KZ750 H2 LTD front fork springs

Hi folks. My front suspension is saying "not more please". Last time I checked the springs were at 483mm service limit (free lenght); and that was 5 years ago.
I am riding my Kawi every day since I sold my car. So I can´t disassemble for measurements.

Since I live in Argentina and buying international is a PITA , I found a local motorcycle spring factory that will make the springs with the following data:

a) Original Free length = 486mm
b) Outside diameter = 25mm
c) Inside diameter = ?
d) Wire diameter = ?

I have found the 2 first from progressive suspension web site.



Does anyone have a fork spring to measure? Thanks in advance.

Free length is not overly important. You can use a piece of PVC pipe to make up any length discrepancy.. Anywhere between 425 - 480 will be fine. Tell the spring guys you need .9 kg spring rate and 1" (25mm) OD. They will decide the wire size needed based on spring rate. Oh and straight rate is better than progressive spring rates. Sonic Springs has a nice write up on this

1981 KZ650-H1 CSR. 462 lbs. single disk front brake.

Spring wire diameter = 4mm (using a digital caliper)

note: Progressive doesn't list the 81-83 650, but they list the 1980 650 which uses the 11-1106 fork spring kit.

Martin: Thanks. So ID should be (25-(4x2)) = 17mm right?

martin_csr wrote: 1981 KZ650-H1 CSR. 462 lbs. single disk front brake.

Spring wire diameter = 4mm (using a digital caliper)

note: Progressive doesn't list the 81-83 650, but they list the 1980 650 which uses the 11-1106 fork spring kit.

1981 KZ650-H1 CSR. 462 lbs. single disk front brake.

Spring wire diameter = 4 mm (using a digital caliper)

ID = 17.6 mm (approximate. using a digital caliper).

OD = 26.5 mm (approximate. using a digital caliper)

Spring seat guide OD = 27.5 mm (fits between the spring & spacer, above the springs)

Spacer above spring OD = 27.1 mm

ps: the spring numbers don't add up, but that's what I got. I measured at several points & both ends. measurements varied by 0.1 to 0.2 mm or thereabouts.

Thanks Martin.

Springs arrived.
Going to install them next saturday.