Swingarm Question: Dogbone Purpose?

[EZ in NZ]

My 83X swingarm has suffered from cancer and is retired. I got an 85X swingarm to replace it with. The 83 does not use a dogbone and the 85 does. I don't have one but do I really need one?

What's the real purpose of the dogbone system? So riders can use different sizes for moving the shock position to adjust height etc?

I realise it spreads the load over two mount points on the swingarm but can I just fabricate a fixed mount on to the 85 Swinger and mount it that way?

Implications?

It looks like some of the aftermarket swingers don't use dogbones (solid mount like my 83) but I wanted to put this out there in case I'm missing something important here before I cut and weld!

Thanks

[hrc85250r]

well, what it does is it makes the speed that the shock compress gradually slow down throughout the travel of the swingarm.....same goes for the pro-link systems, unit pro-link systems, full floater systems and so on and so on.....

[EZ in NZ]

Can you explain how that works? I'm not following. Sorry.

It's a fixed position, the shock mount doesn't move in the swingarm (other than pivot) so how does the dogbone have anything to do with the speed of the compression? It's not a dampening unit. It's a mount. Right?

[EZ in NZ]

No-one else got any info on this issue? I'm waiting to start cutting my swingarm but I thought some of you guys might have chimed in by now. Any comments appreciated. Thanks.

[Red Rider]

well, what it does is it makes the speed that the shock compress gradually slow down throughout the travel of the swingarm.....
Sorry HRC, but you've got this one bassackwards. :D Honda's Pro-Link, Kawasaki's Uni-Trak, Suzuki's Full-Floater, & Yamaha's Mono-X suspension systems are all different names for what is known as a "rising rate suspension." As the suspension goes through it's stroke, the rate at which the shock is compressed increases or "rises." This provides a nice supple ride over the small stuff, but stubbornly resists bottoming out on the big stuff. By the way, Honda's Pro-Link system is superior to all the other suspension sytems out there! :p ;) :D

EZ, I assume you have a 200X. They didn't have any kind of rising rate suspension, just a basic shock-to-swingarm linkage, and I'm not familiar enough with that to give any kind of helpful input, sorry. Best of luck getting your rear end sprung again!

[Rex Karz]

On the 200X it just distributes the force over a larger area.

[EZ in NZ]

OK, thanks guys. So from this I'm assuming it's OK to stick with my plan and make a mount for this shock anywhere on the swingarm I like and not worry about the dogbone or lack of.

To lift the trike a little, I plan to mount the shock higher on the swingarm with a couple of beefy tabs on the top rails.

Good / Bad idea?

[cliff2302]

Thats going to change your suspensiuon geometry. I haven't done anything like this sine i used to race, but if i remember correctly, you will need to get a stronger spring because your giving the swingarm more leverage against the shock/spring. Your gonna have to wait till someone who really knows about this stuff posts though, there are formulas to get the correct spring size and stuff. Good luck

[OldSchoolin86]

Thats going to change your suspensiuon geometry. I haven't done anything like this sine i used to race, but if i remember correctly, you will need to get a stronger spring because your giving the swingarm more leverage against the shock/spring. Your gonna have to wait till someone who really knows about this stuff posts though, there are formulas to get the correct spring size and stuff. Good luck
Your exactly right. By moving the shock forward you will be giving your rear more leverage to compress the spring. It's going to feel weeker the more you move it up.

[EZ in NZ]

Yep, cool, I had thought that would be an issue to consider. Same principle as lengthening a swingarm...creates more leverage and potential range of motion.

I am also looking at a larger/beefier shock to go with this work.

Thanks guys, appreciated.