Dragon 155 rear suspension UPGRADE

[HILLRMK155]

So i just finished prepping my 09 D8 155 for this season. Took it out and noticed that the rear suspension has a lot of sag ( 4/5 inches without nothing on the sled ) i already improved the front ski shocks to 2013 assault clicker shocks but now the rear seems to be the issue...

Ive been reading a bit from what i could find on here

i weigh 250 geared up and def need it to be STIFFER and less sagg!

-change shock position? holes?
-fat boy torsion springs?
-pro rear shocks swap? (fits bolt on???!!!)
-swap full pro rear skid?

anything that helps would be appreciated!!

thanks guys , happy new year

 

[ripalip2]

sent you a pm

 

[sledhed]

Some sag is normal. The heavier torsion springs help. Loaned a set of heavier torsion springs to my friend with an 08 D8, didn't help for him, turned out the front scissor(?) was bent which messed up the geometry of the front of the rear skid. Springs do lose tension over time as well.

The WE air shocks do need rebuilt / recharged every so often too. Probably should be checked each season and depending on miles rebuilt.

Shafts all checked for wear and greased with low temp grease.

I have considered putting a Pro skid under my Dragon, have heard good things about doing that in terms of getting up on top of the snow. They do bolt in only difference is size of the bolts (metric vs. standard), as I have heard. However you still might need new shocks / rebuilt shocks etc. so you might just be buying someone else's worn out stuff...

 

[HILLRMK155]

would a set of rear PRO walkers fit directly in my dragon skid???

would that solve the problem?

 

[jman94]

The pro rmk skid shocks are different lengths than the shocks designed for your dragon's skid.

As mentioned above, there is designed sag in the suspension. I'm not sure of the exact #'s but they are available online through Polaris. Torsion springs can wear out and the walker air shocks are notorious for needing rebuilds frequently.
In my opinion, the pro rmk skid replacement is the best you can do. Even if you went with aftermarket shocks on the dragon sled, the pro skid with stock shocks would still perform better. I Did this to my sled last year and it made a HUGE difference in its climbing on the snow abilities. It is a direct bolt in. I shopped around and got a pro skid for $700 then sold my dragon skid, was into it about $250 total.

 

[mountainhorse]

You really should not see that much sag in the skid... but some.

Springs should not sack out like that unless you had it loaded down during storage.

Since it is a few years old... IMO... Pull the whole skid out of the sled... Pull the springs and shocks and check for smooth motion and broken parts

Check out this thread...
http://www.snowest.com/forum/showthread.php?t=312674

Pull the skid apart... remove all of the pivot shafts. There are 2 on the front arm, 3 on rear arm... Clean the tubes out with solvent and clean the shafts... Re-grease with the grease recommended in the thread... NOT axle grease or heavy equipment grease or blue "marine" trailer bearing grease... follow the greasing instructions.

Check the shocks for ease of return.... Often the front track shock has lost pressure.

You would be amazed at how much better the WHOLE sled works when the skid can move smoothly.... and thick grease or old/dirty grease will hamper this more than you can imagine.

If you have never had the shocks serviced... get it done... and use only a good quality synthetic shock oil like Amsoil 5w "Shock-Therapy".

This service is MUCH more important than you may think... even with 500 miles on the shocks, they could be in serious need of service.

Assemble the skid... Re-install the skid and make sure that the track tension is set to factory specs.


Good luck.





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[MORSNO]

I haven't seen the 5/8" rear scissor relocate mentioned yet. I'm a big fella also, on top of heavier rear springs (.375/47) relocating the rear scissor 5/8" back makes a huge difference and is free (other than 30 minutes of your time).

Not my picture, but this shows the relocate.

 

[HILLRMK155]

So i found a 2013 complete rear skid local!

what is the deal with fitting it? bolt on?? mods?

any advice would be good

 

[jman94]

Direct bolt in... Might need to drill out the mounting holes to accommodate the larger metric bolts. I didn't have to, but others have. Other than that it's a simple un-install and re-install. Tighten up your front track shock for more ski lift/more trenching, loosen for more ski pressure and less trenching. I set my rear track shock a bit stiffer than the Polaris pro specs as the iq chassis is already a bit heavier. Set the track to the stock spec and you're good to go! Hopefully you enjoy it!

 

[dt_rob]

Just bolted a 2012 skid in my 2010 rmk dragon 155. About where should I set the front and rear springs? How much preload? Also noticed rear arm angled back, is that normal? Easy swap otherwise. Thanks.

 

[jman94]

Rear spring set to your weight then adjust for bottoming, the specs should be available from Polaris online.
I put my front track shock just loose enough that it wont slop around without weight (about 3-4 threads showing) when I am climbing or will be in deep pow. If its set up or heavy snow, then I tighten it up to about 3/4" up for more ski lift (can cause trenching). FYI, i am about 6' 235 dressed and ride in the cascades so set up snow mostly. here is a good thread on how the Pro RMK suspension is tuned.. http://www.snowest.com/forum/showthread.php?t=293375&page=2

Not sure what you mean by the rear arm? any pics?

 

[dt_rob]

I can get a picture tonight. I am talking about where the rear arm bolts to the rails. Instead of being straight up perpendicular to the rails, like shown in the picture by morsno above, the arms angle back alittle ways. Instead of drilling my chassis for the 10mm bolts in the pro skid, I just swapped the shafts for the front and rear arms with the shafts in my old skid.

 

[KittinsRtasTY]

I find this topic very interesting. I have a 09 D8 155" and weigh 255 before putting on my gear. Last week, while riding in good, deep snow, I noticed my sled trenched badly, and I had to run WOT. My buddy, who weighs a lot less, rode a new, 155" RMK across the same snow with very little trouble and hardly any throttle. I realize there is a trifecta of things working against me in this situation, but thought a 163" track or a diet was my only solution. I did not realize the pro chassis could be so easily swapped, and will be looking at that for a cheaper solution.

Does a person swap everything included in the chassis (suspension parts, bogie wheels shocks, track), or is there only a few pieces needed to get the desired effect?

 

[jman94]

Dt_rob... I think I know what you're talking about now, the rear "scissor" should look kina like the > sign (less of an angle though). As you compress the suspension, the inner angle will decrease in size, when you pull up on the suspension it will increase until it hits the crossbar with a little notched part on the upper scissor.

Kittens... Was it a new 2011+ rmk? If so I definatly think that the whole suspension geomotry helped him a lot. If it was an older IQ RMK then yes, weight is probably an issue, as it was with me
As for the suspension, take a full pro rmk skid (rails, shocks, suspension, bogies) and directly mount it into your existing suspension hangers.

 

[polrmk]

Has any one done the Fox Air shock rear suspension upgrade from NexTech on an IQ RMK?

 

[KittinsRtasTY]

Kittens... Was it a new 2011+ rmk? If so I definatly think that the whole suspension geomotry helped him a lot. If it was an older IQ RMK then yes, weight is probably an issue, as it was with me
As for the suspension, take a full pro rmk skid (rails, shocks, suspension, bogies) and directly mount it into your existing suspension hangers.

@jman... I seen the same situation again this weekend, with another lighter rider and a PRO. Both times, they were 2013 RMK or PRO sleds, respectively. Guess you get what u pay for . This 800 Dragon is my first sled, and have only had it for two years, so I am really not interested in trading now. A suspension upgrade might be the right option for me.

On a side note, I considered trying the PRO in the deep snow, but was having too much damn fun to get off mine long enough!