Broken Front Sprocket! -- New Pictures

Blue · January 06, 2010, 02:30:45 PM

I took the sprocket off and cleaned it up a bit. The chain rollers look great except for three that had a scuff on them. Nothing major, but not looking like the rest. I also cleaned up the sprocket housing and it appears to be the junk of 19000 miles without being cleaned. It is cleaning up nicely now. The sprockets were aligned correctly, but I did bike this bike this spring with the chain and sprockets on them so who knows the full story. The previous owner was a good guy, bought it brand new, had the bike serviced by a reputable bike shop and gave me a nice stack of receipts. I could see where a bike shop might think he knew more about the scoots than he let on (after talking bikes with him). Anyway, last question: is this the stock front sprocket or aftermarket?

rotation of sprocket ======>

Speeddog · January 06, 2010, 03:48:34 PM

That's an OEM style sprocket, I think it's an AFAM.

I'm pretty sure your bike takes a somewhat oddball sprocket, no 'offset' to it.

Be aware of that when ordering/buying a replacement.

NAKID · January 06, 2010, 04:12:51 PM

That last pic shows a nick on the tooth just to the left of the broken tooth. Furthers my belief that something got between the tooth and chain...

Blue · January 06, 2010, 04:55:48 PM

Quote from: Speeddog on January 06, 2010, 03:48:34 PM
That's an OEM style sprocket, I think it's an AFAM.

I'm pretty sure your bike takes a somewhat oddball sprocket, no 'offset' to it.

Be aware of that when ordering/buying a replacement.

Thanks for the information. The sprocket appears to be "stepped out" the same on both sides.

Quote from: NAKID on January 06, 2010, 04:12:51 PM
That last pic shows a nick on the tooth just to the left of the broken tooth. Furthers my belief that something got between the tooth and chain...

There is also a nick on the preceding tooth that you cannot see in the pictures.

Crazy stuff!

The list grows for replacement parts.

bobwithboobs · January 11, 2010, 03:06:42 PM

had the same problem exept when i bough the bike i noticed there was two teeth missing in the front and the belt was WAYYYY loose and WAYYYY worn as well as both sprkets. didnt really notice any difference other then a pretty nice jerk (chain was soo messed up. almost all the o-rings were non existant). Kind of miss that beat up feel.

Teutonics · January 11, 2010, 03:39:29 PM

Quote from: Speeddog on January 06, 2010, 03:48:34 PM
...I'm pretty sure your bike takes a somewhat oddball sprocket, no 'offset' to it.

Be aware of that when ordering/buying a replacement.

Yes, I can confirm that. You need a different offset sprocket specific to the 900ie bikes.

Fruity · January 11, 2010, 06:37:28 PM

i recently tried fixing a 14t sprocket (bought on ebay and according to the seller it's a ducati oem) on my bike (04 ducati monster s4r) with the old OEM chain that came with the bike (the old chain and the old 15t sprocket was fine). i found some really tight spots and loose spots on the chain, difference of about 1.5 inches in slag, so i blamed it on the old chain. i replaced the chain and still found some tight spots altho not as bad. when i ran the bike something doesn't quite feel right, vibration kind of feel at high speed. could it be the sprocket that's slightly out of shape??? i wrote back to the seller and he was really pissed off saying that i'd stand a better chance of winning the lottery than an oem ducati sprocket out of shape

now i've installed the old 15t sprocket back with the new chain.

thanks if anyone can advice.

Howie · January 12, 2010, 04:43:36 AM

If memory serves me right, the 2000 900S had a different offset on the front sprocket, but the others were the same.

erkishhorde · January 12, 2010, 06:45:30 AM

Quote from: Fruity on January 11, 2010, 06:37:28 PM
i recently tried fixing a 14t sprocket (bought on ebay and according to the seller it's a ducati oem) on my bike (04 ducati monster s4r) with the old OEM chain that came with the bike (the old chain and the old 15t sprocket was fine). i found some really tight spots and loose spots on the chain, difference of about 1.5 inches in slag, so i blamed it on the old chain. i replaced the chain and still found some tight spots altho not as bad. when i ran the bike something doesn't quite feel right, vibration kind of feel at high speed. could it be the sprocket that's slightly out of shape??? i wrote back to the seller and he was really pissed off saying that i'd stand a better chance of winning the lottery than an oem ducati sprocket out of shape

now i've installed the old 15t sprocket back with the new chain.

thanks if anyone can advice.

I didn't know that there was an OEM 14T front sprocket. There could be a few reasons why the guy got pissed when you called him out. One could be that he's pushing crap products and got caught but he doesn't want to take the blame so he's trying to make you back down. Obviously no, you do not stand a better chance of winning the lottery than finding an OEM Ducati sprocket that is out of shape.

Blue · January 12, 2010, 08:09:22 AM

Quote from: Teutonics on January 11, 2010, 03:39:29 PM
Yes, I can confirm that. You need a different offset sprocket specific to the 900ie bikes.

Of course, I already ordered a new sprocket for the bike from Desmo Times (along with other replacement parts). There was no mention of the a special sprocket for my bike on the website. Below is a link to what I bought (sprocket "A"). Will this not fit? If not, is this a dealer only part?

Desmo Times' Steel Countershaft Sprockets - $27-$50

erkishhorde · January 12, 2010, 10:15:17 AM

Quote from: Blue on January 12, 2010, 08:09:22 AM
Of course, I already ordered a new sprocket for the bike from Desmo Times (along with other replacement parts). There was no mention of the a special sprocket for my bike on the website. Below is a link to what I bought (sprocket "A"). Will this not fit? If not, is this a dealer only part?

Desmo Times' Steel Countershaft Sprockets - $27-$50

Don't think that I can answer your question, but here's something I found. I've always been a big fan of CA-cycleworks and they have the sprocket you bought for a few bucks cheaper. But they don't list the 900ie as one of the bikes it fits. Either that or it fits so many bikes that it went outside the bounds of the description box.
http://www.ca-cycleworks.com/shop/catalog/ducati/chain.html
IIRC both Desmotimes and CA-cycleworks are board sponsors so giving business to either one is

. Also, on the CA-cycleworks site, the sprocket for the 900ie is described as having an offset on both sides whereas the one on the Desmotimes site appears to only have an offset on one side. I can't tell you if that matters, though. Just pointing out what I noticed.

Blue · January 12, 2010, 10:26:26 AM

Looking at the CA-Cycleworks website, it appears as though I ordered the wrong sprocket for my monster from Desmo Times (they do not offer the sprocket I need on the site).

It looks like I have some emailing to do!

Thanks for taking the time to help me out.

bigiain · January 13, 2010, 09:34:13 PM

Bah, you've got _miles_ of life left in that one!

(click for a bigger version)

poor-maintenance-big

Blue · January 17, 2010, 09:27:32 AM

Well, I finally got all of the parts together along with the time to put everything back together.

Rubber Boot from Ducati Seattle

Sprocket from California Cycle Works

Case saver from Desmo Times (along with other maintenance items). The rear tire is not installed; I have not adjusted the chain slack as of yet.

I was a bit surprised with how the front sprocket was mounted and secured into place. I was amazed in how much the sprocket plate plays a role in holding the front sprocket in place but also for keeping the sprocket aligned. Are other Ducati's like this (not the newer ones with the big sprocket nut)?

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Broken Front Sprocket! -- New Pictures