rear suspension?

[AFM327]

I know the H and L model have different leverage ratios. Anyone know how the rear spring rates differ between the two? I've heard of different rockers being made anyone heard of the differences?

[zimm]

in essence,

shocks are interchangeable

H models have a more linear effective spring rate than L's

L models have softer springs

in practice,

stock shocks are crap, so interchangeability doesnt matter

stock springs are on the stiff side right across the range due to pillion carrying ability (kit manual specs a softer spring to be fitted)

as to which rocker arm to use.. its personal preference.. I prefer the H rocker with its less progressive action,

[AFM327]

My question was more about the rockers and how they effect the springs. I have two SP race bikes with penske triples, similar to a top ohlins shock, and even though I weigh 220 lbs (15 stone) I need a very light spring with the L rocker and still have tire wear issues due to the ratio. I've also heard of a rocker that was made for the Hawk races bikes and was curious as to the spec differences. The PB article on the RMKD bike got me to thinking about it more a he used the H1 linkage. I plan on making one bike a superbike, ala the rmkd bike and I'd like to play with the ratios. I teach for a trackday provider here so I have plenty of track time for working it out. Anyone have an H1 rocker assembly they'd like to part with? If someone has the specs on the hawk part I'd like that too as I have a friend that can make parts for me with his new C&C three axis machine.

[jake]

a guy who used to race zxrs, comes on here now and again, scooter916 or somethin. Anyhow, he did have what i think where hawk rear linkage.
Ive also heard that the L models linkage causes rear probs. Also, Mike hose maybee able to help.He raced an L to very good effect at the tt, he had a custom linkage on his, and said it really transformed its handling.
im not 100% sure, ill have to go and have a measure, but i think the h2 is different again to the h1 and L..

[AFM327]

The PB article listed the differences on the standard linkages. 50/50 for H1, 65/45 for H2 and 60/40 for L. For those racing and using H1 linkage what is your weight and what weight spring are you using? I weigh 220 lbs (15 stone) and use a 350lb spring with the L linkage, another racer who was about 20 lbs lighter used a 300 lb spring. He also ran a 5.5 marvic mag rear and a 16.5 front with dunlops. I'm fast enough to have won a class championship so I'm not terribly slow, just old and fat.
For comparison purposes I have an SV and it has a 525 lb spring for my weight.

[zimm]

ok,

the H model f3 manual states that the stock spring is 8kg/mm, and to be swapped out for a 7.75kg/mm spring.

my calcs make that

8 (kg / mm) = 447.979317 pounds / inches
7.75 (kg / mm) = 433.979963 pounds / inches

fwiw, ive only ever come across the 50/50 and the 60/40 rocker's
if there is a 65/45 rocker thats H2 specific, i'd be interested in trying one, but cant really complain about the feel of the H1 setup. Certainly for me, its miles nicer than the L setup which i tried on there for one trackday... made it feel like my old L4 .. boingy and harsh with less traction


for comparisons, my bike's a not particularly "trick" H1, im only about 130lbs, and I am "terribly slow".. not old or fat though

[AFM327]

So Zimm, what weight spring is on your bike? Spring weight isn't determined by a note on a page but by rider weight, linkage ratios, track, etc.... If I put a 447lb spring on my bike there wouldn't be any sag at all.

[jake]

i think mine is a 190 ohlins. the guy who had it set up was the same weight as me.
h2 linkage and im 11 stone. feels very soft mine, but feels great on the go

[zimm]

So Zimm, what weight spring is on your bike? .

H1-SP (J1) spring on an L shock.. because it was there.. its crap, and the spring is too stiff for me. I'll get a proper shock for the coming season.

Spring weight isn't determined by a note on a page but by rider weight, linkage ratios, track, etc....

granted .. i was just looking for a reference point re the stock setup

If I put a 447lb spring on my bike there wouldn't be any sag at all

true.. but you've got an L and they do run softer springs than the H.. i just dont have the data here for an L so dont know how different.

the other thing... is whether or not the "dog-bones" locate to the swingarm at the same point on both L's and H's.??. because if not that would effect a noticeable change in the effective spring rate. ("dog -bones" are the same across the range from H1 to L9 btw)

[AFM327]

Well it's good to know that the dogbones are the same, so who has a couple H1 rockers they want to ship to the US? You might see if it's worth just getting the kawi unit revalved with the correct spring, springs are cheap and pretty easy to change. That was one thing my suspension guy told me when I first got the ZXR. He could get the stocker to work well, it would just need more maintenance than the Penke/Ohlins units. I've got a local guy now that helps and we'll service and change the suspension a couple times a year, forks and shocks, the faster I go the more I've learned and the more it needs adjusting. Still never able to run a soft pirelli without tearing, mostly due to the ratio and spring on the L model I think. Maybe switching to an H rocker will help. It's still a whole lot easier on tires than the R1 I use for teaching at trackdays. Too many squids buy liter bikes and while they can't go around a corner with any speed I have to work the 400 too hard to keep up at times. No point wearing out the race bike.

[will#224]

There was a hawk rear linkage and dog bones on ebay a while back, it went for about £70 i think.

It was suggested the whole thing was different in size, the bolt holes were between the h1 and l model and the dog bones corresponded.

I asked for some measurements but he didn't reply, otherwise i would have made a new linkage and dog bones.

[AFM327]

Yea, was it on eBay and bid on them too. It would certainly be nice to have the specs for comparison to the other stock models.

[jake]

There was a hawk rear linkage and dog bones on ebay a while back, it went for about £70 i think.

It was suggested the whole thing was different in size, the bolt holes were between the h1 and l model and the dog bones corresponded.

I asked for some measurements but he didn't reply, otherwise i would have made a new linkage and dog bones.

aye, thats the one im on about. sooter916 on here. he had a few nice bits and bobs. If asked on here, ive no doubt he would of measured it up...

[mick41zxr]

If you have access to a machine shop you can modify a ZX6r linkage to give you the 50/50 ratio of the early ZXR's. Skim down the center pivot to the same as the ZXR & replace the bushing with the ZXR's bushings as the ZX6 uses smaller dia linkage bolts. This will give you a more linear force curve at the rear wheel. The rising rate of the standard linkage generally with play havoc with the damping curve. With this link I run a 10kg spring.
Regards,
MB