Suspension leverage

[thewwkayaker]

Question about suspension leverage.

Longer shock travel to suspension travel gives a "better" leverage ratio.

What is the advantages of "better" leverage ratio?

I understand that a softer spring can be used - but what is the benefit to the rider? More supple ride? Why (if that's the case)?

Just curious (I like to know how things work).

[Ninja]

Lower Suspension leverage, allows the damping in the shock to do a better job of keeping the tire on the ground, and preventing bottoming out. ie compression damping.....

[brentomatic]

Hey WWKayaker,

Do you know Rob Cartwright?

Just wondering...

Back to topic.

B

[thewwkayaker]

Originally posted by ninja #2
Lower Suspension leverage, allows the damping in the shock to do a better job of keeping the tire on the ground, and preventing bottoming out. ie compression damping.....

OK - how/why? Esp. the first point.


_____________________________

And yes I know Rob - he is (or was) on the pro circuit in paddling. I've paddled a few times with him. Why?

[brentomatic]

He's my riding buddy. He is on this board under "C-Note." When I ride, he is the cat that I ride with. I saw your name on here and wondered if you knew him, that's all.

[TheGiggler]

think about a 1" stroke vs 4" stoke on a big bike.

if you land to flat the one option pushes all the oil through the valving over a distance of 1".

the second option, the valving won't see the same load as it does not need to be so restrictive.
say it's compression damping, now instead the valving could be 1/4 as restrictive to get the same overall damping (because it has 4X the stoke).

this is obviously grossly oversimplified.

same thing for rebound. there is a lot of energy from the spring recoil that the rebound damping abosorbs.... by having a longer travel shock the valving is not stressed as much.

also, a longer stroke shock can have more room for oil, so it shouldn't have as bad issues with heat.


really though, the physics says it all. if the leverage ratio was 3-1 the shock sees three times the force as the rear wheel. if the shock ratio is 1-1 then the shock sees the same force as the rear wheel. so if you took these two options and hucked the same cliff, the higher leverage rate puts more force/load ont he shock... hence working it harder.

[thewwkayaker]

OK so clarify this for me - with less force of moving fluid thru the system (which I understood before, as I do for not working the shock too hard) what's the benefit? Why should I care how hard the shock is working (I can see heat being a very small factor)? How is the ride experience changed?

[thewwkayaker]

brentomatic - I've run into Rob twice when biking (well not literly of course) but we've never biked together. I'd actually like to go biking with him sometime - he's such a good paddler, would be interesting to see how those skills/abilties transfer over to biking.

[trail worker]

basically it's all been said above.
I actually loved the 3.5:1 ratio on my old '99 VPS1..sounds like a high ratio, and it's about all you should push on a fox shock..but it was the perfect sweet spot in my opinion
how i loved the abililty of the old green tank to just roll over anything and keep on going. If i could find one in good shape right now i'd get it repainted and ride it like the good ol' days.

[Ninja]

[QUOTE]Originally posted by thewwkayaker
[B]OK - how/why? Esp. the first point.

Okay..... I'm not the type to give people long winded anwsers. First off..... have you really thought about this subject for a while? or did you just post it up for someone else to tell you all about it.

I don't mean to be nasty about it, but really do you think the damping in the shock, is going to work as well when it comes out of the factory set middle of the road ( lets say 500 pound spring and a leverage ratio of 2.7:1). But instead that "said" shock ended up on a Large Rocky Mountain RM7 with a 3.5:1 leverage ratio. With a rider that weights 210 pounds, (ps I'm 6,5) with a 850 pound spring on it. Do you as a Consumer expect the same level of suspension damping, and range. Ie compression/rebound, and bottom out resistance. As a bike that was properly designed, with factory spec in mind. Or is it Just Suppost to Work ( pure f**king magic ...?)

[brentomatic]

Originally posted by thewwkayaker
brentomatic - I've run into Rob twice when biking (well not literly of course) but we've never biked together. I'd actually like to go biking with him sometime - he's such a good paddler, would be interesting to see how those skills/abilties transfer over to biking.

They haven't transferred yet! :lol: Just kidding. We ride "almost" every weekend. I'll fire you a pm when we ride next. Do you have a real name? If so, I'll tell him about this chat.

b

[thewwkayaker]

So nija your saying that you need to be within manufacturing specs. I understood that.

Assuming you are within the specs, is there ride QUALITY for using a smaller ratio?

Yes I thought about this but I can't pin down if the QUALITY of the ride improves (meaning say better small bump performance, better damping, wheel stays on the ground more).

[Ninja]

Originally posted by thewwkayaker
Yes I thought about this but I can't pin down if the QUALITY of the ride improves (meaning say better small bump performance, better damping, wheel stays on the ground more).

Exactly. It does what the manufactor designed the shock to do!

[thewwkayaker]

You are missing my point-

The specs are for a RANGE. Ranges usually overlap.

Within a shocks specs, is it better to use a smaller ratio or does it not matter? Eg. if I have two shocks, one has a longer shock length, both would be within spec for X amount of susp. travel would the longer shock give a better ride quality or would there be no difference?

[Ninja]

Originally posted by thewwkayaker
You are missing my point-

The specs are for a RANGE. Ranges usually overlap.

Within a shocks specs, is it better to use a smaller ratio or does it not matter? Eg. if I have two shocks, one has a longer shock length, both would be within spec for X amount of susp. travel would the longer shock give a better ride quality or would there be no difference?

If both are within spec range, you would probably not notice a difference. But in theory, the longer stroke shock should be easier to "tune" more exactly.....

[derwood]

No PFM involved.....

Its all about how fast the oil has to move through the valving or shims.If you can reduce the speed at which the damper has to move ,you can control the effect of restricting the flow better.This will also keep you from "blowing" the shock.

from what I hear,3:1 seems to be a good number to work with.:)

and from what I understand,OEM shocks are often valved to the charictaristics of an individual suspension design(ie. what works on a norco wont work as well on a kona)

[Ninja]

Originally posted by derwood
PFM involved.....



My Instructor used say that all the time, when explaning how a pnp junction of a transistor works... used to make me laugh.