Noob question: Front spring preload - increases or decrease ski pressure?

[NaughtyPines]

Tried this over in general discussion and was told I'd have better luck over here (still learning this whole innerwebs thing.....)

I'm piloting a new-to-me 2006 RS Venture. I love the comfort, love its ability to haul two medium sized people long distances with ease and I really like the motor. There will be no more two strokes in my life. Ever.

Right now I'm attempting to make the suspension suit me, trying one adjustment at a time and piloting it down the same 3-mile twisty section of trail near my house. So far, I've been trying to increase pressure on the front skis so that it doesn't push as much through the corner, though I'm learning that this a machine that one steers with the throttle to a high degree since there is a lot of engine compression amd weight transfer compared to a 2-stroker.

The only thing that doesn't seem to make a big difference when I adjust it is the front spring preload. When I tighten the ski preload, it just seems to ride stiffer up front and still pushes the corners about the same. When I loosen the preload, it still pushes, but rides softer which is what I tend to like. (If I wanted to corner carve I wouldn't have bought a Venture afterall). All the other adjustments like torsion spring and center skid shock seem to make a big difference with just one "click" worth of change. I'll probably tighten the limiter strap to its last hole this weekend.

So does increasing the ski preload decrease ski pressure or is it the other way around? I'd like to increase ski pressure to reduce pushing in corners, but I don't want a trail ride to feel like a workout at Gold's gym.

Thanks so much.

 

[J1635]

#1 is make sure you have adequate carbide amount on both skis, people spend so much time setting it all up only to find out the carbides are completely worn off in which case nothing will help you. once you know you have a good amount then proceed.

generally if you want more pressure on the front skis then you need to make rear skid adjustments to shift more of the weight off the track/rear shocks and onto the front skis. check out this post

http://www.ty4stroke.com/threads/rs-venture-handleing.53453/

 

[stubb111]

the front springs will not really affect the front ski pressure, you will adjust your transfer rod and rear shock preload for that. your front shock preload will affect inside ski lift once you get it to actually turn. my suggestion would be to try a set of SNOWTRACKERS we have 4 Yamaha 4strokes and run them on all of them and they all turn no matter the trail conditions. "CATMAN" has a really good thread for RS chassis/suspension set-up as a starting point.

ps.... if you do install the snowtrackers be sure to follow their front end alignment instructions as it makes a big difference on final outcome of handling.


just my 2 cents.....good luck

 

[NaughtyPines]

Awesome advice - thank you all.
Went on an all day ride on the venture with the wife on back. Before we left, I tightened up the limiter strap to the last hole (it was one looser than that) and set the rear triangle to medium from soft. What a difference such a small adjustment to the limiter strap makes. The front end seemed much more planted. At lunch, I ended up firming up the rear triangle to Hard which worked out nicely. Combined we are about 370 with gear. It actually behaved like a normal, smooth snowmobile that doesn't have two left feet, despite being loaded up to a total vehicle weight of ~1,000 pounds plus fuel. Worked out nicely and it was actually warm (35F) today so it was a truly great experience. Can't wait to try it out without a passenger.

The last thing I've got to figure out is the transfer rod set up. Still have zero clue how that works so all I did was check to make sure they were tight and even before I took my first long ride. The manual was not much help.

I hope everyone got in some great riding today.

 

[4strokeluvr111]

the front springs will not really affect the front ski pressure

Was going to disagree strongly but then I read the words "will not really". To me, the front spring adjustments are for fine tuning and not major adjustments. Seems like on the Mono skid the adjustment that has the biggest OVERALL effect of front ski pressure is the limiter strap. IMO....

 

[NaughtyPines]

Was going to disagree strongly but then I read the words "will not really". To me, the front spring adjustments are for fine tuning and not major adjustments. Seems like on the Mono skid the adjustment that has the biggest OVERALL effect of front ski pressure is the limiter strap. IMO....

