Shifting problem

[OakLeaf]

If they did a big adjustment - i.e., had to re-position the cable in its clamp rather than just using the barrel adjusters - then the cable and housings will re-seat a bit just as they did when everything was brand new. So, probably normal.

You should learn to do this yourself. It's very simple. Most LBS will be happy to show you.

[Catrin]

If they did a big adjustment - i.e., had to re-position the cable in its clamp rather than just using the barrel adjusters - then the cable and housings will re-seat a bit just as they did when everything was brand new. So, probably normal.

You should learn to do this yourself. It's very simple. Most LBS will be happy to show you.

He appeared to do a fair amount to both front and back - he did more than adjust the barrel adjusters. He also adjusted the stops(?) on the FD to help prevent the chain from falling off.

[KnottedYet]

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?

Indexed brifters have pretty much one click or two half clicks and BOOM the front der is where it is gonna be. Some of the bar shifters have lots and lots of clicks, and your front der has several choices of where it can be. They act almost like friction shifters.

For sake of illustration, assume here I'm talking about a bar shifter with infinite clicks, or friction shifters:

Whaling the shifter to one extreme or the other pops the chain onto the big or small ring, and the derailleur cage (if the limiter screws are set just so) is pretty much out of the way of the chain as you merrily zip through the rear cassette. (assuming here you are not cross-chaining, which I know you know about)

The middle ring can get kind of exciting, because the cage can be centered on the ring, or more toward the big ring, or more toward the small ring. The chain can be merrily whipping through the cage in the middle ring and rub against the cage sides if it is too far one way or the other. If it is a bit too far one way or the other, the chain will rub as you shift the rear der and the line of the chain changes.

There is nothing wrong with the shifter or the der. This is just how it works. It has an arc of travel. At each end of the arc there is a ring ready and waiting. Somewhere in the middle of the arc is the middle ring. You get the chain onto the middle ring, and if you hear chain hitting der cage, you finesse the cage away from the running chain by moving the der a smidgen. (on my twist shifts, it was a couple tiny clicks, on my trigger shifts it was one click, on my friction shifts it is a smidgen) That trims the derailleur.

Here's your experiment for the day:
Take the bike out, ride around, shift into the middle ring. Get off the bike. Look at the chain, see where it sits relative to the two sides of the der cage. Now, move your left shifter a smidgen. See how the cage moves but the chain is still on the middle ring? Move that cage until the inside plate is touching the chain. Now move it until the outside plate is touching the chain. Now move it until it is centered. Get on the bike again. Ride a few yards. Does it make noise? Shift up and down the cassette. If it makes noise, move the left der a smidgen. If that causes MORE noise, move the left der the other way TWO smidgens. Voila! You've trimmed your front derailleur!

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.

[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!)