Pro RMK Suspension

[Joey 14]

I have a 13 pro RMK 155" 800 and a 600. The 800 has Raptor springs on the stock shocks. They are great everywhere except in the trails where a lot of bumps in a row. It starts out ok but then starts to hit hard. So hard you feel it in your stomach. Lol. Feels like your guts are coming out. Any idea on where to start for adjustment? Leave Raptors on front and put stock springs back on the rear or? Thank you

 

[LPIdaho]

I have a 13 pro RMK 155" 800 and a 600. The 800 has Raptor springs on the stock shocks. They are great everywhere except in the trails where a lot of bumps in a row. It starts out ok but then starts to hit hard. So hard you feel it in your stomach. Lol. Feels like your guts are coming out. Any idea on where to start for adjustment? Leave Raptors on front and put stock springs back on the rear or? Thank you

Sounds to me like your front track shock is possibly blown

 

[800xtreme]

Did you call Raptor? They are usually AWESOME at helping guys tune their stuff. They also stand behind their product. I would start there

 

[Joey 14]

Thank you!! I did call and left a message. I will try again. Thanks.

 

[richracer1]

Sounds like you have some shocks that need rebuilt. Putting the stock springs back on won't do anything.

 

[alt]

Did you call Raptor? They are usually AWESOME at helping guys tune their stuff. They also stand behind their product. I would start there

I second that... Best to direct questions to the one that builds the product. Forums as great as they are (and I mean that) can have mixed reviews. Call raptor.
Dan

 

[Joey 14]

Thanks. I will call them. I'm leaning towards I may have to much pre load on the front track spring. It's fine everywhere except in a trail that's real bumpy. And the more bumps the harder it hits. Which those springs are designed to hit soft then get firmer as the keep hitting.
I will call Raptor. Thank you everyone!

 

[mountainhorse]

How many miles on your sled??

IMO... your ski shocks are not rebounding fast enough.

Like LP said..could be a front track shock that has an impaired rebound action.

Sounds like your shock is "packing out" on the rebound side to me...Textbook description you are giving.

Not typical... I'd send them into walker and see if something is wrong. (dirt, debris, stuck rebound valve stack etc.

Could be the springs IF.... IF... the spring installed is a much lower force spring... but the raptors springs have been used on a lot of peoples sleds that don't exhibit your symptoms...

Rebound damping controls the return of the wheel after a compression. It is a
bit simpler than compression damping, as typically it is only working against the
stored energy of the spring, so the forces acting on it are a bit more predictable.
It is important because without it, your wheel would rebound too quickly. Specifically,
you would get bucked all the time and your wheel would drop into every single hole
it could find, sending you over the bars more than necessary. Faster rebound does
not equate to a faster rider.

If rebound is set too slow it can “pack down,” where successive hits result in the wheel
getting deeper and deeper into the travel. This will result in not having enough travel to deal with subsequent hits. Most people don’t realize that a symptom of too much rebound damping is harshness on compression. This is due to the bike riding deeper in the travel, and your hands and feet working against higher forces in the springs. A common fix for harshness is to reduce compression damping, but if you are packing down, it will exacerbate the problem. Another symptom of slow rebound is your bike sitting too deep in turns (especially fast berms). If your bike has the rebound set properly, you won’t be thinking aboutrebound while you are riding.
Pinkbike

.

 

[geo]

Revalving may help but the stock WE's were never intended to be snow cross suspension.

The body's and shafts are skinny for weight considerations. This leads to quick heat build-up and loss of dampening from body distortion and friction.

Really only two considerations. Replacement or slow down when needed.

MO

 

[mountainhorse]

To me Geo...Sounds like something is wrong rather the shocks being inadequate for the task at hand.

In Cali... springtime roads are complete deep washboard for miles.... or the ride in from the Rutherford to the Pemby Ice cap.... with 250 lb riders on stock Walker Evans PRO RMK shocks that dont "pack out"... Sure... from that kind of abuse, you need to service the shock more often... and sometimes the valve shims can fatigue and need replacement...

But the description of the OP is that the shocks are not rebounding fully after a hit... That would mean that the rebound side is too stiff for whatever reason (shocks themselves or rear-suspension shocks/setup). Unless the springs are defective and too light for the application.

Also... The stock Walker Evans shocks are a low cost production shock... servicing them as needed goes a long way. The service interval is dependent on how they have been used.

TRS posted a great valve setup and piston bleed drill chart..... Might be a good option, his stuff is well thought out.

OR.... Go the Extra mile... pull what you have, and buy a complete set of high performance aftermarket shocks.





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[Joey 14]

Thank you all for the info! It's crazy cause it did it on a rid on a trail that was just small bumps for a bit then smooth then bumps. It would take first few nice then it felt like you were riding on a basketball.
But next two trips up north it was normal trails to get to where we were going. It had bumps but not a ton in a row and it ride ok on the last two trips. So maybe it had domething in it causing it to stick and it came out.
Sleds hav been awesome and are fun to ride.
Thank you again.

 

[geo]

I agree with you MH. They're not bad stock shocks for a mountain sled and valving is biased towards a few rollers and not chop for a while. The OP is from Maine so I thought he may spend more time on the trails than we do.

