The question about installing aftermarket camshaft belts in a Ducati comes up quite regularly. Ducati belts are made by Gates to Ducati specifications and are unavailable except from Ducati. Further, Ducati specfies belt tension requirements based on using a Gates belt.
But, Ducati belts are quite expensive compared to aftermarket belts.
There have been a number of changes to the Gates belts over the years because Ducati belt failures have occured frequently in the past. Accurate belt tension values and replacement at Ducati’s mileage and time intervals are important to avoid premature failure. Unfortunately, belt failures are still with us.
I think I’d consider buying aftermarket if GiaCaMoto, Bucci, Dayco or California Cycleworks offered their own warranty to cover engine damage caused by their belt failure. Testimonials from one or two owners, or anecdotal information from a reseller that they’re identical to the OEM belts isn’t enough for me. If you want to assume the risk on an out-of-warranty bike for the sake of a few quid, be my guest.
The financial and failure risk is not trivial.
Keep in mind that Ducati engines are interference engines, that is, the valves will come in contact with the pistons if the timing belt fails. So it’s probably wise not to use an aftermarket belt on an engine that’s still under warranty. If one fails, Ducati won’t pay for the repairs.
Aftermarket belts, although dimensionly correct, can exhibit differnces in internal construction and materials. Ducati’s product specification for tensile and fatigue strength, durability, heat resistance, etc. isn’t published, so there will be some differences exhibited between OEM and aftermarket belts.
For example, one aftermarket manufacturer sells a stronger belt that tests show will fail at higher tension force levels than the Gates belt. So is this a better product?
No, as it turns out.
The stronger aftermarket belt is stiffer in tension, so when you install the belt to Ducati’s cold tension specification, when the engine heats-up the hot tension is higher than you get with the Gates belt. Loads on the pulley bearings becomes excessive, noise increases and heat build-up (from flexing a stiffer belt) increases. So a stronger belt could lead to premature failure.
Just saying.