View Full Version : Is the paralever obsolete?
04-03-2010, 10:31 PM
With the advent of electronic engine control
and stability augmentation, it seems to me
that the paralever function could be better
done by controlling engine speed dependent
on (obviously among other things) the swingarm
It would reduce unsprung weight and parts count
and probably eliminate the fd failures.
04-03-2010, 10:50 PM
I don't see how electronic engine speed control would have any effect on the need for a U-joint that allows the circular motion to be translated across an angle. The whole point of the U-Joint at the rear is the same as at the front of the drive shaft. I'm just a CE not and ME, but I don't see how electronics would make a difference. Not sure I would want additional electronics necessary inside the drive shaft tunnel, and not sure it would accomplish the task....:scratch
04-03-2010, 11:17 PM
The paralever function just does away with the rear of the bike wanting to lift on accleration & drop on deceleration. It transfers the up & down motion of a stock driveshaft equiped motorcycle to the back & forth movement on the rear splines. Therefore maintaining better control of the bike.
The paralever function really has not much to do with RD failures in my view. Its a different animal.
Electronics work well with being able to infinitely adjust suspension travel & firmness etc, but I can't really see a role for it in the paralever.
04-03-2010, 11:17 PM
Is it raining in East Greenbush today?:laugh:dunno
04-03-2010, 11:18 PM
The palaver minimizes the rear jacking up during acceleration. Reducing power would reduce jacking, but, well, that would reduce acceleration.
04-09-2010, 08:48 PM
In the days before the Paralever, the ways to minimize drive-shaft induced jack/squat at the rear of the bike was to make the swingarm as long as possible. But that is not all that feasible depending on the engine and bike. Another method is to position the forward pivot point of the driveshaft off center vertically to the tranny output centerline. This is evident if you look at any current Paralever setup.
The R-CL series has a long swingarm to minimize jack/squat, but it also makes a lot less power than the other R bikes. Also, that was done to achieve much of the cruiser style and low seat of that bike. Look to an old Airhead, old Guzzis, old Yammy XS750, for the bikes with real jack/squat induced by the pinion gear trying to "climb" the ring gear in the solid mounted rear drive hubs.
The function of the paralever design is to transmit the torque reaction of the rear drive hub into the frame. Dr. John proved that years ago with his succesful mods of Guzzi racing bikes, so much so that it became the design for Guzzi. So I doubt any form of engine management could replace the simple effectiveness of the paralever design. Also, it has little or nothing to do with rear drive hub failures as many early Paralever equipped bikes have well over 200,000 miles on the original rear drive components.
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