Hygear Report - 07/08 RTX, 06/07 Nytro, 05 Vector

[garserio]

For those running the Proactive suspension in the 07/08 RTX, 06/07 Nytro or 05 Vector (also applies to Phazer owners, too), you know about this skid's weaknesses, especially the center link that couples the center shock to the rear shock. After 4 seasons of fighting this suspension in my 05 Vector, I made my final attempt to improve it by adding Hygear's modifications. Here is what I bought:

1. Linkage Kit
2. Center shock rebuild, revalve, dual-rate spring kit (Twisted Springs) and add-on reservoir (reZe)
3. Rear damper (In my case the Ohlin) rebuild & revalve
4. Torsion Spring Spacers

Cost: $1,180 incl tax & shipping

Squawk List / Motivation, Results (Reasoning):
1. Severe bottoming, Mimimized by 80% (DR Spring & compression dampening progression)
2. Stutter bump smoothing, Couldn't feel them! 100% gone! (DR Center Spring)
3. Rear kickback (Beaver-tailing), Minimized by 90% (Rear damper valving)
4. Center shock fading, Minimized by 60% (Add on reservior for more oil volume = longer to heat up, more surface area to cool)
5. Center link failure, None noted nor expected since stress of shock coupling is eliminated. (Linkage Kit)
6. Center idler wheel warping, None noted nor expected since kit included beefier wheels with the 6205 bearing. This is a proven solution as noted from my and others past work with wheel improvements. However, the Hygear kit uses a smaller wheel, so the bearing will be spinning much faster which could affect longevity... time will tell.

Bottom Line:
I wish I made this move years ago! This is by far the most comprehensive improvement package available for this skid. It addressed every deficiency I felt the skid exhibited. Although the price may seem high, I feel it lived up to its promises and have spent at least as much over the past few years with "piece-wise" improvements that did not fully solved the problems. I revalved shocks, tried numerous springs, upgraded to Ohlins, beefed up components, and played with every adjustment on the skid logging over 4,000 miles on very rough and smooth trail conditions. Every combination I tried was optimized for one set of conditions. With Hygear's setup, I feel the skid performs extremely well in rough conditions without sacrificing smooth trail performance. This is due to the highly progressive nature of the valving and spring setups. I actually like my sled again!

I had a few small challenges with installation, but those were resolved by speaking with Hygear who spent ample time working with me. It turns out that the linkage kit was developed using a Nytro and it seems that the Vector is touch different with its center shock which necessitated a location change for the center shock mounting shaft. Also, the Vector's torsion springs are lighter and have a slightly smaller ID which necessitated smaller diameter torsion spring spacers. If you choose to install this kit on your 05 Vector like I did, PM me for advice...

In 100 miles of riding, I was able to dial in all the settings. I had way too much rear damper compression dampening in the beginning. The center shock was doing all the work and was bottoming too quickly. I noticed that the rear of the sled was not moving as readily, so I set my rear damper clicker to a softer setting and the problem disappeared instantly. With the addition of the torsion spring spacers, I found the spring to be more efficient with the "Soft" setting being more than adequate for me. This was a plus because I was able to get the desired ride height without having to preload the springs too much. I am running 50% transfer on the rods, full limiter strap length and just enough center spring preload to keep the assy taught at full extension. (If you preload the center spring too much, you will simply "consume" the amount of travel necessary to collapse the lighter spring thus wiping out the majority of your dual rate spring performance.)

So that's my report. I'll update as I log more miles, but right now, I highly recommend this kit to anyone who is distraught about their Proactive and willing to spend the time to dial it all in.

 

[garserio]

I intended to provide pics, but I am having problems uploading them. The server must be overworked.

STAY TUNED...

OK, I got em!



Also, notice the following details in my pics which might be helpful:

1. The "GArserio" W-Arm modification. I continuously welded a 1/8" Thk x 3/4" wide steel strip to both lengthwise W-arm tubes. It wraps around both crosstubes. I also added (4) rear gussets.
2. POR15 black gloss paint on all suspension arms... and yes that is brushed on in 30 deg weather. If you haven't used this stuff before, try it!
3. Outer idler wheels in rear hole location. This effectively increases the spring rate since you decrease the moment of the slider block on the long spring arm. The Vector comes with the lightest torsion springs so this might not be necessary on Nytros and RTX's.
4. Beefed up rail under rear bump stops. Both my rails were cracked, so I welded in 1/4" Thk strips on both sides of the rail and then cut off the sides of the white plastic spacers under the rubber stops.

