Rear Shock Linkage.. OEM, Aftermarket..

[stever250r]

I am wondering about rear shock linkage setup.. My parts bike that I bought for my build is a 87 model.

Looks like I am going to be using a Stock 1988-89 Laeger Frame for my build so my parts bike isnt going to pan out like I had hoped, so I am going to be needing a 1988-1989 Rear Link.

I was just wondering if there were ever any companies that made a aftermarket rear link? I have seen the links with the lowering struts for TT, but I am wondering if there was ever anything like the LSR DC-6 made to be used on the 250R..

Are there any other options besides the stock 1988-89 model rear link?

[troybilt]

Not that I'm aware of. I talked to another member about this same thing, and designing one... Now that I have a CR500 link rear, I don't need one. ....it would be a good project, though...

[Honda 250r 001]

I heard once of a race tech rear linkage. Saw it in am old magazine. I think it was made specifically for a pro rider back in the day maybe? Either that or it was a typo in the specs.

[stever250r]

I didn't think that I had ever seen one either...

Technically, if the Link is good on my 87 parts bike, I just need to replace the shorter dogbone, with the longer 88 dogbone to correct the ratio.... Is that right?

There are plenty out there, I was just hoping for a aftermarket (billet) type linkage...

Thanks for the info..

[trx750gsxr]

me and another guy are discussing this same idea and coming up with a prototype one. what abut an adjustable dog bone?

[hartwill]

Originally posted by stever250r
I didn't think that I had ever seen one either...

Technically, if the Link is good on my 87 parts bike, I just need to replace the shorter dogbone, with the longer 88 dogbone to correct the ratio.... Is that right?

There are plenty out there, I was just hoping for a aftermarket (billet) type linkage...

Thanks for the info.. 86/87 is longer than the 88/89

[C41Xracer]

I was debating making one, I can machine it at work. I guess I better get off my butt and get on it.

[Honda 250r 001]

That would be awesome. Do you think you could make the wishbone part of the linkage aluminum too along with the dogbone? Or would it not be strong enough?

[jcs003]

santo derisi at derisi racing would be a good man to talk to about producing a link. he raced the 250r and his shop has the capabilities to produce something.

[C41Xracer]

Originally posted by Honda 250r 001
That would be awesome. Do you think you could make the wishbone part of the linkage aluminum too along with the dogbone? Or would it not be strong enough?

yeah you could do the dog bone out of aluminum but it wont look like the factory piece. I have an idea in my head but its gonna take some time to make sure the compressed and extended lengths dont change. Leverage ratio might change a little, anyone know where I can find info out on leverage ratios?

[C41Xracer]

Originally posted by Honda 250r 001
That would be awesome. Do you think you could make the wishbone part of the linkage aluminum too along with the dogbone? Or would it not be strong enough?

yeah you could do the dog bone out of aluminum but it wont look like the factory piece. I have an idea in my head but its gonna take some time to make sure the compressed and extended lengths dont change. Leverage ratio might change a little, anyone know where I can find info out on leverage ratios?

[trx750gsxr]

Leverage ratio is not gonna change if your using stock length. I have one already drawn up. Post up pics tonight

[C41Xracer]

My design might change it some, the linkage I have in my head is similar to a trx450r linkage

[trx750gsxr]

I'm going with a some what stock design but aluminum and adjustable.

[mx91a]

I'm in the middle of putting a long travel Elka dual pro linkage and shock from an 04-05 450R on my R with roll design 88-89 style MX swingarm.

Here are the specs on the Elka system:

http://www.exriders.com/vbb/showthread.php?s=&threadid=165845

It's not a straight bolt on modification, I had to drill a new 10mm linkage hole in the swingarm about 3/4" further back than the stock mount, bush the frame linkage mount down to 10mm and to accommodate the narrower linkage and the final step will be to make the shock bolt to the frame a little lower than the 250R as the 450R upper mount is lower.
Once the suspension geometry is finalized and the shock is setup correctly I should have a nice long travel rear suspension with about 11.5" of wheel travel and a healthy amount of down travel compared to the stock shock and linkage setup.

[trx750gsxr]

Can't expect to have people drilling holes in their swingarms and frames.......needs to be direct bolt on. Good concept tho

[troybilt]

If you guys get serious about making some I can do the modeling and drawing work for ya. Don't know if you have CAD available or not just offering to help...

