Bike Issues

[Skunks]

A while ago, my bike developed the symptoms of what I now know to be a 'stiff link'. I suffered for a while before embarking on a multi-week make-my-bike-not-suck project, which has included realigning the derailleurs and putting in new rear brake pads.

Unfortuantely, in all of this I've just made it all slightly less annoying. Or, at the very least, annoying in different ways.

The <a href="http://skunko.damnsw.net/bike-rear.jpg">rear derailleur</a> squeaks when pedaling. It's a fairly shrill metal-on-metal type thing. I'm pretty sure it's the chain rubbing on the metal surrounding the <a href="http://skunko.damnsw.net/bike-close.jpg">upper of the pully-thingies</a> [<a href="http://skunko.damnsw.net/bike-close2.jpg">bike-close2.jpg</a>, <a href="http://skunko.damnsw.net/bike-close3.jpg">bike-close3.jpg</a>]. The red arrows were an attempt to point out what I think is causing the squeaking.

I've fiddled with all the available adjustments, and managed to get it to make less noise, but not none. So, my question is this: what, short of removing metal or randomly bending things into a less-noisy shape, can I do to remedy this?

[slang]

I don't want to sound like a wise ass here, but bikes are so cheap you could get another for about $100 if the noise bothers you that much. Or you could just buy a good set of rear sprockets and derailers. It sounds like the ones you have are (pardon me for assuming) kinda low end/ low quality.

Look at it this way, if you put the cash into some better parts, you can enjoy the bike until *another* component fails.

[wolf]

I dunno. I don't know a damn thing about bikes, but I thought I saw a Shimano logo on some of those components, so he might be starting with some reasonably good quality equipment.

Why not bite the bullet and actually take it into a bike shop to get it looked at? They can tell you whether it's worth putting the money and effort into. Could be an easy fix.

It's probably an obvious question, but... are you keeping the chain well greased?

I used to do a lot of mountain biking on a Trek 930 and a Schwinn something-or-other and almost every time something with the chain was up, grease fixed it.

[Griff]

Okay, no grease. Its too gummy, you'll end up collecting a lot of crud on your chain and you'll muck up your shifting. There are a lot of bike specific lubes out there. My father-in-law is a shockingly cheap er thrifty roady who experimented with a bunch of industrial lubes from work and found one cheap teflon based lubricant that worked well for his purposes. However, if you are mountain biking you should stick with lubes that tend toward dryness.

The first thing to do is to take a look at your derailler hanger see if it isn't bent out of alignment. Looking at 3 it appears that your derailler is not in line. Check the cage and see if its bent.

Is your upper pulley/chain touching the cassette? You may have a little chain stretch. If it is touching you can adjust your chain tension, either with the screw adjust on the rear of the derailler or by removing a couple links.

Also check your pulleys, if they are damaged you can pick up an after market set.

later on Griff

[Uryoces]

remove the cog, and gently bend the part away from the chain. You'll want to make sure you don't alter the geometry, so it will require some two-plier action: clamp at the center and bend it away.

My $0.02 worth

[Skunks]

Originally posted by Griff
However, if you are mountain biking you should stick with lubes that tend toward dryness.

I tend to use it to get to school, which involves a fair deal of steep hills and such. There's little actual dirt involved. Brief googling was unable to turn up one of those cool height-map-thingies, but this city (Astoria, Oregon) has very little flat ground.

The first thing to do is to take a look at your derailler hanger see if it isn't bent out of alignment. Looking at 3 it appears that your derailler is not in line. Check the cage and see if its bent.

I'd considered that; in the years I've had this bike, it's fallen over onto that side dozens of times. The <a href="http://www.parktool.com/repair_help/DAG.shtml">bit of information</a> I initially found on de-bending the doohickies was fairly discouraging, centering around some alignment tool.

How would I know if it's bent?

Is your upper pulley/chain touching the cassette? You may have a little chain stretch. If it is touching you can adjust your chain tension, either with the screw adjust on the rear of the derailler or by removing a couple links.

What's the cassette?

Also check your pulleys, if they are damaged you can pick up an after market set.

