Rear derailleur adjustment not working
I bought a second hand electric mountain bike from a mate, knowing that it was a non runner after some kind of rear derailleur disaster. Sure enough, the derailleur hanger was sheared and the chain was wrapped around everything. After replacing the hanger, took ages to get the right one, everything is back together and working to a point. I lost 2 links of chain, but minor issues, so far.
My mate had told me that the rear gears had been playing up and jamming. Sure enough on the largest cog of the cassette, the rear derailleur is lying almost flat and actually meshes with the cog. You can get into 10th gear but you sure aren’t getting back out again.
I played with the b screw and things got a little better but there is still interference on 10th.
My thinking is either that the chain length is so critical that 2 links has caused this, or that the derailleur suffered some kind of misalignment at some point. As the gears were problematic prior to the final hanger failure, then who knows.
The bike is a Haibike Xduro rc, with Bosch motor and a 1 x 10 gear system and SLX rear derailleur. While I am on here, if I need a new chain, how do I work out the right one? There are just so many options.
My mate had told me that the rear gears had been playing up and jamming. Sure enough on the largest cog of the cassette, the rear derailleur is lying almost flat and actually meshes with the cog. You can get into 10th gear but you sure aren’t getting back out again.
I played with the b screw and things got a little better but there is still interference on 10th.
My thinking is either that the chain length is so critical that 2 links has caused this, or that the derailleur suffered some kind of misalignment at some point. As the gears were problematic prior to the final hanger failure, then who knows.
The bike is a Haibike Xduro rc, with Bosch motor and a 1 x 10 gear system and SLX rear derailleur. While I am on here, if I need a new chain, how do I work out the right one? There are just so many options.
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I've used this chain length calculator for several years and it has worked fine for me
http://www.machinehead-software.co.uk/bike/chain_length/chainlengthcalc.html
Just input the number of teeth on your front chainring and the largest sprocket size at the rear together with the chainstay length and you'll get the correct chain length in inches or links
You set the chain length to the bike, they are sold in fixed lengths (as they wouldn't sell a dozen different sizes of each for obvious reasons) and 116 is common, someone then shortened it, possibly too short, possibly to the exact right length.
Any ten speed chain will be fine (116 or longer) to budget, drop the rear shock pressure and find the suspension height with the longest chain stay effective length, then size it properly. Having posted in a roady section the advice above forgets that not all chainstays are fixed!
https://www.parktool.com/blog/repair-help/chain-length-sizing