Having some fun with the new numbers
no pre load
no cross over

4x identical bath scales zero-ed out then put under each wheel
FL #174
FR #178
RL #270
RR #263

better pic

Yea my spring combo is 43% more down the chart at each inch with the 175/100 than the 80/100.

Your not calculating the crossover there though. I’m thinking of setting crossover at 4 inches. It should jump up to 100lb inch which would max out at about 1050lb at bottom.

I just hope the 100lb spring holds it up!

now the fun begins with the rotax

I see what I can do tonight pretty easy calc.
I will use no preload and see where your at.
This mean the spring adjusters are at zero or just spun down untill they touch the springs

I think your fine on what you have for now. You can fix the rest with valving.

With the shock laying there I will give you a distance from the spring separator to the cross over collars for 4" of shaft compression including sag and ride height.

So you will have a combined rate for four inches and 100 pounds for the rest of the twelve or eight inches. 800 plus 260 or 1060.

I will also provide you a distance for each spring travel before cross over in case you want to change.

Then I will get the spec for each spring as a reference.

Take a look at this maybe call your shock guy to confirm.
Man I hope I am wrong

I did one with a 7" cross over for main spring travel (block)
made an error had to re-post pic
when I plugged in the math check found error, sorry
math check is easy
7" @63.64 +5" @ 100
7 x 63.64= 445.48
5 x 100= 500
445.48+500=945.48

block load on 14" 100 = 961
easy catch.

Adnoh,

You worried me there, but then I see you’ve plugged in the wrong spring heights.

The 175lb spring will be 10”
The 100lb spring will be 16”

Make the 100lb spring block at 11.10”, not 9.6”.

Co at 4” should be alright with about 0.5 clearance

Also, I’m setting up about 1.5” of bump stop seeing as at .6” bump stop my rear end is 1/4” off the floor. And that’s without compressing tires. Also the tires are touching the fenders. So that I don't ruin my fenders, bottom out the frame, or block the spring - I think I need to solve with adding bump-stops unfortunately. Still - calculate for 12", but I recon about 10.5-11" is where its going to bump stop on the shock.

So this Dave-Co suspension needs to be shortened from 12" rear shock travel to about 11" so that fenders clear the tires and skid plate clears the ground. Still much better than stock I guess.

I should have springs and new stops by thursday

Sure glad I’m not going at this alone though. Second sets of eyes are very helpful

Adnoh,

Do you think the 100lb spring will be enough? What about with Rotax weight? I just didn't want to over-shoot with a 125lb or greater.

do you think the springs were just mounted to high. didn't give enough ground clearance from the start

The upper shock mount could have gone 1/2” lower without any bind. The first thing that binds are the axles. I don’t think just 1/2” would completely fix clearance issues though. Needs more bump stop is the easier approach now.

Actually; Fully,

You just got me thinking and looking. Check this out:

https://www.polyperformance.com/fox-2-0 ... ock-eyelet
and
(-8 Heim on the LEFT)
https://www.ridefox.com/fox17/dl/offroa ... yelets.pdf

I have the FOX-213-01-280-B

But the FOX-213-01-350-A look to actually be about 1/2" longer.

For $80 a pair... Maybe I can get another 1/2" of clearance and get back closer to 12" of travel?

Adnoh, thoughts on this before I spend $80?

What is the angle of your axles? If this is setup the way dave told me to do mine, the axles do not have any more travel. take your shock off and make sure at 1/2" longer your axles wont be binding.

OR; FOX-213-01-361-A with a -10 Heim would give me 0.905" more down low. I measured and axles will not bind going that low either!

I've got the rear end off the ground without the shocks currently. I'm measuring 32" from center eye-to-eye of the shock mounts. Axles can rotate easily and I don't feel any bind at all.

The shocks are currently only measuring 31" eye-to-eye.

