Future of Snowbikes
- Thread starter AK_SNOWBIKE_CO
- Start date
I personally would stick with a gearbox for the benefit of substantial over rev when I want it , sure CVT will make it easier for new riders however the spinning weight of both clutches will have a tremendous gyro effect,and adds significant weight , I built custom CVT clutches and clutch kits and great for sleds however snow bikes are all about remaining super nimble and lite and flickable. The rear kit will need totally redesigned as well to have a jackshaft up high under the fender to make room for the secondary . CVTs are not near as efficient as a gearbox and scrub HP that's why the belts generate heat .
Have you ever put a gearbox on a sled?
A
AK_SNOWBIKE_CO
Member
All of the CVT I have seen added to bikes were sled CVT’s and not specifically designed for a bike. If someone made a purpose built CVT for a snowbike application I am sure it could be scaled down appropriately to match the power delivery and keep the mass lightweight. BRC so far as been the only one I have seen to accomplish just that. My only worry is a 500cc engine will only make 50-60hp and CVT will be less efficient at transferring energy than the gearbox (gearbox 9-11% loss vs CVT maybe 20-30% loss?)
Powerhouse customs built one.
Push button electric quick shifter.
Cbr1000 engine with low boost. (Stock compression)
Basically good for wheelies on the lake.
Too much time spent without near full power going to the track to perform on the mountain much less in the trees.
See below.
Post #38 below.
Last edited:
A sled has loads of power so losing the HP in the CVT as belt scrubs/ heats up is acceptable.If ewe don't have the skills to use a tranny then sure go CVT and sacrifice the lost HP and over rev ,the over rev is precisely why the 450 kills the 500 providing the rider is skilled. CVT will be great for novice riders however the gyro of two large spinning clutches will be debacle and that Gyro effect is not subjective and are simple physics.
Cvt losses aren’t what they used to be if you know how to address them.
Innovating — TRS Performance Inc.
www.trsperformanceinc.com
Talk of overrev is basically just taking advantage of low resistance.
Which cvt does very well. (Upshifting)
I'm not a fan of cvt for a lot of reasons but if brc is bumping the 5 honey from 75 to 105hp it will be a good match for a cvt because it will be a lot narrower power band. The sleds run 200 degree exhaust timing and the brc was at about 190. It kept getting better (for me) as I raised it but it did lose the monster midrange and I started riding it more like a 125 which I really enjoy. Most snow bikers like 4 strokes and 300s so I doubt they would easily adapt to a narrow power band 2 stroke so if brc wants to sell the 105hp engine, it will have to have a cvt. But the extra 30hp will more than overcome the efficiency loss in the belt. But man I'll bet the fuel consumption gets pretty bad. It will need a 12 gallon tank like a sled.
I was going to upgrade to a brc gen2 cylinder this year but I need to see if Riley will borrow me a 105hp cylinder to try on a manual tranny before I order a new 75hp one. I might fall in love but will quickly wear out the ends of the clutch lever and shift lever.
I was going to upgrade to a brc gen2 cylinder this year but I need to see if Riley will borrow me a 105hp cylinder to try on a manual tranny before I order a new 75hp one. I might fall in love but will quickly wear out the ends of the clutch lever and shift lever.
A
AK_SNOWBIKE_CO
Member
Having owned a BRC for three years and trying the Gen 2 cylinder I remain skeptical of their 105hp claim. I’d be surprised if it made anything above 60hp without a turbo. The Gen 2 cylinder with triple blade powervalve did make a good improvement but not significant. I don’t buy into the idea that the 500 will make 105hp. They claimed if a 1000cc sled can make 210hp, why can’t a single cylinder 500 make half of that power and unfortunately that’s not how things work. Don’t get me wrong, I want to see them succeed but they need to be realistic about their claims.
lil off topic, but about 25yrs ago Nuclear motor sports made a modular sled engine that was 500cc per cyl and they rated it at 100hp. The motor was ahead of its time, if you wanted a bigger motor you just had to bolt on another 500cc crank case and cyl. It was quite slick. having said that, technology is way better now so why cant the BRC motor make 105HP?
A
AK_SNOWBIKE_CO
Member
From what I can tell, the BRC engine is unchanged from what they currently offer for their dirtbike engine kits. So I don’t see how or where they are going to squeeze another 40hp out of the bike as it currently sits naturally aspirated. Their website currently claims 60+ hp which is believeable. Adding a CVT will likely rob more hp/torque than current gearbox.
I recall following the build on backcountry rebels forums. Was pretty nice.Anybody know what ever happened to TLKD's build that he did for some guy?
View attachment 423959
View attachment 423960
Back in 2014, probably some guy that could afford it but couldn't ride it
But I thought it was for himself ?
I think Thierry is focusing on bike trail building and downhill trike snow bikes.
Ewe can squeeze incredible Dyno HP numbers from any engine however they will not last ,many methods to manipulate the results , Squeezing high HP is done on drag strips and after a few runs engine needs pulled down, Sustainable HP that lives 150 +hrs is the goal , and better than a Juan shot pony.
Last edited:
Similar threads
