LOWERERWICK

So I'm pretty new to this forum thing so sorry if I post this in the wrong area or could have found the info else where.

I have a Schwinn Super le Tour and just had to pull off the derailleur and replace it with a new one from Shimano. It isn't a fancy one by any means but after replacing it I can't seem to get to stop skipping? It isn't skipping a gear but it is making a weird click/skip motion/sound? I played with the limit screws a bit but this was my first time ever replacing a derailleur and I am not a complete moron so I think I did a pretty bang up job but just wondering about the best way to fix this issue. I should also mention that I have and older rear wheel set up with and just cleaned it up pretty nice cogs and all, I also have an older chain. Should I replace the chain? I would replace the wheel but it is not quite in the budget and I also don't really need a fancy pants wheel for this older bike. Should I maybe also replace the front derailleur?

Anyway, sorry if this is weirdly worded or doesn't make sense but any and all help, pointers, and directions would be greatly appreciated. I bought the Zinn road bike book ed.3 which is helpful but lacks some knowledge on older bikes needing to be upgraded.

Thanks!

cycle_maven

A couple of things to check-

The most common and easiest is a stiff link that will feel like skipping. Especially after removing and replacing a chain- did you relieve the pin after driving it back in? Check that all the links in the chain are free-moving. It there's a stiff one, then drive the pin back through the plate a tiny bit to get it to swivel freely.
The next most common is worn cogs and chain. This will be worse when really mashing on the pedals, and worse in one cog than the others. Do the cogs look symmetrical or have they developed shark-fin looking teeth? If they look worn, then they are worn. The fix is to replace the chain and cogs (both because a new chain alone will wear out instantly when running on worn cogs, and skip even worse). Check the chain wear- hold a ruler against the pins and if the chain is more than 1/8" in 12" elongated, then it's well worn out. I replace my chains at 3/32 inch wear and go through about 4 chains per set of cogs in a 9-speed bike.

davidad

The limit screws are only for initial setup. The cable adjusting screw is for fine tuning. Park Tool Co. » ParkTool Blog » Rear Derailler Adjustments (derailleur)

FLJeepGuy

You didn't specify which derailleur you replaced, but I'm assuming that since you were talking about an "older rear wheel", you're also referring to the rear derailleur. Keep in mind that the limit screws only control how far inwards (low limit) and outwards (high limit) the derailleur can move and don't come in to play at all when shifting in between. Everything else is controlled by cable tension and derailleur alignment. The slight skipping and stuttering sound generally comes from the derailleur cogs not being directly in line vertically from the currently selected cog (too far inwards or outwards). This can be adjusted using the barrel adjusters on the derailleur. You also need to insure that the derailleur is not bent either through damage or improper mounting.

LOWERERWICK

@FLJeepGuyYes I am speaking of the rear derailleur, sorry about that. I just put the derailleur on yesterday and everything seems to mounted well and in running order I think it might just be a cog and chain issue but when I get home I'm going to play with cable tension a bit.

Thanks for the response.

LOWERERWICK

@cycle_mavenYeah the teeth are for sure a little sharky. Maybe I will just have to replace the rear wheel after all or get a new cog set and chain. Which do you think will be the cheaper way to go? I mean my chain is beat and old with some rust spots on it so really it is probably just time to this. Now this ruler thing you speak of sounds strange to me is there a video link or something I could youtube on what exactly you are talking about and the how to. You know for the future of my chain and cogs.

Thanks for your response my friend.

FLJeepGuy

If the chattering seems to occur on the inner gears more than the outer gears, you can also check your B-limit screw. It could be that the derailleur is a a bit too close to the gears.

cycle_maven

Just hold a ruler against the chain- each pin should be 1/2" from the next on a new chain. On a worn chain, the pins will start creeping off the 1/2" marks, until at the end of the ruler (12"), the last pin will be offset from the last 1/2" mark by a fraction of an inch- that will be your chain wear. If it's more than 1/8", then the chain is starting to make your freewheel cogs wear out and form the "shark fin" tooth shape. Unfortunately, if the freewheel is worn, it will make a new chain wear very quickly, so you have to replace them in pairs when the chain gets too worn.

A new freewheel isn't very expensive- maybe $10- and a new chain is about the same. You need a special tool to remove the freewheel- if you have a bike cooperative, then they'll have the tool and show you how to use it. Then keep it all oiled well and the new chain and freewheel will last a lot longer.

But it sounds like your problem is more a rattling noise than a skip in the chain. The other posters addressed this pretty well.

mprelaw

I got a Sun Race 6 cog set for my Super LeTour for $11. I also put an 8 speed SRAM chain on there that brought the total bill to about $30.

I don't know how old mine is (it was given to me by a friend) but even though it has 126mm dropout spacing, I couldn't fit a 7 speed set on it.

LOWERERWICK

@cycle_maven Thanks for the ruler info and explaining it. Made way more sense.
@Everyone I went through the whole chain and had to re-lube and bend each piece to fix the little skip. Turns out I just had some rough wear on the old chain and needed to break it up a bit.

Next big move is going to be replacing the existing rear and front cog sets and front derailleur. Hopefully this wont be to big of a task for my experience level. But if it is I'm glad I got you guys to bounce questions off of and get things solved. Also glad that it is not seemingly going to be to expensive.

mprelaw

The front chain rings on mine are 52/40 Suginos, and they're still in great shape despite the age of the bike. With a 13-28 rear set, it isn't the best climber I've ever ridden, but 40/28 gets me up anything around here.

Grand Bois

Cable tension adjustment won't help with friction shifting.