Please help me fix my commencal gears
m_cozzy
Posts: 132
I have had this bike from new from a large internet bike company for about 5 months now & barely used it as the gears are so bad. I had never been able to adjust them so they shift up and down smoothly without jumping & skipping. I could get them to work changing up, but that would stuff them for changing down & vice versa.
The other day I discovered that the b screw, I think its called, had been wound right in to possibly take all the slack out of the chain. Adjusting this to give a 6mm gap I read about made them much better, but it now seems the chain is too long?
This is what it looks like now on the smallest gears, with the derailer wrapping round itself & the chain hanging slack.
This is what it looks like on the largest 2 gears, looks like I could take quite a few links out?
Never had sram stuff before and not too impressed as my shimano equipped bikes are all faultless, but perhaps I have been unfairly blaming them if I have a Friday afternoon special & some fool fitted the wrong chain to my bike in the factory?
The other day I discovered that the b screw, I think its called, had been wound right in to possibly take all the slack out of the chain. Adjusting this to give a 6mm gap I read about made them much better, but it now seems the chain is too long?
This is what it looks like now on the smallest gears, with the derailer wrapping round itself & the chain hanging slack.
This is what it looks like on the largest 2 gears, looks like I could take quite a few links out?
Never had sram stuff before and not too impressed as my shimano equipped bikes are all faultless, but perhaps I have been unfairly blaming them if I have a Friday afternoon special & some fool fitted the wrong chain to my bike in the factory?
Banned from singletrack forum again :-)
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Comments
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First of all get your chain size right - Largest casette sprocket to largest chainring sprocket + 2 links.
You do this without running the chain through either mechs. If you have a chain device DO run the chain through that however.
Then watch this video https://www.youtube.com/watch?v=UH43OCmArUw
Watch it carefully, and follow each step.0 -
It looks about right.
Not sure of the arc on that frame, but with some sag there might be no slack. I'd run less b tension gap than that.
Check your cables are clean and routed properly.0 -
Youve had a bike with bad gears for 5 months and not sorted it out?! About time! If it's a 3x system (I can't see) then that medium cage mech won't be able to cope with large large or small small ring combinations, so your going to have to compromise with a short chain - cant do large large, or a long chain- cant do small small0
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Chunkers1980 wrote:It looks about right.
Not sure of the arc on that frame, but with some sag there might be no slack. I'd run less b tension gap than that.
Check your cables are clean and routed properly.
Not sure there is one, tit pivots at the BB so the length doesnt differ??0 -
Good call regarding sag, I hadn't considered that. Its an x2 at the front.Banned from singletrack forum again :-)0
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http://m.pinkbike.com/news/tech-tuesday ... -2010.html
I found this by far the clearest guide , I run similar set up to you on a hardtail.0 -
Just an update to the thread, following the guides the chain was too long, I took 2 links out, could have done 3 but played it safe. Shifting is now great :-)
Lesson learnt, just because its new doesn't mean its been build correctly.Banned from singletrack forum again :-)0
