JeffOYB

sweeks

It's always a good idea to look at Sheldon Brown.
Here's another Video: .

fietsbob

Rohloff HG sprocket tester

JeffOYB

I've heard of this tool. Any way to do this trick without this tool or without a tool? I'm thinking i'll give it a try just by pullling on a length of chain across some cog teeth and see if the end of the chain catches or not.

Andrew R Stewart 

The HG Checker is less black or white then the methods of measuring a worn chain. As example, IIRC, it is only applicable of cogs smaller then 21 teeth (or so). How strongly the last "special" roller catches on the last tooth's top is very dependent on how strongly you pull on it. I use one nearly every day I work yet I still only use it as an indicator, not a determinate. If time savings is your highest priority then just replace the cassettes with the new chain. Otherwise do the test with actual riding under significant pedal pressure. Andy

HerrKaLeun

Unless the cassette is really new, you should just price in a new one when negotiating price. You are buying a USED bike. Brake pads etc. also will be worn. No one upgrades or replaces everything and then sells the bike. People sell the bike because they anticipate expensive replacements coming up.

One thing you can do is measure the chain. if it has more than 0.5% (or extremely more), the owner didn't replace it in time and you can assume the entire drivetrain is worn out unless it really looks good or it can be proven it was replaced before.

Don't rely on what the seller claims. Every CL bike here was recently "professionally tuned up"

JeffOYB

I'd really like to be able to get a sense of how worn a cassette is. Maybe not possible.

My angle is that I help out at a Bike Co-op. We get a lot of wheels and loose cassettes donated to us. It wd be neat to see how fresh the cogs are, or aren't. When they're really worn i can visually tell. ...When a complete bike is donated w chain we can measure the chain-stretch. ...I wish donors wd add a note to loose items about amount of wear. We can match a light-wear chain w light-wear cassette. We resell a lot of bikes for $100 and don't want to take a lot of time matching things up. Nor do we want to put a lot of fresh/new parts on if we don't have to.

It's fine that the tool only goes up to 21. The skipping cogs are basically always smaller than that.

i suppose we'll just get the tool. i just wondered if there was a handy trick.

Andrew R Stewart 

As mentioned looking at the teeth shape is the quickest way to get a feel. But one needs to see a lot of new and worn teeth to begin to get a good idea of visible wear. Just like having the HG Checker will give you one more data point. It's the using one AND then following through with a judgement and discover the results (the test ride) that is the trick. Being in a Bike Coop will give you all kinds of bikes to learn on. Andy

wschruba

Having also used the tool extensively, I concur.

KMC makes an easier to get, less expensive version, but I would point out: it has a tendency to slip, since the lever portion isn't machined to hold on a tooth shape, like it is on the Rohloff. Without the handle, it fits nicely in a travelling bag, but it isn't a better tool than the original. You can punch out the 9 speed chain that is on the Rohloff and replace it with 11, if that is your bag. Use a Shimano chain and one of their pins, driven in with a 1/8" punch.

Biagiokai

I just got my bike and watched some videos on worn cassette and my looks slightly worn on the smaller rings. A couple teeth are shark fin in total. If it shifts totally fine is there a need to replace anything?

cxwrench

Shifting doesn't mean a thing. Go ride your bike, push hard on the pedals...seated. Does the chain jump?

2_i 

You can always invest in an identical cassette and compare the two directly. It won't be a loss as you will need to replace the current one sooner or later anyway. Telling the wear without experience or reference can be a challenge as the teeth are normally shaped intentionally in various ways to ease the shifting.

grizzly59

Here is a basic idea, goto about 3:30 or ¾ into it

Biagiokai

It seems to be in good shape for the next while. Any idea how much a new chain, cassette, chairing replacement would be with labour? 300ish?