Front Sprocket Alternatives - 14,15,16 tooth 525:-

Direct replacement

1. AFAM (16 tooth) Part Number: 94900-16
2. PBR do a direct replacement as well, in 15 & 16 tooth. Part Numbers : 2129-15 & 2129-16 (If I read their document correctly) Try Red Racing Parts www.redracingparts.com
   (PBR do a range of rear sprockets as well - all sizes between 36 & 46 teeth. Part Number: 4456 -xx, where xx is the number of teeth)
3. Laurence, of Benelliforum fame, can supply the original part, but up to the present, has not had a source of suitable lock washers. Pierpaolo, also of the forum, has recently discovered that the Ducati lock washer, P/N 85110041A, fits the Benelli output shaft. In particular, it locks to the spline, which is good news for those who have sourced sprockets without the circular array of holes.
4. Bike Torque Racing p/n:94900-15 No lockwasher apparent.

Modifiable replacement

1. Ducati use a similar front sprocket on many models, including :-
   944 Sport Tourismo ST2, 916 Strada Biposto, 916 SPS Sport Production, 992 ST3, 996, 998, 999 .....
   Ducati Part Number 449-102-71A
2. JT Sprockets Part Number JTF740-14, JTF740-15, JTF740-16
3. AFAM Part Number 90-0563
4. "MV Augusta - front sprocket is the same across all models so F4 1000 or 750. The center offset was only off by 1 or 2 mm. So I didn't bother to do any machining. Around $80 U.S. Dollar." (benmaw)

If you want to go to a 520 chain

1. PBR p/n 2097 is a 15 tooth steel sprocket, without the circular array of holes. PBR 1031 is a 43 tooth alloy rear (rusty-pie 25 Mch 2012)
2. JTF737-15, Ducati part Number 449-100-71A, which suits the '90-'93 917 Paso Sports. It does need machining both sides.

In Australia, Link International import JT Sprockets. Their Part Number for the JT740-15 is "41-D05-15". It is retailed by most bike shops, including Canberra Motorcycle Centre (15% Ulysses discount) and Joe's Motorcycles.

The boss is offset, and needs to be machined down by 7mm (to 1 mm) to fit, but otherwise it is a much cheaper alternative. One problem though, it is hard - harder than the Benelli sprocket - so a tungsten tool is required. High speed steel won't touch it, but tungsten slices through it like it was butter.

The original JT sprocket top left, the machined JT top right, the Benelli part, bottom left, a lock washer for the JT part, centre, and the Benelli lock washer, bottom right.	Machined JT sprocket installed. The lock washer keys to the sprocket through the 2 threaded holes, and locks the nut as shown.

Works fine. Not a hint of loosening. A lot cheaper than the OEM was in 2006, heavier, but harder, and lasts longer.
There are cheaper alternatives available now (10 years later in 2015). See above.

NB: Chain Gang recommend changing the front sprocket half way through the life of the chain & rear.