I have a problem with my mountain bike rear derailleur - it wont stay in gear in the second smallest cog on the rear cassette. It jumps about - both towards the smallest gear and towards the larges ones. It is a deore XT unit - the one prior to the current series.
Originally I thought it might be a problem with the shifter or the chain or the cassette or the cable. I have replaced all of those (was getting a new wheel, so upgraded from 8 speed to 9 and replaced shifter with deore 9 speed rapid fire and a new cable) - so the derailleur is the only part of the equation that is unchanged.
The same problem happened with the original 8 speed cassette, and now it happens with the 9 😕 Wierd thing is it shifts fine and stays in gear in all the other gears - so I just shift out of that one gear when i notice it jumping...
Any advice (beyond the obvious "replace the derailleur"😉 🙂
How about lubricating the pivot points of the derailleur. It may have some grit that finds its purpose in life is to interfere at that very point.
Quoted post said:
Originally posted by Gnarly I have a problem with my mountain bike rear derailleur - it wont stay in gear in the second smallest cog on the rear cassette.
Any advice (beyond the obvious "replace the derailleur"😉 🙂
You might want to double check the alignment of your derailleur hanger. A lot of times shfting problems occur when it gets bent, event slightly. Either take it to your LBS or use a Park DAG tool (well worth its price in the number of times it will fix shifting problems). Make sure your bike can handle the hangar adjustment (certain frame materials can't).
Thanks guys. Have lubed all the pivot points in the derailleur already, so will look at the hanger as suggested - it is a replaceable hanger so I cant stuff it up beyond salvation....
Originally posted by Gnarly Just wondering if anyone can give me advice.
I have a problem with my mountain bike rear derailleur - it wont stay in gear in the second smallest cog on the rear cassette. It jumps about - both towards the smallest gear and towards the larges ones. It is a deore XT unit - the one prior to the current series.
Originally I thought it might be a problem with the shifter or the chain or the cassette or the cable. I have replaced all of those (was getting a new wheel, so upgraded from 8 speed to 9 and replaced shifter with deore 9 speed rapid fire and a new cable) - so the derailleur is the only part of the equation that is unchanged.
The same problem happened with the original 8 speed cassette, and now it happens with the 9 😕 Wierd thing is it shifts fine and stays in gear in all the other gears - so I just shift out of that one gear when i notice it jumping...
Any advice (beyond the obvious "replace the derailleur"😉 🙂
Sounds like a derailer adjustment issue to me. Check your installation and adjustment sheet that came with the derailer and/or look through the article and great pictures on Sheldon Brown's web site at URL: http://sheldonbrown.com/derailer-adjustment.html Is the shifter, chain, and cassette all new and all 9 speed?
Also, check and make sure your top g pulley moves side to side freely, and that the bolt is tight. You may try adjusting your b-tension screw as well, if it is too far screwed in, as it is sometimes to clear a 30-34 top cog, it may put the chain in too little contact with the cassette in the lower range.
