Replacement for widow maker frame?

Ozarkdreamer

Ozarkdreamer

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Nov 27, 2014
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I have an early commando basket case with a widow maker frame that I want to build as a custom. There are too many parts missing to restore. I have read a few threads about welding in the extra frame member to strengthen it but this bike was raced and even though there are no obvious fractures I am concerned. I can buy a used 1975 frame in good condition locally. Are there any problems using it with the 68 engine?
Ozarkdreamer
 
The steering head is 1 degree less vertical (28 vs 27) than older frames, but everything will fit. If you use the '75 cradle with the older engine, you'll have to modify it so the trans can pivot on the bottom bolt for primary chain adjustment or use the older cradle.
The '75 adjustable isolastics are more desirable than the older type that have to be side shimmed.
 
When the headstock angle changed for the 850 the yokes were modified too and the stanchion holes offset by 1 degree, so an 850 frame needs 850 yokes to retain the geometry it left the factory with, the 850 yokes have the letters ANG cast into the bottom of the yokes.
 
Thanks. I have a newerset of yolks so I will check the numbers. I have the 68 cradle so it sounds like I should use it although a cradle comes with the 75 frame.
 
I would modify the 75 cradle to allow the gearbox to move, as well as the better support for the swingarm spindle using 2 cotter pins you also get the mounting holes for the later stronger center stand.
 
You can use the older cradle as a template for the slots and holes that the new one needs. You'll also need the adjuster hardware.

The SS clone has Mk III yokes on a '71 frame. No ill-handling effects from the mix-and-match of parts.
 
Ozarkdreamer said:
Thanks. I got the swing arm with the 75 frame. Will the 68 rear wheel work on it?
Click to expand...

It can be made to work, but the '75 arm is set up for the conical hub and disc brake. The drum-braked models are slightly different. Chain adjustment is different. Not sure about spacing, but that's not hard to change up. You would do a lot less work using the drum brake swingarm with the '75 cradle.
 
Danno said:
It can be made to work, but the '75 arm is set up for the conical hub and disc brake. The drum-braked models are slightly different. Chain adjustment is different. Not sure about spacing, but that's not hard to change up. You would do a lot less work using the drum brake swingarm with the '75 cradle.
Click to expand...

It would be a good time to get rid of that bolt-up 1968 rear wheel hub too.
 
The 75 swingarm has the extra gussets fitted that come in in 73 or 74, so another reason to adapt it.
 
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