Had the front derailleur adjusted, now it feels like the rear is skipping

Question

Here is the short version. I'm all for adding more once I know what that more is to help answer said question.

I work on the road. I take my Felt ZW75 (http://www.feltbicycles.com/USA/2013/Road/ZW-Series/ZW75.aspx) with me. It rides inside my work van to be nice to it as well as having in my possession after lunch. I had a full tune up done. Then, the front derailleur required two clicks to change gears. I took it to another bike shop and had that adjusted. All happy.

NOW, when I'm riding, and not necessarily under pressure, it feels as though the chain is skipping OR I'm changing gears and changing right back (on the rear cassette). It will do this 4 or 5 times in a row, then quit for a while. All under the same speed and pressure. It seems to not do it in some combinations, but that could be my imagination. It will act the same way on the trainer indoors as well.

I've really only ended up riding it once since the tune up, and three times (once indoors) since the weird skipping. So she is still nice and clean and oiled. In theory.

I am fully capable of taking it to yet another shop. However, I received a copy of the Barnett Manuel and a set of Park tools in a nice little toolbox for Xmas. I'd like to start learning to fix the thing myself on the road, since the whole take it back to the shop isn't exactly an option. The best answer I have found in the Barnett is either the chain, a cog, or the pawls (?!) are worn or dirty. But she really only has ~200 miles on her.

Thanks for the help.

Jennifer

Answer 1

It's hard to tell, but what you are describing does not have to mean that anything is broken. The most likely cause would be improper adjustment of the rear derailleur. It may seem outrageous after two tune ups from two different shops, but you have little to lose in at least trying. Oh, and you will not need your box of tools for this, sorry!

Watch this video. Pay attention to the last part, the barrel tension adjustment, which I think may be what's bugging you. Although the website you linked says your bike is equipped with SRAM, Shimano has a detailed procedure to adjust that tension, which you may want to follow: as far as I know all brands work more or less the same. The document I have linked is for a random rear derailleur, but the SIS adjutment part, which is the only one you should worry about, is the same for all.

If you can't get it to work, then I would recommend getting it to a bike shop. I would think that any of the two you have already been to should at least take a look at it without charging you anything.

Answer 2

From what you mentioned in the comments it sounds like either the mechanic decided to adjust your rear derailleur for you as well and overtightened it, or it's just as possibile that while the bike was riding in your van the derailleur bumped up against something and your derailleur hanger has become a little bent.

If when shifting the derailleur consistently over shifts two gears down through the whole cassette then it's almost certainly the cable being too tight- or too short if you want to get technical. If it shifts fine at one end of the cassette and progressively shifts worse to the other end, then you probably have a bent derailleur hanger.

If it's just an overtightened cable then a couple of clicks clockwise of the barrel adjuster on the derailleur should get it taken care of. If it's the derailleur hanger you're going to need to take it to a bike shop to have them bend it back. Not hard or expensive to fix, it just requires a special tool to gauge the alignment of the hanger.