Anything that'd be particularly indictive of damage?

Thanks for the ideas, everybody.

[Griff]

see what i did was write a long informative humorous reply. i then clicked your park link to see what they had to say and dumped it all. i'll lay it out for ya in the morning. *grumble grumble*

[Griff]

Screw it. Lets just do it now.

My wife reminded me that I spent a couple weeks last summer trying to isolate a squeak on her bike. It turned out to be these very cheap pedals she was using. When you're riding its sometimes hard to tell where the noise is coming from. Her squeak being in the pedal didn't exist when the bike was being cranked on the stand.

The derailler hanger should be pretty much perpendicular to the ground when the bike is upright. If you've got the stomach for it I can lay out how you straighten a hanger the Griff way. Take the derailler off using an allen head wrench. Now the fancy tool part you are going to need... drum roll... an adjustable wrench. Close the wrench on the hanger with its handle pointed in the direction the hanger is bent. Pull or push gently but firmly until it is back in its original position. You can ruin your frame doing this. I wouldn't try it with anything but a steel frame. Your fancier materials can be a problem. You can crack a steel frame doing this as well so here's the deal- If it goes badly I'll have UT delete my response and act as if we never had this conversation.

The simplest fix I'm familiar with involves a little language skill called the mechanics code. Scout out your local bike shop. Find out which night the greasiest young guy/gal in the place closes instead of the owner/manager. Place a cold six pack of home or micro-brew beer in a paper sack. Place the sack on the work bench being careful that the gentle ting of glass is audible. Ask if he has two minutes to look at your bike. From here you have to be able to read folks but generally if you hand him an open bottle he will a) turn out to be juju's Moses in which case you're screwed b) he'll drink while talking you through the fix or c) chase you out and steal your beer.

Cassettes and cogs are the open clusters of gears on your rear wheel.

Pulleys are the little wheels in your rear derailler. If they don't roll smoothly there is a problem like wear around the pin. They usually come right off with an allen head as well.

My preference is to do all my work myself. Bikes are simple machines once you get to know them. It might be wise to let a pro peak at it though if you think you're gonna break something.

[Skunks]

Originally posted by Griff
Screw it. Lets just do it now.

My wife reminded me that I spent a couple weeks last summer trying to isolate a squeak on her bike. It turned out to be these very cheap pedals she was using. When you're riding its sometimes hard to tell where the noise is coming from. Her squeak being in the pedal didn't exist when the bike was being cranked on the stand.

Yeh, there're lots of other noises, too, when I'm actually riding. I'm _pretty_ sure I know the cause of this particular squeak, though, because of the weird angle it's at and how little clearance there is.

The derailler hanger should be pretty much perpendicular to the ground when the bike is upright. If you've got the stomach for it I can lay out how you straighten a hanger the Griff way. Take the derailler off using an allen head wrench. Now the fancy tool part you are going to need... drum roll... an adjustable wrench. Close the wrench on the hanger with its handle pointed in the direction the hanger is bent. Pull or push gently but firmly until it is back in its original position. You can ruin your frame doing this. I wouldn't try it with anything but a steel frame. Your fancier materials can be a problem. You can crack a steel frame doing this as well so here's the deal- If it goes badly I'll have UT delete my response and act as if we never had this conversation.

I'm a little confused by your directions, but I'll take a look and see if I can figure it out.

The simplest fix I'm familiar with involves a little language skill called the mechanics code. Scout out your local bike shop. Find out which night the greasiest young guy/gal in the place closes instead of the owner/manager. Place a cold six pack of home or micro-brew beer in a paper sack. Place the sack on the work bench being careful that the gentle ting of glass is audible. Ask if he has two minutes to look at your bike. From here you have to be able to read folks but generally if you hand him an open bottle he will a) turn out to be juju's Moses in which case you're screwed b) he'll drink while talking you through the fix or c) chase you out and steal your beer.

...And then what?

Amusing though it may be to try, I think I'll wait until I can legally acquire a six-pack of $foo_beer.

