Advantages/disadvantages of progressive rate shock spring

[RM_Dude]

Looks like most people of DRN suggest a straight rate shock spring, but why?
What are the flaws of a progressive rate spring?
What does a straight rate do better than a progressive?
More stable, less bottoming, etc ?

Thanks in advance.

 

[marcusgunby]

A linkage gives progression so we do not need a progressive spring.I believe they are trying to get a softer intial compliance and still good bottoming-the linkage can also be made to achieve this.Also a softer intial spring rate allow the shock to hang down into the stiffer part of the curve-so doing the opposite to what its aim is.

 

[Jeremy Wilkey]

Marcus,
This is gonna surprise you, but... We have begun to exaim the use of progressives in front forks.

BR,
Jer

 

[DEANSFASTWAY]

Alot of times that used to be the trick on big street bikes . FORKS that is .

 

[MACE]

Originally posted by Jeremy Wilkey
Marcus,
This is gonna surprise you, but... We have begun to exaim the use of progressives in front forks.

BR,
Jer

Yeah, baby. Don't forget the external preload adjusters.

I've always thought the reason folks didn't like previous progressives is that the rate crossover was only right for a narrow range of wheel loading*. But you have some ideas to deal with that I bet.


*Heavier or lighter rider or bike mods affect this.

 

[marcusgunby]

Interesting topic-not sure what i think about progressives, other than the ones i have tried on std kwaks were horrid.The theory seems sound to the use of them.
If the airspring takes over (mainly after the 1st part of the travel)then how does a stiffer rate at the end help?

 

[MACE]

I want dead soft at the start, not necessarilly stiffer at the end. Give me soft for 1/3 - 1/2 travel then stiffen up. I want it to do rock fields like my 300lb XR650L and whoops like my WR250. I think soft springs, moderate stiff LSC and light HSC might be the cat's meow. Stiffen me up when I slam a surprise ditch. (Remember I'm a trail squid.)

I'm not sure it is possible to get the progression rate I have in mind simply by altering coil pitch and relying on coil bind to get the variable rate. It may require an opposing spring like a giant top-out spring to get there.

Sort of a lowrider contractive contrivance.

I'm probably smoking crack again. :confused: