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I don't see what the "problem" is here. I've read the whole thread and seen you guys trying to calculate the spring force on the a-arm, but what's the problem?And I do understand it might get more tricky to valve a shock at high ratios, but rear bike shocks have like a 4:1 ratio, and they are revalved all the time. Is valving them on the high-ratio buggy tricky just because the shock mfr.'s don't have disks with the same resolution (larger difference between each shim) as what's available for a rear shock (small differences between shim sizes)?
never used them, is that a 16" stroke shock? are they comparable in price? hope it was assembled right the first time!
Bike shock piston and shim stacks are way different. It's not uncommon to see a bike piston with a stack 1/4" thick due to the high leverage ratio. You also have the shaft displacement compression control on the reservoir and the free bleed control on the shaft (Very few shocks separate rebound and compression on the shaft bleed hole which is why I call it a free bleed.) There is also a couple cubic tones of money in R&D being thrown at them by the big bike makers and an aftermarket tuning industry that would put the normal off-road suppliers to shame. Just about anything can be made to work, it just depends on how much time and money you want to spend on it. Most of the guys running air shocks successfully aren't going on long trips or through very rough terrain. You guys in the mid west just don't have the room or terrain to put things through the paces like we do. From what I have learned over the years as a general rule of thumb, you want to stick to around 1.5-1 on the motion ratio. Higher is harder to tune and builds more heat. Lower and your shaft speeds get really high and can cause seal issues. Getting the valving right on these can also be a challenge due to how light some of the stacks need to be. A small change in the stack will make a huge difference in handling.
Worlds shortest 18" shock LOL. Made them to fit a buddy's buggy so we wouldn't have to chop the frame up (more). Theres only .0625 between the end of the shaft and the weld on top cap at full bump........... It cost's Me about 300$ a piece to make them in parts not counting labor.............
now here in the midwest ie nebraska we do have desert and 1/4 of the state is sand, that sandy area bleeds down into colorado and up into south dakota. given there are fences separating it but there is still room to run full out maybe not for 20 - 100 miles but enough. I will agree that the general rule of thumb is 1.5-1! you are correct for a 50 - 500 mile race through the desert or like terrain these ratio's won't work as I stated above in fact I don't believe air shocks would cut it at all. you would need a shock more like a triple by pass coil over imo. for around here and at LS it has been my experience that these higher ratio's have actually run cooler, not from a meter but by touch. now at LS ( virtually all sand ) and some may disagree but there isn't really room to run full out for 1+ miles simply because of the transitions and lack of room. I do believe that the transitions are enough to work the susp over good depending on how hard you running them. but comparing LS to st anthony's or glamis is like comparing apples to watermelon just doesn't work. but bottom line is each app (design,location,driver) requires a different setup!
trans man was telling me about a 28" stroke shock that king makes, wonder how tall and heavy that one is! judging them to the height of the washing machine I figured 16" but I was close. that's not much clearance to the cap. how much oil will you be able to run like that?
BAM!! That hits the nail on the head.
Has anybody had success with these? http://www.ballisticfabrication.com/Ballistic-SHOCKS_c_110.html
I like the reservoir on the air shock! mark from mark sand trans told me once that fox tired that design but it was too costly and discontinued them.
Reservoirs on air shocks are tricky. There is so much shaft displacement on them that unless your reservoir hose is very large you run the risk of pressure spiking them under hard hits. The Fox air bypass shocks the rock crawler guys run have resis out the bottom but they aren't seeing the high shaft speeds that a buggy would.