I am going to order new 520 sprockets for my '02 F4i.
15 (-1) in the front and 54 (+8) in the back.
I plan on getting the Parts Unlimited X-ring chain.
What length should I get? I can get 120 or 130 link.

 

I ordered the same exact sprockets (-1 +8) for my 02 F4i and I got the 120 link chain and hopefully it works. Not sure though because I didnt put em on yet. Hope that helps. I wouldn't recommend the 520 though because its weak. I got mine in 525.

 

I would get the 130 525 pitch to be safe you could always take out links. That just my .

 

a 120 is fine...you'll probably end up at 116

 

+1 I'm pretty sure that's where I'm at with the same gearing

 

120 is good, buddy went with stock front and 56 rear and had enough. just curious, why 520 pitch?

 

i rode my boys f4 with a 15/64, and broke the brand new 520 chain. go 525 its not worth a few bucks. 520 is for a crf450... 50hp 200lbs. 110hp 450lbs is too much

 

you need four more links than whats on your stock chain divide the difference in stock sprockets and the new by two 8/2=4links

 

Sweet mathmatics but I would never put brand new links on a used chain..