From Mild TO Wild! Posted December 31, 2011 Report Share Posted December 31, 2011 So thinking of mount ideas. These are the stock a arms. Dunno if i want to move the shock mount 2 inches closer to the wheel or have the mount on the bottom of the a arm. Whats the pros/cons to both ideas? stock shock length is 14.75 and trx shocks are 16.75. Ideas and comments appreciated. Quote Link to comment Share on other sites More sharing options...
From Mild TO Wild! Posted January 1, 2012 Author Report Share Posted January 1, 2012 Any ideas? Suspension gurus input please? Quote Link to comment Share on other sites More sharing options...
Larry's Shee Posted January 3, 2012 Report Share Posted January 3, 2012 http://bansheehq.com/forums/index.php?showtopic=47969&st=0 this might help Quote Link to comment Share on other sites More sharing options...
answ3r Posted January 4, 2012 Report Share Posted January 4, 2012 Moving the shocks closer to the wheel will change the motion ratio of your suspension and stiffen it. You'd have to measure the 450r motion ratio and the banshee's modified and stock one to give you an idea of how it would feel. In a world where you could dial in the damping you want in your shocks, you try to be as close as possible to the wheel. That way, it's easier to control small bumps and high frequency oscillations. Quote Link to comment Share on other sites More sharing options...
So Cal Suspension Posted January 4, 2012 Report Share Posted January 4, 2012 Moving the shocks closer to the wheel will change the motion ratio of your suspension and stiffen it. You'd have to measure the 450r motion ratio and the banshee's modified and stock one to give you an idea of how it would feel. In a world where you could dial in the damping you want in your shocks, you try to be as close as possible to the wheel. That way, it's easier to control small bumps and high frequency oscillations. Again with the "motion ratio" ... I hate to see our members fed misinformation. True, that the closer the shock is the easier it is to dampen to small light "choppy" stuff, but works awful in terms of (long) total wheel travel. The closer the shock is to the wheel, the further the shaft has to extend and collapse, for the same amount of wheel travel as a shock mounted 5" in from the spindle. The geometry involved in basic A-Arm systems is such that you have to find that happy medium. You can't run a 18" shock all the way at the spindle, and expect to get the same amount of travel as a 17" shock 4" in from the spindle. It won't happen and frankly goes against any and all common sense. In simple, easy to understand words, your shock will bottom out on itself before you utilize all available wheel travel if your shock is mounted too close to the spindle. It's basic geometry. Don't do it. Quote Link to comment Share on other sites More sharing options...
Coupelx Posted January 4, 2012 Report Share Posted January 4, 2012 wtf is a motion ratio? Quote Link to comment Share on other sites More sharing options...
FullThrottle_06' Posted January 4, 2012 Report Share Posted January 4, 2012 wtf is a motion ratio? Thought the same thing when I read this. Quote Link to comment Share on other sites More sharing options...
From Mild TO Wild! Posted January 4, 2012 Author Report Share Posted January 4, 2012 So i decided this suspension is int worth the risk. ill get the money and buy new. You guys don't need to keep responding to this topic. Quote Link to comment Share on other sites More sharing options...
711jrp Posted January 4, 2012 Report Share Posted January 4, 2012 Again with the "motion ratio" ... I hate to see our members fed misinformation. wtf is a motion ratio? I was quite surprised Matt has not come across this term before, it might be a European thing but it was a hot topic in the pits at any race meeting throughout the 80s. The term was/is used to describe wheel travel vs damper travel, ie if 2" of wheel travel resulted in 1" of damper travel the suspension was said to have a 2:1 motion ratio. The term was actually used much more around inboard damper suspension systems with bell-cranks used to amplify the motion ratio aka "rising rate" . Simply put it might be something like this, the first 2" of wheel travel results in 1" of damper travel, the second 2" of travel results in 1.5" at the damper and so on. Quote Link to comment Share on other sites More sharing options...
Larry's Shee Posted January 7, 2012 Report Share Posted January 7, 2012 Might this be a Brittish description of what us Yanks call rising rate ?? Quote Link to comment Share on other sites More sharing options...
711jrp Posted January 7, 2012 Report Share Posted January 7, 2012 I think that is the case , I did say Aka rising rate. Quote Link to comment Share on other sites More sharing options...
answ3r Posted January 10, 2012 Report Share Posted January 10, 2012 Since english isn't my first language, I'd have a hard time correctly explaining the motion ratio on a forum so I'll let wiki do it for me. It's not totally complete, but it's not so bad. http://en.wikipedia.org/wiki/Motion_ratio @MattSCSS, where thinking exactly the same. When I said the best was to try and be as close to the wheel as possible, I meant when you can design a custom shock with desired damping and stroke. When I refer to "as possible", I mean you have to find the happy medium. As for using shocks from another vehicule, it CAN work, but it won't be good unless you do a bit of math and/or trial and error. Quote Link to comment Share on other sites More sharing options...
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