From my research, and it has been a painful and rarely fruitful one, Spondon made these swingarms to counter the flex on the single sided units that would force the bike to run wide.

They then converted a limited number of TZ frames to utilise the swingarm, house the RS engine and of course cater to the counter shaft on the RHS.

Spondon did confirm in writing the frame number was one of the in-house conversions but that is it.

I have a blurry photo of a completed one and cannot find anyone who raced one. I want to know what parts bolt on and what does not. My inclination is to buy a complete bike and fit the parts.

The tripple clamps are Spondon and have offsets as well.