Wednesday, January 23, 2008

REX-ACME BLACKBURNE

I was inspired by the previous post to research the Rex-Acme marque, since Bernard Hieatt was racing such a machine at Brooklands. Rex-Acme motorcycles were renowned for a short period in the 1920's (say '24-28) for producing some of the most formidable racing motorcycles in England. Lots of success at Brooklands and in the Isle of Man (courtesy of Wal Handley) meant that this tiny manufacturer had great stature in the Vintage period, and the machines are now terribly rare and coveted.

Such was their racing pedigree, they used as their logo the Isle of Man triskelion on their logo (the Latin motto for the symbol - quocunque jeceris stabit; 'wherever you throw me, I stand' - the image is used in Sicily as well. Wiki claims a Celtic origin, but surely the invading Romans had a hand in it's design - triskelion is a Greek word anyway!).
I've seen a few at events around the world (although never in the USA), and none look remotely similar, such was the bespoke nature of their build, combined with years of mechanical changes for competition.

The top two pix are from the Banbury Run in 2007; the bike is a 1927 350cc Rex-Acme with a Blackburne engine (as all the racing bikes seem to have), belonging to Christopher Pierce. I note the Velocette positive-stop shifting mechanism on the gearbox; I think this bike used to belong to Brian Wooley, former editor of the Classic Motorcycle. Brian's bike had the same scalloped Velocette front brake as well. There is an article in Classic Bike from March 1985 which shows this machine, 23 years ago, in Brian's hands, reminding us that we are only custodians of these machines.

Next pic is from British Only; it's a 1928 500cc Blackburne-engined model, which was previously raced in Austria at some point; take a gander at the 'before' pic, which is pretty daunting. To be honest, the bike isn't well restored at all, and is going to need a better job done, with correct inverted levers and properly-fitting mudguards, and some decent paint and plating. The bike is too good to have a half-hearted job!
The 'before' pic shows an interesting feature of the Blackburne engines - their external flywheel. I'm not certain why they used this, as there is a complete set of flywheels inside the crankcase, but I understand that these engines are exceptionally smooth running, so perhaps the outside wheel dampens vibration. Another odd detail is the use of a crowded-roller drive-side main bearing, and a plain bush on the timing-side main... not a recipe to inspire confidence, but it obviously works well here.

The bottom two pix show a Rex at the Brooklands Reunion meeting in 2005, which has a similar early-style saddle tank as above. These first saddle tanks tended to be slab-sided and kind of squared-off, and were usually used for long-distance racing at Brooklands etc. You can see similar designs used by AJS and Sunbeam around this same 1926-28 period (George Cohen has such on his Norton sidecar outfit, too). It looks like this machine is ridden as well, as the owner has bothered to put a small silencer on the exhaust pipe. The carb is a later TT Amal, which I'm sure works better than the original Type 26 Amal track carb, which had no needle and was meant for full-throttle work only.

Here is a youtube video of a Rex-Acme in action! This is Martyn Adams with his 350cc ca '26 Rex.


I'm still researching Blackburne engines!

Here is a list of published articles I've found on Rex-Acme; contact me if you find more, and I'll add them to the list:
Classic Bike, Mar '85
Classic Motorcycle, Aug '90
Classic Motorcycle, Nov '93
Classic Motorcycle, Nov '04
'Historic Racing Motorcycles', J Griffith, '63, Temple Press
Plus, Rick Parkington has been chronicling an affair with his own Rex.

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