Weight balancing a sled

[Eldereldo]

I thought I saw a thread on this, but I can’t find it. I picked up some cheap scales and I want to try setting up my sleds suspension using them, but I can’t find any recommendations on how much weight should be distributed where. I know left to right ideally would be 50/50 but what would you want for front shocks, front of rear skid, and back of rear skid? Would be for technical mountain riding, ie trees, some climbing but not chutes, just normal get over a ridge stuff.

Anyone know?

 

[mountianguy]

I thought I saw a thread on this, but I can’t find it. I picked up some cheap scales and I want to try setting up my sleds suspension using them, but I can’t find any recommendations on how much weight should be distributed where. I know left to right ideally would be 50/50 but what would you want for front shocks, front of rear skid, and back of rear skid? Would be for technical mountain riding, ie trees, some climbing but not chutes, just normal get over a ridge stuff.

Anyone know?

Try the Skinz site I believe that's where I saw it.

 

[AreWeThereYet]

Following

 

[AGGRESIVEZEBRA]

Yeah the skinz youtube channel has a 5 video series on it. here is video one https://www.youtube.com/watch?v=tscVALup6qo

 

[Catrider16]

I also believe Lund did a thread on this subject at one time and it was dismissed by a large majority on this forum. He explained suspension setup effects and weight imbalance with cans. He gave up the thread as some labeled him as a quack.
His years of sledding and experience, i don't know many that can set up a sled for the mountains much better.

 

[teamdirt]

just buy a G4 and your problems will be solved...lol

 

[Eldereldo]

Those things still have torsion springs in the rear. What do they have for adjustment?

 

[mountianguy]

just buy a G4 and your problems will be solved...lol

Some problems may be solved and some will be just starting. Its mechanical and man made there will be issues sooner or later.

 

[Allseasons]

Eldoraldo, the skinz videos helped me better understand what my suspension was doing from to back. But I still needed a day in the field testing different air pressures. Now I have 2 setups I use, 1. trees/meadows and 2. climbs. Most of the time I’m on setting 2 and somewhat struggle down in trees with a hard on the ski/ heavy on the front setting.

But for you, if you are going with the mountain cat, the rear shocks have the lockout setting. I’d set air pressures at a mid way point, and lock out the bugger if I needed to go up and over something for the next basin.

Write down factory settings so you always have a “Ground Zero”

My All around “go to” setting; but if I remember right, I’m heavier than you, but give this a whirl.

Softer settings for lighter snow on rears, stiffer for harder snow
FRS 50-65/110, RRS 135-145/180
Second click for trail and riding, lockout for climbing.
Skis 65/110

Edit; my side to side is way out to lunch, I don’t even notice anymore. The key for my Cat was the front skid shock. To hard, skis off the ground and trench in a climb. To soft and skis are heavy and she tractors around. Weighing sled did nothing for me, but understanding what that skid is doing did. Adjust from there

 

[Rotax_Kid]

When I used to fab my own skids and chassis I'd try to use the 60/40 rule...60% on skis and 40% on track...on track I'd try to shoot for 60% on front arm and 40% on rear arm.

One thing to keep in mind is this was a number of years ago. As the rider kept moving forward the ratio kept changing with a bigger bias to the front end. Used this as a starting point ad worked from there.

L/R split we always tried for a 50/50 split.

With any of the above there were times this was never close to achievable. Tried our best and had to live with it

 

[Eldereldo]

This is what I got today.
Air pressure as per AC settings.

2018 MC

95psi front
60psi center
150psi rear

1/2 tank fuel, full of oil, rear rack with tools rescue stuff etc. I normally carry gas but take it off and stash it when playing.

190 lb rider with gear.

Front Left. 166
Front Right. 162

Center. 159
Rear. 288

So total front 328. 42.8%
total rear. 438. 57.2%

Total weight 766. % front to back right in the sweet spot according to the Skinz video. And sag is correct as well.

Also checked the 2014, full of gas and oil and based on a 200lb rider, has Elka’s so set sag according to their recommendations.

Front left. 175
Front right. 148,

Center. 295
Rear. 200

Total front 273, 39.25%. significant weight difference left to right due to the can and belt drive.
Total rear. 495. 60.75%

Total. 815

Tried to get some weight moved to the front but if I adjusted the shocks enough to make any significant difference, I ended up with to much sag. Also trying to adjust front shocks to transfer weight to the lighter side doesn’t really do anything.

Riding the sleds demonstrate the how much lighter the front of the 2014 is as it is way harder to get to turn on hard packed. It also reveals why I always seemed to have an issue initiating a left side sidehill.

Might try dropping the MC psi to Allseasons values, seems like it would be the same balance, just softer.

 

[Mike270412]

This is the thread I was looking for.

 

[Caper11]

Those things still have torsion springs in the rear. What do they have for adjustment?

They have lots of adjustments if yah know how to tune a suspension.

 

[Caper11]

I also believe Lund did a thread on this subject at one time and it was dismissed by a large majority on this forum. He explained suspension setup effects and weight imbalance with cans. He gave up the thread as some labeled him as a quack.
His years of sledding and experience, i don't know many that can set up a sled for the mountains much better.

Yep, I remember that thread, Lund is right and bang on with his explanations.

 

[Eldereldo]

They have lots of adjustments if yah know how to tune a suspension.

I’m serious, last sled I had with torsion springs you could rotate a cam to load the spring more or less, three positions was all it had. What has the Doo got for adjustability on the torsion springs?

 

[Caper11]

I’m serious, last sled I had with torsion springs you could rotate a cam to load the spring more or less, three positions was all it had. What has the Doo got for adjustability on the torsion springs?

Like I said the are a lot of adjustment with the torsion springs. They make different rate springs, there are now aftermarket spacers.
Ive done air shocks on a doo before. Never again.

 

[JungleJim]

Just remember the difference between Theory and Reality... at the end of the day it will be how it handles in the conditions and terrain you ride. It won't matter how many decimal points you had it balanced to when you're stuck going up hill between two trees!

 

[Eldereldo]

True, but it’s nice to know the relationship between what it feels like and the numbers.

 

[TROLLCAT]

True, but it’s nice to know the relationship between what it feels like and the numbers.

36
24
36

just sayin

 

[AreWeThereYet]

Reviving this thread, just weighed my summit sp, half tank of fuel, full oil, goggle bag, handlebar bag, cfr bars and 4" riser electric and manual start, MBRP trail can.

+/- 2 lbs

FLS 151lbs , FRS 171lbs and rear just under torsion springs 202lbs.

Curious to see the left hand side lighter than the right,.. since I have an MBRP trail can installed.