Mark you may be correct with your assumption re: the extra inch or so in the cradle but I've managed to fit my Trumpy T100SC engine into my bog stock Sprite/American Eagle frame
without having to lengthen the cradle or relocate the swingarm pivot. Having said that, it was an excruciatingly difficult process involving turning the frame and engine upside down and a lot of jiggling involving two people. Once in there, the engine looks well at home though. To make the conversion more feasible it's far better to relocate the swingarm pivot to behind the cradle, similar to what Hipkin did with the latter fastback frame.
Here's Franks take on what I've written. Frank Hipkin is a member of this forum but doesn't post. He usually emails me the information and I post it.
Firstly Mark did you get the leaflet on the fast back trials and scrambles, because I forget sometimes to send to you, there is so much information such as engines the forks materials used, and now I will answer your thoughts regarding the 360 Maico, personally I would have liked you to build similar Sprite to the one That Dave Smith road at the very beginning riding for the works. We did sell quite a few Frame kits for 500cc triumph engines.I've got two of these frames so I'll use the better frame to build a replica of Dave Smiths Maico square barrel powered works bike from 1968, with Franks blessing and advice on the project. That bike could be a bit of a 'double classer' as I could also fit my Maico 250 round barrel engine (
as shown in the photo of the frame in my previous post)to make it legal for pre '65/250. I'll build the Trumpy using leftovers as I described in my previous post. Both of these projects are scheduled a bit down the production line, after the Maico Metisse and Benelli street tracker are completed.
I love Frankenbikes
