My son phoned me yesterday and mentioned that a work colleague of his, a trained mechanical engineer, has ordered his first kit from Caterham. For some reason, the first thing I thought about was those Heath Robinson bits at the end of the DD tube, like a couple of packs of playing cards stuck on there like an afterthought and on which your life depends - that, of course, given that you are not overly fond of rear wheel steering. Just the sort of thing to impress an engineer. Made of nice reassuring aluminium too.
Sorry I can't answer your question, but I would like to know in the first place why those ears are there at all, other than the tube doesn't happen to stick out in exactly the right place for the hole in the bodywork where the wheel goes. Is there any geometric explanation for this arrangement?