Cassette - What Do We Have Here?
 

This is my brothers bike which I'll replace the cassette and chain.
I'm ordering online most likely so want to know what I need.
It's an 8 speed apart from that don't know. Are these all one type (shimano compatible?) or does sram do their own proprietary cassette?
I have a shimano tool and chain whip.

http://i1172.photobucket.com/albums/...hoto%201_1.jpg
http://i1172.photobucket.com/albums/...hoto%202_2.jpg
http://i1172.photobucket.com/albums/...hoto%203_1.jpg
http://i1172.photobucket.com/albums/...hoto%204_1.jpg

The shimano compatible tools should work for the cassette lock nut.

That might be a freewheel instead of a cassette. Might want to make sure before you order one.

I see a cassette lockring. In which case, you need a cassette tool.

Judging by the heavy wear on the middle cogs, you also need a new chain, and possibly a new chainring, too.

The bikes 15years old - too new for a freewheel I think?

Any benefit going sram chain and cassette?

Chain ring is swagged to the pedal arm!

CI think you're right, from looking at the third pic it does appear to be a lock ring for a cassette. Though my 2001 Giant Cypress DX had a 7 speed freewheel.

either SRAM or Shimano Cassettes will work fine.. they are interchangeable...

make sure the chain you get is 6-7-8 speed compatible. a KMC Z51 or Z72 will work fine, but you WILL need to correctly size it once you have the new parts... easiest way is to shift to the SMALL cog in the back, then make the chain short enough to put the derailleur tension arm to a position that is below horizontal by 15 or so degrees. If the old chain was so cut, it can be used as a guide by counting the number of links, then making the new chain the same count... not LENGTH.... COUNT.... the old chain has worn pins/bushings that will make it appear longer.

contrary to popular belief... Chains DO NOT STRETCH, they WEAR.

avoid getting a chain at a big box store... they are sometimes beyond "worn out" spec, directly from the package!

count the number of teeth on the cassette's big and little cogs, then order that range cassette... done!

Thanks!

Chains absolutely stretch. Measure the new chain say to 100 links and then measure the chain when you take it off to the same pin at 100 links. You'll measureably see the stretch.

In fact anyone who knows anything about working on a bike knows how to measure chain wear with a ruler. If you truly live in a reality where you think chains don't stretch, and don't know how to quantify the stretch/wear you probably shouldn't be in an Internet forum giving advice on bike mechanics!

Technically they don't stretch, they elongate due to the pins and such wearing down creating more play in each link. Rubber bands stretch, metal chains elongate through wear. Call it stretch if you want, we all understand what that means here but don't go blasting other posters for using the correct term.

Those are some sharp pointy teeth on the worn out cogs! Steel chain ring?

Don't race to be the biggest knowitall.
[MENTION=412721]Vintage Raleigh[/MENTION] the nicer cassettes and chains have a chrome finish. Match the number of teeth on the big cog. Consider what Alex said about checking the chain ring.

It has a lockring so that's a cassette. Also 8-speed freewheels exist but are very rare.

Guess you didn't see my second post in this thread, but thanks for the extra info and clarification. :)

+1, to that.

ANNND, if one wants to get super-technical.... the plates will stretch ever so slightly, while under HEAVY load... then they resume their previous length... but a seriously accurate "ruler' would be needed, and a fast one, too! it's a molecular metallurgy thing... crystaline bonding shear stuff.

what we silly bike guys deal with is pin wear, and roller wear, and sprocket wear.

+100, It appears the pulley wheels need replacing as well.

Really?

The ones I buy are re-boxed KMCs.
30% cheaper and indistinguishable from a KMC chain from any other source once out of the box.

[1]The experts have spotted the cassette lockring - it's a cassette. (The word "LOCK" printed on the ring in picture 3 is a strong clue!:))

[2]Given the state of the bike, and the fact that it's been ridden a lot without lubricating the chain, I'd say any performance optimization (e.g. SRAM vs other compatible brands) is probably not worth it. Optimize for cost. You may wish to help your bro by showing him how to clean and lube the chain - I could be wrong but it looks like its been ridden w/o lube for a while. Like 15 years!

[3]Before you spend the money, check the front chain ring. If it's worn, you may wish to find a cheap replacement on ebay. But you do need a new cassette and chain as you've pointed out. And as skoda2 has pointed out, you need new derailler guide and idler wheels.

If this is a favorite bike, or it has features you like (it looks bomb-proof - that double top tube with the lock is kind of cool) this may be worth it. Don't know the used bike sitatuation in Oz, but you may wish to price used bikes and compare to your repair cost.

And a chain whip.

I agree on the chain but the crank looks like it has a steel ring. It's probably okay. If it does need replacing, Vintage Raleigh will need a new crank as well. The chainring is swaged to the crank arm.

+1. The whole "chains don't stretch" thing has gotten so tedious. Of course the metal doesn't stretch, but who cares, we all know what the person meant...

Thanks again everyone. This is his daily driver. I've suggested a more robust set up with a heavier chain and sturmey archer hub, but respoke, cold set, new changers, hub, etc = vitually new bike cost wise. I might put together a frankenbike when the grasshopper is ready.
http://i1172.photobucket.com/albums/r565/mling1/-1.jpg

Umm....I can go down to Wal-Mart right now, and buy a new bike with a freewheel.

FWIW, 9-speed freewheels DO exist, but I doubt that they are worth considering.

I'd just get something cheap.

That is a pretty large sprocket in the rear, and the 11T or 12T doesn't appear to have gotten much use, so you could go one size larger if you wish.

Just suggest to to your brother to replace the chain in a little less than 15 years next time.

I can't tell the wear on the chainring. Sometimes one has to replace the whole crankset. The worst wear will be perpendicular to the cranks (the part covered by the chain/chain guard in the photos.

Cassette-$20, chain-$8, pulley wheels $8. Total- $36 + some labor and a good cleaning? A small expense to keep the bike on the road.
A lot of over thinking here.

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