Chain keeps snapping, please help!!!

gazzol

Hi every one
I have a problem, I have a 6 month old Carrera Kraken which snaps the chain nearly every time I go out.
I'm removed the top ring and replaced it with a bash guard and last week I replaced the cassette in frustration but that made no difference either. Other than that the drive line is standard. I have tried several different chains from different manufacturers (none of them cheap) and all to no avail. Sometimes the chain snaps under pressure i.e going up hill and sometimes it just snaps when I'm cycling on the flat not even accelerating!!
I know that there is a problem but I can't figure out what it is. Someone suggested to me that it could be that I'm using the wrong combination of gears front to rear but I know there are bikes out there with just a single ring on the front and I'm sure they use all 9 or 10 cogs on the rear and not just a few in the middle.
Any suggestions would be apprieciated as this is becoming a joke and its spoiling my rides.
gazzol.

cooldad

Either your chain is too short or you are using wrong combinations.
If the chainline is correct you can use the full cassette from the middle ring, but not the big or small.

How are you connecting your chains when you shorten them?
A master link won't cause problems but if you are just using a chain tools to reconnect the links it can cause issues.

Danlube

I don't think this is down to misuse of gears. Sounds like you are not fitting the chain correctly. As cooldad says, how are you doing it?

gazzol

Thanks for your replies, when I fit a new chain I'm using a chain tool to remove some of the links which aren't needed due to it now being a twin ring setup. I always make sure that the links aren't tight after they've been joined. I might take it back to Halfords and develop a severe case of touretts it won't fix the bike but it'll make me feel better.

gazzol

Thanks for your replies, when I fit a new chain I'm using a chain tool to remove some of the links which aren't needed due to it now being a twin ring setup. I always make sure that the links aren't tight after they've been joined. I might take it back to Halfords and develop a severe case of touretts it won't fix the bike but it'll make me feel better.

cooldad

Get a Sram powerlink and I bet your problem is solved.
Abusing someone in Halfords for your inadequacies is a bit silly.

Keith1983

Maybe consider getting a chain fitted by a LBS, if it lasts then look at brushing up on your skills?

gazzol

I might try an sram powerlink as suggested however i feel that the problem may lie deeper than that. The reason I say this is that the last week when my chain broke I had to piece it back together with two links from a previous chain (different manufacturer), yesterday when my chain broke I checked the chain over and it didn't break where it had been joined by me.
Having had a careful look at the bike when I got home I noticed that when the chain is on the middle ring at the front to keep the chain straight 6th gear needs to be selected. As I understand it it should be middle middle right? Thinking about this my problems only started after I returned the bike to Halfords when the bottom bracket started creaking and they replaced it, at the same time they changed the whole chain set. Is it possible that they installed it incorrectly?
Thanks Gary

cooldad

What BB? Pics would help.

gazzol

cooldad wrote:

What BB? Pics would help.

Scuse my ignorance but I don't know what make/brand BB they would have used(the bike is a Carrera Kraken). As the replacement was carried out under warranty I assume it is the factory fitted item. On the basis that the whole bike cost £380 I'm guessing the BB isn't going to be the best that money can buy.
I think that my best option is to take the bike to a pro and get them to sort it. I'll buy a new chainset/BB combo and chain and get it fitted professionally.
Thanks Gary

cooldad

I doubt it needs anything new, just might be fitted wrong. Post a pic should be easy to identify.

cooldad

It uses a powerspline I think so it's possible they fitted one with the wrong axle length. But no idea what size it should be.
Need someone clever here.

mrmonkfinger

edit:

Having had a careful look at the bike when I got home I noticed that when the chain is on the middle ring at the front to keep the chain straight 6th gear needs to be selected

That sounds quite wonky, 2 gears out would mean the crank is about 8 or 9mm too wide.

Maybe its not been fitted correctly or it is just the wrong width.

pots74

Cooldad has given some great advice, it does sound like you have a BB issue! Take it back to Halfords and if they give you any flannel then take it another LBS and get them to check it.

Goodluck and remember take no s**t!