 

[monker]

I have the same setup on my phazer, without the add on rezee. Works awsome!

 

[MyOutdoors]

I'm not trying to piss on your picnic and I'm glad you had great results, but for the same money why wouldn't you opt for an aftermarket suspension?

 

[Turtle]

I also did the linkage kit on my 136" Nytro. Although I only purchased a portion of the kit to keep the cost down. I simply got the linkage removal kit, and a dual rate spring. The results have been fantastic as you have described.
After reading your report, I may just upgrade next season to the revalving, and center shock resi kit. My shocks will need rebuilding anyway.

 

[garserio]

I'm not trying to piss on your picnic and I'm glad you had great results, but for the same money why wouldn't you opt for an aftermarket suspension?

I certainly considered other options such as an Expert-X or grafting in a Ski-Doo SC10-3. However, these options aren't without challenges or additional cost either. For instance, with an Expert-X, what happens when you break a part? Parts availability is much more limited than OEM. Also, for any aftermarket or alternate brand skid, there will be more iterations of shock tuning because you basically become the R&D dept. This drives cost and downtime until you get it right. With the Hygear solution, that R&D has already been done on their dime. The linkage kit includes a few custom parts that could be trouble to get if they break, but they are also very simple parts that can be fabricated by anyone with a lathe and a welder which I both have access to.

So, for me the Hygear solution was an obvious choice. I went big with it and got all the bells & whistles. You can certainly get similar results with Hygear by opting out of the Reze & torsion spring spacers. Another point is that my buddy equipped his 06 RTX w/Monshock with Hygear's kit and it transformed his sled, so I had data to support Hygear's product claims.

If the Hygear solution doesn't stand the test of time, then my next move is a used SC10-3 as you have suggested.

 

[giddy up go]

Maybe a foolish question here but what is this centre link you are referring to and what does it look like? Pic's would help maybe.

 

[ahicks]

When the front shock bottoms, or gets a big load on the botttom mount, this thing rocks back, compressing the rear shock an inch or so. Betting it looked much better on paper.....

 

[garserio]

Maybe a foolish question here but what is this centre link you are referring to and what does it look like? Pic's would help maybe.

Look at picture #1. The link is the black triangular component in the middle with the three bolts, the largest bolt connected to the tabs on the front W-Arm. RTX's are made of aluminum while the Nytro and Vectors have a weaker one made of fabricated steel. Although the RTX one is stronger and less likely to break, the coupling of the center shock to rear causes significant binding action in the skid which is not good for ride quality. I believe the thinking at Yamaha was to create a rising rate type of setup, but as another TY member stated in this thread, "It worked good on paper!"

 

[ReX]

I've been looking over your new suspension setup and I have to say I'm a little confused. I thought the whole point was to get rid of the load inducing linkage between the main shock and the front pivot arm.

Looking at the pictures the same mechanism still exists. This means as the front arm compresses down, the lower mount for the main shock moves forwards; just like it did with the OEM setup.

The only thing that is "disconnected" is the lower mount for the front shock. If you cycle the OEM setup you'll see the lower mount for the front shock didn't really move much stock and the loads imparted on the front pivot arm from the center shock are only simple tension loads. The only reason for lower end of front shock's motion is to allow the linkage for the main shock not to bind.

I'm sure the reason Yamaha included this linkage to the main shock was to reduce the main shock's damping contribution during the upper ~1/3 of the suspension travel. If you cycle the suspension you'll see the lower mount for the main shock moves forwards as the suspension compresses uniformly. This motion causes the shock itelf to see very little compression during the top 1/3 of suspension travel. This is to soften up the ride during the upper portion of travel. Once the skid starts to really compress, the lower connection for the front shock slows down and stops moving. This allows the main shock to start to work hard (once the suspension compresses) and handle the majority of the compression damping for the rear skid. As far as the center shock is concerned, the lower mount essentially stays put (very little relative motion).

I'm convinced the reason the stock setup breaks is due to the loads caused by the main shock on the front pivot arm, not the loads from the center shock (the center shock's loading on the bottom of the pivot arm is much less than the load from the main shock). BTW, I've been examining my suspension carefully and how everything works for many hours today. Hygear's setup still transfers the forces from the bottom of the main shock to the front pivot arm so it will still be likely to break (if a highly damped shock is used and the sled is ridden aggressively).

