Hey friends. Gear system here is pretty tanked — throws the chain at the drop of a hat if I change it more than the first and second front sprocket. Makes riding up hills in traffic extremely nervy eeeeeep. I’m keen to have a crack at replacing it all myself but don’t know where to start — including with what actual cassettes/chains/derailleurs to buy. My friend said the new stuff mightn’t be compatible with a bike this old (80s maybe? Got it from a friend who was chucking it out). Anyway, any advice on first steps would be greatly appreciated!
by wmelv
3 Comments
The derailleur/s is/are probably fine. You’ll need a new freewheel/cassette, chain and chain rings. The size (both number of teeth and Bolt Circle Diameter) should be stamped or etched on the chainrings. There should be a part number or series name on the cassette/freewheel. A chain from Shimano, SRAM, KMC etc that’s rated for the number of speeds that match the number of cogs is a must. 8 cogs = 8 speed chain, 9 for 9 etc. You will probably need new jockey wheels. You might be able to remove the chainrings without removing the cranks or needing specialist tools, but that’s not a given. You will need specialist tools for the chain and cogs, but you don’t have to spend a ton of money (or if you have a bike co-op in your town, they can help). Before you install anything, clean thoroughly and lubricate. Have fun!
> throws the chain at the drop of a hat if I change it more than the first and second front sprocket
That doesn’t mean that anything is tanked – could just mean that your front derailleur is poorly adjusted. If you’re dropping chains on the smallest chainring then your lower limit screw is probably not where it needs to be, a few quarter-turns and you should be good to go. [See the Park Tool video](https://www.youtube.com/watch?v=ZNG7g83lI-s) for instructions.
Of course, if you haven’t ever replaced a chain/cassette then at the very least measure them to see if they’re long overdue or if they have some life left in them. But by itself it shouldn’t cause you chain drops when shifting.
cassette, chain and middle chainring looks worn. this could be causing all your issues
drivetrain is a mix of Shimano 5500 and 6500 components which would put the bike somewhere between 1999 and 2005 (this is also corroborated by the ahead fork and lack of cantilever cable stops).
for parts you’ll need:
130mm middle chainring with 42 teeth that is 9s compatible. shimano doesn’t produce this type anymore. alternatively you could use the “Specialites TA Alizé 130 mm **middle** 42”
9 speed cassette. drivetrain is officially limited to max 27t cassettes (which aren’t made anymore). 11-28 should work fine as well. for example Shimano CS-HG400 11-28
for chain any 9s chain will work. for example Shimano CN-HG53 or CN-HG93
if you have shift problems a cable replacement might also be needed. easiest would be a kit like Shimano Y60098022.
in terms of tools you need metric hex wrenches, a chainwhip, a HG lockring tool (+something to hold the tool (vice, breaker bar,..)), a 9 speed compatible chain tool, chainring nut wrench (you should be able to remove the chainring without removing the crank. if not you also need an Octalink compatible crank puller), bike cable cutter and side cutter. to adjust the shifting you might also need a phillips screwdriver