Well, I am on the way to swapping a Nytro RTX skid into my Rage, the mount points have been figured (maybe, more on this below) and the 136" track arrived last week. I'm a big fan of 136" skids for rough trail riding, and so I'm extending the RTX skid to suit. The easy way looks to be extensions or new 136" rails, but after some research around here it appears that the this may(?) place extra leverage on the skid causing it to blow through travel far too easily during certain types of hits.
Soooo... I started to look and see what other manufacturers were doing in order to build their 136" skids. The first place I looked was Ski Doo's XP Renegade vs their regular 121" machines as the Nytro skid is quite similar to Ski-Doo's SC series. Bingo!(?)...Both 121 and 137 skids use the same arms and most associated parts. The big differences are that the rear arm is relocated about 5 - 6" rearward. The shock and relay rods are suitably longer to stretch the new distance between the arms and the rails are of course longer along with a few other minor details(shock valving etc). The last 1.5" is given to the rails behind the mount point. I'll note that obviously I wouldn't go all willy nilly with the measurements they would have to exact...
Does anyone else think this would be the proper way to get the best performance out the skid as a 136"? Seems like a no brainer way to keep everything balanced as nature intended.
Soooo... I started to look and see what other manufacturers were doing in order to build their 136" skids. The first place I looked was Ski Doo's XP Renegade vs their regular 121" machines as the Nytro skid is quite similar to Ski-Doo's SC series. Bingo!(?)...Both 121 and 137 skids use the same arms and most associated parts. The big differences are that the rear arm is relocated about 5 - 6" rearward. The shock and relay rods are suitably longer to stretch the new distance between the arms and the rails are of course longer along with a few other minor details(shock valving etc). The last 1.5" is given to the rails behind the mount point. I'll note that obviously I wouldn't go all willy nilly with the measurements they would have to exact...
Does anyone else think this would be the proper way to get the best performance out the skid as a 136"? Seems like a no brainer way to keep everything balanced as nature intended.
ahicks
TY 4 Stroke Master
I've run extensions, paying attention to setup details before and after. Honestly didn't see a lot of difference. I did some "tweaking" afterward, but the original 121 may have benefitted from those as well.
Poo, when they sell you as set of 136" conversion rails for use with 121 components, moves the rear arm back 2", uses standard shock, and just moves the attaching link (on the front of the shock) to the rear with the shock.
Bottom line, mixed emotions regarding the benefit of moving the rear arm back when looking at it work involved vs. bang received.
Poo, when they sell you as set of 136" conversion rails for use with 121 components, moves the rear arm back 2", uses standard shock, and just moves the attaching link (on the front of the shock) to the rear with the shock.
Bottom line, mixed emotions regarding the benefit of moving the rear arm back when looking at it work involved vs. bang received.
richierich
TY 4 Stroke Junkie
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I did same thing on my 05 rage using a older nytro skid and my 136" rail extentions.Works just fine for me.The ride improvment is huge.
http://www.richmotorsports.com/store/vi ... OU60VIW199
http://www.richmotorsports.com/store/vi ... OU60VIW199
Thanks for the info ahicks. Moving the arm back and building the longer links and shock are fun time for me... I just want to make sure I'm moving in the right direction. It sounds as though I may, although for limited gains... but gains none the less.
Thanks richierich, I'll keep your rails in mind for future projects. Give Dollar a pat on the head from me...
Thanks richierich, I'll keep your rails in mind for future projects. Give Dollar a pat on the head from me...
This project is moving... I'm using the stock 136" rails that came with my Rage (currently running a Expert X) and adapting all mounts and crossbars from the Nytro skid. The rear arm will move back 6". This will require the shock to be lengthened out to a whopping 21.875" extended and the relay links will extend out to 19.125".
The RTX shocks will be replaced by a set of Fox Zero X shocks. They will have rezi's with Fox's new DSC high low speed compression valves. The links will be simple, just like stock, and probably built from 6061 T6.
Pics soon....
The RTX shocks will be replaced by a set of Fox Zero X shocks. They will have rezi's with Fox's new DSC high low speed compression valves. The links will be simple, just like stock, and probably built from 6061 T6.
Pics soon....
Kevin Garceau
TY 4 Stroke Junkie
Holy smokes..... your going all out. By the time your done you could have bought a 136 that you like 
kudos for thinking of it and then doing it regardless of the cost or process!
kudos for thinking of it and then doing it regardless of the cost or process!
ahicks
TY 4 Stroke Master
<<<This will require the shock to be lengthened out to a whopping 21.875" extended and the relay links will extend out to 19.125". >>>
There no place to mount a crossbar that might allow the use of something a little more standard in the way of shock dimensions?
There no place to mount a crossbar that might allow the use of something a little more standard in the way of shock dimensions?
Cost won't be much... roughly $1400 in parts including the skid, shocks and materials. Deals can be found, and they're making this project quite reasonable IMO.
