Bottom bracket "breaking in period"?

jimmocrates
jimmocrates Posts: 131
edited August 2014 in Workshop
Hi
After much squarking from my BB, I replaced it a few weeks ago (its a shimano press fit/BB90). I decided to upgrade my chainset at the same time to an ultegra.
It now rotates silently and front shifts are smooth as silk.
It does feel like there's more resistance from that area now though. I didn't hold back on the grease when re-assembling, but just wanted to know if its likely that this will "break in" or loosen up a bit or if it's the price I have to pay for a silent BB.
Thanks

Comments

  • Zerotails99
    Zerotails99 Posts: 127
    Theres no such thing as bb breaking in period. Not sure what type of resistence youre talking about but you dont need to over grease.
  • thebadgerboy1982
    thebadgerboy1982 Posts: 266
    A lot of newer bb's have a greater amount of drag. I had this moving from gxp to push fit. Feels a bit odd initially but I don't notice anything when riding
    Thebadgerboy1982@gmail.com
  • keezx
    keezx Posts: 1,322
    The drag comes from the sealings.
    No normal human being will ever notice any of this "resistance" while riding.
    Doubt if its even measurable.
    Must be in the order of 0,000000001% of the total mechanical resistance.
  • DavidJB
    DavidJB Posts: 2,019
    Overtightened the crank?
  • buckmulligan
    buckmulligan Posts: 1,031
    I've never used a BB90, but I notice the same thing with new Shimano HT2 bearings. If you drop the chain off the chainrings and spin the cranks, you can definitely notice a fair amount of drag there; after a few rides, try it again and the cranks should spin really freely.

    I put this down to the mysterious 'seal-drag' of the new bearings; takes a few rides to loosen up and as keezx says, the resistance is going to be miniscule compared to the force your legs are putting out so I wouldn't worry about it too much.

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