thankyou DM, what a marvelous project you have.I will try too find out
wheather. the manxman frame was used earlier than the engine was developed, I presume the frames were designed intially for mechanical marvel, then used on the manxman.excelsior wouldnt have only used one type of frame that ran for a year or so,when it obviously handeled well enough too win the TT then design new frame for the new manxman engine . but I'm guessing really..
cheers tony