WTF?? Chain drive rear disc.....??

I think it's interesting. It looks like the rotor sprocket is approximately the same size as the countershaft sprocket so that means the rotor will be turning a lot faster than it would if it were attached to the rear wheel. This means higher inertia to accelerate as well as decelerate.

However, there is now a gearing advantage between the rotor and the wheel so it will generate more braking force. I've never had a problem locking up the rear on a sportbike so I'm not sure there's a practical advantage. It does give a nice clean look to the rear wheel, though.

Why all of the hate?

 

Would you let it run clubman?

-jim

 

It looks as if the reason for the secondary shaft is to "drive" the disc on the other side....

 

Hey Mongo:

Would this thing pass WERA tech inspection???

Just wondering.

 

The original ATK's were designed by an engineer (Horst Lietner, IIRC). I had one of the 1989 250's and it was a great enduro/hare scrambles bike. These were all hand assembled at the Bombadier factory in Laguna Beach, where the old CAN-AM factory once was. It took over six months to get mine and I bugged the shop owner constantly about when it was gonna be here.

The countershaft rear brake was neat. But as noted; if the chain snapped, you were in trouble....

The ATKs (again, IIRC) were the first production bikes to use inverted forks. The drivetrain side on the swingarm had two raised 'sprockets' that eliminated chain torque by keeping the chain parallel to the swingarm, they can be seen in the photo below. The gas tank was offset wrt height on the left side to allow for a very-high-up-there airbox intake (it wasn't underseat as the one pictured below). And it used a decent rotax motor.

The 604 four stroke was also the first dirty-bike to come with an elec. starter...

Great bikes (if you were weird enough to want them). Thanks for the picture, brings back a lot of memories.


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I had no idea they made bikes in Laguna Beach. Cool!

 

..

 

first thing I noticed besides the ridiculousness of the whole thing was the super awesome amount of front suspension travel. Don't hit any bumps!

 

They've got that covered....you'll notice that there's only about 5lbs of air in the front tire, that'll soften things up!