This happened on my 2nd ride. A total of 43 miles.

I know 7075 alloy isn’t the best material for a sprocket but I expected a little better.
Back to steel for me 🙂

how old was the chain?

Installed with a rock?

The chain was new. The whole drive chain was replaced at the same time.

return?

Power!!

well, i’m no lover of superstar, by any margin, but really – 14T, aluminium, WTF were you thinking to buy it?

Regardles of material, If they sell them surely they should be fit for purpose ?

Jeez, they sell some crap don’t they?

Didn’t realise you needed to be a metal expert to buy stuff from superstar… 🙄

Out of interest what is your chain line like is it perfectly straight?

Chris King, stainless steel, nicely lightened and teeth you won’t need a dentist for.

Might have to give mine a look over, but I did get 12 months about 2000 miles out the last one. Which I thought was good value.

The chain line was spot on. I’m not sure what caused it to star to fail. I’d assume one tooth went and allowed slip which took the others out.
I alos had plenty of chain wrap around the sprocket so that wasn’t the cause.

Didn’t realise you needed to be a metal expert to buy stuff from superstar…

i’m no expert by any means. i just play safe and don’t buy anything from them. 😉

Surely it should be left with 8 tenntaclesteeth?

Aluminium
Sprocket
Not two words I would want or expect to be seen in relation to singlespeed sprocket quite frankly.
Apart from anything else I would imagine that it wouldn’t have lasted long in the grit & filth.

Well what’s this all about then?

They’re not for single speed.

I know that, but I’m just curious as-to why it works fine on a cassette. It is the size of the sprocket [F*D=const.] or is it the fact a cassette can freewheel.

My money is that is should work but the Superstar one is just too crap to tek’ it!

benji, you have a lovely back end there!

Loads from 40t are very! different from 14t, SS grunting up a hill

I don’t think you’re right – I think it’s to do with the tooth profile and the Alloy choice and not the number of teeth.

But I could be wrong 🙂

http://www.emsamakine.com/KPANEL/RTE/resimler/9-_MAK%C4%B0NE_ELEMANLARI_-_ENGLISH.PDF

If you want to work it out!

Is it actually 7075? 7075 is one of the highest strength aluminium alloys available, Renthal have been manufacturing road and motocross sprockets from 7075 for donkey’s years so I doubt that they’ve been getting it wrong for so long.

I suspect that like a lot of Superstar’s stuff it’s cheap Chinese sh!t masquerading as something else.

Or it could be a one off failure of something that was designed and manufactured properly. Trust me they do happen, statistical processes and failure modes being what they are.

What have Superstar said about replacement or refund? I didn’t spot that bit.

Rohloff sprocket after 10,000KM or thereabouts. I didn’t flip it because the seal surface was a bit cruddy.

EDIT – it’s very tough Stainless Steel

I have a nice horror picture of a sprocket that I could theoretically post up, but I can’t post pics so I won’t!

(It’s what happens if you don’t touch a s/s sprocket for several years).

I had one of these:

http://www.endlessbikes.com/products/kick-ass-cogs/

it’s aluminium alloy and ss specific. Ti be fair, I had a 17T, but they make them down to 14T. I had no problems with it at all – except it did (obviously) wear quicker than a steel one.

Currently running a Ti version of this:

http://www.homebrewedcomponents.com/store.php/products/stainless-and-titanium-2-piece-cogs

seemed like it was the best balance of weight vs durability. So far the fact that it was $100 USD has been negated by it lasting nearly 4 years already – barely any signs of wear even now.

FWIW – Homebrewed also makes alloy sprockets.

Return it, but they will probably just say its been used for a purpose it wasn’t intended for, just like they did when my brake disc split 😆

yes return it so you can incur some postage costs in exchange for a condescending explanation of why it was your fault

I wish i was just joking

if its a superstar cog why does it have fouriers logo on it? is it a different version ie: same factory, like the wah wah/nukeproof/superstar pedals? superstar website pic below. either way thats still poor performance and needs to go back for a replacement/refund/whatever

What have Superstar said about replacement or refund?

😆

7075 is actually a good alloy to make this kind of thing from, certainly better than any 6000 series alloys. I blame poor heat treatment after forging!