How do I cure the "Tippiness" in my Apex?

[tsiceman]

I Agree With machzed, I lowered my floats to 30lbs and it was night & day difference

 

[Soldier'spapa]

MXD,

What we have not heard yet is which Apex you ride? I am on an Attak GT.

The concern about loostening preload is that it might (Soften the spring too much and allow for too much compression) The GT has the ability to adjust the compression and rebound characteristics of the shocks. So if you loose some compression resistance by loostening up the springs, you can add to the resistance by increasing compression clicks on the shocks. If you are on an ER the shocks would have to be taken apart and revalved to accomplish the same effect as the clickers. Bottom line is that a softer spring can be offset using shock hydraulics. BTW I have yet to bottom out the front suspension on my GT.... even with the clickers set soft.

The sway bar links the left side to the right and will only affect stability when one side is compressed and not the other. In a left hand corner, pressure (Weight) is shifted greater onto the right ski shock/spring. The body of the sled wants to lean or roll to the right. The sway bar moving together with the right side suspension transfers the movement over to the left side exerting some of the downward pressure, that physics is naturally applying to the right ski, onto the left ski. By changing to a different diameter sway bar you can effect more or less transfer of pressure. The thicker bars have greater resistance to twisting thus exerting more of the actual pressure onto the opposite ski.

I like the bigger 13mm bar coupled with a lower ride height. After all we are talking about "Tippiness" here. The key is (Where the center of gravity is located). Lower always means flatter cornering. Lower is not best however, when is comes to big bump absorption. The challenge is balancing it all out to find the "Sweet spot" with regard to ride and handling while keeping in mind that we are individuals with different preferences.

When tuning a suspension there is a lot to consider. This is one of the reasons I came over to Yamaha this year. Yamaha has incorporated a lot of suspension adjustability into their machines.

 

[Nice Rumble]

Mine did the same thing last year when it still had the stock settings.

 

[MXD]

MXD,

What we have not heard yet is which Apex you ride?

2006 Apex ER

This is all good info, thanks. I ride 99% of the time on trail and mostly ITS stuff so I could probably sacrafice some "big bump" absorbsion for the flat cornering

 

[TurboJamie]

13mm sway bar = Way Better

 

[ReX]

I disagree w/lower the front end concept. More specifically, this is decreasing spring preload on the front shocks by increasing it's length. I've had better luck doing the opposite: increasing prelaod on the front shocks. My theory: Tipping is due to the shock on the outside of the turn compressing too easily. When it compresses, it allows the ski on the inside of the turn to rise off the snow. If the prelaod is increased, it won't allow the sled to dip as easily in the turn. I've experimented w/my Attak & my buddy's RTX. We found 75 psi to be perfect on the RTX. I've got the front springs on my Attak over compressed from what the owner's manual says only by a little. I've never had to mess w/the limiter strap in the rear skid nor do I have a 13mm sway bar (don't need it IMO). It's also necessarry to use body english in the turns, scoot your a$$ off the seat towards the inside of the turn & lean your upper body into the turn as well. My sled easily corners flatter & faster than the Rev's, Poo's & ditch pickles I ride with.

In reality you guys are both right. Reducing or increasing the preload by a certain amount will reduce inside ski lift. The reason for this is a little non-intuitive though.

If you reduce the preload you lower the sled and the center of gravity. This means that in a corner the sled generates a lower moment (less "rolling or tipping force") and tends to corner flatter.

If you increase the preload you raise the front of the sled which increases the center of gravity. This intuitively would increase the body roll on corners - but the key here is the relationship with the rest of the suspension (or how much weight that outer ski has on it). Now when you corner and the inside ski tries to lift, the limiter strap tightens up faster (and with a traditional skid the front track shock unloads faster too). As soon as the limiter is tight, the front of the skid has to be pulled up in the air in order for the sled to roll further (increase inside ski lift) and this puts much more weight onto the outer ski. Now with much more force/weight going into that far outside ski this greatly reduces the body roll any further.

