BUMP STEER IMPROVEMENT

[AKrider]

Looks like you've got the right idea but I don't know whether you will see a ton of benefit? After riding my IQR last season I was disappointed in the handling of my Nytro even after reducing the bump steer. I've not ridden a Phazer so there may be more room for improvement but I personally feel the stock front end on a Nytro is a lost cause. I saw SLP is offering new Nytro's spindles this year, $300 didn't seem too bad.

I've talked to the Yamaha Race Dept and the new XC kit is supposed to make a dramatic improvement in handling. It is the way to go in my opinion.

 

[00-NUKE]

Looks like you've got the right idea but I don't know whether you will see a ton of benefit? After riding my IQR last season I was disappointed in the handling of my Nytro even after reducing the bump steer. I've not ridden a Phazer so there may be more room for improvement but I personally feel the stock front end on a Nytro is a lost cause. I saw SLP is offering new Nytro's spindles this year, $300 didn't seem too bad.

I've talked to the Yamaha Race Dept and the new XC kit is supposed to make a dramatic improvement in handling. It is the way to go in my opinion.

I'm interested in those SLP spindles. They look like the lower A-arm mounts closer to the ground. I'm going to call them today and get the 411 on these. I wanted to develop a spindle that drops the front about 1". There is a guy here on totallyamaha that makes what he calls the "JRE kit" that lowers the whole sled about 2". That's a bit too low for my taste.
I'm sure the XC kit is the way to go, but the $$$ factor is hard to justify.

BTW: Good luck with the Polaris. The 144" Assault was my #2 option when I bought my Nytro. I go back and fourth on whether I made the right choice???? I do love my Nytro though.

 

[AKrider]

I was glad to see someone finally came out with some new spindles. Last year I would have thought they were the fix but I don't believe that now. I would not doubt they'd offer some improvement however and will probably be enough to satisfy most owners as SLP doesn't sell junk. But for what I'd want, I'm confident it wouldn't be enough of an improvement.

When I spoke to my contact with the Yamaha race dept last summer, he explained what the XC kit improved and it addressed all the complaints I had about handling. The 128" track and skid set back is a good idea and will also help improve the handling. I thought seriously about buying the kit. The racer discount is much more reasonable than the $8300 they were asking for the kit last winter. But because my Polaris seized a crank bearing and I had to fix it, I didn't have the budget to buy a kit. Funny how I gave up reliability for ride and handling and the whole 2-stroke engine thing lived up to what most of us expected.

I still think the Nytro has a ton of potential. I'm curious to see what improvements may be brought out in the next year.

 

[AKrider]

I think its a good idea you didn't get the Assault. The 800 motor is a POS in my opinion. One of my buddies, who I've known since high school had an '08 Dragon 800 and that sled was so unreliable it ended his life long brand loyalty to Polaris. He is now in the process of buying his 2nd Arctic Cat M series sled. The new Polaris 800 isn't much different from the '08-'10 motor but has improved a bit. Still lots of threads about blown motors though. I would not buy one. Heck the 600R motor in my IQR uses an 800 CFI bottom end and seized a crank bearing and burned up the water pump gear. I'm not a big fan of anything to do with this motor. The 600R does make good power though. It's also light enough to easily pick it out of the chassis and carry it across the shop. That's good for something, right?

 

[00-NUKE]

I was glad to see someone finally came out with some new spindles. Last year I would have thought they were the fix but I don't believe that now. I would not doubt they'd offer some improvement however and will probably be enough to satisfy most owners as SLP doesn't sell junk. But for what I'd want, I'm confident it wouldn't be enough of an improvement.

When I spoke to my contact with the Yamaha race dept last summer, he explained what the XC kit improved and it addressed all the complaints I had about handling. The 128" track and skid set back is a good idea and will also help improve the handling. I thought seriously about buying the kit. The racer discount is much more reasonable than the $8300 they were asking for the kit last winter. But because my Polaris seized a crank bearing and I had to fix it, I didn't have the budget to buy a kit. Funny how I gave up reliability for ride and handling and the whole 2-stroke engine thing lived up to what most of us expected.

I still think the Nytro has a ton of potential. I'm curious to see what improvements may be brought out in the next year.

I agree! I know these spindles are not "the fix". On the other hand, I am an agressive rider but don't race. I would personally be happy with this sled if it just performed as wall as a Ski Doo or Polaris does straight out the box.

I thought about dropping a 128" or 136" skid in my XTX and pushing it back just like you mentioned. At this point I thinks I'll let the aftermarket companies find a solution and just ride it out until then.

