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Crash damage


Zooter

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I've never done it so it didn't float to the surface of my memory banks, but Foto is absolutely right about fluorescent tubes, that's an excellent redneck tip if you could get a couple of assistants to hold them in place

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Bungee the fluorescent tubes to the rear tire a couple inches off the ground so they fit tight to the front and rear face of the tire on each side then measure the distance between the two as far out in front of the front tire as they go compared to the measurement just in front of the rear wheel, I had 8 foot bulbs.

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6 hours ago, fotoguzzi said:

Iron or wood for a straight edge not reliable. A sidecarist trick is to use long fluorescent light bulb tubes, they are perfectly straight.

Never thought of that, didnt realise they were dead straight. You learn all sorts of things here:) You can of course source yourself a piece of 50X20 aluminium rectangular tube and adjust it for dead straight then drill 4 holes with bolts 2 at each end that are spaced to rest on the fwd and rear edges of the rims to check the alignment. Then you can use it on any bike by just drilling extra bolt holes to suit differing wheel bases and use longer/shorter bolts for different wheel width combinations.The vertical you do with plumb bobs.

The trick is knowing how much misalignment is production based.

Ciao 

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I used a cheap laser level to alignment my Sport's swingarm Not really sure how to rig that for Zooter's frame check . . .

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Get the front fork / wheel in a  straight ahead position and secure it . Get innovative ! You are using the tubes to set front/rear tire tracking . You are using the swingarm adjusting screws to center the front wheel between the light tubes . When you get things like you want it , there will be 0 preload on the swingarm pivot pins . After you do this , it will be SO easy !

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I have no idea where I would find 8ft fluorescent tubes let alone the regular kind. I invention mode,  I could make a couple of crude bow strings. Nothing as straight as a line tight between two points, save the sag in the middle.

I had no idea there is adjustment available in the swingarm! Is that on a particular axis?

A chalk line is pretty straight? That would be a lot easier. The bike sits on a nice concrete floor presently but not a whole lot of room around it.

There's no hole through the porkchop and frame on a Tenni to poke a pipe, ideal as that would be.

It is doubtful how much I can get the wrecker crew to play helper. They will have a hoist but whether it has an engine hanging off it when I get there is unknown.

I remember I used to ride a Vespa. The front wheel was parallel to the back but a good 1.5'' out of straight line! I think it might counteract the off centre weight of the engine. So the defining characteristic is parallel axes? Even harder to measure.

Pausing for thought. Manipulating coffee cups...

...doing head in with the 3D nature of it all. Leaving it for a bit.

Keep the ideas coming.

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On 3/18/2020 at 3:42 PM, gstallons said:

You got that right ! After the last one I saw on this site , they are all but unavailable !

Here is one, $189 US shipped, apparently good, from a 2004 Cafe Sport being parted out. Not clear why - it looks OK from the video walkaround.

https://www.ebay.com/itm/2004-03-05-Moto-Guzzi-V11-Cafe-Sport-OEM-Front-Timing-Cover-Case-Bolts-Assembly/333526403269?hash=item4da7b908c5:g:SJsAAOSwADReVLoc

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If you don't have access to fluorescent tubes, your idea about chalk lines and a straight bow string might be a good one.

I forget what they're called, but essentially little wooden stands to run your strings on, when you're laying out foundation or a construction area on the ground.

You could do the same thing with 4 axle stands or any other things suitable to support 2 strings anchored on one end and a weight on the other to keep the strings tight, position them behind and in front of the bike, run them up close on either side of the rear wheel and you'd get a good idea if the front wheel is aligned straight.

 

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There is always the possibility that Guzzi's factory misalignment was fixed by the impact. Vertical axis is fairly easy to check, but how about checking the horizontal? The spine frame would be more subject to twisting than bending, it would "seem."

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43 minutes ago, po18guy said:

There is always the possibility that Guzzi's factory misalignment was fixed by the impact. Vertical axis is fairly easy to check, but how about checking the horizontal? The spine frame would be more subject to twisting than bending, it would "seem."

The bit that is doing my head in is the vertical component of steering head axis. Horizontal just changes the rake angle. No biggie if the rake changes a smidge and easy measure track to confirm.

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Full circle.

If both wheels are plumb up and down at the same time then both wheels should be pointed in the same direction. Anything else is frame twist.

Can the rear swing arm adjustment screws accommodate a bit of that twist? Do they do that in the factory as a final assembly step? I never heard of it before.

 

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5 hours ago, docc said:

I used a cheap laser level to alignment my Sport's swingarm Not really sure how to rig that for Zooter's frame check . . .

I found the laser alignment fight club thread.

Looks like the intent is to shift the whole swingarm across rather than each end fore and aft?

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3 hours ago, po18guy said:

There is always the possibility that Guzzi's factory misalignment was fixed by the impact. Vertical axis is fairly easy to check, but how about checking the horizontal? The spine frame would be more subject to twisting than bending, it would "seem."

Everyone seems to be forgetting that when the engine is fitted you get a massively rigid structure esp with regards to twisting. The truth is this thread is all a bit crazy to be honest. From someone that has bought around half a dozen wrecks and repaired them the only way to be sure how straight they are without alignment tools is to check the vulnerable areas like engine/gearbox mount points for cracking and steering head area for distortion and eye up the forks in relation to each other and put your hand up at the auction.

Get it home and evaluate properly stripped down and hope you got it right. Its always worked out fine for me. Most bikes dont get bent unless they hit something fairly solid or cartwheel and then you generally get frame member distortion and or engine mount damage and bent forks.

Ciao 

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