Ive got a 525 erv 2 on my 999r.
I ran a 520 on my 998s no worries, but went for the 525 this time.

There's no good reason not to fit a 520 if you want to, if it's good enough for a superbike etc...........
Just make sure it's a decent one or it will last around 23 minutes before you need to replace it! :lol:

[Edited on 23-6-2005 by desmojen]

A number of owners have changed to a 520 chain size for weight savings. The arguement being that if a 520 chain is OK for a race bike it’s OK for a street bike.

Bad idea.

The chain manufacturers recommend 520 chains for 750-900cc bikes and 525 chains for 1000cc bikes on the road. A 525 chain is wider, with thicker plates, so it’s about 10% stronger than a 520 chain.

For example, the DID Exclusive Racing Series 520ERV2 chain has a tensile strength of 8,250 psi. with a weight savings over an 525HV chain of around 128 grams. Since the 520 and 525 chains need different sprockets, replacing the rear sprocket at the same time with an quick change rear with an aluminum sprocket will save an additional 475 grams.

A number of race bikes will use a 520 chain with no problems, but a race bike’s chain is inspected and replaced much more often and the lighter weight of a racebike results in lower chain loads than the street bike version. No matter how much horsepower a bike has, the maximum chain tension occurs during a wheelie, so the weight of the bike-plus-rider is the controling factor.

Heavier street bikes (and riders) will experience higher chain tension than race bikes.

Another factor that will affect chain survivability is front spocket size.

Ducati bike models have a wide range of torque output and the size of the chain and Ducati’s selection of sprockets reflect this range of outputs. All Ducati current models, except the 748 and 749, come with 15-tooth front sprockets. The 748 and 749 series (with the exception of the 749R) all have torque outputs below the 78Nm of the original 916, so they are supplied with 14-tooth front sprockets. The 748’s get 520 chains. The more powerful 749R (82Nm) is 15-tooth.

The 749’s get 525 chains, probably more for parts standardization than for strength. I remember from the product introduction that that was one of the major design objectives of the new models.

Starting with the higher torque 916-series (and 749R), and continuing with the 996, 998 and 999, the factory moved to a 15-tooth front sprocket and a 525 chain. Why? Because more torque means more chain tension and a 15-tooth front sprocket lowers the tension in the chain by seven percent. A 525 chain has a tensile strength that’s ten percent higher. So you get an overall 17 percent stronger setup.

Still-higher torque SP, SPS, R and Corsa models output over 100Nm so how do they survive with 14-tooth sprockets and light-weight 520 chains? That’s easy. Once you get over a certain torque level (for a given weight bike) the bike will wheelie before the chain tension exceeds it’s strength limits. At least for awhile ... chains on these bikes don’t usually see 15,000 miles of service.

So, what does this suggest about changing our final drive components? Three things.

First, as a general rule, it’s better to increase the rear sprocket size to avoid the higher chain tension resulting from a smaller front sprocket. Changing from a 15 to a 14-tooth front sprocket will result in a seven percent higher chain tension.

Second, the heavier the bike, the higher the chain tension needed to make it wheelie and the higher the maximum chain tension it will experience. So, a 680 pound 916-plus-rider will generate a higher chain tension than (say) a lightweight Corsa-plus-jockey or even a Suzuki GS-X. When a chain under tension elongates 10 percent, it needs replacement - frequently for a Corsa bike.

Third, combining a change to a smaller front sprocket with a change from a 525 to a 520 chain on a higher-torque model Ducati will significantly weaken the final drive load capacity. Reports of chain failures are common enough, so it may not be wise to ignore this point for the sake of saving 275 grams of chain weight.

I knew mighty Shazaam would say something like this. :D

comprehensive as ever Shazaam, nice work,.

Yep, he's a walking enciclopedia :cool:

You took the words right out of my mouth :D

You talk a lot. :D

No, cos the Sigma R looks like it could pull a ship and is way too much overkill, even for a 999R. The thing is huge!

Ah ha. Weve been here before.
the 520/ 525 thing was explained to be by jhp as this.

Hold a full match (525) between your finger and thumb, bet you can break it. Now with half the match (520 smaller) try again . Its a lot harder to break!!;)