It’s been awhile since the last Newsletter, because, overall, there hasn’t been a lot to report. The Netley Marsh and Beaulieu Autojumbles in early September were somewhat ABC-less: the only item I saw for sale was a framed “original” photo of an ABC racing-outfit for about £20…Keith supplied the version you can see below, for much less! Howard & Lorna Burrows duly appeared at Steve & Carol Hall’s stall at Beaulieu, and we learned quite a lot about the late, great Harry Beanham, evidently a very talented man, but capable of considerable waywardness, too. Sorting out his estate was a real marathon, but fortunately, his several ABCs are now in safe and appreciative hands.

Restorationof an old motorcycle is an intensely personal pursuit, in just about every possible way. The pace at which one works, its priority among one’s other pursuits (and duties!), the amount it’s allowed to cost, how much work one does oneself and how many tasks are farmed out to skilled friends or professional craftsmen, how good the finishes must be, and how true the final result must be to the original specification: all these matters are decided upon by the individual restorer, and it’s safe to assert that no two of them think exactly alike. For me the most important thing is, simply, that we have restorers!

In recent weeks, I’ve been privileged to have been copied on (hugely) technical discussions between John Emanuel and Martyn Round. These have centred on Approaches to Procurement of Alternative Engine Components: crankshafts, con-rods, pistons, cylinders and valve-gear. Summarising, Martyn’s writings concern the work he’s actually done on his engines, while John’s thoughts are still at a more theoretical stage. Should you decide to tune in to Martyn and John, please keep me copied on developments, I find it really stimulating! Indeed, all progress reports on restorations would be welcome, particularly with photos. Steve Hall continues to steam ahead with his Sopwith model, and a future Newsletter will feature some of this.

Giovanni Orlando is being particularly innovative, in the matter of production of valve-lifter arms, gearchange arms (the ones that live inside the pressed-steel covers), and (gearbox) clutch-levers. They appear to be bronze castings, and Giovanni hopes to have some for general distribution after Christmas.

Richard Johnson’s recent advert in the VMCC Journal for an Andre steering damper for his Sopwith turned up trumps, if rather expensively. Does anyone have steering-damper experience? My bike, like his, feels wobbly at speeds of less than about 20mph. This, I ascribe to the enormous trail of the front fork, and I’m not sure if a damper would help much. Anyway, Richard’s vendor has a second damper for sale, if anyone’s interested.

No reaction so-far, to my piece in the November VMCC Journal entitled ‘Seeing Double’, but I guess it’s early days yet. Did entente cordiale go further than we thought?

On the Sopwith exhaust valve-lifter system:-

This was another of those Bradshaw afterthoughts that remained unsorted: in theory it was fine, but in practice, it worked so badly that it was often discarded.

The principal problem was that the L-shaped return spring on each lifter arm wasn’t strong enough to overcome the internal friction of the Bowden cable that operated the arms. Typically, the arms couldn’t retract enough, and would be fluttered by the tappets for as long as the engine ran. If stronger springs had been fitted, all might have been well, but there was scarcely provision for the fitment even of the thin springs that were used.

My solution has been, basically, to fit a single helical compression spring coaxially round the Bowden inner cable, between the cable-ends of the lifter arms. To get the right spring characteristic, the spring is only about two inches long, and to give a neat appearance, it is enclosed within a telescopic (tube-and-plunger) housing. The present O.D. of the housing is half an inch, pending procurement of slimmer components. Because of the limited movement of the handlebar lever, and hence of the cable, reduction of lost motion to a minimum is necessary for successful operation. All that this entails, in fact, is (a) placing a suitable number of ¼” plain washers round each tappet, outboard of the crankcase and inboard of the tappet-end of each arm, and (b) adjusting the length of the cable. Although an ABC engine can usually be started without the use of a valve-lifter, stopping it is much enhanced!