Bicycle Mechanics - BB Problem with LBS
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I will be going back to my LBS tomorrow due to an ongoing problem.
My "plastic" BB non-drive side cup had a crack so I took it in today, they replaced it with a metal one, which I thought "great", this should be an upgrade and at least be stronger.
Listed below is the problem, and what can you tell me whats wrong with it so I know what to say at LBS before I go, I would like to print off the replies of those who know what their talking about and take it with me as reference:
Here are the details and some observations;
The metal cup they installed is flush with the frame, there is no locking piece/nut (should there be one?).
If either crank is flexed towards or away from the bike by hand you can see the other crank moving the same, it is loose.
By moving the crank this way I can also see that the BB cup they installed is moving back and forth also, which I am sure is not correct.
What damage may have been caused by this repair?
I bought this bike one month ago to the day (bought on 6-16-07).
Any help and thoughts on this will be a great help for me, I would like to be able to ask the correct questions/concerns before I go in tomorrow.
This post tells in more detail original problem I had with my BB:
07-16-07, 07:58 PM
The metal cup they installed is flush with the frame, there is no locking piece/nut.
This is normal. For a Shimano square taper bb (the only type that ever came with a plastic nds cup) the nds cup is supposed to thread in until it is tight against the bb cartridge. There is no shoulder or lockring.
If either crank is flexed towards or away from the bike by hand you can see the other crank moving the same, it is loose. By moving the crank this way I can also see that the BB cup they installed is moving back and forth also, which I am sure is not correct.
This is NOT normal. It is possible the metal substitute cup is from the wrong model bb and is not a tight enough fit on the cartridge body, or it wasn't installed tight enough to bottom out on the body. In any event it's not right.
What damage may have been caused by this repair?
Probably none unless the threads were damaged during installation. I expect you are ok once the bb is installed correctly.
07-16-07, 08:08 PM
Sounds like the wrong cup, a 68mm cup for a 73mm BB or a proprietary cup for an off brand BB. Depending on the brand they could probably get the whole BB warrantied.
07-16-07, 08:21 PM
Just one bit of advice:
Most bike shops are staffed with people that do want to help you solve your problems. If you're hostile with them, they'll still fix the problem, but if you're civil and treat them as human beings...they'll still fix the problem and you'll both come out smiling.
Thanks for the advice all this helps me a lot. I think I'm ready then for my trip to the shop tomorrow, any others thought or opinions on this issue are still welcomed.
As far as being civil...I always try to handle myself in a courteous manner, stern when needed, but I keep it low keyed and polite. BTW, the "staffing" at the LBS is 3 brothers their sister and her son, their dad started the store in 1974; he is almost 90 and still works there part time.
What I really find upsetting is that they should have known how to PROPERLY repair the bike and to have made that repair before I brought it home and had to find out for myself that it was wrong.
I hope to have a positve reply back here tomorrow night :)
07-17-07, 07:18 AM
Yeah, I was hoping to get to you before you got to this stage. In my experience, most LBS mechanics will throw any old NDS cup in there and tell you you're fine. When I cracked my last one, I went to two different shops to get another spare cup. I got three cups from the two shops, and all three were different sizes. So you CAN'T just throw any old NDS cup in there. I hope you get the whole BB replaced.
And I disagree with the statement that the NDS cup doesn't do anything. It keeps the cartridge from moving in the BB shell, and, as such, needs to be torqued in place correctly. Just not too much. I've never cracked mine when installing, just when removing.
07-17-07, 11:35 AM
I've never cracked mine when installing, just when removing.
That's exactly what I experienced.
Well today I got my bike back. They installed a new Stonglight BB with a locking nut. By looks alone, it at least inspires some confidence that it is indeed a stronger BB overall, I'm sure their about as tired of seeing me walk in as much as I hate going, they assured me that it is indeed better than what was in it.
I only gave it a 3mi test ride tonight and no trouble, now I just hope it will lasts.... time will tell.
Again thanks for the help with the replies.
07-19-07, 06:22 AM
Sounds like you did alright then. Not sure if you ever stated what bike this was, but for the most part, the Bottom Bracket is an area that a lot of companies skimp on and put the cheapest one they can in there. For the most part, the Stronglight should be a much better quality and durable. Of course it might have been the only one they had to put into your bike also, but it does sound like you got a deal.
I hope you thanked them for fixing it!
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