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AWD Moto, next big thing?

They've raced 2WD motorcycles in Dakar. They didn't win.
They've raced 2WD motorcycles at Erzberg. They didn't win.

Conclusion: Skillz trump tech.:party
 
If you could disconnect the rear wheel, the front end burnouts would be awesome.
 
jdubau said:
Its a torque biasing system so most power is at the rear, it applies more power to the front when its needed like a differential/transfer case on an awd car.
From their site>>
"Christini's patented mechanical All Wheel Drive system delivers power from the motorcycle transmission to the front wheel through a series of chains and shafts. There is no energy-robbing hydraulics involved.

The lightweight all-mechanical system works similar to that of AWD systems found on four wheeled vehicles. The AWD system (powering the front wheel) is driven at a slightly lower rate than the rear wheel (approximately 80%). Under optimum traction conditions, the rear wheel is actually driving faster than the front AWD system. One-way clutches within the front hub allow the front wheel to freewheel under these conditions. At this point, the AWD system is effectively passive. Though the front AWD system is turning, it is not actually transferring power to the front wheel. When the rear wheel loses traction, the drive ratio, relative to your forward speed, changes. The AWD system engages, transferring power to the front wheel until traction is reestablished at the rear wheel.

The way the front system works is like pedaling a bicycle down hill. You are pedaling, but because of gravity (acting like the rear drive) the bike is traveling faster than you are delivering power. When you get to the bottom of the hill and slow down (similar to what happens when the rear wheel spins), you will begin to power the bike again.

An added benefit of AWD is that the front wheel does not want to wash out. When a front end tucks, the wheel stalls, stops turning, and begins to push. With the AWD system, as soon as the wheel begins to stall, power is delivered to the front wheel, forcing it to turn. With the front wheel under power, it is nearly impossible to wash out the front end."

The concept sounds really cool to me, especially on a dirt bike/dual sport, They say it adds less than 15lbs to the bike too, with this system over a hydraulic type.
Click to expand...

do you work for them? cuz it sure sounds like you do.

as for the energy loss. 1/10th huh? i don't know if that is proper or not, since i am not an engineer. but, changing one type of rotational energy into another loses quite a bit of power. on a car for example, you may have 100hp at the flywheel, and say, 97hp by the time you get past the diff. that energy then makes a 90 degree turn to the half shafts and you lose even more power.

on this 2wd bike, how many times must that energy go through some type of gearing or device to eventually get it to the front wheel?
 
Well wouldn't there be almost no energy loss while the rear wheel has traction? It'd just be free spinning as the front wheel would be propelled to spin normally and it's power unit would be spinning at a slower speed. Only tome you'd loss much to mechanical energy loss would be when either the front stops spinning or the rear spins up (no different than TC loss)
 
jdubau said:
"Christini's patented mechanical All Wheel Drive system delivers power from the motorcycle transmission to the front wheel through a series of chains and shafts. There is no energy-robbing hydraulics involved.
Click to expand...

Who told them that chains and shafts don't rob energy?

Last I heard, chain drive motorcycles were expected to lose 15% between the crankshaft and the rear wheel.

How is a "series of chains and shafts" supposed to be any different?

I like the hydraulic system because of all the parts in a front end that move so many different directions.
Hooking it all up with hoses is a lot simpler (thus, cheaper) than using "a series of chains and shafts", not to mention whatever "differential" system they've worked out to transfer the power as needed, which requires nothing special with a hydraulic system.
 
jraice said:
Well wouldn't there be almost no energy loss while the rear wheel has traction? It'd just be free spinning as the front wheel would be propelled to spin normally and it's power unit would be spinning at a slower speed. Only tome you'd loss much to mechanical energy loss would be when either the front stops spinning or the rear spins up (no different than TC loss)
Click to expand...

If the "chains and shafts" are disconnected while the power isn't applied to the front wheel, that's true, but I can tell you as an owner of a 4WD truck, you lose power through the front drive system if it's connected to the wheels. That's why we have locking hubs.
 
xgambit said:
from Ohlins 2 Wheel Drive Bike



2wd-yamaha-r1-3.jpg
Click to expand...

So when you apply power to the front wheel, what keeps the contact patch from trying to find a way around the steering axis?
 
With the front wheel under power, it is nearly impossible to wash out the front end.

Lol... Try hRder
 
xlcr said:
So when you apply power to the front wheel, what keeps the contact patch from trying to find a way around the steering axis?
Click to expand...

Not much so presumably it would resist the turning moment from a front end "tuck" - which acts in the opposite direction. With power on, its possible that front would still slide at the limit but not tuck - that could be interesting.
 
Carlo said:
Who told them that chains and shafts don't rob energy?

Last I heard, chain drive motorcycles were expected to lose 15% between the crankshaft and the rear wheel.

How is a "series of chains and shafts" supposed to be any different?

I like the hydraulic system because of all the parts in a front end that move so many different directions.
Hooking it all up with hoses is a lot simpler (thus, cheaper) than using "a series of chains and shafts", not to mention whatever "differential" system they've worked out to transfer the power as needed, which requires nothing special with a hydraulic system.
Click to expand...

I believe they are saying that it robs LESS power than a hydraulic system. There is probably much less drag and it weighs less as well, also doesn't a hydraulic system require some kind of pump to apply power?
Keep in they use one way clutches to keep things free wheeling when not in use as well
 
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The quote in question is talking exclusively about when the front is not engaged. At that point, the system is pulling some power from the bike but it is it is going to be very minimal. There will be much more significant loss in the drive mechanism but at the point where you are applying power to the front, you will never be WOT and will have plenty of power to spare.
 
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