So instead of increasing the ski preload, with a monoshock skid you can get the same effect by tightening the limiter strap and reducing the weight transfer setting a little (with a traditional skid you'd also have to reduce the front skid shock preload to get the identical effect). This also has the advantage of not increasing the center of gravity so its more effective than increasing the ski preload. If you're not bottoming out and feel you can lower the front end and still not bottom out you can get the maximum inside ski lift reduction by lowering the front end and simultaneously tightening the limiter strap/reducing weight transfer.

If you tighten the limiter too much (or raise the front too much) the limiter will start to tighten up while cruising over small bumps without even cornering. If this happens the ride will suffer. Also reducing the weight transfer will stiffen up the ride by forcing the front of the skid to compress whenever the rear of the skid is on a bump. I found with the monoshock skid, reducing the weight transfer too far made the ride quality suffer quite a bit more than tightening the limiter.

The best way to set ride height (IMO) is to make sure you have enough to control bottoming out and handle the way you ride. I adjust my sleds front ride height to handle the bumps and then adjust a combination of the limiter and weight transfer control to dial in weight transfer and control inside ski lift. With the 05 RX-1/06 Apex ER line we found the stock preload on the front was about right for us.

I do run the 13mm sway bar and this improves inside ski lift a lot more than just adjusting the suspension. It does make the ride harsher when hitting a bump with only one ski though.

 

[Coondog2707]

How much does pioneer sell the bar for?

 

[mark]

90 USD

 

[SledFreak]

I still think with just a 13mm sway bar, you need to re-valve your shocks.....

 

[NY_Nytro]

I disagree w/lower the front end concept. More specifically, this is decreasing spring preload on the front shocks by increasing it's length. I've had better luck doing the opposite: increasing prelaod on the front shocks. My theory: Tipping is due to the shock on the outside of the turn compressing too easily. When it compresses, it allows the ski on the inside of the turn to rise off the snow. If the prelaod is increased, it won't allow the sled to dip as easily in the turn. I've experimented w/my Attak & my buddy's RTX. We found 75 psi to be perfect on the RTX. I've got the front springs on my Attak over compressed from what the owner's manual says only by a little. I've never had to mess w/the limiter strap in the rear skid nor do I have a 13mm sway bar (don't need it IMO). It's also necessarry to use body english in the turns, scoot your a$$ off the seat towards the inside of the turn & lean your upper body into the turn as well. My sled easily corners flatter & faster than the Rev's, Poo's & ditch pickles I ride with.

I had my first run with my new Nytro this past weekend. Initially I had the Floats set to 60 PSI. After 180 miles myself noticed and the rider behind me commented on the inside ski lift. He said exactly as you : I need to increase the spring preload on the ski shocks (he was unaware I had Floats) as the outside shock is compressing too easily, he said. So I increased pressure in the Floats to 70 PSI. The next day on the return trip the sled was noticably much worse. I realized the tippyness was not body roll but a tippyness because the outside ski was not compressing and whole sled was tipping. So I then lower the pressure to 55 PSI and it was near perfect. I will probably go down to 50 PSI.

 

[NY_Nytro]

Mine did the same thing last year when it still had the stock settings.

Your picture shows IMO that increasing ski preload shouldn't help. The angle of the outside A-arm still show little compression even at such extreme inside ski lift.

 

[nate007]

Increasing front preload is not the entire equation. If you lower the front of the sled, you need to be sure that the rear suspension is adjusted to run at a different angle, but the right combination should be a shorter spring via replacement. If you just tighten spring, the front end will defintely raise= higher center of gravity. Do as Machzed said, and get the frnt down enough,(but not to hit the front end on stuff on te trails) and add a spring that has a comparable spring rate with a shorter lenght. I have the same issue now, and this is the route I'm taking.
Nate