But,,, my first year on the poo I revalved a couple of times (done it before) and ended up pretty close to the TRS set-up funny enough. Even ran the green 185 spring from my 2012 Cat lol). Very similar to what Holz recommended for the Cats' (pretty close suspensions) back in '08 too.
My suggestion is based on time spent at aggressive trail speeds (I like it all lol). The WE's flex and fade in 4 or 5 min. A similar Fox gets you 20 or 25 min. Not much different in design but flow, fit and function is very different.
The WE's will toast their fluid ridden hard in 500 miles or less and a Fox will go 2000 miles ( or a season basically).

The Pro was never designed to be trail ridden hard. It does what it was designed for the best of any. If you want to spend hard time on the trail the biggest improvement is the shocks IMO.

You lucky 2015 snowcheck guys can ignore lol.

 

[Joey 14]

That must be what's happening! On the trails the shock gives up and spring is designed to hit soft and then harder and harder and that must be what I'm feeling is riding on the spring. I will make some adjustments.
Thank you all for the info!

 

[TRS]

The Walker Evans shock fluid breaks down relatively fast. As quick as 100 miles on a PRO. It loses it's lube and heat transfer properties.

 

[mountainhorse]

SHOCK OILS... WHAT TO USE, WHAT'S OUT THERE?

The Walker Evans fluid seems to be a mineral based shock oil??

I've looked up some premium shock fluids...all Synthetic.

Wondering what to use and why?

What about viscosity ("weight")? Can you effectively tune a shock with diff viscosity?


I can find: (probably more)

Redline (1wt, 2.5wt, 5wt, 10wt)
http://www.redlineoil.com/Products.aspx?pcid=18

Amsoil (5wt, 10wt)
http://www.amsoil.com/shop/by-product/other-products/suspension-fluid/

Lucas (5wt)
http://lucasoil.com/products/motorcycle-products/synthetic-fork-oil

Maxima synthetic (3wt)
http://www.maximausa.com/product/synthetic-racing-shock-fluid/

Torco (4.7wt)
http://www.torcousa.com/torco_product/rsf.html

.

 

[LoudHandle]

Changing the weight of the oil has been the poor man's way of tuning motorcycle forks for decades. Yes, you can tune with fluid viscosity (weight). I'm no suspension guru, but I know that much. It stands to reason that a shock would react the same. The thinner the fluid the faster it will move thru the orifice/s in the piston. The heavier the fluid the slower it moves thru. All common sense, for the most part.

But like anything else, switching the brand of oil as well as weight, introduces another variable into the equation and increases the likelyhood of an undesired effect.

I think it best left to the professionals who have done the R&D with their fluid of choice and the valving that works with it.

 

[TRS]

Changing the weight of the oil has been the poor man's way of tuning motorcycle forks for decades. Yes, you can tune with fluid viscosity (weight). I'm no suspension guru, but I know that much. It stands to reason that a shock would react the same. The thinner the fluid the faster it will move thru the orifice/s in the piston. The heavier the fluid the slower it moves thru. All common sense, for the most part.

But like anything else, switching the brand of oil as well as weight, introduces another variable into the equation and increases the likelyhood of an undesired effect.

I think it best left to the professionals who have done the R&D with their fluid of choice and the valving that works with it.

Well said, the shock fluid industry does not conform to a standard. There viscosity is vendor specific, one vendors weight doesn't cross directly to another's . I went to Amsoil years ago because of its consistency and (experienced) extended maintenance intervals. Its ability to dissipate heat well.
Check this out. www.transmoto.com.au/comparative-oil-weights-table/

 

[TRS]

Here is another for your reading pleasure
www.sweepracingusa.com/iframe/cst_truth.htm

 

[JP-RaptorShocks]

I have a 13 pro RMK 155" 800 and a 600. The 800 has Raptor springs on the stock shocks. They are great everywhere except in the trails where a lot of bumps in a row. It starts out ok but then starts to hit hard. So hard you feel it in your stomach. Lol. Feels like your guts are coming out. Any idea on where to start for adjustment? Leave Raptors on front and put stock springs back on the rear or? Thank you

Joey - Jake and I talked about this post and he had the following to add. Hopefully this helps.

"Joey, I thought we would chime in here and see if we could shed some light on what you might be feeling and how to fix it. First off we never get feedback from the field from customers that are experiencing this issue and we’ve had very positive feedback on spring packages. I think the first thing I would do is have your shocks serviced as Mountainhorse mentioned. We’ve seen a fair amount of inconsistency with mass produced shocks like the Walkers. This doesn’t mean that they’re bad shocks at the end of the day for a production sled but Polaris does squeeze their suppliers very hard on cost and let’s face it shocks have several components and they do require that you get all the air bleed out of them to work properly. I personally know the owners of WEE very well and trust me they are smart guys but they probably rely on a room full of people to get it right every single time and that doesn’t always happen. Get the shocks right and get a good baseline the first couple rides this year and be sure to bring your setup instructions with so you can make changes in the field on the fly. If at this point you’re not happy give me a call and some feedback on what the vehicle is or isn’t doing and we’ll formulate a plan. As most of our customers are aware of we will back our product in every way so if it’s an issue on our end we have your back until we get it figured out for you.
Hope this helps and thanks for choosing Raptor Performance Shocks, Jake"

 

[Joey 14]

Thank you! I will call walker Evans and see what it will take to get the shocks looked at and decide to let them or give you a call to see what u think from here. Thank you!