Stever250r, your inbox is full... email me and we can discuss what you're wanting.

crownlineboats@hotmail.com

[trx750gsxr]

I use mastercam x5.....thx tho

[troybilt]

I use ProE Wildfire 5,... plus I write software for linkage synthesis, would be nice to find an optimal ratio for XC & MX, etc... not just copy the stocker, like the original posted asked, similar to the DC-6 linkage.

[trx750gsxr]

Its not gonna be a copy of the stock linkage. Its gonna be adjustable. -1 up to +2.5. I will post up a pic or two tonight of my design with open criticism........

[troybilt]

Sounds sweet man, if they are anything like those swingers as far as quality they will be awesome!! Thanks for working on this, again glad to help if need, but sounds like you've got it taken care of..

So just to be clear, are these going to be similar to the durablue adjustable links used for TT racing, only these will not be for TT racing specifically, of course?

[trx750gsxr]

Not exactly sure what one you are talking about. Could you post a link? Thanks

[stever250r]

Here is a link to the Durablue lowering strut.. .. It was just the adjustable dogbone used with the stock link/wishbone...

http://www.durablue.com/prod_display/Lowering_Kits/13/0.php

Like Troy mentioned above, these were specific to TT racing, and I have never heard of or seen one used on the MX Track.

The Idea sounds great, and if you guys can make one.. EVEN BETTER... Keep us Posted.

If you make it happen, I would like one!!

[trx750gsxr]

Why couldn't you use the durablue one on mx? Looks like it would hold up....

[stever250r]

Originally posted by trx750gsxr
Why couldn't you use the durablue one on mx? Looks like it would hold up....

I have wondered that myself, but have never seen or heard of it being used for MX..

It probably could be used, but still has to be used with the stock Wishbone...I was looking for or wanting a complete stock replacement like the Lonestar DC-6 Link.

[trx750gsxr]

Do u have a web link to thelonestar linkage ur talking about?

[trx750gsxr]

It seems to me that they flipped the"dogbone" to the front and moved the pivot point (where the shock mounts) slightly forward to reduce shock kick.....would you want the lower shock further back so the shock is on more of an angle for less shock kick?

[stever250r]

It seems to me that they flipped the"dogbone" to the front and moved the pivot point (where the shock mounts) slightly forward to reduce shock kick.....would you want the lower shock further back so the shock is on more of an angle for less shock kick?


I guess you already found the link, but here it is for others...

http://www.kbmotorsportsonline.com/chassis-components/linkages/dc-6-shock-linkage.html

As far as your question above, I guess less kick would be the overall intention or gain that we would be looking for...

How it is accomplished, would require more reading on my part, but you seem to have a good idea of what would need to be done..

Is it less shock angle or more shock angle that would give us the results we are looking for?

[trx750gsxr]

some body wanna chime in? im not much into jumping. i like looking good and going fast but not a scolar when it come to suspension geometry. can use mmy software to generate it and machines to produce it just need some vitals....

[C41Xracer]

The lonestar link is what im wanting to make

[trx750gsxr]

Here is what i got so far. Thinking that it will be adjustable for the mx guys and be affordable to even the average pocket book. Just a basic durable adjustable linkage until we get down to the bottom of it. Maybe even to 5 or 10 and pass them out and let the community try it out....any inputs fellas....

[trx750gsxr]

Here is what i got so far. Thinking that it will be adjustable for the mx guys and be affordable to even the average pocket book. Just a basic durable adjustable linkage until we get down to the bottom of it. Maybe even to 5 or 10 and pass them out and let the community try it out....any inputs fellas....

[trx750gsxr]

oops sorry for the over post

[socal]

I installed a 88-89 length Laeger swingarm on my 86.Should I be using a 88-89 dogbone as well?

[trx750gsxr]

if its just the length that changed then no you dont. You have a swing arm for an 86 just the length of an 88-89???

[C41Xracer]

The swingarm doesnt matter its what shock you have

[trx750gsxr]

Its a combo of everything. Shock, linkage, and swing arm IMO

[socal]

Originally posted by trx750gsxr
if its just the length that changed then no you dont. You have a swing arm for an 86 just the length of an 88-89??? Yes,its the Laegers 86-87 swingarm with 88-89 length and a Elka shock.

