I streched my RTX SE to a 136 now i've got a question

[dirkdiggler]

Not that I've done this My skid collapses really easy. Did anyone else do this with their sled and if so did you have to get a stiffer spring or did you just dial up the adjusters??

 

[lucky_7]

I know LJ 452 stretched his SE to a 128. PM him to see his thoughts.

 

[Grimm]

Are your skis and suspension sitting flat on the ground and not up on sled dollies?

 

[dirkdiggler]

Yep flat as a pancake

 

[towerrigger]

I stretched mine to a 144 and it also collapses real easy also. Doesn't seem to matter what setting I have the spring on. I guess I'll find out when the snow flies how it will ride.

 

[JcHawk]

My XTX also collapses very easy,especially compared to my old Crossfire.My dealer says that's the way it is suppose to be,better ride in the smaller bumps.

 

[towerrigger]

Well I just checked mine again tonight. After driving the sled onto the trailer and around the garage it seems to be a lot better. I hadn't moved the sled since I installed the rails.

 

[Port-Parts]

Here's some info for you guys in regards to the spring rates on the rear of these sleds and the available options and some ideas to try to get the ride back after extending the skid. If you extend the rails on a sled and have the skid in the same stock mounting locations it is like adding extra leverage over the shocks/springs on the skid and this is why they collapse easier and will bottom excessively if you ride it with the stock spring combination and most likely you will not be able to get the correct rear sag after extending it. On the 08 Nytro models the stock rear torsion spring tension is measured at 193.9 kgf/mm/deg. For all the 09 Nytro 121" (including the RTX and SE) models the torsion springs have been lighted up to 142.8 kgf/mm/deg to provide better small bump compliance. Yamaha also offers a set of torsion springs rated at 214.2 kgf/mm/deg for heavier weight riders. Depending upon how far you have extended the skid and what year sled you have (08-09) will dictate how much heavier springs you will need to bring the ride back to stock like performance. Shock work may also need to be done but until anyone has some serious time on these set-ups that is hard to speculate but I believe the adjustability of the stock shocks (especially in the RTX models) will be a benefit to getting the ride dialed in as compared to non adjustable shocks.

Here's some retail pricing on the springs and part numbers and currently they all are availble.
142.8 kgf Left 8GL-47473-20-00 Right 8GL-47474-20-00 $142.96 Each
193.9 kgf Left 8GL-47473-00-00 Right 8GL-47474-00-00 $67.71 Each
214.2 kgf Left 8GL-47473-10-00 Right 8GL-47474-10-00 $67.71 Each

Another shock preload tuning part that is available are the torsion spring adjustment blocks (stock ones have three positions S - Soft, M - Medium, and H - Hard). We offer the X-Click suspension adjustment blocks made by Driven Products which have a fourth overload type position which may be useful when tuning a skid in that has been extended. The X-Click adjustment blocks sell for $39.95 and we have them in stock and hopefully in the near future will be loaded onto our website for purchase. If you need some before that happens feel free to give me a call.

 

[Alatalo]

For all the 09 Nytro 121" (including the RTX and SE) models the torsion springs have been lighted up to 142.8 kgf/mm/deg

Hmm, my suspension theory is obviously very, very different compared to Yamaha...
Anyway, this is quality information.
Thank you very much!

 

[dirkdiggler]

Here's some info for you guys in regards to the spring rates on the rear of these sleds and the available options and some ideas to try to get the ride back after extending the skid. If you extend the rails on a sled and have the skid in the same stock mounting locations it is like adding extra leverage over the shocks/springs on the skid and this is why they collapse easier and will bottom excessively if you ride it with the stock spring combination and most likely you will not be able to get the correct rear sag after extending it. On the 08 Nytro models the stock rear torsion spring tension is measured at 193.9 kgf/mm/deg. For all the 09 Nytro 121" (including the RTX and SE) models the torsion springs have been lighted up to 142.8 kgf/mm/deg to provide better small bump compliance. Yamaha also offers a set of torsion springs rated at 214.2 kgf/mm/deg for heavier weight riders. Depending upon how far you have extended the skid and what year sled you have (08-09) will dictate how much heavier springs you will need to bring the ride back to stock like performance. Shock work may also need to be done but until anyone has some serious time on these set-ups that is hard to speculate but I believe the adjustability of the stock shocks (especially in the RTX models) will be a benefit to getting the ride dialed in as compared to non adjustable shocks.

Here's some retail pricing on the springs and part numbers and currently they all are availble.
142.8 kgf Left 8GL-47473-20-00 Right 8GL-47474-20-00 $142.96 Each
193.9 kgf Left 8GL-47473-00-00 Right 8GL-47474-00-00 $67.71 Each
214.2 kgf Left 8GL-47473-10-00 Right 8GL-47474-10-00 $67.71 Each

Another shock preload tuning part that is available are the torsion spring adjustment blocks (stock ones have three positions S - Soft, M - Medium, and H - Hard). We offer the X-Click suspension adjustment blocks made by Driven Products which have a fourth overload type position which may be useful when tuning a skid in that has been extended. The X-Click adjustment blocks sell for $39.95 and we have them in stock and hopefully in the near future will be loaded onto our website for purchase. If you need some before that happens feel free to give me a call.

Kevin Based on your findings and the conversation we had about this what direction do you think i should go "Stiffer spring or the adjusters?

 

[gormleyflyer2002]

sounds like you could use the 08 harder 214 kgf option.

i wonder why the 09 springs are more than double the $$$....?

interesting info, thanks Port

 

[LJ 452]

sounds like you could use the 08 harder 214 kgf option.

i wonder why the 09 springs are more than double the $$$....?

interesting info, thanks Port

Anyone know if Cat or other springs will work?

When I did the 128" I didn't notice a difference at all. In fact when I get on the sled it hardly moves (sags) at all. And I'm not exactly small. 250 lbs. With that 128" extension isn't much so I may not have the same effect as the 136". My first guess would be that the tail of teh skid is touching first, one thing you could try would be to drop the pressure in the floats to something around 30 psi, this is just to dtermine root cause, I woundn't ride it set that low. This should drop the front and hopefully pivot the sled forward. This of coarse should be done with everthing on the ground, no dollies on the skid or skis.

 

[Port-Parts]

LJ 452 - I haven't been able to find any springs from other manufactures that are a direct swap with the Yamaha springs in regards to length, rate, and such. I spoke with Dirk today and believe the stock 08 torsion springs with the X-Click adjusters should get his set-up extremely close without going overboard.

 

[NyTrOMaNIaC]

I just purchased a set of the X-Click spring blocks, nice product. There's a 4th overload side to these compared to just 3 positions on the stock blocks, supposed to offer a 15-20% increase in preload over the Hard position on the stockers. Judging from a quick look, I'd say the X-Click blocks will offer even more preload being that the channel where the spring sits is not as deep as the stock plastic blocks, so there will be more pressure on the spring even in the same Hard position, and that's without going to the 4th overload setting. I'll take a few pics later today with them installed on the sled.

 

[Borch]

Looking to do the same - 136". As people start to make this change can we list out the parts we will need to make the change? Maybe make it a sticky?

Also what track would you reco? was thinking of going with the cobra 1.35" would that be a good choice. Ride mostly WI and MI trails and some off trail/ditches.

Best,
CB