I agree with your observation. Just moving the limiter strap tighter by a single inch made more difference than all the tweaking of the front spring preload (latter seemed to mostly affect ride quality) and even the front skid shock, which did make a difference when I played with that.

Any idea which way to adjust the two control rods? I don't know how they work or which direction moves the weight bias towards the front of the sled. I almost never take the Venture off trail so I like keeping the skis on the ground. Trying to steer it through body english seems like it would be attempting to veer the Titanic by leaning over the guardrail.

 

[4strokeluvr111]

I agree with your observation. Just moving the limiter strap tighter by a single inch made more difference than all the tweaking of the front spring preload (latter seemed to mostly affect ride quality) and even the front skid shock, which did make a difference when I played with that.

Any idea which way to adjust the two control rods? I don't know how they work or which direction moves the weight bias towards the front of the sled. I almost never take the Venture off trail so I like keeping the skis on the ground. Trying to steer it through body english seems like it would be attempting to veer the Titanic by leaning over the guardrail.

Oh....you don't have the Monoshock on your sled? My bad! My comments on the effect of limiter strap vs. ski shock are still valid.

If you have two shocks in the skid and the front shock has a spring around it, loosening/lengthening the spring will add more weight to the front end. Doesn't take much on a Yam 4S to have a big effect on ski pressure. In any of the sleds I have ever owned with 2 shocks in the skid, I have always accomplished what I wanted as far as front end weight by adjusting the front track shock spring. I've never touched a limiter strap setting.

I have ZERO experience on a 2-up yam 4S suspensions but based on past experience with another brand of 2-up sleds, if you want to have the SAME ride and handling with one or two people on the sled, you are asking too much of the chassis and suspension. You will likely have to have to compromise.

EDIT - I just looked over the parts fiche for your sled. Please understand that I have never owned a Venture, but the principles of "what does what and it's effect on "X"" is essentially the same on a 2 shock rear skid. I'm just trying to help you here.

I have a couple of questions first:

1. Is the front track shock spring length adjustable? Does it have a collar to adjust the tension (aka preload) on it? I can't tell by the fiche.

2. Your rear skid had two different sets of spring adjuster blocks right? The lower one is meant for 1-up or 2-up riding I believe? When you move the block a certain way it raises the forward facing torsion spring arm which will put lots more tension (preload) on the spring. Raising the block would be meant for 2-up riding.

The upper triangular blocks are for setting the preload on the torsion via the short upper arm. In your case one could view this as being a fine tuning type of adjustment.

I won't bore you with what the torsion springs do and what the shocks are supposed to do and how they work in tandem.

What I would try to accomplish via the upper and lower torsion block setting is that when you are on the sled by yourself or riding 2-up, you should have 3-4" of "sit in". I'll assume you know what this means. If not, let me know and I'll explain further.

As to your question about the Control Rods. The less distance you have (less threads showing) your sled will not rock back and forth on accel and decel. I THINK for how you want the sled to react you want the setting at the minimum (less thread showing). I don't know what the measurement for "minimum" is but you should be able to find that out either on this site or through a dealer.

Two changes/upgrades I would consider if I were you:

1. Go to a one size heavier front swaybar. I can't tell if yours is 11mm or 11.8mm stock but I would go one size higher to ether a 12mm or 13mm. This will help keep the skis down in corners.

2. Install a rebuildable, gas, adjustable clicker rear track shock. IMO...what you have in there now is junk for 1-up riding much less 2-up riding.

Used (no need to buy new) shock and swaybar are likely available from Travis at barnofparts.com at great prices

Lot's to digest here. I'm sure others will chime in as well.