Looks like I can go with a FOX-213-01-361-A and get another 9/10" of down reach. (With -10 Heims)

So I measured and measured for about an hour + tonight on new shock eyelets. While I think the longest eyelets would likely work OK, I wanted to err on the side of caution concerning axle angles because with the FOX-213-01-361-A being much too close for comfort. I was going to be right on the edge of axle limits (Was measuring down to 1/16" points where the axle started to bind vs not bind). that's just too close.

I went ahead and purchased the the FOX-213-01-350-A which should get me an extra 0.545" of travel/clearance. Clearance to the floor is better, and the tires are away from the fenders by about a half-inch. This eyelet also lets me re-use my heims and spacers without costing more. Basically it was twice the price to only get an extra 0.35" with a heavy axle bind risk. I might even only need to use 1 bump-stop, plus theres also less risk of blocking my 16" lower spring @ 4" crossover.

Hope FOX-213-01-350-A works better than what I have now as standard.

Eyelets |End to eye | Extra down | Bearing size
FOX-213-01-361-A | 2.585 | 0.905 | .625x1.1875 <-- Slight bind risk within 1/16" variance. Also needs new bearings and spacers. Cost of $150
FOX-213-01-350-A | 2.225 | 0.545 | .5x1 <--Purchased. Should be a straight swap-in with no risk nor fabrication. Cost only $80
FOX-213-01-280-B | 1.68 | Std | .5x1 <--Whats in the machine now. Scrapes rear skid and tires-to-fenders.

One thing to think about is the shocks on there now have had valve work to function on the pilot.

I would have to check my notes that are buried somewhere but if memory serves 27* or 27.5* is the max down you want to run the axles, it is the outer joint that binds.

I would also suggest that you check plunge on the inner joint.

I moved my rear wheel back a little over 2 inches further then where Dave had it.

Beat me to it.
I also moved mine back and also out.
This allowed for better placement of the veichle at full bump. Mines not davco with a different set up.
What helps with long travel is moving the wheel center back. It helps a lot with handling as well. When you move out it changes the axle plung at full droop and compression allowing great placement of the shock and wheel travel. If you have old cup it moves the balls to a newer portion for a tighter clearences on inboard cup.
Since we're on the subject look at the front shock placement on the lower arm. You find it better located out an inch or two. This will help with high center as well as wheel rate. It like adding spring rate. It will or should handle a lot better. Since I don't have one or access to one I'm only going off of pictures. Just something to think about.

scpilot66,

I measured axle angles tonight. With the current 31" Fox shocks at full extension, my axle is only angled as follows:
1. With a protractor directly on the middle of axle: 22.8 degrees
2. Add to that, the 1/4" camber angle of the tire (Which bends the outer CV up a slight ammount: 0.67 degrees
TOTAL axle angle with 31" shock is only 23.47 degrees.

Adding 1/2" of suspension travel making the shock 31.5":
1. With a protractor directly on the middle of axle: 24.8 degrees
2. Plus 0.67 degrees in camber: 25.47 degrees with 31.5" shock

Now, with adding 1" of suspension travel making the shock 32":
1. With a protractor directly on the middle of axle: 26.7 degrees
2. Plus 0.67 degrees in camber: 27.37 degrees with 32" shock

So, if you are saying that at about ~27 degrees I run the risk of bind; I should be fine then with a 31.5" shock at <26 degree axle angle.

66 has his dialed in can not better advise than that. Plus he has one and has reworked it. Glad to see him posting about this great source.

I got my springs and bump stops in today. I had to order the 1/2" extended eyelets and so they're of course on back-order. I do have to say though that the 10/16" spring combination will really allow me to target almost any crossover point imaginable. I'm very glad I did 10/16" springs! I'm still just hoping my bottom 100lb spring will be enough for jumping.

Hello Eric, sorry for the slow reply, to much going on right now.

