Newbie Seeking Help With BB!

humpy

Hi all,

I have a Carrera Fury '07 and have recently started having problems with what I first thought was just a loose crank, but have taken it to various LBS' and all have said the BB is knackered. I believe the BB currently fitted is that of an ISIS type. I've read/heard that these typ of BB's are not very reliable and have been advised to change setups.
Now, this is where i'm stuck! Do I ditch the current crankset/bb (Truvativ FiveD/ISIS BB) and go for something like a Shimano LX Hollowtech II chainset, or do I replace the existing ISIS BB for one that has proven reliability? SKF FR300 BB, maybe?

If I was to change the chainset, would I have problems with gearing (SRAM X7 Derailleurs) or would it be compatible?

Any advice would be very much appreciated.

Cheers

Neil

delcol

i run a sram x7 set up rear mech shifters with a shimano lx crank set and lx ront mech on my santacruz heckler. the shifting is spot on never had any trouble....

humpy

Thanks for that delcol. My front mech is a SRAM X7, so would that still be compatible with a Shimano LX Crankset? Sorry if my questions sound like utter sh*t!

delcol

yeah it should be..

the only reason i got a lx front mech was the guy in the shop when i got the heckler said sram are good but their front mechs are crap and advised me on shimano..

supersonic

Yep, it will!

Though I'd get this:

http://www.merlincycles.co.uk/?fn=produ ... egoryId=12

tjm

blimey, that is good value!

Shame I didn't notice that when I just ordered this.....
http://www.merlincycles.co.uk/?fn=product&productId=1234&categoryId=12

supersonic

Ah well! You will have to get your frame faced (as the Deore HT2 uses external bottom bracket) - will cost you 10 - 15 quid at a shop.

tjm

you can do anything with a file

(not that I am suggesting everyone wrecks their frame trying to face their BB with a file!! )

humpy

Thanks for that link supersonic.

Do I need to measure my crankset or are these sizes - 22/32/44 rings, 175mm cranks - taken from the above link, the same as the existing crankset? If not, could you tell me where I need to measure? Does the numbers 22/32/44 stand for the number of teeth on the crank rings? Where is the 175mm measurement taken from? (i'm presuming it's the crank arm length)

Cheers

Neil

delcol

neil
the 22/32/44 is the number of teeth on each chain ring.

the 175 mm refares to the lenght of the crank arm...

tjm

delcol wrote:

the 175 mm refares to the lenght of the crank arm...

measured from the centre of the bottom bracket to the centre of the pedal axle in case it is not clear.

humpy

Cheers delcol and tjm.

I see there is no mention of BB size in this link - http://www.merlincycles.co.uk/?fn=product&productId=1332&categoryId=12 - so does the BB supplied with this chainset fit any frame?

tjm

I'm not 100% sure but I assume that chainset has an octalink BB. In that case I have never used one so I can't say....
But it would do not harm checking your BB shell (68mm?) and then asking Merlin. I've found that they are very helpful on the phone.

EDIT: I'm also assuming the BB axle length will give you the correct chainline as well but you might want to check that too.

humpy

Yeah, I will give Merlin a bell tomorrow with regards to BB sizes etc.