My preference is to do all my work myself. Bikes are simple machines once you get to know them. It might be wise to let a pro peak at it though if you think you're gonna break something.

I'm not very worried about breaking it. The bike's pretty old; I've had it upwards of five years now, and I've been fairly actively growing the entire time. A bigger/better/faster bike wouldn't hurt. I'd spring for one now, but it's not really necessary yet. My motivation for wanting to fix it on my own stems from the fact that it's an option (no stress if I fuck something up) and general stinginess on my part (no income == little motivation to spend money).

'Sides, it'd be kinda fun to know how to do this sort of stuff with some degree of competency.

[Griff]

...And then what?

The best outcome would be to befriend a mechanic, who'll show you what you need to do. Some shops let you rent bench time so you can use their tools and ask them questions. Picking up a good bike maintenace book would be a good idea. Some of the better books are available on cd rom. I haven't looked at the cds but I understand they do a nice job of walking you through fixes.

One thing I didn't mention last night is a replaceable hanger. A pretty good percentage of aluminum frames have hangers that bend or break easier than the frame. If you have a hanger which is removeable you can go to the shop where you bought the bike and get a replacement.

[Skunks]

I was fiddling around with the derailler, having removed it from the frame and trying to get it back on. After removing the chain from the front derailler to give myself a little more room to move it around, I got it positioned so it'd screw back in. After a few turns, though, I couldn't screw it in further. I've been unable to get it fully screwed back in; I think I've got the angle wrong, or something.

However, in playing around with it as it is, it seems to shift better. The alignment of the upper pully seems better, and the chain <a href="http://skunko.damnsw.net/bike-close4.jpg">isn't touching the support metal for it</a>.

However, the derailler's hardly screwed in; it has a good cm of <a href="http://skunko.damnsw.net/bike-gap.jpg">open threaded-metal</a> visable from above. I haven't tried putting much force on the allen wrench, for fear of munging the threads (if I haven't already), and I don't really think it's rational to just leave it as is.

So, is there some trick to screwing it back in? And where should I be looking for bentness?

For the record, wolf, the whole drivetrain looks to be Shimano. It's a Trek 830, with Shimano logos on both the derailler and the pedals.

[Griff]

Originally posted by Skunks
After a few turns, though, I couldn't screw it in further. I've been unable to get it fully screwed back in; I think I've got the angle wrong, or something.

Yah, it sounds like you're cross threaded. You'll want to back it out and clean the threads both on the derailler bolt and in the frame. If possible, I always start turning a bolt without a wrench but I don't think you can do that with this bolt because you can't reach the head. Be very careful never to force it, you could strip the threads. Try to wiggle the head of the bolt a little to try to catch the thread properly. If you can't get it you may be going to the shop to get someone to run a tap through the frame threads to clean them up. Since you're headed for the shop anyway...

If it is shifting better with the derailler one cm out, the hanger may be bent toward the frame. From the photo, though, it does not appear that the hanger is bent significantly. Could your derailler cage be bent? The pulleys should be on a straight line perpendicular to the floor when the bike is upright. You should also look for cracks in the derailler body and make sure the bolt isn't bent (unlikely).

Before we got this far I should have asked if you if it was shifting smoothly and if you had adjusted the cable tension using the knob on the back of the derailler or on your right shifter.

Was the squeaking constant or just in particular gears? If its only in the low (large) gear your stop could be maladjusted.

[Skunks]

It was shifting fairly smoothly. Squeaked more in the largest gear. It started squeaking more after I fiddled with the H/L screws and indexing, but was pretty bad before. It may have started after a prior attempt, though.

I'll take a q-tip/toothpick to the threads when I'm less-sleepy.

[Skunks]

Hah! I was screwing in at the slightly wrong angle. Got it, though! And without sleep, even!

The lower pulley is significantly outward from the top one, viewed from above. The rubbing is back, but it doesn't (currently) squeak.

If it's likely to be a shifting-cable-tension thing, I'll hold off until I can replace the cable; it's getting kinda ragged at the end, and one strand is out of place (making a kinda neat pattern, but it's probably a trivial/inexpensive thing to replace, so why not?)