PRO RMK build my way

LoudHandle · Jan 14, 2017

I recently picked up a MY '14 PRO Ride RMK 155" as the previous owner's insurance company totaled it out due to what looks to be the stock can getting so hot it melted a lot of stuff on the right hand side. Side Panel and fender, coolant hose, noticed the starter bendix is quite worn so I'm assuming it at some point was trying to run and shaved 1/8"-3/16" off of the bendix gear. The CF over structure has a crack most of the way around about an inch above the lower right lug where they always seem to break (even though the owner has never rolled the sled, nor hit anything; the original owner used the sled exclusively for getting up our local mountains in order to snowboard / ski back down). Recoil rope is melted off. Coolant hoses, and can mounting rubbers are scorched as well.

The 800 caught both rings on the exhaust port on the MAG cylinder so it will get sent to INDY DAN to work his magic with a long rod. Meanwhile I'll put in a 600 for her to learn with.

I'm building it for my 12 year old daughter.

***Update***; I ended up selling the chassis (as this winter, jobs at work have been a little on the lean side). I have enough parts to build an Aluminum version of that I'd hoped would eventually become a full Carbon chassis. I'll be doing very close to the full extent of the light weight mods I've hinted at over the years. I will be doing my drop and roll and 9 tooth drivers this time around, and will be documenting the weight loss compared to stock and what I did to the stock and / or aftermarket parts to further lighten them.

LoudHandle · Jan 14, 2017

Steering post; stock verses ALT's TI post and '10 Rush bushings

Stock Flat Top Post and all the stock mounting hardware; 1362 Grams Total weight

Alt Imp's TI flat top post, PMS's Handlebar Clamp with TI fasteners, 2010 style Rush Post mounts with TI fasteners; 697 Grams Total weight

Saved 665 Grams, nearly half the weight of stock. I may lighten the handlebar clamps more as they are still as delivered and over kill.

**Note** to use the MY '10 Rush bushings you need to use the stock aluminum shim under the bushings to get the correct offset for the steering stops to function and retain full travel.

LoudHandle · Jan 15, 2017

Front Structure; My Lightening of the lugs and inserts and TI tube upgrade

Stock (as removed) Faux Carbon Fiber Front Structure; 1115 Grams

Stock Steel Fasteners; 232 Grams

So the stock Faux Carbon Fiber Front Structure assembly weight is; 1347 Grams

Stock Aluminum cross tube with Titanium down tubes, Lightened lugs; 1275 Grams

This is the one that I'll use on her sled

My choice of Titanium (structural) and aluminum (coil and solenoid) fasteners; 101 Grams The shouldered Titanium bolts are for the front bumper and the nut is for the ground lugs. I upsized the bolts to 8mm so I could tap the lug and save a nut. Plus the use of a shoulder bolt will make more sense when I get to the bumper post.

So the Total weight of the front structure assembly I'll use on her sled is; 1376 Grams
So while I did not save any weight on this version, I can live with the 29 Gram gain for the piece of mind, knowing it is Bomber and will last forever.

While were at it; here is what I use on my sleds with the Faux Carbon Fiber Cross tube retained as it sees much less stress than the down tubes due to the design of the Polaris Bulkhead, sure the shock expert some compression force onto the tube but the majority is directed upwards and absorbed by the bulkhead itself, even under sever bottoming. Also I did not want to chance melting the plastic coil and solenoid mounts releasing the glue. After buying most of the donor stock parts new (As my offer to buy damaged front structures went largely unanswered). The Titanium tube is thinner walled than the Faux Carbon Fiber so the curved aluminum washers you see on the scale are shims to make up the difference. You'll notice I ported the needless weight out of the cast aluminum tube inserts as well.

Stock Carbon cross tube with Titanium down tubes, Lightened Lugs; 1141 Grams

So with my same fasteners of choice this version weighs; 1242 Grams
Saves 105 Grams over stock and no worries of the fragility of the Faux Carbon Fiber

***NOTE*** I'll update this post soon, as I have my answer to breaking the cast bumper tabs. I built a jig to enable me to router an 1/8" step in the lug where it meets the bulkhead and I'll glue a teardrop on each side that I cut from 1/8" aluminum. That will make the bumper mount a double shear instead of a single shear joint and enable me to do some light logging without worries.

volcano buster · Jan 15, 2017

Nice thread.

Any thoughts on a 660 instead of the 800?

LoudHandle · Jan 15, 2017

volcano buster said:
Nice thread.

