setting up paralever swingarm
 

What is the correct way to position the swingarm on a 91 paralever GS. I have just fitted a new shaft and assume the swingarm should be dead center, measuring the gap betweem swingarm and frame at the front bearings. However, when I do that the shaft fouls the casing when the shock is on full streach. ie with the bike on the centrestand. It runs fine if I offset the swingarm a few mms to the left. What are the opinions on this?

I've always set mine up with the same clearance either side? My understanding is that the output from the gearbox & the drive shaft will be mis-aligned causing premature failure of the UJ.

What shock are you using? If it's aftermarket & longer than standard, this may account for the problem? I have a standard shock at home where the damper has failed. I'll measure it's length from centre to centre of the mounting holes & post the result here later if needed.

I've since sold my airhead Paralever but I'll alsocheck out my Girlfriends bike, she's running a WP shock that is about 5mm shorter centre to centre.

Steve

Measured the spare shock, centre to centre is about 490mm, give or take a mm or two.

Steve

The manuals insist the swingarm be central, even give a tight tolerance that is to be followed.
I've had a paralever (spit) fail and I put it down to too hard shock (ie too long) creating too acute an angle on paralever (spit)

Field tip. Get an old screw driver and grind down to correct size to fit the required space - that way you can space the swingarm up without vernier guage or similar (must get round to doing this myself). The taper on a conventional screwdriver works as well, note how far it pushes in and balance on both sides - may be a handy tip for emergencies

[This message has been edited by Fritz (edited 25 May 2004).]

I managed to do mine with a regular pair of Vernier calipers.

Steve

Feeler gauge works for me and it's always in my toolkit..

Blimey, your feeler guages must go up to some thickness to meassure a few mm ?

Exactly my thoughts?

It's nearly a year since I did this but I'm sure I remember there being several (4 or5?) mm gap either side?

Steve

just use a whole bunch of blades, like about half a set or so, and fine tune as needed... been doing mine that way forever, works a treat. Easier than measuring.

------------------
Grant Johnson

Seek, and ye shall find.
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One world, Two wheels.
www.HorizonsUnlimited.com

thanks. I use feeler guages, setting up the shaft centrally is no problem. The bike is fitted with a hagon shock, so maybe the lenth of the shock is the problem, but I;m still not sure if it is better to run the shaft offcentre or have it central and touching the casing on full streach. neither seems ideal

It might be the shock but are you sure your frame is straight? What about the engine is it mounted right? There should be some “special” spacers between the engine and the frame (four total), are they still there?

Getting the shaft to run true & straight is the most important thing to get right. If it's wrong, it WILL wreck your UJ on the shaft.

Have you measured the shock length (centre to centre) & compared it to the measurement I gave in an earlier reply?

Steve

Thanks for the info. The shock is 500mm so a little longer than stock, Im not sure this is all the problem though. Anyone else got the same problem with a hagon fitted?

this is not exactlly a Airhead specific paper but maybe can be of some help for your specific needs and for sure a bunch of great info for oilhead around here

http://www.advrider.com/forums/showt...threadid=11349

enjoy and hopefully will give you guys a little more data

Shock length IS a problem.

The standard length produces around 17 degrees of U joint deflection.
There is a limit on the U joint deflection where the U joint will make internal contact between one side and the other.
In addition to that there is also a velocity (speed) variation between input and ouput htat is 0 for 0 degrees deflection, but increases with incresed deflection angle.

The standard G/S is at about the limit of the U joint deflection. For that reason I'd not go beyond it.