Forum menu
I need gears sorted out for 47k mountain bike ride tomorrow morning.
At the moment they won't shift, stuck in the biggest cog and its making a grinding noise.
I think the B Tension Screw is causing the jockey wheel to get too close to the cassette.
I notice that it appears that the B Tension Screw has nothing on the back of it to wind into!
I'm sure I've got the cable tension wrong as well but I think I need to get that B Tension Screw in the right position first before attempting that.
I've taken some photos I was wondering if anyone else could have a look and see what is wrong:
[img] https://www.flickr.com/photos/96480480@N05/33055211914/in/dateposted-public/ [/img]
[img] https://photos.google.com/photo/AF1QipOIiEI7c7rQwLZCkuWelJTmiVXyEO8YC6QrezUn
[/img]
[img] https://www.flickr.com/photos/96480480@N05/33055212034/in/dateposted-public/ [/img]
Good the mech be bent, ie if it worked before and doesn't now?
And if you need 'more' b-screw either put a longer one in or if you've not the correct one then turn it around and put it in from the back.
It has gradually got worse. Then it started to cause me a lot of problems. Then I tried to fix it by adjusting the B Tension screw and Barrel Adjusters, only to make it a lot worse.
https://m.pinkbike.com/news/tech-tuesday-sram-rear-derailleur-adjustments-2010.html
Try this video guide - always works for me. Disconnect the cable and start from scratch. Maybe start with the b screw about halfway about.
Are you running a huge cassette or just an 11-36? If it's an 11-40 / 11- 42 and a 10 speed mech then the b screw will probably need to be all the way in (I've got a 10 speed Sunrace 11-42 and the b screw on my sram GX 10 speed mech is wound all the way in.
Yes, it's a huge cassette. 11-42 converted by a mechanic to 1x10.
In which case follow that video - disconnect the cable and get the max / min limit screws set so you can get all the gears moving the mech with your hand.
Then connect the mech cable with it quite tight - make sure before you do that you wind the barrel adjuster on the shifter most of the way in.
Think you need to get the top jockey wheel as close to 6mm away from all the cogs as you can - this is what the b screw adjuster is for. Sounds like it might be hitting the gears so jamming against the one gear.
Fine tune the shifting with the barrel adjuster.
Just a thought - 1x10 is quite sensitive to chain length too - not that I'm an expert. I found different advice - anything from wrap the chain round the biggest cog without going through the mech then add two extra links - or another guide suggested adding 4 links. I did 4 links and seems ok.
Can't see from your pics, but if it's a Sram mech and the B-tension screw has nothing to press on, you've either broken something, or not fitted it correctly and allowed the collar with the lug that presses on the mech hangers lug to rotate so it's not actually doing anything.
I'm going with coatesy's answer above - zooming in on pic 2 looks like the end of the b screw is pointing into thin air. Either collar is not in correct position or b screw bent, it's not pushing against anything just now
I can only see 2 pics, one of which is the limit screws - are you sure it's the B screw you've been adjusting ?
My bet is that your mechanic has put in an extra-long screw that has slipped over the lug on the dropout
Is it the 'mechanic' from your other thread?