Does my BB need a service?

Equipment
1

When changing my chain i noticed my pedals don’t spin for anywhere near as long as I’d expected. On other bikes I’d push them a little and they just go by themselves for ages before slowing.
Thing is, this bikes a couple of years old, but 75% of the miles I’ve done have been indoors, very rarely has it got wet, and the 7k miles I’ve logged are mostly “strava estimates” based on the trainer speed.

Here’s a link to a quick video, Hope it’s clear enough. Am I cheating myself of a few watts?

It’s worth noting that it’s still very smooth, no issues whatsoever, no noises

Thanks

2

Yeah… rub it in to the face of people who have bough a new, shiny, carbon bike and get 2 revolutions from the bb :wink: (not me, but looking at the video of bike building this is pretty common)

Here is the example of what you get when you BB is new and “perfect”: Dream Build New 2021 BMC Teammachine SLR 01 - YouTube (around 5 minute mark)

3

That looks fine to me.

1 Like
4

Oh, that video’s interesting. Looks like mines ok compared to that, thanks

5

If there’s no play and no noises, it’s probably fine. I’d take the cranks off and feel the bearings directly.

Modern BBs can’t really be serviced anyway - you’d just replace the bearings.

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6

That “test” is strongly influenced by the type of lubrication, type and state of seals, and other such variables that have either no or negative influence on real performance. Take an old-school threaded BB, get rid of all lubrication, mount it back dry, without ball cages and a bit on the slack side, and it will spin forever. That doesn’t mean it’s a good setup.

2 Likes
7

As long as it’s not gritty or sticky then it’s fine. That looks good to me

1 Like
8

Thanks all