I have a Giant bicycle that I bought back in '96. Don’t know alot about gear maintenance, my chain is rubbing against the derailer and if I adjust it out from the chain it’s hard to shift gears. My gear system is Shimano STX, anyone got advice or a good bike maintenance website that has gear adjustment info. I can go to?
There is very little to adjust for derailleurs. A couple of set screws to limit the travel in or out.
Does it have indexed shifting? Is it rubbing in your lowest gear or your highest gear? I’m assuming you mean front derailleur, is this correct?
I assume you mean the front derailluer? You might try www.shimano.com for the original setup/installation info. It sounds like your cables have stretched, so if you follow the instructions for setting it up as new, it may solve the problem. Or if you’ve done lots of miles, it may be time for a replacement.
Sometimes on the bikes with a whole lotta gears, having your chain going from the innermost on the back to outermost on the front (or vice-versa) causes some rubbing. I don’t know if there’s anything you can do about this, but unless you really need all 21 gears, just shift.
(and this is exactly why I hate indexed shifting)
Yes it’s rubbing the chain in the highest gear. I assume it’s the front derailer but I suppose if the back one is out of alignment w/ the front that will cause problems too :mad: .
Indexed shifting Boyo Jim ? Not sure what you are talking about, but my shifters are the twist type on the grips.
How bad is it rubbing? I have bent mine back with my fingers and it worked. Try it before you do anything really time/money consuming.
“Jingle bells” are almost as bad as “wild pigs”…
When in doubt consult Sheldon: http://sheldonbrown.com/derailer-adjustment.html
If you’re hearing chain rub, it’s almost certainly the front derailer, not the back. The only way the rear derailer can cause any rub is if the low stop isn’t set right and you can shift the cage into the shield over the spokes, which would make an entirely different sound. What’s probably happened is your chain has worn a bit, which allows it to flex from side to side more, meaning that the derailer has to push it further to get it to move from gear to gear.
Front derailers can be hard to set satisfactorily, since (especially with lower end stuff like STX) they often have to be set to move past being in line with the chainwheel in order to shift onto a larger chainring (down usually isn’t a problem), and then the chain will frequently rub. What I do is adjust the high stop so that it’s just possible to flip onto the largest chainring when one is in the 3rd largest cog in the back. You shouldn’t be using the biggest ring/biggest cog gears anyways, since the lateral deflection on the chain wears it badly, and trying to get into the big ring when the chain is coming from so far to the left just makes the adjusting problem worse. Your middle ring/middle cog combos will give you similar gear ratios, and are better for the drivetrain.
If you’re still getting chain rub on the derailer when you’re on the big chainring, the only other thing you can do is back the shifter off after the shift. I’m not sure how STX twist shifters for the front are set up - if they only have three stops, you can’t really do this. My twist shifter for the front has many shorter clicks, and you can twist all the way to get the chain to move, and then back off one click to move the derailer back into a spot where it won’t rub.
Hope that helps. This isn’t really that difficult, but it’s a lot easier to demonstrate than it is to describe.
Gorsnak, former bike messenger
If Sheldon doesn’t help, the chaps at Park can get you moving - and they’ve got pictures.
The easiest thing to do is just take it in for a service. But yeah sometimes it is very difficult to impossible to have it set up for smooth gear changes and not be rubbing slightly on the derailer.
Indexed shifting is when your shift levers have a kind of “snap to” position for each gear position. With indexed shifting, you gear lever makes an audible “click” as you move through each gear.
It can make keeping your gears adjusted more difficult. As your shifting cables stretch, your chain will will be derailled and moved when your lever is in a different position that when the cables were taught.
I’m probably not describing this very well, but indexed shifting needlessly complicates adjusting your derailluers.