144" skid

[Rockmeister]

Hey LB!

I know what you are saying about keeping the geometry right.
Have a 121" doo skid want to put in my '05 Warrior.
Thinking a 7.5" set-back.

Am I bettter off with extensions to a 136"?
(Would rather have the 121" footprint on the hardpack though.)

If I understand you correctly, the track attack angle, front arm angle, back arm angle, and the track return angle have to be pretty close to each other.
Is this correct?

If so, how do I keep them pretty close?
And how close do they have to be?

Please, educate us!

Thanks!

 

[LazyBastard]

Some of it has to do with the design of the suspension. Not being familiar with the doo skid, I'll make the assumption that it is fairly conventional with torsion springs and transfer blocks.

Now for a skid with lower angle arms, you can go with a greater stretch/setback while still being "good enough" than you can with a skid with steeper arms (yam suspensions tend to have very steep arms). Reason for this is that the setback will have less of an effect on the approach angle with the lower arm angle than with the steeper angle.

Now many people go with 7.5" on the yam 121" skids with results that are more than "good enough", so I would guess that 7.5" should be fine for you.

Regarding relocation or extension, it really shouldn't make much difference on the geometry since the skid is a parallelogram, or close to it, but you really need to take one thing into account... a 7.5" relocation will shift your weight center significantly, and as a result, your sled will will be quite front-heavy. This way you're also moving the track center back by the full 7.5" rather than only 3.75, which means that your steering radius will be more along the lines of 151". On top of that all, you will be putting a lot more work onto the front suspension than there was before. I'm certain that if you relocate 7.5" back, you will NOT be satisfied with the handling or front suspension performance.

 

[Rockmeister]

Thanks LB!

Going to let that soak into my brain for a while and see what it makes of it...

lol

 

[Nikolai]

I have set back a few skids in different sleds and mismatched brands. It increases ski pressure and kills your weight transfer.

Do not set a skid back more than 4"(use a 136 skid for a 144 track). Anymore than 4" and your ride quality will be gone.

I have personally never had issues though. As long as you move the skid straight back it will be fine. Say you hang the rear of the sled from the garage ceiling, you would essentially just unbolt the skid and pull it straight back. The front and rear arms need to come back the same distance, and they need to stay on the same plane with the driveshaft. It really isn't hard.

 

[Ding]

Aw man, I missed the group hug . . .