I do like the way your front pivot arm is reinforced though. That alone would greatly reduce the breakage caused by the main shock loads. Also Hygear's shock valving and spring combination sounds like a nice setup as far as ride quality and bottoming resistance.

As I mentioned in my PM, now that I'm running decent high speed compression damping in my main shock, I've too experienced the same broken front pivot arm issue you've been seeing. This is the first 07 RTX with a broken front pivot arm that I've heard of (but I'm sure there are more). The stock damping for the main shock on the 07 RTX is so weak that the pivot arm used on this sled handles the loads without any failures.

Mine broke while cruising on a moderately rough trail while on a saddle bag trip on a very cold day. With the -35° C temperatures there was a huge amount of ice that had built up over the ~1000km, plus I had ~50 lbs of saddle bag load on the seat, not to mention my 240 lbs ready to ride. My suspension was working very well until the pivot arm rear shock linkage disconnected at the bottom, allowing the main shock's lower mount to pivot freely. Basically my sled was still rideable, but with the main shock's linkage to the front pivot arm broken, the rear shock doesn't do any damping for a lot of the suspension travel (bouncy ride).

 

[ahicks]

<<<I'm sure the reason Yamaha included this linkage to the main shock was to reduce the main shock's damping contribution during the upper ~1/3 of the suspension travel. If you cycle the suspension you'll see the lower mount for the main shock moves forwards as the suspension compresses uniformly. This motion causes the shock itelf to see very little compression during the top 1/3 of suspension travel. This is to soften up the ride during the upper portion of travel. Once the skid starts to really compress, the lower connection for the front shock slows down and stops moving. This allows the main shock to start to work hard (once the suspension compresses) and handle the majority of the compression damping for the rear skid. As far as the center shock is concerned, the lower mount essentially stays put (very little relative motion). >>>

You're right. I was monkeying around with mine again last night. Couldn't figure out just what the objective might be with all that "monkey motion" going on down there. Your thought regarding reduced damping on the top part of the downstroke allowed me to get my head wrapped around it. Thinking about it still this morning, this linkage is also very likely directly responsible for the "bucking" I haven't been able to put my finger on. Not only is there very little/reduced damping on the upper third of the downstroke (As you were able to put together), there is likely an increased
"butt launching" effect on the upstroke as the front linkage forces the bottom of the rear shock up on the up stroke. What a POS!!!

 

[ReX]

<<<I'm sure the reason Yamaha included this linkage to the main shock was to reduce the main shock's damping contribution during the upper ~1/3 of the suspension travel. If you cycle the suspension you'll see the lower mount for the main shock moves forwards as the suspension compresses uniformly. This motion causes the shock itelf to see very little compression during the top 1/3 of suspension travel. This is to soften up the ride during the upper portion of travel. Once the skid starts to really compress, the lower connection for the front shock slows down and stops moving. This allows the main shock to start to work hard (once the suspension compresses) and handle the majority of the compression damping for the rear skid. As far as the center shock is concerned, the lower mount essentially stays put (very little relative motion). >>>

You're right. I was monkeying around with mine again last night. Couldn't figure out just what the objective might be with all that "monkey motion" going on down there. Your thought regarding reduced damping on the top part of the downstroke allowed me to get my head wrapped around it. Thinking about it still this morning, this linkage is also very likely directly responsible for the "bucking" I haven't been able to put my finger on. Not only is there very little/reduced damping on the upper third of the downstroke (As you were able to put together), there is likely an increased
"butt launching" effect on the upstroke as the front linkage forces the bottom of the rear shock up on the up stroke. What a POS!!!

The bucking completely goes away with the right amound of center shock rebound damping.

I'm not going to give away Mike Carver's revalve setup, but I will say the rebound stack on the center shock produces something like 8 times more rebound damping over stock. Whatever the actual increase is, it is absolutely huge - and it works!

Once the valve stack is updated properly, the 07 RTX becomes as stable as any sled out there. To be honest, I've never ridden a sled before that is as stable as mine on rough trails. There is absolutely no bucking, no kick back, no "bounciness", no springing high off bumps, just rock solid stability - always.

Get your shocks revalved. You will be absolutely amazed at the improvement.

 

[garserio]

I've been looking over your new suspension setup and I have to say I'm a little confused. I thought the whole point was to get rid of the load inducing linkage between the main shock and the front pivot arm.

