I have an issue with my rear derailer on my MTB, it's a Shimano 6 speed, and it's always a gear in front. i.e. when I shift to 3rd gear, it jumps to the 4th sprocket, etc. When in 1st gear, it's on the 2nd sprocket, so if I adjust the chain and manually place it on the 1st large sprocket (i.e. 1st gear), and set off, it immediately jumps to the 2nd sprocket, giving me 2nd gear, then I'm back to being a gear in front. So, I'm missing a gear, as I have no 1st, and I'm always a gear too high. I haven't 'messed' with it much yet, thought I'd ask first, as it may be a simple adjustment which I can hopefully do perhaps. Thanks!
Rear Derailer - Is Always One Gear Too High
- Thread starter pbar
- Start date
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betty swollocks
large member
This sounds like a simple question of cable tension.
Manually place your chain on the second smallest sprocket (2nd one in) and select the matching gear on the shifter. Now cycle the bike (or put it in a stand and rotate the cranks) and see what he chain is trying to do. If the chain tries to skip onto a bigger sprocket or actually skips up, the cable is too tight and needs to be loosened. To do this wind the barrel adjuster in (clockwise). Do this a quarter of a turn at a time until the chain stays on the appropriate sprocket.
Next, click the shifter up one gear and see if the chain moves up accordingly. If it does, click up once more and observe whether he chain moves up accordingly again. Keep on repeating this until all clicks on the shifter match all the sprockets on the cassette.
Remember, if the chain shifts up too much, it's too tight and if the chain is too sluggish coming down, the cable is not tight enough and needs tightening by winding the barrel out - anticlockwise.
This process may involve a bit of trial and error before all gears change sweetly up and down.
The gears may behave slightly differently actually riding than on a workstand.
Good luck and hope this helps.
Helpful youtube video
Manually place your chain on the second smallest sprocket (2nd one in) and select the matching gear on the shifter. Now cycle the bike (or put it in a stand and rotate the cranks) and see what he chain is trying to do. If the chain tries to skip onto a bigger sprocket or actually skips up, the cable is too tight and needs to be loosened. To do this wind the barrel adjuster in (clockwise). Do this a quarter of a turn at a time until the chain stays on the appropriate sprocket.
Next, click the shifter up one gear and see if the chain moves up accordingly. If it does, click up once more and observe whether he chain moves up accordingly again. Keep on repeating this until all clicks on the shifter match all the sprockets on the cassette.
Remember, if the chain shifts up too much, it's too tight and if the chain is too sluggish coming down, the cable is not tight enough and needs tightening by winding the barrel out - anticlockwise.
This process may involve a bit of trial and error before all gears change sweetly up and down.
The gears may behave slightly differently actually riding than on a workstand.
Good luck and hope this helps.
Helpful youtube video
Thanks for your reply. I have done as you mentioned and it's been much better. I can now run through all the gears, one by one, it's the best it's been for ages. I had to turn the adjuster anti-clockwise, quite a way in fact, must have been 3 full turns or so before the gears started to change up/down properly. I only had a little run out tonight as a test, but very pleased. It took me about twenty thousand hours though, another turn, another turn, etc. I also cleaned some crud and dog hair (don't ask) out of there and I think I'll have partially black finger skin for several years. Oh, and the added bonus of a super strength left bicep, with holding the rear end of the bike up by the saddle for what seemed like hours on end whilst I changed gears and spun the pedals with my other hand to check the adjustments. I'm lovin it! Thanks again.
John Ponting
Guru
- Location
- Herts
pbar said:
Reaqdy for next time - have you got a shed with a wooden beam or plank in the roof? Screw a hook or eye in to the beam, hook in a lop of washing line and hang the bike from the saddle. If you have enough space, use 2 screw in hooks and hang the bike from the handlebars as well as the saddle.
betty swollocks
large member
pbar said:
You're very welcome: glad you got it sorted.
Before I got a workstand, I used to hook the saddle over a broom handle resting across the backs of two chairs!
summerdays
Cycling in the sun
- Location
- Bristol
Mechanic's wipes are good too
