A two-wheel drive, road-legal supermoto

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Last year, Christini announced that it was getting out of the custom game and into manufacturing its own motorcycles. The Philadelphia, PA-based maker of “All-Wheel Drive” systems currently has a range of two dirt bikes. A 300cc two-stroke that uses a GasGas motor and a 450cc four-stroke; the latter forms the basis for this new supermoto. It’s the first time ever that a two-wheel drive motorcycle will be manufactured in volume for road use.

Two-wheel drive has been one of those just-over-the-horizon bike tech things for over a decade now. Yamaha and Ohlins co-developed an R1 equipped with a hydraulic system last decade, never resulting in anything consumer facing. Christini has, for years, converted dirt bikes to two-wheel drive using a more efficient, but rather complex, mechanical system. It claims that its solution results in “less than one percent power loss.” Advantages include an increase in traction available for acceleration and a decreased tendency for low-sides.

Christini’s system works like this a chain mounted to a secondary countershaft sprocket runs up to a gearbox mounted on the main frame rail; that drives a shaft which runs under the tank to a bespoke steering head; counter rotating bevel gears located within the head tube transfer power to the lower triple clamp; two small chains then send that power out to a counter rotating drive shaft mounted on each fork leg; those telescopic shafts run down to the front hub, spinning a one-way clutch freewheel.Power is sent to the front wheel at about 80% of the speed of the rear wheel. So when the rear wheel loses traction, the rear wheel spins faster than the road speed of the front wheel, engaging the one-way clutch in the front hub and sending power to the front wheel. A lever on the handlebar allows riders to discontinue use of the AWD system when desired.

The system, which adds about 15lbs of weight, sounds way more complicated than its intuitive reality. Just get on the bike, ride it, and appreciate the extra traction and increased confidence in the front tire. That latter aspect should be a massive boon to a supermoto, where extreme lean angles and slides are the norm.

“Traction and safety in wet and treacherous terrain both on and off road are dramatically improved by AWD enabling a broad range of riders to achieve performance levels far superior to a normal rear wheel drive motorcycle,” explains Christini. “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 Christini supermoto is priced at $8,195. No word on availability.

  • smoke4ndmears

    so…
    when are you guys going to ride it???

    • http://hellforleathermagazine.com Wes Siler

      When Christini returns an email…

  • http://www.postpixel.com.au mugget

    Nearly impossible to wash out the front end? Well that is going to take some pretty extreme riding to test out – I can barely imagine a regular supermoto with sticky tyres being likely to wash out the front on a good surface, let alone an AWD supermoto!

    • Miles Prower [690 Duke, MTS 1200]

      “…on a good surface”

      I’ve never ridden a supermoto on a track, but I “washed out” the front end of my KTM 625 SMC many times on the road (and in parking lots) — usually from hitting something as innocuous as a cherry-sized rock or a random piece of rubbish. Having my foot down mid-turn always saved me from low-siding. (I’ve since sold my SMC.)

  • Maxwell

    Being that the front tire is now asked to cope with the rigors of turning and accelerating, it seems if anything it would be easier to lowside. The tire can only offer “x” amount of traction. If under normal circumstances you use .8X to turn the motorcycle, and now you’re asking for another .5X to accelerate, you’ve run out of friction circle.

    Same thing applies to cars, especially AWD ones. Without clever differentials, AWD cars tend to understeer like crazy (loss of front grip) because the front tires are asked to accelerate and steer.

    • Sean Smith

      Christini employs a clever differential.

      There’s a one way clutch in the front wheel hub and the front wheel is overdriven. Until the rear wheel is moving faster than the front (how much depends on your sprockets and is adjustable), there’s no power going through it. When the rear spins up, having power go through the front makes it go exactly where you point it.

    • zero

      You’re right, it doesn’t offer more grip, but it changes the force vector. So even if the same overall grip is available, the direction that the grip is no longer pointing the center of the radius of travel but a bit forward as well.

      AWD cars use torque vectoring to achieve the same result. Send the torque to the wheel that will rotate the car most in the desired direction.

      Whether this is actually helpful for lowsides or not is to be seen, but that is the theory.

  • Campisi

    Time for a blurb on the Megola.

  • 80-watt Hamster

    I’m mostly impressed that they were able to price it at less than $10k, let alone a bit over $8K.

    • http://www.TroyRank.com Troy R

      Agreed 8k is amazing for all this low-volume tech. The system is really for extreme, relatively slow speed off-roading I imagine.

  • Mike

    So what kind of engine is the 4-stroke?
    I’d think that parts availability would be rather important for something that gets rebuilt more frequently than your typical streetbike.

    • Sean Smith

      According to the guys buying them, it’s a chinese CRF450X motor that makes good power, doesn’t blow up and uses Honda parts.

  • oldblue

    Looks like quite a neat execution.

    I’m just hoping that this will see the birth of the limitless stoppie. It’s about time the stunt crowd had something new to try.