https://www.sheldonbrown.com/chains.html#wear

or more specifically -

https://www.sheldonbrown.com/images/chain_worn_sprockets.gif

This photo is a worn cog in front of a new cog

 

i saw that one but that isnt the one i was looking for. i know sheldon had that picture comparing regular spaced teeth to shark teeth

 

I have a very hard time with this

So i have this lady friend who was having problems with her road bike. WIthout getting into the long story, I realize that her cassette and chain were worn. I taught her how to check for a worn chain (using a ruler), but we were having trouble in telling if a cassette is worn. I told her to look for the "shark profile" and the elongated U's on the grooves. Being the visual person that she is, she did not know the degree of sharkness or flatness of U's I was talking about.

So basically what I'm asking is for pictures of a worn cassette vs a normal one. I know sheldon brown's site had it before but for some reason i cant find it

I have a wall full of cassettes, and I have hard time telling which ones are worn. I have the Park tool that checks them, but it's just too vague. So, pictures might show new versus really worn out cogs, but it's the kinda worn out cogs that I find cause problems.

The best way I can tell? I put in a new chain, then ride the bike. Put it in each cog, then stand and mash hard. If the chain skips, the cog is worn. Might want to conduct a "control" test with new chain and new cassette first.

Also, I find that some cassettes get worn in just one cog, or at least the chain might skip on just one cog. The really gripes me when cassettes now are $200-$350 (Campy).

One of the worst things I ever did was installing a new chain on my Cervelo P3 just before I did the team 508 a few years ago. I thought the DA cassette looked new, but the chain started skipping so badly on the 11 and 12 cogs that I had to stop using the bike in the event. If I'd have just left the old chain on, I'd probably have been ok. Or, for really important events, be sure to change out both cassette and chain together, I guess.

 

looks mean nothing...

There is one simple test for worn cogs. If you install a new chain and the chain skips under a heavy load, like when pedaling standing up a hill, the cogs that skip are worn out. A worn cog will not look significantly different than a good one.

While changing chains before they reach 1/16" per foot elongation is good advice, it will not prevent cog wear.

It is entirely possible to wear out a chain and not come close to this much elongation. My chains typically show 1/4 of this allowable elongation after 6000 miles, but the rollers are worn excessively, which warrants a new chain. Unfortunately, even with a chain that is not stretched, at least one cog may also be worn out after 6000 miles. To double the life of the cassette, alternating the use of two chains will prevent chain skip until both chains are worn.

 

Saving serious $$

Also, I find that some cassettes get worn in just one cog, or at least the chain might skip on just one cog. The really gripes me when cassettes now are $200-$350 (Campy).

I have a secret plan to save you serious money. Don't buy Record cassettes! Or even Chorus. You will get perfect shifting with Veloce or Centaur cassettes, save a lot of money, your cassettes will last much longer, and you'll never notice the few grams difference in weight (one or two swallows of water). You can send me 10% of your savings if you want to thank me

 

Unless...

Don't buy Record cassettes! Or even Chorus. You will get perfect shifting with Veloce or Centaur cassettes...

You've got a wheel with an aluminum freehub body. Then, the all-steel cassettes can notch it up pretty badly. Yeah, this happened to me.

On those wheels, you should get the cheapest cassette with an alloy carrier, I can't remember if that's centaur or chorus these days.

I get Veloce cogs for everything else. Like Kerry says, they are the same... and as a bonus they are all loose, so if you wear out one you can just replace it, should you need to. And they are like $60...

 

I'm an idiot

I have a secret plan to save you serious money. Don't buy Record cassettes! Or even Chorus. You will get perfect shifting with Veloce or Centaur cassettes, save a lot of money, your cassettes will last much longer, and you'll never notice the few grams difference in weight (one or two swallows of water). You can send me 10% of your savings if you want to thank me

Sometimes I just do stupid things for no good reason. Yes, it makes absolutely no sense to spend that kind of money on a titanium cassette. On my commuter bike, I run Veloce, and, yes, it works perfectly fine. For no good reason, though, on my race bike I want top of the line, lightest (or close to it), everything. Tell you what, I'll send you 10% of my winnings... ;-)

 

Not even

You've got a wheel with an aluminum freehub body. Then, the all-steel cassettes can notch it up pretty badly. Yeah, this happened to me.

I think you didn't tighten your cassette lock ring enough. I put 64K miles on a Record hub with aluminum freehub body, nearly all with separate (no carrier) cogs. You could just barely see where the cogs met the freehub body. If the lockring is up to torque, the cogs aren't moving and chewing the freehub body.