This is my purpose built. 3 years and I still haven't painted it. (Too busy riding) the front is a stock 380 frame but I cut off everything below the swing arm bolt to move the track forward then attached remaining frame directly to the side panels. The 380 is a vibrating beast and this 3 point attachment to the side panels really helped knock down the vibes. This build works great and I cringe when I have to ride a crappy conversion kit. The conversion market needs to do a 180 and go a totally different direction.
Very nice build! Maybe the way to go to, plain simple has a lot of advantage! the need of a CVT vs shifting gear I think vary a lot with the terrain you ride. Around here we don't have may climbs, but we have a lot of very tight terrain. If I had to just pick a power plant for my project and don't worry about any budget I think I would have chosen a 450 4t with electric start and fuel injection... Add to it a Rekluse auto clutch and I think It would make a very capable an forgiving setup.
CVT are nice but very large to stuff in a small build like mine and make it larger was not a desired option. Plus I don't think the inertia of those clutch would help the light feeling that I'm looking for. Even with a Blast 400 engine, I still don't now if I would be able to fit those clutch without having them hanging on the side of the bike... (I would still like to try it trough)
Last point in favour of a 4t, the exhaust is not a problem anymore.... 2t expansion chamber become a problem very soon when you increase the CC's. The YZ250 pipe was manageable but it took many hours to figure out how to make all of this go together in a decent way! The Blast pipe plus the cvt I think would be a nightmare to fit.
All in all the yz250 I got was a good deal that I could not pass and at the end I find many advantage to it like the lowest inertia possible and it's physical size. Plus it should have some decent power with the weighted flywheel and V force3. What scares me the most is the potential lack of torque that could make it hard to ride for a newbie like me.
You’ll be just fine with that power. Can’t wait for some ride reports!
The yz is harder to stall than the big bore 4 banger... and personally there is so much rolling inertia with the kit I don't see the reason for a recluse... there is very little slipping of the clutch...normally you just on the gas even cutting through the steep and deep. Much different than with wheels in my opinion... I almost think you loose a lot of power with not having a regular clutch because it starts slipping at bad times...
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Highly recommend removing the flywheel weight for snowbike use.
Real nice job there, looking forward to hear the ride reports. Looking forward to the future of snow bikes, especially when seeing builds like this.
First ride report! Last week I took the opportunity to do a little rip on this thing! There was just about 6in of fresh snow. Anyway I have to say that it is more powerful than my expectation! It is very light in the handling and I like the riding position for now. The steering is a bit on the heavy side but I suspect the wide ski and low snow condition doesn't help a lot.
On the suspension side, the front double A arm deal is just working... I can not tell it is there vs any other setup so for the moment this part of the build is up to my expectation. I will follow it to see how it age up and it it wear up to quickly. For the back suspension I'm not as happy as with the front one. There was way to much transfer, I feel the mountain bike shock is way too small to limit any transfer since there could be some high force generated. So I have done my best to lock the MTB shock (acting like a coupled suspension) and it was way better. So for the next time I think I will install a small bushing to lock the transfer and completely couple the rear suspension (that will just allow the rail tip to get up to climb on snow). Even with the MTB shock locked I was still able to get the front ski to lift from the ground since the bike is so short and the CG is over the track. So I think I will have success this way.
Last one was the cooling, just like some have pointed out in previous post the cooling was the major issue. The weather was not very cold and there was not enough snow to have the engine in a bloc of ice so the radiator was the only source of cooling... Well at the end this is the way I want it to be, the radiator do the cooling by itself so when I close everything with panels everything will be happy. But the small cooler and the minimal amount of coolant in the system made it get hot very quickly and the temp was climbing. Well it was not a surprise like pointed by some here! So like Said before the plan was to add a tunnel cooler to do the major part of the cooling. Also this way I will get a lot more coolant volume and better capacity.
So I will probably test it this way and build a thermostat to control the cooling and bypass both radiator. Also I will add a short section of snow flap on the end of the tunnel to provide a surface for the snow to hit and make its way up to the tunnel cooler. Bonus that will keep snow off my back and my helmet haha!
Here is a couple pics of the work done on those modification!
Here the cooler is just a 22in section of an M8000 long cooler, cut and welded to close it up. It looks good, it is quick and free! Thanks to the local dealer for the scrap part!
Here we see the bungs for the hose, just two little pice turned on the lathe and welded to the shortened cooler.
On the suspension side, the front double A arm deal is just working... I can not tell it is there vs any other setup so for the moment this part of the build is up to my expectation. I will follow it to see how it age up and it it wear up to quickly. For the back suspension I'm not as happy as with the front one. There was way to much transfer, I feel the mountain bike shock is way too small to limit any transfer since there could be some high force generated. So I have done my best to lock the MTB shock (acting like a coupled suspension) and it was way better. So for the next time I think I will install a small bushing to lock the transfer and completely couple the rear suspension (that will just allow the rail tip to get up to climb on snow). Even with the MTB shock locked I was still able to get the front ski to lift from the ground since the bike is so short and the CG is over the track. So I think I will have success this way.
Last one was the cooling, just like some have pointed out in previous post the cooling was the major issue. The weather was not very cold and there was not enough snow to have the engine in a bloc of ice so the radiator was the only source of cooling... Well at the end this is the way I want it to be, the radiator do the cooling by itself so when I close everything with panels everything will be happy. But the small cooler and the minimal amount of coolant in the system made it get hot very quickly and the temp was climbing. Well it was not a surprise like pointed by some here! So like Said before the plan was to add a tunnel cooler to do the major part of the cooling. Also this way I will get a lot more coolant volume and better capacity.
So I will probably test it this way and build a thermostat to control the cooling and bypass both radiator. Also I will add a short section of snow flap on the end of the tunnel to provide a surface for the snow to hit and make its way up to the tunnel cooler. Bonus that will keep snow off my back and my helmet haha!
Here is a couple pics of the work done on those modification!
Here the cooler is just a 22in section of an M8000 long cooler, cut and welded to close it up. It looks good, it is quick and free! Thanks to the local dealer for the scrap part!
Here we see the bungs for the hose, just two little pice turned on the lathe and welded to the shortened cooler.
Yes It was not there for the first ride, I just added it yesterday. Before I had just the small air radiator in the front.
Thanks! Yes we will see if it get better soon. For now allmost all the snow have melted, I'm glad I have tested it and not waited!
There is no thermostat at the moment but there will be one soon, I just have to fab the housing for it. It is on the to do list with the snow flap/ tunnel extension before the next ride!
You have done the build I was dreaming of in my head... really strange to then see it in the back of your truck as that is the exact same truck I have (same color and everything).
The world aligns in weird ways sometimes. Build looks great, I think you are definitely on the right track.
The world aligns in weird ways sometimes. Build looks great, I think you are definitely on the right track.
Well that is a special coincidence! I think it is a sign that you have to start building one haha!
Might as well do some heated bars while you are at it!
Did you get any more snow yet for further testing?
