Trying to adjust derailleur... Im new to this
 

I searched my problem , skipping chain under load, and decided all I needed to do is adjust the derailleur. I can get it perfect in only one gear then when I take it to a different one the problem still exists.

If the cogs are worn how do I know? how far are they supposed to be from each other?

Any help is greatly appreciated.

-Webb

How old is the bike? How many miles has it been ridden? How often do you lube the chain?

Assuming unworn and decently clean parts.... Most shifting problems are due to stretched cables. Shift into the highest (smallest) cog in the back and check the cable tension. It should be snug but not tight. Shift slowly through the gears. The chain should jump positively to each cog going up or down, and shouldn't make any noise once it's seated. If it's "hunting" to the next lowest gear, then your cable is too tight.
If it tends to fall down on to the next highest gear...It's too loose.

Another common condition is a slightly-bent hanger for the derailleur. Some of these are made of very soft aluminum, and must be checked frequently.

More information needed.
Have long have you had this bike and have you made any recent changes?
New chain? If so, did you measure the old chain for stretch?
Are the shifters, rear derailleur, and cassette or freewheel fully compatible?

well the story is, its a 92 trek 1100 suntour edge components. Im unsure of the mileage but its got some miles on it. Ive only had it for about a week and only had one good ride... that was all uphill. It didnt start the skipping until I was about 50 feet from the top.

I'm not familiar with those particular components. Just guessing here, but do you have a 7 speed freewheel in the back with down tube shifters? Or it could be a cassette instead of a freewheel check at www.sheldonbrown.com for the difference if you don't know.
Is the shifter for the back indexed, a click-stop for each cog (gear)?
It's possible that the chain and cogs are worn out and need to be replaced. Fortunately those are not really expensive.
Try measuring the chain for stretch. A foot of chain should measure 12 inches over a 24 pin interval. Use a good steel ruler and measure any 24 pin interval.
You may need to take it to a bike shop for help.

thanks al, It looks like I have a freewheel :(

Looks just like this one only it doesnt say shimano, *edit: upon second measurment it seems I have 25 pins over a 12 inch interval... what does that mean?

http://www.sheldonbrown.com/free-k7/...wl-shimano.jpg

Alright, I did some uber careful measuring of the rear gears. Some look rather old but nothing too bad the first gear and fourth gear are both warped, only a bit though. so now the question is how do I replace this? I cant find any place that carries new freewheels so change to cassette? Theres the other problem, the trek 1100 and other aluminum frames of the year had a rear wheel spacing of 126mm.

any help is really appreciated guys.

New freewheels are available; Nashbar usually carries several with different cogsets. You will likely need to go to a shop to have the old one removed; they all seem to require different tools and can be a bear to remove. Last time I had it done they only charged me 5 bucks.

However...Highly unusual for these rear cogs to become bent or warped; they are very durable. By design, some teeth are angled slightly to facilitate shifting. Are you sure this isn't what you're seeing?
Another thing...A common problem with freewheel rear ends is bent axles. The axle bearings are much farther inboard as compared to a modern freehub, and often smaller in diameter as well. Might as well check that while you're at it.

When you put the new freewheel on, be sure to coat the hub threads with a layer of grease to prevent seizing later on.
Best to put the tool in a vise lay wheel flat on it pushing down and slowly unwind. You don't want the wheel hopping off of the tool.
Probably best to let a bike shop do this.

New freewheel needs new chain.

Shift the gears before the load is applied.

Bikewer, I did notice it was only one tooth on each cog. Whats happening though is the chain is hanging on one tooth on each cog causing the chain to either try and change gear or just skip, I measured the chain and in 12 inches there was 25 pins exactly maesuring from pin to pin.

That's not possible. Your chain should be 1/2 inch from pin to pin. Take another look.

it must be the way im counting the pins because the links are 1/2 inch apart. I guess I just need to go to a bike shop and get em to help me in person.

24 x .5" = 12"

Very carefully line up a pin with the first inch mark on your ruler. See if the pin at the 12 inch park is slightly beyond the 12 inch mark. If so how much?

This is because either the first pin or the last pin is not a part of the 12 inch interval. It may make sense for you to measure from the left edge of the first pin at the zero inch mark on your ruler to the left edge of the pin that should be at 12 inches. That last pin is actually within the next 12 inch interval.
This reminds me of the old problem of why January 1 of the year 2000 was actually not the biginning of the 21st century.

Ha, I think I have it now. And sadly it looks like the chain is perfect.

Now bear with me here, as I sit turning the pedals while looking very closely at the cogs it hangs on only one tooth. This is on the first (largest) gear. It appears the tooth is leaning or rather twisted towards the spokes. Bikewer was saying that one tooth would be leaned to aid in shifting but wouldnt it lean the other way if that were the case?

Keep in mind that when you measure across the 12 inches of chain that you're looking for a difference of a 1/32 or less as being within the OK region and a gap of much over 1/32 inch as being not OK.

Yeah, Im using a steel ruler with 64ths on it, if anything its a gnats hair over which I guess would be normal.

I think I would take a good look at that tooth and try to decide if it's been bent or if it was meant to be that way. If you are sure the the chain is hanging up on it then why not use some pliers and bend it back to where you think it should be. I don't see that you have anything to lose by trying it.

Why don't you take a picture of the offending tooth? It could be that one got bent.

That article is pretty good - bringing me back up to speed with some changes since I left - at that time you simply replaced the chain when you got a new freewheel and did not expect a new chain to work on an old freewheel (which could also create skipping problems - particularly if the chain had been allowed to rust on the bike and was replaced to sell it) - but that freewheel does not very worn. I can't recall ever measuring a chain - it was just a given that you replaced it with a freehwheel change and those wore out quickly enough.

Generally a 1/16th inch stretch is the accepted maximum. A good cassette or freewheel should outlast 3 chains if you don't allow the chain to stretch more than 1/16th inch.

Okay, so heres a pic of a couple teeth on the freewheel. there are more like these it seems to skip on all of these but not all the time


http://i253.photobucket.com/albums/h...geot/003-2.jpg