Looking at the pictures the same mechanism still exists. This means as the front arm compresses down, the lower mount for the main shock moves forwards; just like it did with the OEM setup.

REX,

I read your post a few times to envision all your explanations and would like to add a few other observations...

With the stock setup, any load imparted on the center shock was transferred through the pivot link and ultimately caused a torsion load on the rear crosstube of the front arm. (This is the primary factor in front arm failure, not bottoming as it appears at first glance) You very accurately described the pivot link's motion and how it moves the rear damper forward and how that affects total compression dampening progression. This motion still occurs with Hygear's kit. In fact, that is the only reason why Hygear maintains this pivot link, otherwise the rear damper could have been solidly mounted the the rails as well. However, all the pivot link now sees is the loading from rear damper's dampening... there is no center spring load on the pivot link any more. In the stock configuration, the pivot link experiences the full dampening and spring load of the center shock plus the dampening load of the rear damper. Sometimes these forces were additive and sometime subtractive depending on the terrain the skid was traveling through. There are combinations of these forces that causes the pivot link to fail as many have experienced like myself.

So, Hygear's linkage kit isolates the loading of the two shocks, keeping only the lightest of loads of the rear damper through the pivot link and the heaviest of loads of the center shock transferred right to the rails. I believe this kit will solve all pivot link failures and all torsion failures of the front arm. Time will tell if I'm right... I WILL keep honestly updating this post as time goes on. If I wasn't an engineer, I would have thrown in the towel 4 years ago, but as much all these repairs cost me in time, $, and frustration, the challenge of solving them is part of my irrational snowmobile passion. It sounds like you might suffer from this affliction as well...

 

[garserio]

The bucking completely goes away with the right amound of center shock rebound damping.

I'm not going to give away Mike Carver's revalve setup, but I will say the rebound stack on the center shock produces something like 8 times more rebound damping over stock. Whatever the actual increase is, it is absolutely huge - and it works!

Once the valve stack is updated properly, the 07 RTX becomes as stable as any sled out there. To be honest, I've never ridden a sled before that is as stable as mine on rough trails. There is absolutely no bucking, no kick back, no "bounciness", no springing high off bumps, just rock solid stability - always.

Get your shocks revalved. You will be absolutely amazed at the improvement.

That's good to hear that there is another (working) option out their besides Hygear's kit.

After getting some more miles on my Hygear kit, I am quite satisfied with all aspects except it does still have a bit too much kickback on low frequency bumps. It completely eats up all high and mid freq stutter bumps, but the big rollers still give me too much kickback and I believe that is all from my rear damper, especially after I decoupled the shocks. I am going to call Hygear and see what they might be able to do to eliminate this. I am running the Ohlin damper which might be the problem. Back in 05, that was my only option until Yammie came up with their own piggyback damper which I believe is better than the Ohlin and probably more tunable. Hygear's kit was developed with the Yammie shock not my Ohlin, so chances are I have to go through another iteration of rear re-vavling to get it completely right.

 

[ReX]

REX,

I read your post a few times to envision all your explanations and would like to add a few other observations...

With the stock setup, any load imparted on the center shock was transferred through the pivot link and ultimately caused a torsion load on the rear crosstube of the front arm. (This is the primary factor in front arm failure, not bottoming as it appears at first glance) You very accurately described the pivot link's motion and how it moves the rear damper forward and how that affects total compression dampening progression. This motion still occurs with Hygear's kit. In fact, that is the only reason why Hygear maintains this pivot link, otherwise the rear damper could have been solidly mounted the the rails as well. However, all the pivot link now sees is the loading from rear damper's dampening... there is no center spring load on the pivot link any more. In the stock configuration, the pivot link experiences the full dampening and spring load of the center shock plus the dampening load of the rear damper. Sometimes these forces were additive and sometime subtractive depending on the terrain the skid was traveling through. There are combinations of these forces that causes the pivot link to fail as many have experienced like myself.

So, Hygear's linkage kit isolates the loading of the two shocks, keeping only the lightest of loads of the rear damper through the pivot link and the heaviest of loads of the center shock transferred right to the rails. I believe this kit will solve all pivot link failures and all torsion failures of the front arm. Time will tell if I'm right... I WILL keep honestly updating this post as time goes on. If I wasn't an engineer, I would have thrown in the towel 4 years ago, but as much all these repairs cost me in time, $, and frustration, the challenge of solving them is part of my irrational snowmobile passion. It sounds like you might suffer from this affliction as well...

