# Bike shifts fine in repair stand then won't shift into certain gear while riding



## MHCBH (Jan 9, 2009)

I recently had a a tune-up and new chain installed by my local shop. Since then, my bike won't shift into a specific gear while I'm riding (basically when I'm climbing in my small ring up front and largest cog in the rear, when I up-shift one gear it won't shift so I have to shift twice to get the chain to move up). I took the bike back to the shop and thought we had the problem fixed but alas, when I took it out riding again, same problem. I looked at things more closely at home and noticed that the bike "seems" to shift fine through all gears when it's on the work-stand but once again won't hit that specific gear when riding. BTW I have SRAM GX shifters and an X9 RD. Any suggestions on trouble-shooting since my shop isn't very close to my house. Thanks in advance for any advice!


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## Le Duke (Mar 23, 2009)

Then adjust cable tension and screws so it shifts properly under load. This is pretty common. Probably just need more cable tension coming out of the shifter. 

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## J.B. Weld (Aug 13, 2012)

IME 9 times out of 10 that problem can be cured by installing a new cable & housing, even if the old one looks OK.


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## Cleared2land (Aug 31, 2012)

I agree with both above suggestions, however, the LBS should have ensured correct shifting prior to returning the bike back to you. Assuming this wasn't a problem prior to dropping your ride off with the LBS.


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## Scott In MD (Sep 28, 2008)

Bent derailleur hanger. Take it to good LBS and they can straighten with a tool that you don't have. 


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## Cleared2land (Aug 31, 2012)

My thought is that if it was a bent hanger, it would have been experiencing shifting problems prior to taking it in for a tune up. At least it's my assumption that it wasn't having issues prior to the tune up based on his post.


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## ewarnerusa (Jun 8, 2004)

New chain but old cassette? Cassette may be too worn to mesh properly with the new chain and it is hanging up on the cog when you try to shift out of it. Especially in only certain cogs which are likely your "favorite" cogs, or at least the ones you ride in the most often and have therefore worn them the most. A shop would probably at least suggest this as a culprit though because it means they get to sell you a new cassette along with the new chain. 

Normally if the derailleur is having trouble shifting the chain from smaller cogs to larger ones, you need to increase cable tension by backing out the barrel adjuster a few quarter turns. If it is having trouble moving the chain from larger cogs to smaller ones, then that might imply there is too much tension and you need to relieve some by turning in the barrel adjuster a few quarter turns. But it is far more common for cable tension to decrease over time rather than increase, so I don't think it sounds like the culprit here. Then again, it is free and easy to try so this first. 

Bent hanger is also a good guess at the culprit. Also cheaper than buying a new cassette.


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## bing! (Jul 8, 2010)

When I fixed shifting issues, its a process of elimination. 

Check cable.
Check cable routing.
Check limit points.
Check shifter for damage and lubrication.
Check chain for stretch.
Check chain length for suspension bikes. Did they cut it too short for travel?
Check derailluer for damage.
Check hanger alignment and bolt.

Thatll usually do it. Hard to say without inspection.


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