apologize in advance. Total Noob question. I have very little knowledge about “wrenching” on my bike.
So I brought my bike into the LBS last week for a major tune. I was told the BB was shot and so it was replaced along with a getting a new chain and some other minor tweaks.
today I put the bike on the trainer and when the resistance went up, things did not feel as smooth as I’m used to. I then noticed that the crank could move “horizontally” back and forth a few millimeters. Maybe just 2-3). I’m wondering if this Is acceptable and I just never noticed before, or if this means something was not done correctly.
thanks!
Nothing’s perfect due to tolerance stack but I’d say that’s a lot. There’s spacers that are that thin depending on the components you have.
I’m assuming they torqued the crankset to spec.
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That’s definitely not normal. I would take it back and have them look at it. If they just did work that requires removing the crankset and they reinstalled it incorrectly they shouldn’t charge you for the correction.
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That sounds like a botched repair job. If you don’t have it fixed now right after the repair (for free/cheap as the LBS botched the repair), the BB will need replacing again very soon.
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Yep, take it back, sounds like a couple of 1.5mm spacers are required to prevent any horizontal movement. But even with that movement it should have moved smoothly.
I’ve done both extremes, added one to many spacers before, torqued up and its been almost unmovable. Other way, after greased and a ten miles test, eventually felt some sideways movement, wasn’t noticeable from the start.
One test I do after torquing is with the chain off the ring, spin the cranks and they should appear to spin forever…and an aggressive horizontal shove/pull to sense any sideways movement.
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There should be no noticeable movement of the bottom bracket except for the radial turning of the cranks.
Take it back to the bike shop. They’ll make it right.
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Thanks guys.
Taking her in today
Could it be the plastic pre-load cap needs an extra few turns? Just in case it saves you a trip…
Agree with others that it sounds like you need an additional spacer to properly preload the cranks. On my 30mm spindle equiped bikes I use the SRAM preload adjuster which simplifies the process of assembly, check, disassembly, add/remove spacer, assembly…