Very nice work.
A few things that I learned after 3 Timbersleds and 2 one off builds.
1: Shim the ski rubber so the front of carbide is 1/8” higher than the rear. (Tight rubber required)
2: Put the chain to the track-shaft inside the tunnel. (See #3 and 4)
3: Doing the direct drive like you did would allow you to eliminate the shaft extension by offsetting the motor very slightly left then building the gas tank to the right to balance it out.
4: Taper the top of the “tunnel” for smooth leg sweeps front to back.
5: Your “tunnel” could be UHMW plastic and hold much less snow. (Longer would keep snow off the helmet)
6: if at all possible run a track that is not spliced, that killed trackspeed on my sxf450 with a spliced 2.75x129 track.
Again, zero criticism here just wanting to pass my lessons learned on.
A few things that I learned after 3 Timbersleds and 2 one off builds.
1: Shim the ski rubber so the front of carbide is 1/8” higher than the rear. (Tight rubber required)
2: Put the chain to the track-shaft inside the tunnel. (See #3 and 4)
3: Doing the direct drive like you did would allow you to eliminate the shaft extension by offsetting the motor very slightly left then building the gas tank to the right to balance it out.
4: Taper the top of the “tunnel” for smooth leg sweeps front to back.
5: Your “tunnel” could be UHMW plastic and hold much less snow. (Longer would keep snow off the helmet)
6: if at all possible run a track that is not spliced, that killed trackspeed on my sxf450 with a spliced 2.75x129 track.
Again, zero criticism here just wanting to pass my lessons learned on.
I don't think there will be any hard spot in my A arm design. The way the suspension geometry is designed make the spindle go up and back just like a fork would do even with a pointed down A arm like I have at ride height. There is more than just to A-arm there to make this happen...
Sure a fork set could be made to minimize the load on the headset, I explored this Idea but the fork I had were a lot thiner in the area above the seals... the actual triple clamp area is quite beefy and I did not trust the fork structure to lower the bottom clamp and make the header like 16in long.... But in the end I'm sure there is a way to make that work and it could be the simplest solution and as light as my setup. Plus a fork set would clear a lot of space for the exhaust.... Let see what the future reserve!
it is a 12.5in x 120in for the moment, I could easily go longer if needed. The preload on the rear arm slider in the rear suspension will control the ski pressure just like a snowmobile, so it can be tuned and I can also make the rear suspension coupled by just locking the rear MTB fox float.
For turning radius I get as much as a bike, around 45deg each side. Let us see your project in the future!
First, thanks a lot for taking the time to share all the testing you have done! Also thanks for all the build info that you posted on the forum, I have checked every of them and they are very inspiring!
1. that could be easy to do and I bet I make a good difference in the approach angle of the ski!
2. I have seen a few build this way and yes I think it will be a no brainer in the future! On this one if I have problem with the actual setup or the next one for sure! Like you said in 3 there is a lot of advantage that make the build simpler and more robust!
4. I have a small angle in the top sheet metal but notting very noticeable
5. True! there might be a snowflap mounted as a tunnel extension in the near future, this would prevent getting snow all over my back and act as a tunnel but give less restriction as an actual one since it will be able to bend if needed.
6. Well this splice is not my favourite choice but I didn't want to throw a 1000$ track to a project that I was not sure what it would end up like.... So the 20$ track plus few hour of work was a good deal... But this might as well get replaced for performance and reliability.
Again thanks a lot for your input and taking the time, as you know with your builds there is still a lot of question and a lot of work ahead!
12,5x120x2" (older timbersled) tracks can be found for super cheap and they work pretty good for 90% of the snow condition we get in Quebec. I ran those for a couple seasons until I found a good deal on a 12,5x120x2.5 track. This is all on my custom tedesled-like kits.
You should start a thread and post pictures of your builds.
Last pictures i find of yours were from 2015.
Now I am thinking seriously about trying the a-arm front end on my raptor build. Did you look into using a snowmobile spindle before you decided to make a custom one?
Nice to know, but I don't mind buying a new track for it at full price if the project meets expectation! For me the spliced one is a cheap way to test the concept, plus I can still decide what track length I want at the end... I may go longer if needed, then I will just buy a 129 or a 137. We will se how it goes.
Not really, the geometry had to be spot on and there is no way an existing spindle could fit.... The only one that could have been made to work I think would be the AC mountain spindle, but the work to make it fit would have been far superior than the work to build one from scratch. It is not made to be on an A arm pointed forward, steering would have been almost impossible to make work on one side. Also, important to mention that snowmobile have next to no ''trail'' built into the spindle.... It is needed for a bike type machine to give the self standing at speed. (caster wheel effect)
But be aware that the steering setup to achieve a zero bumpsteer is not simple on the setup I have made... Cad work was very helpful on this one!
An Arctic Cat blast engine would be pretty amazing on this machine...........
So is the bump steer eliminated by increasing castor as the front compresses? That can't even happen with a normal fork the castor reduces when the fork dives.
This looks awesome! Even more important than the weight (IMO) is the position of the track getting it more up under the user instead of hanging out the back. That will make a huge difference in ski pressure and fun factor!
The picture with weight shows a side panel in the background.
You must have done a few different iterations of design and fabrication.
Care to share any of your lessons learned? ?
You must have done a few different iterations of design and fabrication.
Care to share any of your lessons learned? ?
Bump steer is eliminated only by a good design and precise geometry (the hard part hehe)! Caster remain the same (within a certain tolerance) the same thru the travel just like a fork setup.
