Shifting problem

[Catrin]

I'm trying to remember what kind of shifters you have on your flat bars, so I may be completely off here.

Has anyone explained "trimming" the derailleur to you?.....

Of course, if you can't move the front der a smidgen and eliminate the noise you get from changing rear cogs.... then what I've just told you is useless and your shop needs to give you a hand.

But maybe it would be useful for someone else.

I have trigger shifters - and someone has explained how to trim it - though it is only available to me if I have shifted up from the granny chain (per my LBS). I will try your experiment this afternoon. I tried to trim yesterday with the smidgen click on the shifter - but little seemed to help when I was in the middle chain. That does not mean that I was trimming it correctly...

[KnottedYet]

I have trigger shifters - and someone has explained how to trim it - though it is only available to me if I have shifted up from the granny chain (per my LBS). I will try your experiment this afternoon. I tried to trim yesterday with the smidgen click on the shifter - but little seemed to help when I was in the middle chain. That does not mean that I was trimming it correctly...

Seriously, get off the bike and watch the derailleur move. It's really cool, and it's the best way to see how it works. Watch how the chain line changes as you go through the cassette. Watch how the chain gets closer and farther from the der plates.

Seeing how it all moves and works together will help you diagnose things when they're goofy. Anything you see helps the mechanic, too.

And if you figure out why the chain is rubbing on the der cage so hard that it's making noise and trying to shift all by itself, you might be able to fix it on your own! (which is always VERY cool!)

[OakLeaf]

You'll need to be turning the crank and the wheel for it to shift. A workstand is really helpful here, but you can find something to hook the top tube or the nose of the saddle on, or have a friend hold the rear of the bike up off the ground for you (I know you've mentioned grip issues, so holding it yourself might not be feasible).

[KnottedYet]

Or you can do what I do: ride, shift, stop and look. ride, shift again, stop and look.

I've tried to hold the bike up and spin the pedals and shift and every dang time I've somehow managed to drop the bike on my own head. It's like magic.

Someday Santa will bring me a repair stand. (and a house, and a dedicated garage just for playing with bikes!)

[withm]

You may be able to use the rack on your car (depending on what rack system you have) to support the bike while you spin the pedals and shift.

Before I got a repair stand, I could set my bike rack up on my deck railing. Enabled me to do a few repairs this way, but the low height made it hard on my back to do anything too involved.

But since this problem only shows up in the middle ring, and she has said she's had the chain come off a few times, I'd check for a worn or bent sprocket on the middle ring. Sight down the middle ring while slowly turning the pedals and make sure that every tooth is aligned.

[Catrin]

The FD behaved better on my ride today - but there were not many hills today so I spent a good amount of time in the big chain. After dinner I will get my rack back on my car and get the bike up there and see what I can see.

Thanks for the advice on how to proceed and at least it will help me discuss it a bit more intelligently with my LBS if I need to later this week. They will be installing/adjusting my new saddle so it will be good timing.

I really hope it isn't a bent sprocket - that sounds expensive The fact remains that whatever the problem is - adjustment or something else - it seems focused on that middle ring. To the best of my memory THIS bike has not fallen over on that side...

Once I move in the fall, I am going to start saving for a work stand. I think it will make everything easier and help to keep that nice new apartment looking nice.

[KnottedYet]

I really hope it isn't a bent sprocket - that sounds expensive

Naw. $20-$25.