Fork Springs

CLEMTOG

Hero member
Racetech do variable pressure springs for Laverda's for the 180's and 120's, I think a choice of three according to your weight and riding preferences, great website allows you to input and get answers.
CLEM
 

Tippie

Hero member
Location
Dr?bak, Norway
Couldn't find variable there Clem but just search on phone. They didnt used to have them, had an explanation about why. Maybe they have changed. Maxton dont either. Different schools of thought, variable or non.
 

piranha-bro2

Hero member
Location
Melbourne
A guy at a suspenders place in Melbourne told me the Wilbers springs they sell are single rate but actually perform better than dual rate springs sold by other manufacturers. Sounds like RT and Maxton would agree.
 

Vince

Hero member
How it works with Race Tech is its hard enough to dial in the damping with one spring rate, using muiltirate just added way to much complication. As an example, Icon shocks come std with Muiltirate springs, its a design decision to deal with the possibility of pillioning plus luggage. I don't pillion so why would I want to compromise at least half the rear suspension travel for something I don't do. It also impacts, little pun, on setting sag as suddenly you arrive at a harder spring and sag stops its consistency. I have heard muiltirate springs are being used in some racing applications in KTMs for high speed woops in Desert racing, my twin shock Ohlin's on my 82 Husky came with dual rate or 2 separate springs. One long and one short, the later soaked up small bumps, in my case it would completely spring bind so I needed the heaviest rate one, not available in Oz so Steve Cramer the Oz distributer got one from Sweden. They work so well when correct. I think its to add some rising rate effect on there long travel, in short road type shocks its a bigger compromise for what travel you get. Anyway it still seems counterintuitive to me and that's exactly what I also said in that Physics question a while back. If it works for you the OK.
 
Last edited:

Dellortoman

Hero member
Ohlin's on my 82 Husky came with dual rate or 2 separate springs. One long and one short, the later soaked up small bumps, in my case it would completely spring bind so I needed the heaviest rate one
It's supposed to bind Vince. That's how it works. If you select a closely wound spring that's so stiff that it'll never bind, you'll have created a single rate spring system.

With a dual rate system, both springs (or parts of springs if it's all one spring) compress when loaded. As the springs compress, the spring rate is constant, up to the point that the closely wound portion binds. Then the bound part effectively becomes a solid spacer for the remaining part of the spring, thereby changing the spring rate because the effective spring is now shorter.
 

Vince

Hero member
I take tour point Cam but that short softer spring went bound with just my weight sitting on it, it did nothing at all except become a solid spacer. When it was suppose to take up the small hits. Towards the end of twin shocks on Dirt bikes Ohlin's started producing apparently cartridge type damping. Anyway those shocks are still by far the best example of any rear suspension I have used and that includes the way more modern Showas that were dialled in and revalved by Terry Hays on my late model Husky.
 

piranha-bro2

Hero member
Location
Melbourne
Your lighter spring was simply the wrong weight, Vince - it has to be dialled in the same as your heavier one. Maybe the heavier one should be the shorty and only come into play when the 'std' spring is fully compressed when you hit an almighty bump that would bottom your suspenders out. That's a novel take on it!
 

Vince

Hero member
It was the short lighter spring that was wrong, replaced by the colour coded Purple spring supplied from Sweden, the hardest in there system as it was not available in Oz. The short soft spring took out the small braking bumps into corners and the long spring worked on big hard landings from jumps. That model of Husky came in either Endro with approx. 230mm of rear travel and MX or Desert Racer with 300mm of rear travel and the same forks for both. I acquired the longer MX shocks from a mate and yes it has a crazy high seat height. Rally fun to ride though especially when I fitted the disc brake Kawasaki MX forks and my first Race Tech Emulators.
 

Dellortoman

Hero member
I take tour point Cam but that short softer spring went bound with just my weight sitting on it, it did nothing at all except become a solid spacer.
Ok, that's a different scenario to what I was imagining. I guess it's intended for a lighter rider than you. So yeah, if it binds up as soon as you sit on the bike then you need a stronger small spring. As Quentin said, the springs should be the a similar rate. I guess single springs wound as a dual rate are a better match than two separate springs. Both parts of the spring are wound from the same piece of wire, so will compress at similar rates until the closely wound section closes up.

I suppose the other approach is to lose a bit of weight. But as a fat bastard myself, I know that's easier said than done.
 

Tippie

Hero member
Location
Dr?bak, Norway
make sure you are looking at the Racetech USA site
CLEM
That is the only site that comes up for me Clem. Could you give a link to a different one for us.
interesting is that when I put in a Corsa with 80kg rider, normal riding, it had 0.85 springs, lighter than it had recommended for my SF.
 

Ventodue

Hero member
<snip> When I put in a Corsa with 80kg rider, normal riding, it had 0.85 springs, lighter than it had recommended for my SF.
FWIW, Tippie, it's what the UK importer (PDQ Motorcycle Developments) came up with for my Corsa (me, same weight as thee).

Am very happy with the result. Trail braking greatly improved :)
 
Top