Shock linage ratios

fj1289 · Post by **fj1289** » Tue Sep 20, 2005 9:53 pm

Do changes in shock length change the progressive rate of the shock linkage? I assume (yeah, I know the danger of that...) the shock length won't actually change the ratio, but changes where you are on the curve. From reading earlier posts, changing the length of the dogbones causes a change in the progressive rate of the shock linkage. Shorter dogbones make the ratio more progressive. I assume longer ones will make it more linear (less progressive). Bottom line, EXUP shocks are longer than Genisis shocks. If swapping (for instance a nice used Ohlins from an EXUP) an EXUP shock to a Genisis, would you be better off with the Genisis or EXUP linkage? (is the EXUP linkage more or less progressive than the Genisis link). I also assume (again...) it would require longer dogbones to keep from chain sawing the top of the swingarm. Thoughts?

gatecrasha · Post by **gatecrasha** » Mon Sep 26, 2005 4:00 pm

hi matey, i have tried the following here on my bike, 88 genesis with standard shock and shorter dogbones, exup shock with 88 dos and again with exup dogs, if your serious about using the exup shock you really would need to balance the extra length of the shock with longer dogs to balance the height issues back to a level gound, i would recomend try fitting the exup shock and jacking the bike to a height you feel looks right regarding the ride height, then measure the distance between the mounts, our old mate dr jim could then do a suitable set of dogs to match this the only other slight problem i found when fitting the exup ahock, was the mount/union of the adjuster on the exup shock, you'll find it fouls on the top cross bar, it should be fairly easy without actually dismantalling the lineage to turn,using vice grips and get the thing out the way of that cross bar, lemme know how it goes, i ended up running the genesis shock with mad dogbones that give a larger than standard raise to the rear suits my more aggressive riding style, and adds to the bike flickability through traffic when, in combat mode in traffic<img src=http://www.ezboard.com/images/emoticons/devil.gif ALT=":evil">

dragracer1951 · Post by **dragracer1951** » Mon Sep 26, 2005 4:40 pm

Uh... get on the bike and weigh each wheel swap shocks and get on the bike and weigh each wheel. raise or lower rear till weight is same as before Jim <img src="http://img.photobucket.com/albums/v209/ ... Cheers.gif" style="border:0;"/> <img src="http://img.photobucket.com/albums/v209/ ... states.gif" style="border:0;"/> Hey Kid...Is my taillight working?

gatecrasha · Post by **gatecrasha** » Mon Sep 26, 2005 5:34 pm

uh ??? jim i refer to the fact that the longer exup shock raises the rear far too high, and if used would require the dogs altering to bring this down, easy way to find length of the dogs required to do this matey, *edit* if the exup shock was fitted to the bike with standard exup or 88 genesis dogbones he wouldnt be able to get his leg over to weigh it<img src=http://www.ezboard.com/images/emoticons/happy.gif ALT=":D"> trust me them buggers go way up in the air, didnt you see the pics i posted in the photos?? i said it could be done, never said it didnt look rediculous without the linkages altered<img src=http://www.ezboard.com/images/emoticons/tongue.gif ALT=":p"> : cheers Edited by: <A HREF=http://p072.ezboard.com/bexupbrotherhoo ... ecrasha</A> at: 9/26/05 3:38 pm

gatecrasha · Post by **gatecrasha** » Mon Sep 26, 2005 6:16 pm

heres an exampl pic of my bike from way back that was previously posted in here, it shows the bike with the exup rear shock and linkages, the angle was far too extreme to be practicle to ride safely, and as chris has previously mentioned would of sawn the swinger, <img src="http://i6.photobucket.com/albums/y223/g ...  this pic shows my bike with the genesis shock fitted with a +35mm lift <img src="http://i6.photobucket.com/albums/y223/g ...  it should give an indication of how extreme the exup shock was, and also that if the exup shock was to be fitted, then a set of custom links would need to be made, i gave an example of how to attain the length of the linkages required for the bike to sit correct, and an insight into the issues i had previously faced <a href="http://phpbb-host.com/phpbb/index.php?m ... HAZ-custom M/C's</a>

fj1289 · Post by **fj1289** » Mon Sep 26, 2005 8:51 pm

My plan is to use the EXUP shock and longer dog bones. From what little I know of these progressive linkages, I think it will make the suspension less progressive. First, I just wanted to make sure I wasn't going to cause any unanticipated problems -- like creating a regressive suspension ratio or making the suspension overpower the shock with too much leverage. Also I'm just curious if anyone knows any rules of thumb for suspension changes on these bikes - things like if you shorten the dog bones 10mm you increase the progressive ratio 10%, or you make the spock spring effectively 5% stiffer... [NOTE those last statements were hypothetical ONLY - and are not accurate to my knowledge!] The thread a while back on the Dutchman racing linkage got the mind wondering about these things....

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