Nyper build thread

[earthling]

It makes sense that with the front flange forward and rear flange the opposite there should be some tension in the arms so that the flanges are the primary wear surface. But it only needs light tension to accomplish this.

 

[Nikolai]

True. For now I think I’ll leave the back one unmodified so the a-arm/ball joint is in the correct position and then just modify the front bushing a little so there’s slightly less pressure on it.

I decided a few weeks ago I wanted to go back through the steering and front suspension one more time and get it as light as possible. Small gains to be had but I don’t want to leave anything on the table when it comes to the front end.

I’ll start with the tie rods first. I cut 0.20” off the outer rod end studs, replaced the steel washers I was using as spacers with aluminum spacers I made and got titanium bolts and nuts for the steering arm side.

Steel bolts & nuts, steel washers, cut off stud pieces

Ti bolts, Ti nuts and Alu spacers

Tie rods complete with all hardware only 1.42 lbs

On the steering post, I rounded off the corners on the aluminum bushing straps, replaced the steel bolts and steel K nuts with shorter low profile torx head titanium bolts and thin titanium nuts. These bolts just happen to come in black.

Steel hardware

Titanium replacements

4.88 lbs for the entire steering setup. Includes the steering post, lower pivot tube, straps, all hardware and tie rods.

On the suspension side of things I ordered titanium bolts to replace the 4 upper a-arm and 4 shock bolts. The tie bolts were way lighter, all 8 steel bolts were like 186 grams iirc.

Ti and steel comparison

All 8 Ti bolts.

I couldn’t find a titanium replacement for the upper a-arm rod end bolt. It’s an oddball size. But I did figure out that a K nut fits and they are way lighter.

Factory nuts

K nuts

In all I reduced the front end hardware by 0.26 lbs.

I also cut 0.20” off the lower ball joint studs. I got the complete front suspension weight down from 19.5 lbs to 19.23 lbs. Not a huge gain but I won’t think about the front end anymore and can focus on other stuff.

I’ve also been working on redoing all the ski hardware to try and get a complete ski under 5 lbs. I’m not quite done though, will be a few days before I’m ready to post the details.

 

[Nikolai]

Trimmed down both steel mounts to match the rounded off straps.

Left the rear a-arm sleeve unmodified.

On the fronts, the shoulder stock is 0.170”, I took it down to 0.080” and then made 0.090” aluminum spacers. That took nearly all the pressure off the a-arm.

Suspension and steering are 100% done, there’s nothing left that is going to bug me.

I’ll start wrapping up the skis next.

 

[earthling]

fantastic work as always!

 

[Nikolai]

A little more bling. Always wanted to replace the 8mm engine mount and starter bolts with Ti.

 

[74Nitro]

Pretty. When Yamaha came out with the 700 Viper in 2002, it featured the first digital speedo. The sensor gear mounted on the end of the drive shaft was held on with a fancy hollowed out bolt. However, that was where the bling started and ended lol.

 

[Nikolai]

I have a 7075 bolt coming to the replace the Ti bolt currently securing the speedo gear lol. Ordered some 7075 hardware for the skis a week ago and got one 10mm for the speedo gear and also a couple 6mm to secure the sensor. Eventually I’ll get a few more for the chaincase cover. There’s a ton of weight to be saved in hardware.

 

[Nikolai]

Finished the ski bushings tonight. Weights are for all 4 bushings. Listed left to right.

- Factory steel 146.78 grams or 0.32 lbs
- Alternative Impact titanium (bought these years ago) 80.76 grams or 0.18 lb
- 6061 aluminum 49.80 grams or 0.11 lbs

These are the wear bars I made years ago. I just cleaned the surface rust off and painted them. They are made from 7/16 x .035 4130 tubing with a .040 strip tack welded to the bottom to keep from wearing thru the tube. Securing them are aluminum washers and 5/16-18 aluminum nyloc nuts.

Total weight for both wear bars with washers and nuts is 0.70 lbs. The stock wear bars with washers and nuts weigh 1.62 lbs for both.

For the ski bolts I ordered titanium bolts from Mettec since they have the forged heads and are stronger. M10x1.25x145 with flanged nyloc tall nuts.
Factory bolts and nuts 0.50 lbs
Ti bolts and nuts 0.27 lbs

Still waiting on my 7075 hardware to get here and then I can wrap up the ski loops.