Any thoughts on a 660 instead of the 800?

As stated in the first post, it will get a 600 (low mile, take out '13). The 800 will go to Indy Dan for the Long Rod upgrade and will then go into another build. Even the 600 is overkill for her as she last rode a stock 120.

volcano buster · Jan 15, 2017

Ok, I jumped to the conclusion that the 800 was going back in it for her.

The 660 is pretty fun though.

LoudHandle · Jan 16, 2017

I concur; I've always been fond of the 600 and all of it's variations. 660, 685, 727, 797. Back to the next installment.

LoudHandle · Jan 16, 2017

Steering Geometry Changes and ALT's TI mid-post upgrade

I'm going to start by briefly touching on what I feel is a very beneficial geometry change to the PRO Ride RMK's

This photo shows the primary difference between the Rush mid-shaft (Left) and the RMK mid-shaft (Right). As I've posted elsewhere on SW; by moving the tie rod end inboard to the Rush position or trading to the Rush Mid-Post, you go from a 1:1 steering ratio to a 0.75:1 steering ratio. Or in other words; by turning the handlebars 45 degrees, equals 60 degrees of ski movement. The advantage to this is you don't have the bar end in your crotch when doing tight turns or hard counter steering. And in my opinion the steering effort is so close to the same it is negligible. If you trail ride a lot, it may not be for you, but it's ultimately no harder than the rush sleds geometry wise.

FWIW; The Rush hole is exactly 1" inboard from the RMK hole. For those wanting to modify the stock part. I have not modified the 3 ALT's mid-posts I have yet but will be quite soon.

P.S. All these stock parts are for sale if you want or need something, PM me. I've acquired a lot of stock parts for R&D over the last 5 years or so and they need to go now. So I can start on the AXYS version.

Stock PRO Ride RMK style post; 777 Grams

Stock steering bushing with aluminum strap and steel fasteners; 148 Grams

The stock mid-shaft bearing, stud, nut, and snap ring; 62 Grams

So the stock mid-shaft and fasteners; 987 Grams

ALT's TI steering mid-shaft with stock plastic cap; 385 Grams

Rush 2010 style steering bushing and aluminum extrusion mount with current stock aluminum strap for spacing and my choice of Titanium fasteners; 77
Grams

Also worthy of mention; I had to router a slight radius to the Rush bushing to clear the gusset weld on the ALT TI mid-post at the top. Not a big deal just bolted two of them back to back and did a few doughnuts on my router table with a piloted 3/16" Radius round over bit.

My light weight fastener of choice; Ceramic Hybrid bearing, modified 10mm Titanium V-brake stud, 2 large aluminum drilled 6mm washers, 2 10mm aluminum crush washers (which I also use to seal the brake banjo fittings), 2 6mm x 10mm Titanium Torx drive button head screws, snap ring; 32 Grams

So the ALT TI mid-post with my choice of fasteners is; 494 Grams

A savings of 493 Grams or HALF the weight of stock

From left to right, my renditions of the lower bearing stud; stock, Aluminum (decided not worth chancing a aluminum fastener shearing with a tree hit and rendering the sled unridable), 10mm TI bolt with thin TI nut for retainer/ spacer, Final choice- The modified TI 10mm V-brake stud

This pic shows the modification to the Titanium V-brake stud. Left; Titanium 10mm V-brake stud, Center; I part the excess off in the lathe and face and chamfer the end of the DD that fits thru the bulkhead for the lower fastener of the mid-shaft, Right is the waste or parted piece

An additional note; all the PRO Ride mid-posts I've had my hands on can benefit from a little shimming. I use one or two of the aluminum 10mm sealing washers to space the mid-post up (placed between the bearing stud and the bulkhead) so that it is tight to the upper bushing shoulder and removes all vertical play.

LoudHandle · Jan 16, 2017

Stock verse ALT's TI Steering Idler

Stock steel Idler with stock bearings, aluminum bearing spacer, and stock 12 to 10mm reducing bushings, and the stock steel fasteners; 395 Grams

ALT's Titanium Idler with Ceramic Hybrid bearings, 12mm OD x 10mm ID Titanium tube bearing spacer between the stock 12mm to 10mm reducing bushings to take the bolt crush load, I sourced a shorter TI bolt as the one ALT provided was too long, IMO; 189 Grams

The shorter replacement bolt for the long one provided by ALT IMP; 40 Grams
Saves 206 Grams

I'm still playing with / planning an even lighter fastener setup. I've run the gauntlet of fasteners ideas with this side as well, still looking for the coup de gras.

