Help!!!!

[Canadian Rx-1]

I'm want to improve te ride and handling of my 2003 Rx-1 ER. There are so many choices I just wanted to see what works. I find the rear too stiff and get ski lift up front. I don't want to invest in springs, 04 style rear shocks etc. if only to need a new skid or Ohlins. Please help me out.
Thanks.

 

[LazyBastard]

First off, spending is NOT investing. An investment is something that you put some money INTO, and expect to get MORE out from. There is nothing that you can put into your snowmobile that you could even dream of breaking even on.


To make the front end handling better, you need straight-rate springs, updated swaybar, and updated links. There is nothing you can do to get out of spending $$ on the swaybar and links. You can put rubber blocks into the springs where the coils are the TIGHTEST to make them of a more linear rate.

For the back end: The stock shock is way to soft. If you put the FRA on MINIMUM (highest position from ground), the shock will be too weak to stop the sled from bottoming. Without putting in a harder shock, the only thing you can do to compensate is to put the FRA on MAX and use the SPRING to resist bottoming. Set the spring preload as low as you can to set the sag-in to specs. Also take the vinyl spacer from the LOWER end of the control rods, and cut them in HALF. Half the spacer makes for a smoother ride.

 

[POWERHAULIC]

I disagree with LB, all you need in the front are the straight rate springs, 140# are my favorite. you don't need the bars and links.

In the rear Replace the rear position shock with an adjustable dampning Ohlins, then have a nice ride and handling. 8)

 

[LazyBastard]

The bar and links make 50% of the difference. If you're happy with it being only somewhat *better*, and still unsatisfactory, then by all means, only play with the springs.

 

[LazyBastard]

I disagree with LB, all you need in the front are the straight rate springs, 140# are my favorite. you don't need the bars and links.

In the rear Replace the rear position shock with an adjustable dampning Ohlins, then have a nice ride and handling. 8)

Yeah, the answer to everything is "spend spend".. read again, he asked for fixes that didn't COST!

 

[POWERHAULIC]

LB I am saying that there is no need to spend more money on the links and bar, it works great with just the springs.

 

[LazyBastard]

But your suggesting to spend MORE money on the springs and the rear shock. More benefit can be made by putting overall less money into just the bar and links. The back suspension can be setup to be good without spending any money, the front springs don't cost ANYTHING to fix, just need to block the part with the lower rate with rubber.

 

[Canadian Rx-1]

spending

Let me clarify. what I should have said was that I didn't want to waste money. I know you have to pay to play. I just wanted the concensus as what was the best way to go.

 

[MrSled]

the springs are the fix....IMO...the links and the bar are just a added bonus....dual and triple rate springs are the biggest joke in handleing ...they only shine in straight line riding..

 

[Swiss Sledder]

I did the links and swaybar in March and noticed a 25% improvement. Springs are now installed but I haven't tested yet. Everyone on here says do the straight rate springs! I would focus on the front end first, and have the springs installed. Ride and if still not happy, install links and swaybar. But first get the front end working the way you want before moving to the rear.

 

[LazyBastard]

Right, and as I was saying, you can simulate straight-rate springs just by blocking the tighter coils (lower rate section) together so that they can't compress.

 

[01srx+03rx1]

Has anyone tried just changing the bar? I talked to Bruce at Pioneer and he recommended just changing the bar to 12mm. I took his advice and ordered the 12 mm bar. In thinking about this, it seems kindof a viable solution for this reason. The torsion of a solid homogeneous linear-elastic shaft goes as the 4th power of its radius. That is, a small change in diameter caused a large change in the spring rate, due to torsion, of the shaft. Lets assume a nominal bar radius of 1.0 unit (the units don't matter). Now lets add 20% to the bar radius, i.e. 1.2 units radius. Taking 1.0^4 results in 1.0 and taking 1.2^4 yeilds 2.07. Therefore in a real world case of, say a 10mm bar being replaced by a 12 mm bar (a 20% increase in radius) the force applied, or transfer in this case, from one side of the suspension to the other will be doubled in going from 10mm to 12mm, all things being equal! Now lets think about effect of replacing the links. They are 50% longer. This has the effect of REDUCING the spring rate as the square of the radius change. Therefore the longer links lower the force transfered by this relationship 2.07/(1.5)^2 = 0.92. For the combination of longer links and an 11mm bar we get 0.65! Interesting huh?

Granted, I haven't accounted for the ratio change due to the angular relationship change of the longer links vs. the shorter ones. I assumed small angle changes. If I get some free time, I'll measure it out and try to calculate the effect of that change.

Using the assumption above and simple math and physical material properties I get the following factors relating nominal roll resistance to bar and link changes.

To summarize:
10mm bar - 50mm links nominal roll resistance
10mm bar - 75mm links 0.44 * nominal (less roll resistance)
11mm bar - 50mm links 1.46 * nominal (46% more roll resistance)
11mm bar - 75mm links 0.65 * nominal
12mm bar - 50mm links 2.07 * nominal (100% more roll resistance)
12mm bar - 75mm links 0.92 * nominal

 

[MrSled]

Wow, that is deep ..... one thing, my experience tells me on paper it will always look good until you put it in action, sometimes subtle changes make a bigger impact.

 

[jimmie d]

I was ready tio get out my sliderule.

 

[SIMMER]

01srx+03rx1 I ONLY changed the bar last year (went to a 12mm) and noticed a bit of a difference I would say 30% seat of the pants feel. This year I have the Straight Rate springs from Bruce as well. Hoping to get much more of an impact. I also have a set of links and a 11mm bar to try as well.

One thing I have learned with the pro-action especially is that your adjustments in the rear skid greatly affect the front end.