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from what i understand a lower leverage ratio is better then a higher one. or is it not that simple? the santa cruz site shows the wheel travel and shock stroke, so i calculated the leverage ratio. both bullit and heckler are single pivot, so they can be compared. the same goes for the v10 and the blt - both are vpp.
so why the huge difference?
and what effects has it got?

bullit - 2.85
heckler - 2.38

v10 - 3.63
blt - 2.22
 

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Equal opportunity meanie
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No leverage ratio's are ever constant for a rotating system. They always end up being a projected curve. The shape and slope of the curve is what determines the behavior of the back end through the stroke (along with the axle path).
 

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^^^ both very true..^^^

but you have to ask your self why all other mtb mfg as well as moto, off road, just about any high performance suspension application strive for a lower leverage ratio (longer/large shock).
Also keep in mind, that 'Joe' works for SC....there is no way he is going to say that lower average leverage rates are benefical when their flagship bike (V10) has the highest rate (worst) in the bike biz.

Lower rates allow lower spring rates (at extremes like a heavy rider on a v10, you might not be able to even find the proper (high enough) spring. Because of the lower leverage and lower spring rate, the shock sees lower forces.....and thus can utilize lighter valving (damping). All this equates to a more controlable, easier tuned, and lower stressed shock if a lower rate is achieved.
 

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Equal opportunity meanie
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Less damping required = smaller/lighter shock design available, (or vice versa, everyone wanting smaller/lighter shocks lets them get away with lighter damping without sacrificing durability on a lower leverate frame).

The MTB world is days behind the moto world when it comes to suspension tuning. I for one still believe that higher initial leverage ratios and a progressive curve is necessary to overcome the marginal damping that MTB shocks can offer in their current form. There just isn't any reliable way to make a lower leverage frame/shock quite as compliant as a higher leverage combo with a good leverage curve without major MAJOR tuning modification (which still ends up sacrificing the necessary end stroke resistance because of sheer volume - or lack of - in the shock).
 

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Pivotal figure
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Basically (very much so!) if the ratio is lower you'll have a softer spring and a longer shock stroke. This gives the damping portion of the shock more room to work which makes tuning much more precise. Of course it's a bit more complicated since ratios aren't usually the same throughout the stroke, that's where my eyes kinda start to glaze over and I start daydreaming.
 

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Elitest thrill junkie
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brake jack said:
from what i understand a lower leverage ratio is better then a higher one. or is it not that simple? the santa cruz site shows the wheel travel and shock stroke, so i calculated the leverage ratio. both bullit and heckler are single pivot, so they can be compared. the same goes for the v10 and the blt - both are vpp.
so why the huge difference?
and what effects has it got?

bullit - 2.85
heckler - 2.38

v10 - 3.63
blt - 2.22
Nope not that simple. As other's have stated, it changes through the travel. A low-leverage bike can suffer much more stiction/friction than a high leverage bike. So the shock pivot bushings, shaft bushing, the suspension pivots, all will contribute to some resistance to travel, and a higher leverage bike would not have that resistance. The high leverage bike is harder on the shock though, so the materials and quality of the shock are more critical, a bigger piston-face or fluid displacement may also help with the high-leverage bike, and the spring rate sometimes ends up being a limiting factor, but on a low-leverage bike you run into a similar problem because you need smaller incriments of spring weights. For a high-leverage bike it may be ok to have springs from 400lb to 800lbs in 100lb incriments, but for a low-leverage bike you need springs from 200lb to 400lb in 25lb incriments. The point is that there are limits and negatives, and just because something is "low leverage" or "high leverage" doesn't mean it's good or bad. My "low leverage" foes had real crappy suspension compared to the competition, my current "high leverage" bike is very nice and has a good suspension curve.
 

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Ideas Above My Station...
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It just the ratio of; Shock Stroke : Travel.

In Simple terms:

So if you have a bike with 5.75" travel fitted with a 2.875" stroke DHX for instance the ratio is 2:1 because for every inch the shock moves, the rear wheel moves two.
1:1 is perfect in theory because each inch of travel is using less of the capacity of the shock. Tuning differences are far better affected on a lower ratio set-up, because a small change on the shock, means a small change on the travel.

If for instance you changed a setting that effected the mid stroke of a shock, say the middle 1" on the aforementioned 2.875" DHX, then on a bike with 8.625" travel (A ratio of 3:1) would have its mid stroke effected also but because of the ratio of 3:1 the effected travel would be 2.875", meaning the change has been mutliplied. So a small change shock-side of things results in a larger difference in travel, this can make it harder to control settings, when small tweaks can result in huge changes.

So in theory a lower ratio means you can make smaller tweaks, and so make smaller adjustments to the travel, meaning finer tuning.

This also applies to deficiencies, andinaccuracies in the shocks performance / settings., and inaccuracies in the shocks performance / settings. A small deficiency in the shock would result in more of the travel having the ill-effects in a higher ratio set-up.

This is of course all 'In- theory', as many different suspension designs means that the effects of shock stroke are very different anyway.

A ratio of much over 3:1 would result in alot of pressure on a shock, and much higher operating stresses, because the compression force would be so high and it would be very hard to tune successfully.

Wow, having done years of physics / mechanical dynamics, its harder to explain than i thought, so apologies if thats hard to understand. Its late here now.
 

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Orange-Goblin said:
It just the ratio of; Shock Stroke : Travel.

In Simple terms:

So if you have a bike with 5.75" travel fitted with a 2.875" stroke DHX for instance the ratio is 2:1 because for every inch the shock moves, the rear wheel moves two.
1:1 is perfect in theory because each inch of travel is using less of the capacity of the shock. Tuning differences are far better affected on a lower ratio set-up, because a small change on the shock, means a small change on the travel.

If for instance you changed a setting that effected the mid stroke of a shock, say the middle 1" on the aforementioned 2.875" DHX, then on a bike with 8.625" travel (A ratio of 3:1) would have its mid stroke effected also but because of the ratio of 3:1 the effected travel would be 2.875", meaning the change has been mutliplied. So a small change shock-side of things results in a larger difference in travel, this can make it harder to control settings, when small tweaks can result in huge changes.

So in theory a lower ratio means you can make smaller tweaks, and so make smaller adjustments to the travel, meaning finer tuning.

This also applies to deficiencies, andinaccuracies in the shocks performance / settings., and inaccuracies in the shocks performance / settings. A small deficiency in the shock would result in more of the travel having the ill-effects in a higher ratio set-up.

This is of course all 'In- theory', as many different suspension designs means that the effects of shock stroke are very different anyway.

A ratio of much over 3:1 would result in alot of pressure on a shock, and much higher operating stresses, because the compression force would be so high and it would be very hard to tune successfully.

Wow, having done years of physics / mechanical dynamics, its harder to explain than i thought, so apologies if thats hard to understand. Its late here now.
well put:thumbsup:
 

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atomicAdam said:
just to put this out there - doesn't what really matters is if you like the ride or not?
Absolutely, unless you cannot find a spring rate (either small or large) or shock with proper damping for your combination of weight and abe leverage ratio...
 
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