Here is a little on this weeks evolution of the Steering Idler fastener;

Steering Idler; Stock Bearings, reducers, spacer, and stock steel fasteners; 137 Grams

Steering Idler; Stock Bearings, reducers, Titanium spacer / fastener combo; 64 Grams

Steering Idler; Hybrid Ceramic Bearings, reducers, Titanium spacer / fastener combo; 61 Grams

These are the two Titanium screws that I weighed the Updated Idler hardware with; 8 Grams

These are what I actually installed the steering idler with (as they matched the screw I used for the Mid-post; T30 drive); 7 Grams

The Final weight of the ALT IMP Steering Idler with my final rendition of TI Hardware with Drilled Aluminum washers. Fasteners are; 2 TI M6x10mm T30 drive screws, 2 drilled Aluminum M6 flat washers, 2 TI M10 V-Brake studs shortened ~0.5mm and connected top to top with a TI M6x25mm stud, Stock 12mm to 10mm reducers were reused with Ceramic Hybrid Bearings; 161 Grams

So the ALT IMP TI Idler with my final choice of fasteners saved 234 Grams!

Additionally; I wonder if the extruded aluminum AXYS idler is the same actual / functional dimensions and what it might weigh as it runs bushings (no bearings).

LoudHandle · Jan 16, 2017

Tie Rod Boot Fasteners

The ten steel tie rod boot bolts; 66 Grams

Ten Aluminum button heads for the tie rod boots; 19 Grams

The Aluminum fasteners; Save 47 grams! In this near zero stress application are Less than 1/3 the weight of the steel they replace!

Ten TI M6x10mm T30 drive screws; 18 Grams

The Titanium fasteners; Save 48 grams! In this near zero stress application you don't need the TI but was a little surprised they beat the aluminum on weight!

Both the aluminum and the TI fasteners are the same thread as the steel fasteners.[/B]

LoudHandle · Jan 22, 2017

Update; Sold the stock chassis, So I'll be doing the full enchilada on the build

***Update***; I ended up selling the chassis (as this winter, jobs at work have been a little on the lean side). I have enough parts to build an Aluminum version of that I'd hoped would eventually become a full Carbon chassis. I'll be doing very close to the full extent of the light weight mods I've hinted at over the years. I will be doing my drop and roll and 9 tooth drivers this time around, and will be documenting the weight loss compared to stock and what I did to the stock and / or aftermarket parts to further lighten them.

SNWMBL · Jan 23, 2017

Great attention to detail, I look forward to updates. Few people take the time to do much more than bolt on lightweight parts. My Nytro has been on the table for over 2 years now and I'm just starting to see an end in sight(hoping to ride next winter). It's not worth cutting corners to sacrifice quality and save time.

On a side note, where are you getting your Alu hardware from? I've been using LighTech from OPP racing. Most of it is 7075 and you can get it in whatever anodized colors you want. They have a great selection but I'm always looking for other sources.

LoudHandle · Jan 23, 2017

SNWMBL;

I agree, when we are building sleds at this level (without sponsorship) there is no need to rush thru it. A cliche' comes to mind; "The Devil, is in the details!"

Thanks, I'll check them out, don't remember them coming up on any of my web searches. I source some from various Ebay stores, TorontoCycles.com, PRO-Bolt, and others.

SNWMBL · Jan 23, 2017

LighTech has a huge selection of nearly every style of fastener. I had checked with Pro-Bolt a few times but they usually didn't have what I wanted in stock or not in the same color(needed many different sizes all in blue). This is strictly for aluminum hardware. I've got no clue what they're Ti selection is like. The quality sure seems good though.

I'm not doing any Ti hardware due to the cost, but the aluminum is easy for me to justify. Huge weight savings to be had in non structural applications. All hardware in the pic only weighs 102.4 grams.

sportsterdanne · Jan 24, 2017

On the Axys two of the five bolts are replaced with plastic "x mas tree clips" should be lighter tha alu bolts.

This is a build i would love to do, i really like the planning process and finding small places to loose weight.

Keep it up i will follow this !

LoudHandle said:
The ten steel tie rod boot bolts; 66 Grams

Ten Aluminum button heads for the tie rod boots; 19 Grams

Saves 47 grams! The Aluminum fasteners in this near zero stress application are Less than 1/3 the weight of the steel they replace!

And the aluminum fasteners are the same thread as the steel fasteners.

