[dix]

I have upgraded the front springs of my ProX2 to #150's and the rears to .375's which I understand is what some guys are using on the 440's. The sled rides nice enough up front but really soft in rear, and has little botoming resistance. Basically, the front of the sled rides a lot higher than stock, causing the front 2/3 of the skid to sit off the snow. From what I can gather, this causes the skid to collapse several inches before it begins to couple and the front and rear shocks are not working in unison.

Im wondering what is so different between the XR skid and the X2 skid that makes this an issue? I am considering relocating the front torque arm mounting point lower in the chasis to compensate, but it seems to me that this shouldnt be required if the same setup works in the 440.

I have measured the front ride height at the edge of the bonnet at 18.75 inches, and am wondering if that is way off for the ride height? If anyone with a xr 440 could throw a tape measure on the front of the sled and give me a ball park to shoot for. Id rather not mess with the mounting points of the skid if I dont have to so Im trying to tweak with the existing skid. Any help would be appreciated.

 

[dix]

OK by way of an update, I hauled the skid out last night and mover the shock mounting point to the forward position. This lowered the front of the skid about 3/4 of an inch. I had to drill new holes in the limiter strap to compensate for the extra height but thats minor. Seems to be just about right for where I need to be, the skid still doesnt quite sit flat on the floor when fully extended, but sits nicely flat when set with a little sag oin the skid. Im still concerned that the front rides too high wit these springs. The front edge of the hood rides almost 20 inches high leaving only about 1 inch of rebound left in the shocks. I am a bit affraid that the shocks will see excessive wear from topping out hard on a regular basis, is this a legitimate concern? I am wondering if the skis / carbides on the race sled are lower profile than the regular edge skis? this would effectively lower the front of the sled and make up for the extra height from the springs, does Anyone know? how about C & A's? I know the 440 edge race sleds run #165 springs from the factory so Im thinking I should be fine with 150's

 

[pockets]

How much spring preload are you running?

 

[dix]

Very little preload, just enough to keep the springs from chucking a retaining collar.

 

[mk2g60]

You need to have your shocks revalved. Just throwing different springs on there & moving stuff around won't fix it for you.

 

[dix]

Fresh rebuild when I changed the springs. May go with a revalve to xr 800 spec.

 

[proxr 440]

It is normal for the front 2/3's of the rear skid to not touch the ground on the XR 440's. I am the original owner of my sled and that's the way it was set up from the factory. If you do some research on the XR 440's you'll learn alot about the suspension, there are pre drilled pilot holes in the tunnel where the front torque arm mounts. It is recommended to lower the mounting point of the front torque arm in the tunnel if you stud an XR because it requires 2" studs. If it's not studded it is recommeded to leave it in the upper position because of the approach angle for the track from drivers to rail tips. I believe the guys that have lowered the FTA mount have also trimmed their rail tips to keep everything moving ok. You might be able to raise the rear suspension mounting point instead of lowering the FTA.

I don't run any extra idler wheels (I only have the rear axle wheels) and the front of my hifaxs barely wear at all, but the rear 1/3 of the hifax's wear very fast (probably because of the excess pressure on the rear of the skid and the 1.75" lug track not getting enuf show up there on the trails). The XR also has different shock valving than the X2, the XR comes stock with .347 rear torsion springs (X2 uses .359's) and stiffer valving than the X2. I weigh 250#'s and I ran the stock springs and shocks with all clickers in pos. 6, alot of preload on the front springs and and the rear torsions set in the firmest position. I just had all 4 shocks rebuilt a little bit stiffer and changed my rear torsion springs to .405's. the front end never had any sag at all and the rear used to sag alot, with the .405s it doesn't sag at all and only moves about 2-3" if I stand at the back of the running boards and jump up and down, and that's with the torsion springs in the softest position and the shocks set on 3.

 

[dix]

Thanks for the info, its exactly what Im looking for. I guess the difference isnt so great between the two, other than the fact that the 440 is valved to be stiffer through the stroke and theerefore doesnt bottom as easily. Ive had a look and my sled doesnt have pilot holes for a lower mounting point. However, I have found hat with the relocation of the front shock mount it may not be necessary.