With my Pilot, it is setup to specifically race the roughest courses, the only way I can compete against the new machines is to out suspension them and so far that is just what she does. The new machines advance so much every year I know the time will come when they will beat me, they already kill me on power and top speed.
My suspension is so soft you would not think it works but it does, it is not the best for jumps because it is so soft but for everything else I use it for it amazes me what I can do with her. Even at full top speed across rough terrain she is as stable as a Pilot can be, I get her going fast enough to hear my tires whining over the Engine with my helmet on, bit scary sometimes to be honest but she takes good care of me.

I run 25x12x10 tires in the rear, for more ground clearance but mainly for more top speed. It does not bottom out the frame with 24x11's or the 24x12's (my shocks bottom), I run 7psi in the rear tires and 6psi in the front, on some courses I may run a little more pressure but that is my main #'s.
I do routinely smash up my front skid, belly pan and rear skid, especially the rear skid plate mounting bolts, not because it bottoms out but because of the terrain I race on, rocks and such, my front skid also gets it really bad because I use my front bumper as part of my suspension or rather my savoir, when I am hitting the big whoops it works as a ramp to pull me over the stuff I hit going to fast.

I use 100% of my suspension, she has a true 12 inches in the rear and 13 5/8 in the front.

This is just my 2 cents and I am sure not what you want to hear but this is what I would do,
I will get my notes out and get you some better #'s this weekend

I think you need to get those axles down to 27*, I use a digital angle gauge. The big thing you need to do for all of this is to level the pilot and lock it down in place leveled, no movement. At 27* the shock should bottom before the frame. With those shocks you should get 12 inches with them straight up and down, at some point I plan to change the angle of my rear shocks, side to side and front to rear, I think you can get 13 + with the 12 inch shock, the big problem there is for one the battery box and ground clearance, I have not jumped on that road yet but hope to some day.

Next is getting the axles happy through there travel range, play with where things are at, turning it by hand you will find where the axle cv's like to be and where they give you the most travel without bind, the outer cv is where the cv bind itself will come from but you also have to pull the inner cv boots off, clean out all the grease and check and adjust plunge, the more travel you get the further out you need the plunge to be, with 12 inches of travel if you run the plunge deep in the cv cup the axle shaft itself will hit the outer edge of the cv cup, my rear upper arms are not as good as they need to be so I can not pull my plunge out as far as I would like to, for that reason I had to cut down the inner cv cup, the outer edge on the inside, I tapered it all the way back to the large outer retainer ring, I left enough metal for the retainer ring to be solid in place but also cut out as much as I could. I was able to get a new pair of 4x4 tuff axles which I have wanted for ever but I can not run them yet because they will hit the inner cup, my axles now are right there, I had to pull them back apart and cut even more metal out at one point because they were hitting/marking the axle shaft.

All of this while keeping tow, camber and BALL JOINT BIND in check, with the narrow rear and that much travel you get some serious camber changes.

Another thing I would check is the straightness of your axles, everything back there is going through enough, an axle that is out of straight even a little will wear things out over time.

I have run my Pilot as hard as you can run one, I have not worn out any front or rear ball joints, they are all tight. I do have 2 rear high quality heims that I have worn out and one bent rear lower arm, I was surprised on the 2 heims, one on each side.

The handling of her I think is as good as it gets.
Here are a few pics. (hope you don't mind), you can see in the pics. how compressed my right rear is.

Looks great! Where I ride is more tight twisty trails. I feel the need for stiffer rear end so that slides are a bit easier. Some of this will change when I gain Rotax power. I don’t think I jumped too much going from 80/100 with unusable crossover to 175/100. It should only be 50%more spring down under 5” and the same at full tilt.

I’m really glad I found shock eyelets for my setup. Seems maybe to me my upper shock mounts were fabricated almost an inch too high by Dave-Co. The extended eyelets should get me close to or right at 12” with no binding and only 1/2” bump stop.

I received the new longer shock eyelets today. I’ll be playing with these and adding bump stops later today.

I should be able to assemble the shocks with new springs and all now that all parts are in.