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General Category => General Discussion => Topic started by: Rough Edge racing on April 25, 2020, 07:04:18 AM

Title: Tonti frame swingarm "location"
Post by: Rough Edge racing on April 25, 2020, 07:04:18 AM
 Is there a spec for the swingarm location within the frame rails?  Or is it just equal spacing on both sides.. ?
  Can you say from actual experience if the swingarm is left or right too much it could cause  driveline vibrations...?  This assumes the bearings are properly adjusted...Thanks
Title: Re: Tonti frame swingarm "location"
Post by: Chuck in Indiana on April 25, 2020, 08:09:00 AM
Just equal spacing both sides. I use calipers, but that is no doubt overkill.
Title: Re: Tonti frame swingarm "location"
Post by: Rough Edge racing on April 25, 2020, 08:24:58 AM
 Thanks,I have messed with quite a few Jeep and hot rod driveshafts, but no knowledge of what you can get away with on a Guzzi 
Title: Re: Tonti frame swingarm "location"
Post by: acguzzi on April 25, 2020, 09:08:41 AM
from my experience there is not a lot of play anyway, but I have heard of people offsetting the swing arm to get more tire clearance so I'm guessing its not critical, given the accuracy of a typical alignment methods for a chain drive I can't believe a couple of millimeters makes any difference.
Title: Re: Tonti frame swingarm "location"
Post by: Wayne Orwig on April 25, 2020, 11:06:18 AM
I suspect if it is too far off, you are going to wear the splines on the transmission, and the U-joint will wear in the carrier bearing.
Title: Re: Tonti frame swingarm "location"
Post by: pehayes on April 25, 2020, 12:14:33 PM
but I have heard of people offsetting the swing arm to get more tire clearance

That would be me.  Many years ago.  73 Eldo.  Used a 5:10 X 16 rear rim/tire.  Swingarm was offset by at least 1/4" in order to get the center of the rear tire following the center of the front tire.  .  Many, many miles without issue.

Patrick Hayes
Fremont CA
Title: Re: Tonti frame swingarm "location"
Post by: moto-uno on April 25, 2020, 02:56:08 PM
  Has anyone noticed if there is an increase in vibration( probably very little) ? Long ago I turned a longer piece of tubing that would fit snugly in
the swingarm bearing and the other end opened to fit tightly over the output shaft splines . That way I was able to check for free turning and simply
measure the amount of stick out of each swing arm screw and copy on final assembly . It's cheap and pretty much guarantees the carden joint
isn't spinning off center ( some might consider it a bit much , but it was cheap and easy ) . YMMV  :wink:, Peter
Title: Re: Tonti frame swingarm "location"
Post by: mtiberio on April 26, 2020, 09:02:43 AM
guzzis have dual u-joints, perfect alignment is not required (and was a feature of later tonti Californias). When I raced, I ran a huge rear rim and tire in a notched swingarm. I had .4" (10mm) of offset to the left for the rear wheel. I ran the swingarm as far to the right as the adjuster screws and locknuts would allow in an attempt to get the rear wheel at least somewhat back in alignment with the front. from my experience that alignment being necessary for stability was over rated. The bike was harder to push into left turns than right however as the CoG was definately right of a line connecting the tire contact patches.
Title: Re: Tonti frame swingarm "location"
Post by: Petrus Rocks on April 26, 2020, 11:25:46 AM
Rough Edge is posting about my Guzzi.  We installed a new Cardamon joint and seal, maybe a new rear tire  The vibration starts being noticeable about 55-60mph, gets worse as speeds climb.  Haven't ridden it this year so I'm not sure.  Possible the tire needs balancing.