Ok - I've got a 92 F2 that I've resurrected from neglectful previous owners.

The bike was regeared 14/? at some point, with a 108Link generic no-name chain. PO said that it had an aluminum rear sprocket, but it had started skipping so he had put a new rear on a few months ago, and the bike was laid down shortly after the new sprocket was installed with very little mileage afterward. It now is equipped with a steel 43T.

Chain was so stretched that the adjusters were all the way out on the swingarm, and still had too much slack. I'm guessing the previous gearing was 14/45 or 46 maybe. To get the bike back drivable, I cut the chain down to 106Links *Just for the time being - no lectures, I know it needs a new chain and I shouldn't trust something that badly stretched*

1st question - the steel rear sprocket has plenty of life in it - shows no sign of wear, and I know what worn sprockets look like. I'm thinking of just doing a chain and new front sprocket. (ok that may be more of a statement than a question - but any issues anyone sees here?)

2nd question - front sprocket needs replacing, unless it can be flipped to get a little more life out of it? I'm going to keep the 14T gearing even if I need to replace.

3rd question - I measured the roller width on the current junk chain - .25", so that indicates I've got a 520 setup right? Don't the chain numbers break down into the first digit is the # of eight's of an inch between pins (5/8"), and the next 2 numbers have a decimal between them indicating the # of eighths in the width of the roller? 20 = 2.0 = .25"

4th question - with only 1T down in front, should I still be looking for a 108link chain?

 

the chain size should be printed on the chain or at least the sprockets. If your unsure just take the old sprockets in to shop to check. You can visually tell the difference in chain sizes.

don't flip the sprocket, besides many sprockets are offset and don't do that anyway. Just replace it, their cheap and you need it.

 

1. IMHO, if the rear sprocket was put on without replacing the chain by the original owner and shows no wear, I'd continue using it.
2. I'd get a new one.
3. Inner roller width .25" and 5/8" pitch = 520
4. Don't know wheelbase, so can't comment on length. I always buy a 120 in the box and cut them.

 

Thanks for the replies. Avid - unfortunately the chain and both sprocketsare completely devoid of brand name or sizing stamps, and I've had them off the bike for cleaning and shortening, couldn't find anything. I'll be replacing with a reputable brand. For as much as I spend on my bicycle drivetrains, I know that "good" chains just flat out work better and last longer.

Randy - thanks for affirming my understanding of the measurements.