I thought the front mount point for the shock and link needed to stay the same place in order to keep things operating as they should? Anyway, the longer shock won't be difficult to build... I'll have a parts list for it in the coming days. Figuring out the new increased length of it and the links required some simple geometry. After arriving at the numbers I thought it sounded kind of long, so I went searching for the Ski Doo Renegade shock dimensions, turns out the rear shock is 21.88" extended... guess I didn't do to bad.
I thought the front mount point for the shock and link needed to stay the same place in order to keep things operating as they should? Anyway, the longer shock won't be difficult to build... I'll have a parts list for it in the coming days. Figuring out the new increased length of it and the links required some simple geometry. After arriving at the numbers I thought it sounded kind of long, so I went searching for the Ski Doo Renegade shock dimensions, turns out the rear shock is 21.88" extended... guess I didn't do to bad.
ahicks
TY 4 Stroke Master
Maybe I'm confused. Which skid do you have? What year Nytro? Proactive or Dual shock?
The other thing I was thinking is that the further back you mount the upper rear idlers (beyond optimum), the more the tendency to release track tension as the suspension compresses - all else being equal. Affects springs too. You don't need as much spring when relocating to the rear.
The other thing I was thinking is that the further back you mount the upper rear idlers (beyond optimum), the more the tendency to release track tension as the suspension compresses - all else being equal. Affects springs too. You don't need as much spring when relocating to the rear.
The skid is a Dual Shock from an 08 Nytro, quite similar to the Ski Doo SC series skids.
ahicks
TY 4 Stroke Master
bjowett said:
All I've seen is pictures of it, but if conventional design (there's a short link holding front of rear shock now, right?), all you need is something to hold the front of the rear shock so it sits at about the same angle it is now (to control starting/finishing shock speed/rate). The skid doesn't care about anything other than that. Not much point in getting crazy with a new shock to reach the original mount if you don't want to.
Yeah, short link... interesting. I thought that all had to do with proper coupling.... Hmmmm. I'll have to think about the shock, though I already ordered a few parts.
Here's a pic of the 136" vs the 121". The front arm mount is the only place the 136" rail is lacking, so a simple bracket added to the mount from the 121" will allow it to fit on the 136".
Here's a pic of the 136" vs the 121". The front arm mount is the only place the 136" rail is lacking, so a simple bracket added to the mount from the 121" will allow it to fit on the 136".
ahicks
TY 4 Stroke Master
Coupling is all about the blocks ahead and behind the link on the bottom of the rear arm. Nothing else affects coupling. Rear coupling block also controls transfer, so there's always compromising going on with that setting (if using coupling). For that reason, many (including myself) don't use rear coupling much, using the rear block to control transfer alone, and avoiding rear coupling all together with shock valving that's right on the money for you/your sled. I do use forward coupling, but a lot of that reason is to prevent the rear shock from taking all the shock when the suspension tops out. FWIW
This project is going quite well, and I should have some more pictures up today. The relay links are done, and all arms are mounted to the rails.
The front Fox Zero X 37mm Shock has the newer(?) aluminum high flow 3 slot gold piston. Having never valved for one of these pistons, I based the valving off available info, which boils down to Polaris IQ snow cross and Arctic Cat 08 and 09 snow cross Sleds. For 09 the Cat machine is offered in a cross country race version, with much lighter valve stacks than the designed to land doubles snow cross stacks, so I'm starting there.
The rear shock is a Fox Zero X 47mm with the usual 4 slot piston. This rear shock is long, and thus it gives me some room to try a little trick that works with rezi shocks, relocation of the port that feeds oil to the rezi. Moving this port up the body about 1.5" will give the last the 20% of travel a boost in dampening of roughly 15 - 18%. As the piston passes the port suddedenly all the fluid that is being displaced by the shaft has to flow back through the piston to reach the rezi, where as with the port at the end of the shock all displaced fluid is being pushed ahead of the piston. While not a huge gain, it is a little extra right where it is needed.
The front Fox Zero X 37mm Shock has the newer(?) aluminum high flow 3 slot gold piston. Having never valved for one of these pistons, I based the valving off available info, which boils down to Polaris IQ snow cross and Arctic Cat 08 and 09 snow cross Sleds. For 09 the Cat machine is offered in a cross country race version, with much lighter valve stacks than the designed to land doubles snow cross stacks, so I'm starting there.
The rear shock is a Fox Zero X 47mm with the usual 4 slot piston. This rear shock is long, and thus it gives me some room to try a little trick that works with rezi shocks, relocation of the port that feeds oil to the rezi. Moving this port up the body about 1.5" will give the last the 20% of travel a boost in dampening of roughly 15 - 18%. As the piston passes the port suddedenly all the fluid that is being displaced by the shaft has to flow back through the piston to reach the rezi, where as with the port at the end of the shock all displaced fluid is being pushed ahead of the piston. While not a huge gain, it is a little extra right where it is needed.
Nytro skid in 136" version, as nature intended (I hope)
