I'm having a problem with shifting that I simply cannot resolve.   The symptom is a double shift problem.  IE. one click, it won't shift, click again, it'll shift twice.  Using the trim adjustment only changes the problem from happening on the way "up" to on the way "down."  Happens most often on the smaller cogs.  And even when it DOES shift, it's not very smooth... chain sometimes rides up on top of the cog before moving over, etc.

I've been living with it for some time now (couple months) and at this point I have swapped just about everything on the drive train that is related to rear shifting.  Derailleur broke so that got swapped, swapped to my older cassette, swapped the Der hanger, rear shifter broke so that got replaced, new cables/housings.... and yet the problem persists.  The only thing I haven't replaced with brand new is the chain.  But, the chain is not that old, I swapped it in May of this year, and I have serious doubts as to that being the problem.

This problem may have coincided with a rather big crash at RRT... and my bike is by no means new or babied... I've maintained it well but it does have it's fair share of crashes on it... and I'd say I ride pretty hard overall.  So, I'm actually beginning to think that maybe the frame is bent or out of alignment somehow?  {shrug} I'm really just spitballing at this point as to what this could be as I'm out of ideas.  Anybody out there have any suggestions or ideas?  Help!  This is driving me nuts!!! 

traildog wrote on 08/16/14 at 12:28pm:


When I first started having the problem, der hanger was my very first thought.  However, I replaced it with a new one and it did not solve the problem.  I also swapped to my older cassette, torqued to spec... no luck. 

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New bike solves the whole issue. 

You mentioned a new chain, perhaps a 10 speed when you need a 9 speed or an 11 speed where you need a 10 speed. I could see how a slightly too narrow chain could cause an issue like that but I'm really just throwing it out there. Did it work we'll before the new chain?

Just had a bike in the shop with similar shifting woes and found that the axle was cracked and shifting under pressure.

Ran into the same problem a few years ago, after many new parts due to a crash the shifting was never quite right. The shifting to the large gears was ok but not crisp, going up the gears could be adjusted fine but down suffered, adjusted for down and up suffered. The problem was due to the cable routing and the bends having too tight a radius. I made the loop to the rear derailleur a bit larger and the problem was solved. One more thing when cutting cable housing is to make sure the opening is round and allows the cable to move freely and use the cable caps.

Whoa, I'm a bit behind on the replies.  Thanks everyone.  The one thing mentioned in here that I haven't looked at was the axle.  I'll inspect it.   

I certainly like RobP's idea the best so far The funny thing is, I've already begun planting the seed for a new bike for next season with the wife.  As usual, she just shakes her head and says "whatever."  That's a "go ahead" in my book.

Still experiencing the problems btw.  I haven't really tried anything more than what is mentioned in my original post.  Lately, I've been just going 2 gears each time I want to shift, which 75% of the time results in one cog change.  I just go two, and when it shifts one, I click back one... all of which results in a really ridiculous habit that I am forming, lol.

One thing occurred to me as I read the post about chains.  I remember when I swapped out the chain, the length didn't align exactly to a link when I put it side-by-side with the old chain.  I can't remember if I went a half link shorter or longer but I wouldn't think that could be causing it.  Besides, it shifted fine for a while (2 months of riding 5X a week) before the problems started to occur.  I think that's what makes this the most mysterious - it was fine with the exact gear for a while and this problem just started happening seemingly out of no where.

I'll be taking a look at it again later today (will check the axle and inspect hub) and will post up if I find anything.

ludey wrote on 09/02/14 at 12:51pm:


There many more knowledgeable people on this forum than me, but my understanding is that when you measure a new chain against an old one they're not going to perfectly correspond because of the "stretch" in the old one. When measuring, every 8 or 10 inches or so you need to re-align the links to end up with the same number of links, rather than try to have the same length. But I don't know if that will have any impact on your problem.

RobP wrote on 09/02/14 at 4:51pm:


Yeah, I typically go with a new cassette every 2 chains.  In this case, I replaced them new at the same time.  All was good for a while.  It was only when I started having problems that I swapped back to my older cassette just to see if that fixed the problems.  When it didn't, I put the newer one back on.

So, can you explain a little bit more on the metal type of my front chain rings?  How can that effect the shifting on the rear derailleur?