 

[kinger]

What is your latest estimate on the total weight of the sled?

 

[Nikolai]

No idea to be honest, I kinda quick keeping track of the weight loss. There’s been so many changes along the way with frame design, hardware, ect that I stopped trying to add it all up. I will be surprised if it is over 400 lbs though.

Body shrouds will be minimal and super light. I’ll only need a few CF and thin aluminum panels to enclose portions of the tunnel framing, just enough to block the header and keep my feet out of the track.

The only places I’ve added weight are my oil tank which will end up slightly heavier than stock being thicker aluminum. And I need to make an aluminum fuel tank that I’m assuming will weigh a couple more lbs than the factory 7 gal plastic tank. I’ve thought about a CF tank but I think aluminum would take far less time and be easier to work with.

My ski hardware showed up today. I think once I get skis on I’ll get the motor and header/turbo back in, clutches on and weigh it just to get an idea of where I am at.

 

[Nikolai]

My order of 7075 bolts from Pro Bolt USA finally showed up today.

I got a 10mm aluminum speedo gear bolt
Factory steel bolt 28.28g (with gear 60.93g)
Titanium bolt 11.46g
Aluminum bolt 5.69g (with countersunk gear 25.51g)

I also got 6mm aluminum bolts for the speed sensor.
Steel bolts 12.76g for both
Aluminum bolts 4.36g for both

The factory ski loop bolt at the top is an 8mm bolt but the hole is 10mm.
Factory 8mm steel bolts and nuts 45.44g
Aluminum 10mm bolts and nuts 20.36g

The bolt at the bottom of the ski loop is a 6mm steel bolt. I drilled and tapped pieces of 1/4”x.035 chromoly tube and got 5mm aluminum bolts.

Factory steel bolts and nuts 61.15g
Chromoly tubes and aluminum bolts 26.96g

Factory hardware all together on the left 1.06 lbs
My hardware on the right 0.50 lbs

My hardware and wear bars 1.20 lbs (factory hardware and wear bars 2.68 lbs)

Skis done. I am all little disappointed in the weight. It’s 11.21 lbs for both skis complete. One of the skis was .3 lbs heavier than the other, I can’t visually see a difference but one must have more material in it. I was hoping to be lighter and I don’t want to cut these skis to drop weight. If the sled comes in at 400.5 lbs I will cut the skis. I am using the DuraPro ski rubbers which weigh twice what the factory rubbers weigh but the factory rubbers are junk so it’s worth it.

I had read on the Snowest Forums that the DuraPro rubbers fit perfect with Grippers on Cat spindles but they sit a little high and the rubbers are hard and won’t compress much. I don’t want to put that much force on the rubbers trying to get bolts in. I’ll probably cut the rubbers down.

19.23 lbs front suspension
4.88 lbs steering
11.21 lbs skis
35.32 lbs for all of it. Would have liked to come in under 35 lbs but it’s still way lighter than what I had on my Nytro. Ski center to center will be a little under 36”.

As soon as I get the ski rubber situation figured out I’ll get the motor in.

 

[Nikolai]

Got the ski rubbers fit and skis bolted on for good. Ski Stance is right under 36”.

 

[Nikolai]

Need to revisit paneling for the tunnel sides. Local plastic supplier has 4x8 sheets of .060 HDPE for $188. Thinking of maybe cutting the side pieces out of this and then just zip tying them in a few spots to the frame tubes? Would be easier than welding tabs and using rivets. Any thoughts?

I was going to do carbon fiber panels but HDPE is light, durable, snow won’t stick to it and it would be much easier to work with. It would only be for the sides, around the header and flex pipes will have to be aluminum to handle the heat. Was originally thinking of using some .040 7075 sheet I have but snow sticks to aluminum no matter what you coat it with and it’s heavier than HDPE.

 

[YamaSpark]

I would go with the HDPE for the sides.
Maybe you could have the aluminum top panels Teflon or Kynar coated? Maybe go with 6061, as it's more corrosion resistant.

 

[Nikolai]

I bought the HDPE. Figured I should commit to something before getting stuck in analysis paralysis again.