 

[00-NUKE]

I think its a good idea you didn't get the Assault. The 800 motor is a POS in my opinion. One of my buddies, who I've known since high school had an '08 Dragon 800 and that sled was so unreliable it ended his life long brand loyalty to Polaris. He is now in the process of buying his 2nd Arctic Cat M series sled. The new Polaris 800 isn't much different from the '08-'10 motor but has improved a bit. Still lots of threads about blown motors though. I would not buy one. Heck the 600R motor in my IQR uses an 800 CFI bottom end and seized a crank bearing and burned up the water pump gear. I'm not a big fan of anything to do with this motor. The 600R does make good power though. It's also light enough to easily pick it out of the chassis and carry it across the shop. That's good for something, right?

Thanks for the heads up! I've heard some of the same stories from others about Polaris's 800's. I have heard that people are now starting to buy the 144" 600 RMK, add the wider A-Arms to it, and change the track to a 1.5". That seems like crawling into another bag of worms? It seems to me that back in the trailing arm days, we didn't have these problems. It's just a shame that the traditional riding position sucked so bad or I'd climb back on an 02' Doo.

Looks like I'll press on with the Nytro for now. She's dependable.

 

[AKrider]

My old Yamaha dealer told me when Yamaha decided to drop 2-strokes and go all 4-strokes they did it because they felt that EPA compliant 2-strokes were a dead end road. Seeing the issues Doo and Polaris have had confirms they were pretty much right. At least with Polaris you can turn the oil pump up on the consumer models and that makes the 600 CFI pretty bulletproof. The dumb greased crank bearings in the eTech cause more problems than they solve IMO. Cat is living off their credits and their 800 is far more reliable than the other 800's because it can get oil.

What's funny about the 600 RMK 144 is that it uses the same skid as the Assault. Install some higher end shocks and a guy basically builds his own small bore version of the Assault.

The skid set back on the 121 Nytro's is to help reduce the excessive transfer and ski lift of the stock Nytro. The XTX uses the older Vector/Venture type rear skid and it works pretty well but doesn't hold up to really aggressive riding. I broke the front arm and cracked the rails in my '05 Vector in the span of three XC races and two seasons of aggressive riding and that was with a revalved center shock and replaced rear shock from a '06 Nytro. The 121 skid setback won't work on the XTX because the 144" track is too long. I would not go with a 136" Monoshock either as that is a comfort/cruising rear skid and won't hold up to really agressive riding.

I've not done any searching for ride reports but the SLP spindles might do exactly what you are looking for. http://www.slp.cc/catalog.cfm?pageID=de ... uctID=2044

The price is right but I wonder if they are correcting the '08 or the '09 to current? Looks like the tie rod mounts are on the outside of the spindle which is the flawed '08 location. The tie rod mounts need to be on the inside edges of the spindles like an '09 to reduce bump steer.

 

[dburrowes]

isnt there an aftermarket spindle for our sleds that sit taller. In theory this this mod looks good. i will be following this thread for sure.

 

[00-NUKE]

isnt there an aftermarket spindle for our sleds that sit taller. In theory this this mod looks good. i will be following this thread for sure.

You mean aftermarket spindles with stock height? Or Taller than stock spindles?
I really don't think you want to go taller than stock with the spindles. The engines center of gravity is already tall enough.

IMO: The skinz concept kit has the right idea by pushing the ski's forward, but I am REALLY happy with my GYTR's after I got the valving dialed in, and will not drop anther $600-$1,000 on shocks just to make the kit work. And the XC kit is just outragiously expensive for someone that doesn't race.

 

[00-NUKE]

My old Yamaha dealer told me when Yamaha decided to drop 2-strokes and go all 4-strokes they did it because they felt that EPA compliant 2-strokes were a dead end road. Seeing the issues Doo and Polaris have had confirms they were pretty much right. At least with Polaris you can turn the oil pump up on the consumer models and that makes the 600 CFI pretty bulletproof. The dumb greased crank bearings in the eTech cause more problems than they solve IMO. Cat is living off their credits and their 800 is far more reliable than the other 800's because it can get oil.

What's funny about the 600 RMK 144 is that it uses the same skid as the Assault. Install some higher end shocks and a guy basically builds his own small bore version of the Assault.

The skid set back on the 121 Nytro's is to help reduce the excessive transfer and ski lift of the stock Nytro. The XTX uses the older Vector/Venture type rear skid and it works pretty well but doesn't hold up to really aggressive riding. I broke the front arm and cracked the rails in my '05 Vector in the span of three XC races and two seasons of aggressive riding and that was with a revalved center shock and replaced rear shock from a '06 Nytro. The 121 skid setback won't work on the XTX because the 144" track is too long. I would not go with a 136" Monoshock either as that is a comfort/cruising rear skid and won't hold up to really agressive riding.

I've not done any searching for ride reports but the SLP spindles might do exactly what you are looking for. http://www.slp.cc/catalog.cfm?pageID=de ... uctID=2044

The price is right but I wonder if they are correcting the '08 or the '09 to current? Looks like the tie rod mounts are on the outside of the spindle which is the flawed '08 location. The tie rod mounts need to be on the inside edges of the spindles like an '09 to reduce bump steer.

