Need opinions on my bike's bottom bracket - is it loose?

[Tim Hall]

cheers for the input guys on this, do you think though that there the bottom bracket looks loose judging by the photos?

I'd say yes. Or if not loose, not quite installed properly. The cup you show is normally what is called the fixed cup and on the other side is the adjustable cup. The side with the fixed cup is installed first, and done up tight, which normally means the shoulder of the cup goes flush against the frame, with no gap. The adjustable cup is then installed. This cup is tapered, so as it gets wound further into to the thread, it presses harder on the body of the bottom bracket.

It looks like either your fixed cup wasn't done up tight to start with, or has worked loose.

 

[andrew_s]

A crank taker offer and a bottom bracket doer upper will cost less than £30.

You'll also need a largish adjustable spanner to turn the other tools with

 

[Gravity Aided]

Or a ratchet. I will also admit to a 3 foot breaker bar.

 

[Arjimlad]

Or a bench vice. Pop the tool in the vice then use the frame to turn it round. Bear in mind that the threads on the BB cups are reversed on one side. i.e. not lefty-loosy-righty-tighty

 

[jamsw73]

I'd say yes. Or if not loose, not quite installed properly. The cup you show is normally what is called the fixed cup and on the other side is the adjustable cup. The side with the fixed cup is installed first, and done up tight, which normally means the shoulder of the cup goes flush against the frame, with no gap. The adjustable cup is then installed. This cup is tapered, so as it gets wound further into to the thread, it presses harder on the body of the bottom bracket.

It looks like either your fixed cup wasn't done up tight to start with, or has worked loose.

Ok I see. What do you think I should do next?

I really don't feel confident enough to carry out a DIY job like this. I assumed this is a problem that came with the bike when I bought it about 9 months ago so it would be covered under some sort of manufacturer's gaurentee, but the retailer is saying that the gap in the bottom bracket looks normal judging from the same photo.

 

[Smokin Joe]

You'll also need a largish adjustable spanner to turn the other tools with

Everyone should have a decent adjustable spanner.

 

[Benjifield]

Has the bike just developed a creak or has it been like it since new?
And is there any side to side play in the crank arms?
The bottom bracket should be torqued up to around 35nm.
There are a few tools required to do the job with a square tapered bottom bracket just to get the arms off let alone tightening the bottom bracket up.
To me £30 is a little steep. Should be around a £15 job and thats usually with replacing the bottom bracket aswell.

 

[Andy_R]

No he hasn't yet, the tightening job would cost around £20-30.

ermm...it's a 5 minute job with the right tools. You decide.

 

[Smokin Joe]

Has the bike just developed a creak or has it been like it since new?
And is there any side to side play in the crank arms?
The bottom bracket should be torqued up to around 35nm.
There are a few tools required to do the job with a square tapered bottom bracket just to get the arms off let alone tightening the bottom bracket up.
To me £30 is a little steep. Should be around a £15 job and thats usually with replacing the bottom bracket aswell.

If bike shops are supplying and fitting a bottom bracket for £15 no wonder so many are going bust. Nip into your local garage and see how much they charge for fitting a set of plugs.

 

[Benjifield]

Didnt mention supplying the bottom bracket. Just the labour to replace it. In the right hands it's a 10 minute job so why would you rip the customer off?

 

[Smokin Joe]

Didnt mention supplying the bottom bracket. Just the labour to replace it. In the right hands it's a 10 minute job so why would you rip the customer off?

Minimum one hour labour charge by nearly all tradesmen. Nothing's a rip off provided the price is stated in advance.

If you want pocket money repairs you have to learn to do them yourself.

 

[Profpointy]

Everyone should have a decent adjustable spanner.

yebbutt you should never use an adjustable spanner ... unless no-one's looking.

Joking aside I've got a big monster 18" one (where's Fnaar?) - which I got quite (relatively) cheap - and it's a proper Bahco one too. It doesn't get used much, but occasionally there's a big nut (eg bottom bracket adjustment) which it fits and I don't have a proper spanner for.
Also to be fair, bike bolts and nuts in smaller sizes are not usually done up that tight, so a 6" adjustable is quite hand for bike jobs

 

[jamsw73]

ermm...it's a 5 minute job with the right tools. You decide.

Didnt mention supplying the bottom bracket. Just the labour to replace it. In the right hands it's a 10 minute job so why would you rip the customer off?

Has the bike just developed a creak or has it been like it since new?
And is there any side to side play in the crank arms?
The bottom bracket should be torqued up to around 35nm.
There are a few tools required to do the job with a square tapered bottom bracket just to get the arms off let alone tightening the bottom bracket up.
To me £30 is a little steep. Should be around a £15 job and thats usually with replacing the bottom bracket aswell.

I agree with you guys, £30 is steep. But I think maybe that's a flat minimum fee they charge their service, and the mechanic did tell me they could do a very 'thorough' job, probably other checks to make sure the bike is spruced up, honestly don't know. I don't fancy fixing this myself that's for sure, so I might look elsewhere to get a cheaper quote?

what bugs me is whether this sort of thing is covered under the bike's warranty, because it seems like a fault that was present when the bike was purchased from you're all saying about the bracket looking loose

 

[Smurfy]

ermm...it's a 5 minute job with the right tools. You decide.

I'd say it would take much longer than that, because although it is the fixed cup that appears to be loose, the adjustable cup needs to be adjusted after tightening the fixed cup. To do both cups means removing and replacing both cranks, because you can't get a feel for bearing adjustment with the cranks on, and in any case the cranks get in the way of adjusting the cups. Of course one could assume that if the bearing was correctly adjusted before the fixed cup became loose, all that needs to be done is tighten the fixed cup as much as possible, but that would be a gamble.

 

[Globalti]

I think £30 is quite fair for the job. Nobody will ever get rich from repairing bikes so it sounds as if that shop or mechanic has realised that the only way not to bleed money is to charge a realistic rate for their time, not just doing the job but the entire "diversion" of time, the investment in tools, the heating, lighting, rent, rates, insurance, wages, biscuits and tea bags.... the lot.

And the mechanic has taken a gamble, because if the job turns out to be fiddly or complicated he's going to be spending more time on it. Possibly since the OP has been riding the bike with the BB loose, the threads are worn and will need special attention, perhaps some locking compound.