Cannondale Bad Boy 8 '08 Chain torsion problems

maveco

Am new to cycling, just wanted some advice, would really appreciate any info regarding the chain/eccentric bottom bracket problems on my new bike.

Basically the chain is so loose that you can pull it off. The bottom bracket has been adjusted, but seems to move back into the original position, and I have been told that I cannot shorten the chain. I need to send the bike back, and have hurt myself a few times when the chain pops off. Am really frustrated. Every time I get the bottom bracket adjusted, after 20 miles it is back to its original position again.

Anyway any info would be greatly appreciated

GrantyBoy

who told you that you cannot shorten the chain?
I don't follow how bottom bracket adjustment will adjust the chain tension. How is this part moving?

maveco

Evan cycles, have said that the chain cannot be shortened.

The torsion is created by moving the eccentric bottom bracket, as the frame has no horizontal dropouts.

el_presidente

Whoever said you can't shorten the chain is a liar

name & shame!

Find another bike shop or learn how to do it yourself. try Parktool.com for starters

el_presidente

Also it sounds like your Eccentric BB is either faulty or being set up wrong. Not many bikes have these so it wouldn't surprise me if Evans didn't know what they were doing.

Don't send the bike back as it is a good machine but insist to Evans that they fix it or replace the BB

They may say you cannot shorten the chain as taking out a link will make it too short. If this is the case then it's even more important that the Ecc BB is sorted. talk to the manager at Evans and demand satisfaction

attica

I think El Presidente is right in his second post.

An Eccentric BB shouldn't change position, that's the way they're designed.
Go to Evans, have a hissy fit, have another!

Get their mechanics to learn how to set one up if need be!

Took me 30 seconds to find this:-
http://en.wikipedia.org/wiki/Bottom_bracket (look right at the bottom of the page)

and then this:-
http://www.evanscycles.com/guides.jsp?item_id=532

Kick some lazyboy ar$e! Good luck.

maveco

Yes I have all the factsheets, also downloaded the info from Cannondale, for single and double wedge eccentric bottom brackets.

I think the bracket is faulty. The bike is going back to Evans, but am really disappointed with the situation, I understand completely the way it works, I have had it rebuilt and it still moves after minimal usage.

As I said thanks for the advice, the bike is great but I will get the components changed and then learn how to fix it myself.

As for the chain, I thought a half link would sort it, or a different chain, but Evans mechanic said that would not sort it.

maveco

Also thanks for the parktool link. I need to buy the tools to do this myself

thanks everyone

marcusjb

I have the same bike and had similar issues with the bottom bracket - I will say they do get better - seems to take a while for the bracket to bed in and stop slipping so much.

I don''t think the cannondale design is that great on the bottom bracket - I wondered if anyone had any stories with alternatives (of which there are not many - the Bushnell seems to be the main one out there. Anyone any views on it?

maveco

Evans took my bike away and sent off for a part from Cannondale - took 3 weeks!. The bike is perfect now. So if anyone out there has the same problems, there is a cure.