I have looked into it last year but I have the feeling that by the time you fit a primary on it it become a very wide setup for a snowbike... actually it would be exactly like a 800 cat minus one cylinder, so remove about 6in of a normal twin. I guess the blast engine with primary will be around 20in wide overall, plus you get a secondary to fit in.
In my case It did not fit with what I had in mind!
Actually no, this snowbike is really the first iteration and, nothing has been tested before. The side panel you see in the background is one form my cousin snowbike kit. He built a conversion kit just like an aro from scratch and it just happen that he needed some aluminum welding done on this part. I got to use those new big welding skills
I bought a Tig welder in January for this project and it was a pretty steep learning curve to learn on a project like this but it was fun!
Based off these two pictures and measurements taken from a proclimb chassis I’m estimating the width to be 16-17” at the widest.
Put that wide point in front of the footpegs and it’s just clearing a little snow in front of your leg.
Videos posted by adult AC riders in deep snow show the engine has good potential to power a snowbike quite quickly. (65 hp claimed)
Main gains i see are: EFI, 3 stage exhaust valve, engine reverse, cold weather tuned from factory and cvt holding the engine at or near peak power through a broad range of trackspeeds.
Sorry for the derail.
Put that wide point in front of the footpegs and it’s just clearing a little snow in front of your leg.
Videos posted by adult AC riders in deep snow show the engine has good potential to power a snowbike quite quickly. (65 hp claimed)
Main gains i see are: EFI, 3 stage exhaust valve, engine reverse, cold weather tuned from factory and cvt holding the engine at or near peak power through a broad range of trackspeeds.
Sorry for the derail.
I add a few image of the building process, first few picture you can see the building process of the swing arm and A-arm to ensure they are exactly matching the 3D model and to ensure accurate design and proper geometry. Every suspension part were made that way, lots of time invested but the quality is spot on!
Then you can see the exact same jig in the design process in CAD, the 3D model of the jig allowed me to produce a set of drawing to machine the jig parts.
At the end I have jointed the rail built last summer, if I ever do an other monorail I will try to make it simpler because this one is a lot of machine work... But sure it is nice to look at all theses parts and the assembly.
Then you can see the exact same jig in the design process in CAD, the 3D model of the jig allowed me to produce a set of drawing to machine the jig parts.
At the end I have jointed the rail built last summer, if I ever do an other monorail I will try to make it simpler because this one is a lot of machine work... But sure it is nice to look at all theses parts and the assembly.
Well If it is closer to what you have in measurement it would be a great fit! I have tried one last year in the BLAST LT chassis and it was good for the type of machine it is, but in a lighter snowbike chassis I think it would really be a great fit performance wise.
Can't wait to see some used on on the market... Or even better let AC do their homework and offer us a factory snowbike just like they have in Patent!
You should start a thread and post pictures of your builds.
Last pictures i find of yours were from 2015.
Actually it felt like nobody cared about anything else 'but Timbersleds back then so I didn't bother posting much. Also, I did a updated version in 2018 and it works really good that now I just focus on riding. I've reached a point of diminishing returns for the design I think haha !
Did you make your own footpeg brackets to bolt to the side panels or was there some from a bike that could be purchased? Most the bike ones I've seen mount to the bike at a weird angle.
Also I can't get real excited about 65hp with a cvt. It won't perform any better than what we have power wise but the chassis in the AC pattent looks about right for proper handling. I enjoy shifting too much and if they offer a beginer friendly cvt bike all our secret riding spots will become tracked out real fast by rental snowbikers!
Also I can't get real excited about 65hp with a cvt. It won't perform any better than what we have power wise but the chassis in the AC pattent looks about right for proper handling. I enjoy shifting too much and if they offer a beginer friendly cvt bike all our secret riding spots will become tracked out real fast by rental snowbikers!
Grind the bumper inside the yamaha peg mounts until the peg sits level.
I used ktm pegs in yamaha mounts the same way.
The only gains from cvt will be at each shift. Manual transmission engine power output follows rpm.
Example from yz450f, Engage 1st gear at 30 hp rev up to 60 hp (1-10 mph trackpeed) shift back to 35 hp rev up to 60 hp (8-18 mph trackspeed) shift back to 35 hp rev up to 60 hp (16-27 mph trackspeed)
Example from ac blast engine: rev to 4000 rpm engage at 30 hp rev up to 65 hp hold at 65 hp as trackspeed raises through 5-10-20-25-30-35 mph........
Power to the snow gets you places.
It would be different for sure.........
Dodge a tree and the 1 second delay before downshift slows you down ( low hp output due to low rpm) , uphill switchback turn and downshift at the same time lose momentum, come over a rise and gain speed across a flat spot before hitting the steep, upshift, then downshift losing momentum at both shifts. (Moment in time with zero power transfer to the snow)
Reading some Data logs of streetbike races is a great way to see the time spent between shifts with zero acceleration.
In comparison asphalt friction to a tire compared to snow dragging down trackspeed.
The lack of acceleration seems more important. (Or deceleration in the case of snowbikes)
For me mistakes made with a manual transmission snowbike kill the fun factor (1-1.5 second delays in power delivery not letting me keep momentum and get above the tree or over the ridge), tight trees and steep canyons are my favorite terrain.
I find myself body English riding the snowbike when the going gets tough, this leaves me not in position to make optimal shift movement.
The R6 and ninja 636 bikes both went great in wide open spaces, the yz450f and sxf450 both went well in shallow snow and my turbo axys rmk goes great everywhere i can crush trees and dodge them.
I want the best of all 3 worlds......
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Looking at my 800 pro ....drop the recoil and you could really narrow and centralize the motor and cvt ...
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