Ask MO Anything: MotoGP Drive Chain?

Good question. We shot this one off to Neil Spalding, motorcycle racing journalist extraordinaire and author of the excellent MotoGP Technology (2nd Edition, 2010).

“Rossi,” Spalding responds, “is usually on DID’s finest ERV3 in 520 size. Maximum mileage is about 500 km. The only real difference in the final drive is that titanium sprockets are used, since launch control beats the crap out of aluminium (sic) ones.”

520- and 525-sized chains are generally found on 600cc sportbikes and middleweights, with a ⅝-inch “pitch” (distance from pin to pin) and an inner width of ¼- or 5/16-inch respectively. The 530 size usually found on 1000cc streetbikes uses the same ⅝ pitch, but with an inner width of ⅜ in.

DID claims an 8,660-pound tensile strength for the 520 ERV, a weight of 3.3 pounds per 100 links, and it also claims its X-ring design greatly reduces friction compared to an O-ring chain. The “No-ring” days, when people were looking for every ½-hp on their RS125s, seems to be just about over. Some things, like drive chains, may be too highly evolved for even the big factory teams to improve upon. At around $140 on Amazon, the ERV might be the most affordable component on a MotoGP bike. As for lube, the sealed X-ring design isn’t going to need anything, especially if it’s being replaced every 300 miles. But we have seen those guys spray WD-40 on entire bikes before packing them up in their crates.

Actual titanium sprockets, on the other hand, seem to be much more difficult to source. Titanium is heavier than aluminum, harder to machine and more expensive. The factories must think it’s worth the added expense, though, when it’s time to activate launch control and send all 220-plus horsepower to the rear tire ASAP. Spalding speculates those Ti sprockets are made in-house.

The third edition of Neil Spalding’s MotoGP Technology should be out in mid-2017!

PS: In reference to last Monday’s AskMOAnything, dealing with MotoGP clutches, here’s a quick video of the fastest way to disassemble one. Thanks for sharing, Evans Brasfield.

As always, direct your motorcycle-related questions to AskMoAnything@motorcycle.com, though some say we’re better at non-motorcycle-related ones…