Sheetmetalfab · Jan 24, 2017

SNWMBL said:
Great attention to detail, I look forward to updates. Few people take the time to do much more than bolt on lightweight parts. My Nytro has been on the table for over 2 years now and I'm just starting to see an end in sight(hoping to ride next winter). It's not worth cutting corners to sacrifice quality and save time.

On a side note, where are you getting your Alu hardware from? I've been using LighTech from OPP racing. Most of it is 7075 and you can get it in whatever anodized colors you want. They have a great selection but I'm always looking for other sources.

While attention to detail is great......

Riding is too.....

https://vimeo.com/200938535

Today.
Johnson pass.

SNWMBL · Jan 25, 2017

Touché.

LoudHandle · Feb 6, 2017

Upper Connection of Front and Rear Over Structures

//snowest.com/forum/forum.vb/picture.php?albumid=3576&pictureid=34302
Stock Front Structure Upper Casting

//snowest.com/forum/forum.vb/picture.php?albumid=3576&pictureid=34303
Spot Faced to 10mm for Titanium M8 V-Brake Stud Installation

//snowest.com/forum/forum.vb/picture.php?albumid=3576&pictureid=34304
Titanium M8 V-Brake studs installed

These are the 4 Titanium front and rear upper connection bolts shown and weighed previously
//snowest.com/forum/forum.vb/picture.php?albumid=3576&pictureid=34305
My Rev. 1 Titanium bolt choice for the upper structure connection; 39 Grams

Upper Over Structure Fasteners, 2 Each of Two different thread length M8 TI V-brake studs, and Four TI M6 button head shoulder bolts with 8mm Shoulder; 40 Grams

By going to the Titanium M8 V-Brake studs, I did not save any weight Scale was reading 39-40 Grams same as the M8 TI bolts above, but gained some shear strength. As the M8 V-Brake studs are M8 thread with a 10mm Shoulder, 8mm Shank, with M6 female thread in the top. Add to that the M6 Shoulder bolt; M6 thread, with 8mm shoulder to retain the proper fit on the tube and insert.[/B]

LoudHandle · Feb 11, 2017

Fixed Length Tie Rod Hardware Evolution, (Rack)

Fastener Evolution for the Fixed Length Tie Rod (Rack); From Left to Right, Stock M10 Steel Torx Large Button head, My Rev. 1 Titanium M10 replacement, My Rev. 2 Titanium M8 with 10mm shoulder (to retain alignment and sheer strength), My Rev 3. Titanium 10mm V-brake stud (shortened both ends) the 10mm is retained on both sides of the shoulder for alignment and sheer with a M6 Titanium Torx Button head with a M6 Drilled Titanium washer under the head and another one under the Titanium V-Brake style cone nut washer

Stock M10 Steel Torx Large Button head; 85 Grams

My Rev. 1 Titanium M10 replacement; 39 Grams

My Rev. 2 Titanium M8 with 10mm shoulder (to retain alignment and sheer strength); 22 Grams

My Rev 3. Titanium 10mm V-brake stud (shortened both ends) the 10mm is retained on both sides of the shoulder for alignment and sheer with a M6 Titanium Torx Button head with a M6 Drilled Titanium washer under the head and another one under the Titanium V-Brake style cone nut washer; 19 Grams

For an ultimate reduction of 66 Grams, just shy of 4 1/2 times lighter than the stock fasteners. If you choose to not round to the tenths decimal place (4.47368)

LoudHandle · Feb 11, 2017

QD verses C3 verses My upgraded C3 belt drive

Stock PRO Ride QD weight; 1155 Grams

C3's Steel Idler faster bolt with steel spacers and standard bearings as delivered; 143 Grams

My Titanium Fastener with Drilled Titanium spacers and Ceramic Hybrid bearings; 98 Grams

Titanium Idler bolt, with Titanium spacers, and Ceramic Hybrid Bearing saves 45 Grams I also have Titanium stud material to make the tensioner bolts from, just haven't got to it yet.

C3 Belt drive, Mitsuboshi Giga Torque GX Belt, lightened with Ceramic Hybrid bearings in the tensioner, Titanium tensioner bolt and Drilled Titanium bearing spacers; 1295 Grams for 2.63:1 ratio

While the total assembly does weight 140 Grams more in this ratio. The actual rotating weight is far less (761 Grams for the pictured ratio). So in round numbers 2/3 the rotating weight of the stock belt drive.

PRO RMK build my way

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