View Full Version : Anyone tried EX500 fork springs? are they stiffer?


RBN
January 21st, 2014, 10:02 AM
Took the rescued ZZR out for a blat today and it rides real nice! But holy hell the forks are unrideably soggy!, I'm about 85kg and these bottom out at the slightest hint of a pothole, which we have millions of round here.

So naturally I've come home and made up a couple of 2" spacers and shoved them in but to be honest it ain't much of an improvement.

So it's got me thinking about the old wrecked ex500 skeleton that's dumped at the bottom of the garden.

Reckon those springs'll be a lot firmer?

[UPDATE] They now have about 3.5" long spacers installed.................and are just about right (insert stunned expression here).

InvisiBill
January 21st, 2014, 12:52 PM
Stock Gen2 EX500 fork springs are .585kg/mm. According to RT's calculator (http://racetech.com/ProductSearch/2/Kawasaki/EX250%20Ninja%20250R/1986-2007), that's good for a ~110lb PreGen rider. Gen1 springs are longer, but I believe they're the same overall rate.

The good news is that you should be able to find plenty of Gen2 EX500 springs, as they're worthless on the bike in stock form. For a 100lb rider, they recommend going up to .75kg/mm spring. Even for a 31lb rider (an odd number, the lowest their calculator (http://racetech.com/ProductSearch/2/Kawasaki/EX500%20Ninja%20500R/1994-2009) will accept) they recommend a spring 10% stiffer than stock. From what I've seen about stock springs on several bikes, I'm pretty sure Kawasaki has no idea how to calculate spring rates. "Fork springs for a 300lb rider coupled with a rear spring for a 100lb rider? Sounds perfect!"

FYI, the Gen1 has 36mm forks and the Gen2 has 37mm, like the PreGen/NewGen. However, the Gen2, NewGen, and PreGen seem to be able to share parts (all three use the FRSPS2938 and FEGVS3501), while the Gen1 is different (FEGVS3301, no spring listed). I'm not sure exactly what the real differences are.

EX250 PreGen (http://racetech.com/ProductSearch/2/Kawasaki/EX250%20Ninja%20250R/1986-2007)
EX250 NewGen (http://racetech.com/ProductSearch/2/Kawasaki/EX250%20Ninja%20250R/2008-12)
EX500 Gen1 (http://racetech.com/ProductSearch/2/Kawasaki/EX500/1987-93)
EX500 Gen2 (http://racetech.com/ProductSearch/2/Kawasaki/EX500%20Ninja%20500R/1994-2009)

KawiKid860
January 21st, 2014, 05:06 PM
I can tell you that EX500 fork springs sure aren't stiff in an ex500 haha.

If it's a true EX500 (87-93) I believe it will have 36mm fork legs, the Ninja 500 (94-09) has 37mms.

choneofakind
January 21st, 2014, 11:05 PM
They're a little better, still a little light for me and I'm a leightweight. Just go and get springs that are correct for your weight on the racetech calculator. These will work okay but will still be a tad soft.

RBN
January 25th, 2014, 07:56 AM
That's great, thanks for the info. I figure it must be worth a go, even if it just lets me put 2" of spacer in instead of 3.5" :P

choneofakind
January 25th, 2014, 08:50 AM
Determine your spacer length needs based on the sag of your bike.

More spacers does not a stiffer front end make.

Proper spring rate and damping does that.

RBN
January 25th, 2014, 12:52 PM
Determine your spacer length needs based on the sag of your bike.

More spacers does not a stiffer front end make.

Proper spring rate and damping does that.

Aye agreed, and if I was setting it up for good handling then I would certainly go down that route.

FvnnyL3tt3r1ng
January 25th, 2014, 01:02 PM
I have some sonic springs that I have yet to throw in. I'm trying to get enough seat time so that I can really feel all the differences in handling between the stock (crap) and the upgraded springs.