Not to sure on the liabillity issuse , just wait till some one crashe's with one fitted , although it prob will be a RACE ONLY option , but surely he still has a" Duty of care " to ensure the item is worthy of the job its intended to
I used to work at Metmachex who make swing arms and frames for just about anything. We were doing mono shock conversions, full frames and much more in the mid 90's.
Never had a single issue with stuff failing and claims etc.
You could use the liabillity argument with just about any aftermarket item. What if an aftermarket ally pressure plate disintigrated and locked the clutch up while doing ***mph. What if a non termi can fell to pieces and dropped on to the back wheel while on the move.
Using my own knowledge of welding ally, which is dated now, as long as there is some internal brace done to overlap the joint and the weld has full penetration I think it would be OK from the point of view of strength. If you look at the new style 749 / 999 swing arm it is an ally welded construction.
As for looks, performance etc I would not like to comment.
Dont get me wrong if its they say it strong enough , who am i to disagree . I am not trying to imply its not up to the job , just interested on how you would get aproval to use it on the road / or not
I am just wondering if it would be an option over the mag swingarm ??? ,but then are you technicaly alowed to use a mag arm on the road ??
Plus i belive when using the mag arm you need a new shock linkage ??
Just me thinking out aloud !!!!!!!!!!!!!!!!!!!!!!!