More new bike woes

[Accy cyclist]

I was lucky today. My bike came to a sudden halt as i was riding down a hill. Luckily i was only doing about 12 mph and the tarmac was wet so i skidded a bit which stopped me going over the handlebars. My front derailleur mount had worn loose causing the derailleur to jam the chain against the chainset which brought the bike to a halt. I'm pretty useless at repairs especially roadside repairs(please no questions and debate about my repair inadequacies) so i walked the bike home the 3 miles and phoned my friend who works at Evans Cycles in Preston. He wasn't working today so he picked me up and took me and my bike to his shed to examine the damage. On examination he told me that the bottom bracket was too long for the bike. He told me that whoever had assembled the bike had used a bracket for a triple chainset and the chain was slipping off the chainset (It's happened about 10 times) as it had nowhere to go. I'm annoyed with the place where i bought the bike from as they sold me the bike with the assurance that it would be suitable for climbing steep hills(I started a thread about this soon after i bought the bike) Anyway, my friend fitted a more suitable cassette and things were going along just fine, but now i have to have a new/shorter bottom bracket fitted,otherwise my chain's going to keep slipping off. More expense which to be fair is the bike shops fault.
I don't know what to do. Should i just accept they've sold me a bike with not suitable parts and replace them when necessary, or ask the shop to compensate me? I'm peed off because they're either stupid to fit the wrong components or they knew what they were doing but thought whoever bought the bike wouldn't notice.

 

[Smokin Joe]

Take it back and demand that the correct bb is fitted at their expense.

 

[Old jon]

I am normally a peace lover. A shop that sold me a bike like that, I would ask for my money back right now. Any delay would cause me to repeat my request whilst holding the shop manager firmly by the throat.

 

[Pale Rider]

I agree the bike shop ought to fix it, but you may have trouble explaining the problem.

A couple of mm in the length of the bottom bracket can make the difference between an installation that works properly with a particular chainset and one that doesn't.

If the bike shop staff are mechanically inept, they may genuinely not grasp what you are on about.

Your Evans mate has already done you a good turn, but if he was prepared to go to the shop with you he could explain the problem and make sure you leave with the correct length bottom bracket.

Bottom brackets are not expensive, so it may be less complicated not to argue the toss too much over who should pay for it.

 

[Kbrook]

Is a bottom bracket for a triple longer than for a double/ compact? The bracket surely is compatable with the frame, not the chainset? Someone put me right if I'm wrong.

 

[boydj]

Square taper bottom brackets will have different length axles for double and triple chainsets.

 

[Smokin Joe]

Is a bottom bracket for a triple longer than for a double/ compact? The bracket surely is compatable with the frame, not the chainset? Someone put me right if I'm wrong.

Frame's are standard, chainsets require a matched BB in type and length.

 

[Pale Rider]

Is a bottom bracket for a triple longer than for a double/ compact? The bracket surely is compatable with the frame, not the chainset? Someone put me right if I'm wrong.

I don't profess to be an expert, but cranks/chainrings and chainline are relevant.

The linked article mentions getting the right length to a mm or two is 'doing quite well'.

I suspect that's where Accy's at, the fitted bottom bracket is close to the right length, but not close enough for reliable performance.

https://janheine.wordpress.com/2013/01/02/bottom-brackets-demystified/

 

[Mrs M]

I am highly untechnical (please excuse) but if the wrong bit was on the bike I'd take it back and as them to correct it.

 

[GrumpyGregry]

Sorry for your woes with the bike I am glad you were unhurt in what could have been much worse.

 

[Accy cyclist]

Thanks for the replies so far. If i'd bought the bike from a main dealer i'd be contacting them, but then surely a main dealer wouldn't fit the wrong component! I can't see me getting anywhere with this shop unless my mate agrees to go with me to tell them of their error and as he's always busy i don't think he'll be up for it. Maybe if i phoned them up to start with and told them what he said they might say bring the bike in. The trouble is they'd probably insist the BB is the right one and then i'd have to prove that it isn't. We're told quite a lot that buying bikes on line has the draw back of not having the free service and advice you'd get from a local buy it in the shop dealer,but in future i'll take my chance with one of the main dealers. At least their bikes should be assembled correctly and if they aren't they'll accept their mistake and put things right!
When i took the bike back the other month after my Evans mate told me they'd fit a wrong cassette they mumbled something about you knew what you were buying at the time. No wonder the shop's up for sale!

 

[screenman]

I always thought the BB was fitted at the factory.

 

[derrick]

Not sure what you are trying to say here,
My front derailleur mount had worn loose causing the derailleur to jam the chain against the chainset which brought the bike to a halt.
How does that stop the wheel from turning?

 

[Accy cyclist]

Not sure what you are trying to say here,
My front derailleur mount had worn loose causing the derailleur to jam the chain against the chainset which brought the bike to a halt.
How does that stop the wheel from turning?

The chainset wouldn't turn due to the front derailleur forcing the chain tightly against it and the chain itself had become wedged down the side of the smallest ring on the cassette. Both combining to stop the wheel from turning.

 

[steve50]

I was lucky today. My bike came to a sudden halt as i was riding down a hill. Luckily i was only doing about 12 mph and the tarmac was wet so i skidded a bit which stopped me going over the handlebars. My front derailleur mount had worn loose causing the derailleur to jam the chain against the chainset which brought the bike to a halt.

I can understand the front derailleur working loose and jamming the chain wheels but what caused the rear wheel to lock up and cause you to skid?
Edit; just seen above post