don't be tempted by the pretty gold colour....sprocket

[rictus01]

As some will know the (new to me) Aprilia pegaso has been going through some checking and servicing, the chain and sprockets needed changing and were done as promptly as I could get them, the rear sprocket was a Renthal gold "hard anodised" one, I've used alloy sprokets before on small trials bikes but never on anything bigger, I won't be doing so after seeing the state of this one.

https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-snc6/269220_10150898943074135_930222728_n.jpg

https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-ash3/538279_10150898943204135_1916240730_n.jpg

https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-prn1/533425_10150898943459135_1332488525_n.jpg

https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-ash3/598477_10150898943574135_781049664_n.jpg

And just in case you can't see how badly the profile has worn, here's a new steel one below for comparison.

https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-ash3/556367_10150898943854135_1945241154_n.jpg

you have been warned.....

[Bibio]

no no, you have it wrong those are the new anti-wheelie design.

[Eulaca]

I don't think you're supposed to use a sawmill blade for a sprocket. How long had that been on the bike?

[Specialone]

Holy crap, that's wore the hell out of that.

I've never used the alloy ones but I've always wondered they can't possibly be as strong /durable.

[rictus01]

As some will know the (new to me) .

How long had that been on the bike?

I've no idea, but it wasn't OEM and even badly looked after the originals should have lasted 12,000 or so (conservatively), then it could only have been on for a maximum of 6,000 miles at most by my reckoning.

[injury_ian]

I'm surprised you got any drive out of that....

On a side note, you cannot assume that the C&S was previously replaced because of wear, on the tarty Street Triple forum people change out C&S's regardless of age or wear just because they want a shiny gold one!

[rictus01]

anything is possible, but as the person I bought it from was the second owner and had only done 4,000 miles in the first year (just commuting) and 246 miles in the second that he owned it (spend most of the year parked up as he moved and started taking the train to work), I doubt he's the type to "fashion" change things.

[Geodude]

Oh dear that looks dodgy, how did the chain not jump off those gums. What do you recommend as a good make Rictus?

[rictus01]

the chain didn't jump because it had plenty of adjustment left in it and the chain was still fairly good, I "bow stringed" a bit, not something I'd normally do or recommend (but I knew I was changing the whole lot anyway), but it did the job the steel chain dug into the alloy and it got tightened every other day.

just the standard steel JT sprocket will do, or if you're really flush and want the flash look get the stealth type ones (alloy centres and steel tooth ring).

Cheers Mark.

[Geodude]

Cheers Rictus as usual your advice goes into my biking notebook :)

[rictus01]

keep it handy, once senility finally kicks in with full force, I just may have to have a browse through...;)

[Geodude]

Haha will do :)

[muzikill]

How many miles did you do on it?. Could it have been a fake?

[andrewsmith]

Wow!

I won't be fitting renthal Anodized anytime soon.
You could have always found http://forums.sv650.org/showpost.php?p=2712670&postcount=1

http://img825.imageshack.us/img825/7391/imag0073p.jpg

[flymo]

I've used these before and never seen wear as bad as the one you have. Perhaps this wasn't maintained properly, perhaps it was a faulty anodised batch, who knows.

If a sprocket could get as bad as that without the owner noticing then my guess is that the chain was equally as neglected.

[Lozzo]

I'm with Flymo on this. Our race bikes always have Renthal anodised alloy sprockets and get abused with little or no maintenance in real terms. In four years of running a ZX10R in Bemsee Powerbikes and three years of a 675 Daytona in Superstock 600s we never had one rear sprocket wear anything like as bad as yours. The bikes aren't just used once a month through summer, they get used all year round as trackday instruction bikes so spend a huge amount of time being caned on track.

I've just bought 7 lightly used Renthal alloy rear sprockets in different sizes for my CBR600 track/race bike and expect them to last the lifetime of the bike

[Bibio]

looks like the chain has been rubbing on one side only which would explain the excessive wear so possibly the wrong sprocket for the bike.

[Dabber]

Wow,,that is bad. Don't recall seeing a sprocket that bad.

[Whitty]

I'm with flymo and lozzo, I have them on my race bike which also does a lot if trackdays and still look good as new. I just check adjustment every ride or wheel change, keep it clean and lightly lubed. Think a lot of people have chain too tight which makes chain dig into sprocket when susp compressed hence wrecking hardened surface. Once you are through that it may as well be made of chocolate.

[rictus01]

as I've said the chain and top sprocket weren't in bad nick, if I'd have had the history I may have just replaced the rear, but obviously when you get a secondhand bike you just don't know.

Alloy sprockets were originally developed for competition; where the weight saving can have a significant advantage, but then the bike gets far more attention than your average road bike, so any wear would get changed out sooner rather than later, I see no significant cost saving over steel and now having seen possibily the worst conditioned sprocket in a very long time myself, I'll not ignore experience.