It was a big deal when AWD was first brought to the competitive off-road motorcycle scene but the technology hasn't really taken off like some predicted. Christini Technologies has brought a mechanical form to the public that could serve a lot of riders.
Steve Christini readily admits to being only an enthusiastic beginner in off-road motorcycling, but that hasn't stopped him from imagining, designing and crafting technology that could change the way off-roaders and OEMs develop their bikes.
Two-wheel-drive motorcycles are nothing new, but the way the mechanical engineer from Pennsylvania's Villanova University has approached them with his business, Christini Technologies, Inc.
is not only revolutionary but functional for sport riding. We got a chance to ride some pre-production Christini machines at the Maxxis EnduroCross and came away excited about the experience.
Typically, when someone mentions 2-wheel-drive motorcycles the first images to splash across one's brain are those of Rokon utility vehicles or the Ohlins hydraulic system available for Yamahas. The Christini AWD system has a little in common with both, with the key word being "little."
Coming from a mountain biking background, Steve had seen attempts at shaft-driven all-wheel drive systems before. It was to these motor-less transports that he and co-inventor Mike Dunn first developed and patented the Christini AWD system. The natural progression would be to move into motorized sport which is exactly what he did. After countless hours of development, the Christini motorcycle AWD system was patented in 2001 after which the company has been tirelessly tweaking and improving the original design.
Christini uses a mechanical system that utilizes chains and drive shafts to power the front tire, as does Rokon. Both are American companies, but that's where the similarities stop. Unlike Rokon owners, Christini users have no intention or need to haul a trailer, disc harrow or run power accessories with a PTO system. That's because the Christini kit is going to be available for the Honda CRF250R, 250X and 450X in January or February with plans to expand into the KTM lineup later in 2007. Name the last time you saw someone plowing their fields with an aluminum framed enduro bike and I'll show you a half-cooked farmer with too much spending money.
Making room for this gearbox is one of the big modifications to the frame.
Hardcore racers and recreational riders will both find the benefits of a Christini system since the modern marvel known as suspension is still incorporated - a challenge for shaft and chain-driven AWD. Perhaps the best known option for real off-road motorcycling up till now has been the hydraulic Ohlins system. Developed in conjunction with Yamaha for the WR450F, the Ohlins setup has one major drawback that seems to be universally bitched about - sapping engine power. Christini claims that the total amount of loss with their AWD system is 1/10th of a horsepower. Natural speculation combined with our quick riding impression has left us to doubt it truly drags so little. However, we're certain that whatever it is, it isn't much.
Here's how the whole thing works: A sprocket mounts outside of the existing countershaft sprocket, piggy-back style. That drives a chain up to another sprocket that turns a right-angle gearbox which is located inside the left spar of the frame, under the rider's knee. From there a solid shaft runs into a custom steering head which completely replaces the stock unit. Where the steering stem once sat is now a set of counter-rotating bevel gears which transfer power into the lower triple clamp. There, two small chains attach to a telescopic driveshaft on the front of each fork. Using linear ball spline bearings, these shafts eliminate torque effect and allow the suspension to move up and down. The driveshafts attach to a special Christini front hub and transfer the power through one-way clutches.
Having the damping effect on the steering is a good thing at high speeds but it wasn't the greatest thing for trying to delicately pick through a rock garden. It takes some getting used to.
All told the system buttons up nicely and is well protected by its location inside the frame. Exposed parts are covered with fork guards and an aluminum cover plate which keeps the rider from shredding his left pant leg in the initial drive chain. Also, a lever mounted to the left handlebar allows for the system to be engaged or disengaged on the fly. Both wheels spin the same speed on the ground but the front wheel drive system runs at a variable percentage, between 50-95%. That means that if the rear wheel is getting full traction it will overpower the front and the 21-inch meat will spin freely. However, as the rear wheel slips, that variable power ratio catches back up and provides power to the front wheel. Basically it's like a version of Positraction on an automobile.
One of the catches with having a one-way clutch system on the front hub is that the drive must be disengaged to move the bike backwards. That means any time you have to rock back and forth it is pretty tough, and as Christini says, not too good on the system, though they have yet to suffer any major mechanical failures. Makes sense. The on/off switch alludes to Christini's MTB background as he chose to utilize an oversized thumb shifter produced by Shimano, a well-known maker of bicycle components. Once it is disengaged, jackknifing the bike around the parking lot is no more difficult than dealing with the claimed additional 15 pounds. Ohlins claims 19 pounds for its hydraulic system.
During the painfully short time that I rode the 250R and 250X versions, I didn't notice much hindrance from the weight, but I could feel the AWD effects on the steering. When the power being transferred up front, the system acts as a kind of steering damper. In my situation that amounted to a bit more effort on the bars, but outside the tight confines of the Orleans Arena and the god-forsaken EnduroX course, I'm sure the sensation would be more welcome than not. What I did get a good demonstration of was how beneficial the AWD becomes once you're stuck. Over the course of the weekend I saw plenty of back knobbies get smoked in the rock pile as riders tried in vain to power their way out of a crevasse. When that happened to me I simply weighted the front end, eased the clutch and let the front wheel pull me up and forwards. As simple as that I was out of the hole and on my way to the next one.
The special Talon hub with one-directional clutches is not only functional, but beautiful as well. Everything on the Christini kit is well crafted.
Will this technology be a fit on the motocross track? Probably not, but Steve and his gang never intended to emancipate the moto slaves from their rear-wheel shackles. This technology will shine in mud, ruts, sand, slippery roots and rocks and hillclimbs - standard off-road fare. If this is your kind of riding then a call to Christini might be in order, but getting hooked up with your own AWD system isn't that easy. First off, the frame and front suspension of your CRF (or future bike) has to be modified. That means completely dismantling your steed and shipping the pieces off to the Christini crew in Philadelphia. Once there they will return another frame that's already been modified along with your prepped fork and the rest of the kit. Frame kits include an AWD frame, modified OEM fork, AWD system, alloy Talon front hub, custom fuel tank, engagement switch, billet alloy triple-clamps and a complete plastics kit with Christini graphics and seat cover. Your original frame will be inspected, modified and prepped for the next customer.
What that means is a lot of down time and wrenching. One way to avoid the mechanical struggle is to buy a bike new and inform your dealer before they unpack your bike from its crate that you want the frame sent to Christini. That should help with some of the hassle, but there is still the issue of a the remaining price tag, which essentially doubles the cost of your CRF, maybe more depending on what you buy.
To help justify the cost I did a quick search on the internet that turned up loads of personal accounts screaming praise for Christini AWD bicycles. Based on our initial impression and those of other journalists, the same positive comments will soon follow from enamored motorcyclists.
In addition to the EnduroCross event, Christini has been testing/showcasing its product at the Red Bull Last Man Standing (shown) and the World Enduro championship series.
Even more encouraging were the positive words about the company and customer service. It reaffirmed my feelings that the guys at Christini are genuine enthusiasts who have put their heart and soul into making a good product. Every one of the people I interacted with was completely friendly, helpful and dedicated to making sure the system was working for me. With such an investment of time, money and effort to have a Christini AWD system installed on a bike, the first thing I'd need to know is that there is a crew ready to help me with even the slightest hiccup.
Though my pathetic attempt at surviving the pro EnduroCross course was hardly a test, it was enough to convince me that this product has unimaginable potential. Trust me, it is unimaginable because most of you have never ridden anything like it. When you do, you'll probably come away with a better appreciation for what Christini AWD technology has to offer. Suddenly $6700 doesn't seem so stiff.
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