 

[J1635]

] if you want to have the SAME ride and handling with one or two people on the sled, you are asking too much of the chassis and suspension. You will likely have to have to compromise.

exactly this, no matter what you do that sled will never ride like a single, its always gonna be a steerable bathtub.

sharp dual carbides every season if theyre wearing down too. Also keep in mind the higher up you move those spring retaining rings on the front skid shock the more pressure your putting on the hyfax at the front of the skid, if its too tight you will burn through those sliders pretty quick

 

[4strokeluvr111]

Also keep in mind the higher up you move those spring retaining rings on the front skid shock the more pressure your putting on the hyfax at the front of the skid, if its too tight you will burn through those sliders pretty quick

Wouldn't it be "down" not up? If you're putting more pressure on the spring (doing down on the clip) thus taking weight off of the front end you'll be putting more pressure on the front of the rails.

Add the extra wheel kit in front and run the track lose to compensate?

 

[J1635]

Wouldn't it be "down" not up? If you're putting more pressure on the spring (doing down on the clip) thus taking weight off of the front end you'll be putting more pressure on the front of the rails.

Add the extra wheel kit in front and run the track lose to compensate?

those 2 locking nuts on the shock in the front of the skid. if you run them higher up on the body moving towards the seat, it pushes the skid down and makes it tighter where the track first connects when it exits the drivers. he doesnt have a wheel kit on it, which is why im telling him if its too tight hes gonna burn through

 

[4strokeluvr111]

those 2 locking nuts on the shock in the front of the skid. if you run them higher up on the body moving towards the seat, it pushes the skid down and makes it tighter where the track first connects when it exits the drivers. he doesnt have a wheel kit on it, which is why im telling him if its too tight hes gonna burn through

Are the locking nuts on the top or bottom of the shock? If they are on top and tightening them DOWN compresses the spring, then you are putting more pressure on the rails.

 

[J1635]

Are the locking nuts on the top or bottom of the shock? If they are on top and tightening them DOWN compresses the spring, then you are putting more pressure on the rails.

this is how mine is mounted and this is how its shown in the manual, lock nuts are on the bottom

 

[4strokeluvr111]

this is how mine is mounted and this is how its shown in the manual, lock nuts are on the bottom
View attachment 106407

Yep you are right!

 

[NaughtyPines]

Completely awesome information.

I have been leaving the 2-up block in the "up" position since it only seems to make a difference in the last few inches of travel like overload springs so 99% of the time riding 1-up it seems to make zero difference from my limited experience.

Took your advice on measuring the rear sag. Seems by myself it's best on "medium" with 3" of sag and I put it on "hard" when I have my passenger. That seems to work well. You nailed it for how I want the sled to react so I'll be playing with the control rods tomorrow morning and see how that goes. (First I'm going to go groom with my old beater air cooled Polaris, though)

I don't expect the Venture to handle like a race car - just want it to follow the line I want it to follow without much effort. Of course, being a large couch, it will push in the corners if I'm going too fast, but it's not designed for that. As it sits today, the only adjustments I need to make when going from 1-up to 2-up are turning the triangle to "hard" from "medium" and one more click of preload on the skis.

Preload on the center skid shock is set at "2" out of "5", with "5" being the firmest. From reading the other posts, that should be good for hyfax life (?)

Thanks!

 

[NaughtyPines]

exactly this, no matter what you do that sled will never ride like a single, its always gonna be a steerable bathtub.

sharp dual carbides every season if theyre wearing down too. Also keep in mind the higher up you move those spring retaining rings on the front skid shock the more pressure your putting on the hyfax at the front of the skid, if its too tight you will burn through those sliders pretty quick

I know it will never have razor sharp handling as that isn't the point. Just want it to be easy to ride either by myself or with a passenger and for it to go where I point it as long as I'm not pushing it too hard. With a passenger I never go over 40 mph and we usually cruise around 25 mph. Yup, I never have a health insurance claim....

So the higher the front skid preload, the faster the hyfax wears? Just want to make sure I'm getting that. I'm at a firmness of 2 out of 5 on that spring preload and running about 1.5" of track sag in the middle using gravity (no weight) since that's what everyone on here seemed to agree on.