While it is true that eliminating the link from the bottom of the center shock to the front pivot arm will remove the center shock's load being applied to the bottom of the pivot arm, if you consider the magnitude of the load applied by the center shock's linkage vs the load applied by the main shock's linkage you'll see that the center shock doesn't really place all that much load on the bottom of the front pivot arm when compared to the main shock.

Try cycling the suspension and look carefully at the relationships between the various bits and pieces. You'll notice that the center shock's lower mount hardly moves at all and therefore cannot produce much torsion load on the front pivot arm's lower offset connection. The center shock's lower mount is virtually stationary throughout the entire range of suspension motion, while the lower offset connection on the front pivot arm moves several inches in total. Doing the math you can see there is no geometrical multiplication factor on the loads applied from the center shock and only a divider.

On the other hand, if you look at the lower mount for the main shock and compare the motion wrt to the lower offset connection on the front pivot arm there are times when the pivot arm's connection point hardly moves, yet the lower mount for the main shock moves substantially. This creates a substantial geometrical multiplication factor on the main shock's loads being applied to the bottom of the front pivot arm in torsion. I recall that the worst case multiplication factor occurs near the top of travel. This means that if you come off a large jump and suddenly and very rapidly attempt to compress the rear of the skis (slight tail landing) that at this instant the bottom of the front pivot arm recieves a huge and sudden torsion load through the offset connection.

I haven't worked out the exact numbers, but if the center shock applied a load on the lower pivot arm in torsion of 10% of the damping/spring force (times the length of the offset connector), while the main shock's effective applied load is more like 300%, it is the main shock that is the driving force that potentially breaks the bottom of the front pivot arm.

I have ignored the simple tensile load that the center shock applies to the bottom of the front pivot because simply pulling on the offset connector isn't likely to break it (torsion applied to the lower tube is the issue). Also at best the tensile load is roughly 1:1 with the center shock so again, no multiplication factor.

I guess we could argue that every little bit counts, but it is the main shock that is the main driver.

As far as kick back, if you are feeling kick back even on smaller bumps (obviously much less on smaller bumps, but if you unload your weight off the seat and running boards you can still feel the "bounciness"), it is most likely the center shock that needs more rebound damping. If it is absolutely non-existent on smaller bumps (even when you totally unload the sled), then it will likely be a combination of the center and main shocks that need more rebound damping.

Everyone I've now talked to who has successfully controlled kickback on the ProActive CK has done it by greatly increasing rebound on the center shock. To my surprise, some have had good success by actually reducing the rebound damping on the main shock while simultaneously massively increasing the rebound damping on the center.

My sled is essentially running stock rebound on the main and a huge increase in rebound damping on the center. Compression damping is stock or stiffer for the bleed ports (very low speed), softer than stock for the first stage (low/mid speed), a moderately stiffer than stock in the second stage (mid/high speed), and much stiffer than stock in the 3rd stage (very high speed or when you hit a really big "ouch"). Stock only had a single stage so once a big enough bump is hit to flex the valves open on that stage, the shocks allow the sled to easily bottom out. I've done some performance tests recently and discovers that it takes a jump that gets my track off the ground by approximately 3 feet (sled horizontal in the air) with me sitting on the seat (not standing) to "just" use the full travel of the suspension upon landing (and it doesn't hurt my back at all - stock I was often jarring my back several times per ride since I like to ride sitting down most of the time). To be honest I suspect I could also be happy with the suspension a little softer in mid/high speed compression, but when I'm in the mood to ride hard this setup really hits the mark.

I'm still completely baffled as to why Yamaha doesn't at least add a second stage to their shock valving so bigger hits don't slam the suspension into full compression. They could even soften up the first stage a little if they wanted to provide a soft ride, yet provide much better bottoming control with a moderate second stage. It also doesn't make any sense that they run so little rebound damping on the center shock.

BTW, I have the valve stacks from a REV MXZ and it is amazing to see the difference between the 07 RTX valve stack and the REV. The suspension geometry is quite similar between both sleds, yet relatively speaking the REV has huge rebound damping on the center shock and 3 stages of compression damping on both center and main. The shocks themselves are essentially identical between the REV and the RTX. They even use the exact same pistons and valves (just different bleed ports on the pistons and different valve stacks), are the same length and are the same diameter (36mm).

I think you'll be very pleased with the stability and performance once you get enough rebound damping dialed in (it most likely needs more in the center, especially if the current damping was tweaked from stock).