Bicycle Mechanics - Rear Derailleur Teeth and Innermost Cog Teeth Bumping

When I use the easiest gear combo there's this annoying clicking sound. I have three rings up front and seven in the back. It seems that the bottom little wheel on the arm of the rear derailleur is down too close to the innermost cog in the back, so that the teeth on the little wheel and the innermost cog anre bumping each other.

Any ideas how to fix this? There are also other shifting issues, like the front derailleur having a hard time going to the innermost gear, and the fifth cog in the back causes chain rubbing up front, so I don't know what problems are inter-connected, if they're connected at all. . .

Ugh, getting frustrated, should I just take it to an LBS? I've only had the bike for about five weeks,and took it for its free tune-up at Dick's Sporting Goods last Saturday - the shifting wierdness didn't start until the week after that! :mad:

Not a comprehensive answer, but here are a few comments:

By easiest gear, I assume you mean the smallest chain ring (the three rings up front) and the largest cog at the back. If they are touching, my first thought would be that the derailleur is not the right one for the rear cluster and the bike should have come with a derailleur capable of handling the cluster that is there.

Is this a brand new bike? Did you buy this from a bike shop? (Dick's Sporting Goods does not sound like a bike shop.) If so, they should make it right. NO part of the rear derailleur should rub on the cluster at any time.

Hard time shifting to small chain ring in front in front: Does this bike have indexed (click stops) for the front shift lever? In any event, there are two adjustment screws on the front derailleur. One limits the outward travel, one the inward travel. Sounds like the inward travel limit screw is maladjusted.

Fifth cog in back causes rubbing in front: By fifth cog, I assume you mean the largest cog. Unless the front derailleur is indexed, you can eliminate the rubbing by making a small adjustment with the front derailleur lever (as you ride) whenever this happens.

It kind of sound like Dick's Sporting Goods is just a store you bought the bike from and not a bike shop. They may be kind of clueless about how to set up a bike.

If you had bought this from a bike shop (LBS) they would make things right, adjusting things, replacing the rear derailleur if necessary. If Dick's will (and can) do this, have them. They sold you the bike. If not, take it to a LBS to fix -- and ask them to explain stuff to you, what was wrong and how to fix it yourself the next time. You may have to buy a different rear derailleur.

Bikes are easy to work on (much, much, MUCH easier than a car), but DO require some knowledge, skill, a few tools and the desire.

Cheers,

if the rear derailer cog is rubbing the 1st gear just screw in the the screw where the derailer is attached to the frame. push the RD a little forward to avoid stripping the screw out and then screw it in a few rotations until there is no rubbing.

the cogs rubbing has nothing to do with adjustments or limit screws. it's solely form that screw i told you to screw in.

If you have a single-spring derailleur, follow Beachbum's advice. If you have a double-spring derailleur, such as many Shimanos and Simplexes, increasing the upper spring's tension or adding another inch to the chain may help.

I forgot to mention that rear derailleur angle adjustment screw.

To John E: Nice to see someone else with a Peugeot UO-8. We finally replaced ours as our primary bikes a couple years ago. Our UO-8s are now only ridden on our rollers. Having a triple chainring and a 9-speed cassette with indexed shifting on our Trek 520s makes it too hard to go back to a simple 10-speed, vintage though it is. Ah, but there are so-o-o many happy miles on the Peugeots.

To John E: Nice to see someone else with a Peugeot UO-8.

I originally bought my current UO-8 as a bare frame ($24 dealer cost in the early 1970s), when I worked at Bikecology. I built it up for my wife, with UO-18-style upright bars, but recently converted it into my commuter and cyclocross machine. (The only cycling my traffic-averse wife now does is offroad, on my mountain bike.) With aluminum rims, aluminum cranks, SunTour barcons, and KoolStop brake pads, my UO-8 is one of the best low-end 10-speeds I have ever ridden. About 10 years ago, my wife and I both rode similar-vintage UO-8s, until I retired my other UO-8 with a cracked chainstay.

Ok, first let me say, "I am a butthead." Now that that's out of the way.

The reason the rear derailler was bumping the largest cog in the back was very simple. I don't have a bike stand, so I turn the bike upside down to work on it. When I did that gravity took over and pulled the rear derailler arm down too far, causing the rubbing! The strange rubbing doesn't happen when the bike is in its normal orientation.

The original reasons I turned it over in the first place seemed to have been for the most part corrected, I think. I loosened up the L limit screw so that the chain would drop down onto that smallest chainring up front. (I have friction shifting for the front derailler and indexed shifting for the back.) It still seems to hesitate more than it did before. The other shifts in the front are good, and in fact any shift to the middle chainring is smooth as silk. But it seems like I can't have any tension whatsoever on the chain if I want it to drop down into that smallest, most inward situated chainring. That's normal?