the grease and seals of the bearings.
    It will spin very smooth and light, but only a short time.......
  • new2br
    new2br Posts: 57
    Thanks for the replies which are somewhat reassuring, though I would probably be happier if I could get a single revolution from a spin of the crank arm!

    I did check the tensioning bolt which was only hand tight so I dont think its an installation/overtightening issue. But as an indication of tension, I am able to balance 7 pound coins on the tip of the crankarm (when horizontal) and the weight doesnt move it - if I had any more coins I think it would prob start moving but ran out of coins! So although the motion is smooth I would have thought it would affect pedalling efficiency having to push that extra 7 coins worth pedal resistence?

    Do you think this still sounds normal? - if not will make a call to supplier...
  • keef66
    keef66 Posts: 13,123
    The bearing preload cap is only supposed to be finger tight using the little plastic tool and with the pinch bolts undone.

    Any tighter and you'll be applying too much sideways force to the bearings and they'll wear prematurely.
  • new2br
    new2br Posts: 57
    Sorry when I say hand tight i meant finger tight - ie using the shimano crank removal wheel tool I was able to easily loosen and re-tighten to no more than putting lid back on toothpaste tightness - if you do put lid back on that is :-)
  • desweller
    desweller Posts: 5,175
    When the bearings are brand-spanking new, the seal nip on the crankshaft is at its greatest. As you ride it the seals will wear a bit and you'll find that the crankset will spin more freely off-load.
    - - - - - - - - - -
    On Strava.{/url}
  • new2br
    new2br Posts: 57
    Sounds like everything is pretty normal then - panic over. Thanks for the comments and reassurances...Cheers

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