[TLR-Online]

Design looks good so far! Just wondering how this is gonna hold up in MX/XC Racing... Check out this thread:
http://www.exriders.com/vbb/showthread.php?s=&threadid=427009&highlight=linkage+broke

I have had a set of these control a-arms for my car... http://www.metcomotorsports.com/products.asp?cat=95

Check out the round gold piece in the middle of the billet part. It is removable and the threaded rod threads into that instead of the aluminum. I would guess the round piece is grade 8 steel for strength. You would have to completely rip that round piece out for them to fail...If you just threaded into the aluminum, it might tear the threads out.


We all appreciate you taking on this project!

[trx750gsxr]

That's a good idea as well.....could use two snap rings to keep it centered on the block. Guess it wouldn't matter once its threaded

[wilkin250r]

Originally posted by trx750gsxr
Why couldn't you use the durablue one on mx? Looks like it would hold up....

I believe the strength is fine, it's the TRAVEL that becomes an issue.

I have a similar adjustable dogbone on my 86. Extending the dogbone will change the swingarm angle, effectively bringing the rear wheels "up" (or bringing the seat down, whichever way you want to envision it), but doesn't significantly change the shock angle and location.

So you get similar wheel travel, but since they start in a different location, the swingarm can actually travel far enough to contact things under the subframe (like the exhaust) before the shock bottoms out.

And I did some basic leverage analysis years ago, and I believe the extended position of the dogbone also effectively softened the rear shock, so not only are you able to hit something under your subframe, but you're more LIKELY to as well.

My brake caliper will hit my muffler on heavy landings.

[trx750gsxr]

Correct me if I'm wrong.....will stiffing up the shock compensate for this?

[trx750gsxr]

Ahha that's why the lonestar dc-6 looks to as the shock mount on the linkage was moved forward.......

[troybilt]

Good points Wilkin, that's why I felt the whole rear suspension needed to be laid out in mechanism to do this right.

The dc-6, is a long travel setup, so you effectively use a longer body shock as well. Not just a linkage for the stock length shock, its also supposed to cure the bucking problems with the 450r...

I think the adjustable link is a great start, but once you change the length, you need to adjust the shock length in concert... to keep the same up and down travel.

Here's how I would proceed. need someone with just a roller setup, remove the front and rear shocks and set the frame on a 2x4 to get the correct up travel for MX, (measure the resultant length of the rear shock) w/stock length dog bone for baseline. Then set the frame on 13" box to get the correct down travel, w/stock dog bone... now, using the adjustable dog bone, redo the same measurements for different lengths of dog bone, and plot out the corresponding extended and retracted shock lengths. This will give us a curve for determining Shock length vs. dog bone length. Also, forgot to mention the need to measure the travel of the bottom of the rear wheel too, to get the ratio of shock travel to rear wheel travel. I know good ratios on 450's are in that 2.1:1 range... The 250r ProLink is a progressive rate suspension, i.e. its not constant so we're looking for the slope. This is just how I'd start to tackle the linkage myself.

[trx750gsxr]

How bout I make something I will send it to ya, you try it out and we go from there?

[troybilt]

I would but my mx bike is CR500 linkage, rear. Now, I'd like a billet one for that!!!!!! ;)

I know there is several running the stock dogbone and link on MX bikes.

[trx750gsxr]

If you send me pics and dimensions I could make that billet one a reality

[socal]

Originally posted by troybilt
I would but my mx bike is CR500 linkage, rear. Now, I'd like a billet one for that!!!!!! ;)

I know there is several running the stock dogbone and link on MX bikes. This is my dilemna Troy.Im now running the 88-89 swingarm I got from Dan,with the Elka I got from you.Rite now I have the 86-87 linkage/dogbone.Would I benefit from changing the entire linkage and dogbone to 88-89,or just the dogbone,or will it be fine the way it is?Any input would help,thanks...

[wilkin250r]

Originally posted by trx750gsxr
Correct me if I'm wrong.....will stiffing up the shock compensate for this?

Sort of, but that's really not the way you want to tackle the situation.

In a nutshell, let's pretend you have 11 inches of wheel travel, because at 12 inches you smack your exhaust. The lowering linkage will bring your wheels 3-inches closer, but doesn't change the shock and travel. Now, if you use that same 11 inches of wheel travel, since you started 3 inches closer you've effectively moved 14 inches, which is more than your allotted 12. Now you have repair bills.

Stiffening up the rear shock can possibly keep you from damage, but now you're looking at STIFFER shock, LESS responsive, and overall LESS wheel travel. This is the opposite of progress.