520/525 chain

Ok with Snetterton coming up I need to buy some new gearing for the race bike. However I don't know if the bike has had a 520 chain conversion or not.

What do I need to measure to find out? I've tried to figure it out myself but seem to be having a bit of a slow day.

try this link

http://www.z1enterprises.com/referen...ntypesize.aspx

Ahh excellent, cheers for the link.

It looks like I need to measure the width of the rollers in the chain, not including the plates.

why not just look at the sprockets. All mine have got 520 in the part number thats stamped on it

[embee]

Originally Posted by chunkytfg

why not just look at the sprockets. All mine have got 520 in the part number thats stamped on it

Don't rely on this, I fitted an aftermarket sprocket (+1 g/box) and it is stamped with 520 but it is definitely a 525.

Just measure the thickness.

The first number is the pitch in "eighths of an inch" so a 5XX is 5/8" pin to pin, the second and third numbers are the nominal sprocket thickness in 1/8" units but without a decimal point, so X20 is 2.0 eighths (1/4"), and X25 is 2.5 eighths (5/16"). The sprockets are actually slightly under the nominal size to give side clearance.