Author Topic: Are there any rising-rate twin rear shocks?  (Read 2459 times)

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Offline John Orchard

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Are there any rising-rate twin rear shocks?
« on: January 26, 2014, 01:26:17 am »
Anyone know of any twin rear shocks that have either an increasing damper rate as the shocks goes through its travel, or even 2-stage damping with the second half 10-15% stiffer on compression & rebound.

I don't care what anyone says, if the first half of the travel is controlled by a lighter spring there has to be a lighter damping rate to suit the spring.

I tend to think that Yamaha might have been on to something with their BASS, pity it only relieved compression damping.
Johnny O - Tahition_Red factory rider.

Offline FourstrokeForever

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Re: Are there any rising-rate twin rear shocks?
« Reply #1 on: January 26, 2014, 09:08:00 am »
This is where your suspension guru comes into play John. It's all a matter of shim stacks and the size and placement of the oil flow holes.

All the springs do is hold the bike up off the ground and control the weight of the person on the bike. Once you have the correct spring for your weight and riding style, then the dampening circuit may need to be altered to achieve exactly how you'd like the suspension to behave.

Have you tried playing with oil volume and different weights? 
Arrogance.....A way of life for the those that having nothing further to learn.

Offline JohnnyO

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Re: Are there any rising-rate twin rear shocks?
« Reply #2 on: January 26, 2014, 10:25:27 am »
The initial 'softer' shims in the first part of the stack work in the early part of the shock stroke and the harder shims come into play on the big hits.. It's already sorted.
TBM you can only adjust oil volume on the basic emulsion shocks, not on anything with a bladder or piston separating the oil and gas.
ITC Ohlins from a Husky are the closest you'll get to progressive damping with an internal piston and bottoming cone stiffening the shock action towards the end of the stroke..

Offline shelpi

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Re: Are there any rising-rate twin rear shocks?
« Reply #3 on: January 26, 2014, 10:49:58 am »
Buy new shockers with high/low speed compression adjuster ;)

Offline Slakewell

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Re: Are there any rising-rate twin rear shocks?
« Reply #4 on: January 26, 2014, 12:39:26 pm »
Were not the 84 Husky's marketed as dual rate?
Current bikes. KTM MC 250 77 Husky CR 360 77, Husky 82 420 Auto Bitsa XR 200 project. Dont need a pickle just need to ride my motorcickle

Offline JohnnyO

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Re: Are there any rising-rate twin rear shocks?
« Reply #5 on: January 26, 2014, 12:43:00 pm »
Were not the 84 Husky's marketed as dual rate?
I've already mentioned the ITC shocks on the 83/84 Huskys..

Offline John Orchard

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Re: Are there any rising-rate twin rear shocks?
« Reply #6 on: January 26, 2014, 01:34:17 pm »
Thankyou for your input guys, Walter kind of answered my question.  I'm not interested in high/low speed compression adjusters, I figure if the shocks are set-up with the right valving to suit spring & rider then there is not a great need to be adjusting anything.

If the shock is under the control of the light spring (as in dual-rate springs) for, say,  for 70mm of the first part of the shock travel, then I want the damping to be light enough to let the suspension work correctly.  When the shock is under the control of the stiffer spring for the next 70mm I want the damping to be strong enough to control the spring.

I'm not interested, for now, about speed related valving changes, just 'piston position' related valving.  Walter I don't think one should have to buy a YSS with hi/low comp adjusters just to get a shock that matches dual-rate or progressive springs.
Johnny O - Tahition_Red factory rider.

Offline FourstrokeForever

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Re: Are there any rising-rate twin rear shocks?
« Reply #7 on: January 27, 2014, 08:54:23 am »
Sounds like you want your suspension to behave as most of us would like it John. Supple enough in the top of the stroke to soak up all the small sharp edged type bumps and yet be stiff enough at the end of the stroke to resist bottoming for the big jumps and fast sharp hits. If you already have progressive springs, you will need to modify the internal dampening circuits by way of adding, removing and or replacing shims and perhaps the bottoming cone. Rebound circuit will need adjusting the same way, without the bottoming cone of course. This is as far as I go with my knowledge of rear suspension. In the past I have sent suspension to my tuner of choice and have always been pleased with the mods. Mind you, that was for my moderns and I haven't felt the need to tinker with the old stuff other than rebuilding and spring rates.
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Offline 80-85 husky

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Re: Are there any rising-rate twin rear shocks?
« Reply #8 on: January 27, 2014, 03:57:53 pm »
The ITC's are probably as best as you can get with an armchair ride but capable of soaking up the big hits. the catch with the ITC is big smooth dips where the stroke doesn't achieve enough speed to invoke the high speed damping and drives into the bottom with a shocking bone jarring clunk. white husky riders learn to get up on the pegs when they see these coming up :o