Nice picture of a prototype BSA WB30 fitted with the Dunlop rubber saddle, Talflow air filter and the (barely functional) first attempt at an alternator powered lighting system. It also employs the full range of 'lightening' modifications to enable it to meet the stringent weight limits laid down by the War Office in the initial specifications..
The high level exhaust system is from the 1940 B29 'options' list.
Trials soon indicated the bike was too light for purpose and that the alternator system wasn't ready for use...Later versions had larger brakes front and rear, a conventional mag/dyno lighting system and battery, a low level exhaust to allow for the fitment of panniers and pillion equipment, further modifications to the engine and a significant amount of the weight saving features removed in the interest of durability and function...In fact the later version was a very different (and heavier) bike, more akin to a Matchless G3 in specification and had it been produced in quantity would have been better suited to the task..Funnily enough I am just completeing the overhaul of one of the gearboxes used in this and other models.....Ian
email (option): ian@wright52.plus.com
And isn't she lovely
email (option): ahum@quicknet.nl
I reckon it's a petrol spillage. This bike has the very early footrest set up as well (with matching 'super long' gear lever.) The rubbers were mounted directly to the footrest bar with no rearward offset. This was altered to metal forgings of the same style as those on the M20, but with less offset than on that bike. This one would have had the aluminium rocker covers, replaced on later versions by steel pressings. Some examples carried a riveted on plate on one cover that recognised the patent held by Sunbeam Motorcycles for the hairpin valve spring arrangement. This was patented by Sunbeam in the late 20s. Later WB30s didn't have this plate as the hairpin springs were replaced by conventional coil springs. Also, BSA purchased the Sunbeam name and rights from AMC during the war and therefore owned the patent from that point.. Interestingly the 1940 B29 Silver Sports and the early WB30 (which used the same basic engine layout) were the only BSAs to use this spring design. They were removed from the WB30 after they were found to contribute to increased valve guide wear..
Although the engine looks very like a B31 (which it became with further development) there are a number of fundamental differences, not least of which was a substantially lighter crankshaft than that fitted to the B31. This was inherited from the B29 which was a sports model and was probably retained for the WB30 only because of its lighter weight...So it would have revved quite well...Ian
email (option): ian@wright52.plus.com
Hi Hamish..Of the example in the photo...none. Though this may have been the only one initially as it was a prototype. Of the 'early' type WB30 which is similar to this, there are 3 or 4 but none of them have retained the original electrical system and all have panniers and bags fitted... There is evidence to indicate that at least some of the 50 machines of this early spec. pre production batch that were built had their engines changed for the later type.
There are 3 'late' type WB30s..All are from the RN contract for 100 machines. So currently 7 known examples survive...I know there is an incomplete bike in Malta and another incomplete one in Scotland..Here's the late type WB30 I restored a couple of years back..
This is in more or less standard spec. for the late type WB30 and the differences are pretty plain to see...Ian
email (option): ian@wright52.plus.com
Hi Ian,
Is this the same bike?-
Do you know if any of those alternators and headlamps still exsist?
I've noticed that all the available photos of the prototype hybrids had this same set up, so I am trying to find a set for the Ariel/ Matchless.
Cheers, Mick.
Hi Mick..Yes that could be the same bike...but note the different horn location and lack of air filter. As the horn is in the correct location in the forum picture, if it is the same bike yours would be a later picture I should think, after the horn was moved and the filter removed... You can see the tubular rear stand well in your photo which replaced the forged stand fitted to the B29 and was particular to the B30. The small 5" rear brake can be seen clearly as well, which was matched by one of the same size at the front. Both these were replacd with 7" units on later versions, so it was probably a bit difficult to stop a B30 from speed initially! The brake plate of the later 7" front brake is also a 'B30 only' part...I'm not really sure why this was altered from the 7" type fitted to the B29. Nothing exists of the alternator related parts to my knowledge...Bearing in mind the system didn't work well and was fairly rapidly replaced, it probably all ended up in a skip at the back of the BSA experimental shop (metaphorically speaking..they didn't have skips then ). The system output was ridiculously low as indicated by the wiring diagram and bulb ratings. The headlamp had a small dry cell battery fitted inside it to (briefly) power the pilot lamp. I think that reappeared on the D1 Bantam didn't it?...but with the batteries held in a metal tube..Alternator systems didn't reappear until well after the war and even then they weren't too clever as they had no way of regulating the output of a 6 volt alternator other than switching in and out the alternator coils, thus making for a complicated system with ignition and lighting fully integrated..Ian
email (option): ian@wright52.plus.com