I contacted SLP. They don't have any of the tech specs on these spindles, nor do they even have them in stock yet.

However, When you and I were performing all of the testing on the stock spindles, I found that the height location of the tie rod mount on the spindle had a significant impact on bumpsteer as well as that the inner and outer locations during the midrange area of movement. There is no way to tell if they improved any of this on these SLP's until I can get one in hand or at least some specs on them. I'll let you know as soon as I find out.

 

[AKrider]

Too bad SLP didn't have the specs. I don't recall off the top of my head (would have to go back through the thread) as to where the tie rod mount needed to be but I wonder if SLP took that into consideration? They make no mention of whether you need short or longer tie rods depending on your year. If there mount is on the outside of the spindle than I'd say they've not addressed the bump steer issue.

The spindles looked to have more trail and to lower the front end of the sled. More trail should be good but lowering the front end has its pros and cons. Good for cornering but bad for bashing bumps. Being billet they should definitely be stronger than stock and that would be good.

Chris left a criptic mesage on his blog about the 14's so maybe they are finally going to do something different? The racer price for the new front end is still pretty steep, especially if you don't have floats and have to buy new shocks with spherical bearings top and bottom.

 

[00-NUKE]

Too bad SLP didn't have the specs. I don't recall off the top of my head (would have to go back through the thread) as to where the tie rod mount needed to be but I wonder if SLP took that into consideration? They make no mention of whether you need short or longer tie rods depending on your year. If there mount is on the outside of the spindle than I'd say they've not addressed the bump steer issue.

The spindles looked to have more trail and to lower the front end of the sled. More trail should be good but lowering the front end has its pros and cons. Good for cornering but bad for bashing bumps. Being billet they should definitely be stronger than stock and that would be good.

Chris left a criptic mesage on his blog about the 14's so maybe they are finally going to do something different? The racer price for the new front end is still pretty steep, especially if you don't have floats and have to buy new shocks with spherical bearings top and bottom.

Looks like I'm going to stick with my stock spindles at least one more year. I decided to stick my money into the rear skid and see what else comes down the pipeline for the fron end of the Nytro. If someone doesn't come out with a good solution, I'll probably just bite the bullet and go with the Skinz concept front end next year. At this point, I am financially committed to my Nytro. I've got over $5,000 just in upgrades. I still don't regret it because I'm still the one pulling people out of the woods every year and it handles goodish.

 

[birkebeiner]

So for a '09 and newer Nytro, the conclusion is; leave it stock or go for Skinz or the Yamaha racing front end? I.e. no gains to be made by the mods you tested in this thred?

 

[00-NUKE]

So for a '09 and newer Nytro, the conclusion is; leave it stock or go for Skinz or the Yamaha racing front end? I.e. no gains to be made by the mods you tested in this thred?

IMO: You are correct. The "FIX" would be the Skinz Concept or the Yamaha racing front end. These updates allow the Nytro's weight to be better distributed from front to rear. By pushing the skis forward, you allow the skis to pull the weight of the snowmobile through the corners instead of having the weight directly on top of the ski adding "push" in the corners.

There have been some worth while "Improvements" that we learned from testing for your average consumer on a budget. I had to create a 3-part spindle during my testing to gain a full understanding of the Nytro's handling flaws. By lowering the center of gravity, you create a similar affect as you would by pushing the ski location forward. After gaining some tech specs from SLP, I decided to try their spindles. Their updates are consecutive with my findings. They drop the lower A-arm mounting point 1-3/8" from stock along with changing the tie rod mounting position to improve bumpsteer. The only other change that I would have made was to raise the upper A-Arm mounting point on the spindle. This helps to maintain carbide "bite" as the suspension compresses by keeping the spindle in a vertical stance throught the suspensions travel.

A supplier known on this site as "JRE" has created a similar spindle that drpps the lower A-Arm mounting pint about 2" from stock. For my riding style, I feel that 2" is a bit low, however riders that stick to the trail 80% or more would probably love it.

If you decide to add shorter spindles, I would recommend changing the rear suspension height to match.

I have not received my SLP spindles yet, but will confirm these dimensions and any handling improvements following some further testing.

THANKS!

 

[birkebeiner]

Thanks a lot Nuke!

I've read a lot about the JRE spindles as well, but also sceptical to the 2" drop of the front. Also, what I don't quite get is that some people on the JRE spindle threads are saying you get most of the travel back by increasing your front shocks preload, raising the sled. But how are you lowering the CoG if you drop the hight of the spindles but then stiffen up your suspension to raise the hight of the sled again...?

Anyway, interesting reading. I should probably not spend any money on my sled because I ride way too little to justify the upgrades