The
following blog relates to the second of Alan’s race bikes, built in the early
70s.
Following
the premature demise of Big Al’s first ‘Coultas Special’, he was on the lookout
for a more suitable frame with which he could build a racing Velocette 500. In
1972 he purchased the chassis of the Myers Manx, the second frame built by Bert
Myers and raced by his son Tony. The rolling chassis consisted of the MK2 frame,
Norton forks fitted with a Yamaha TD1C front brake and a 7R brake at the rear.
MK2 Myers framed Coultas Special |
TD1C front and 7R rear brakes |
The much
modified engine from his first ‘special’ was considerably off-set in the frame
to mate with a Norton AMC gearbox and clutch. Other than this engine, Alan used
no futher Velocette components. Stood on 18” rims, the bike looked very low and
mean, to the uninitiated a Seeley MK3 lookalike. Many different make of front
brake were tested over the years, but they never seemed to meet with the universal
approval of riders. Some liked discs and others were happier with drums, at one period a 7R front wheel was also fitted.
Alan Coultas, Alec Swallow and Wally Dawson |
The bike was
now very competitive in 500cc clubman’s races and many good results followed.
Sadly as with his previous ‘special’, cracks started to appear in the main
frame tubes over time. As he was happy with the overall performance of the
bike, Alan bought the MK3 Myers Yamaha frame. This was again modified to fit a
500cc Velocette engine, two cross-tubes being fitted to the rear of the engine
and gearbox. He also purchased the Campagnolo front and rear discs brakes that
were used on the Myers Manx. This consisted of a twin disc arrangement on the
front and single on the rear, both being mechanically operated by cable.
MK3 Myers framed Coultas Special |
The bike was
small enough to support a Yamaha fairing and was altogether a very good looking
and purposeful machine.
Big Al looking suitably pleased |
A five speed
Quaife gearbox was now fitted and gave a useful improvement in race performance.
Over time the Campagnolo brake operating mechanisms were replaced with Lockheed
hydraulic calipers and eventually the discs were also replaced with cast-iron
items. The original Campagnolo hubs were retained.
Alan also made his own drive-side crankcase halves. As you would expect from a joiner, the patterns were made of wood and included a larger main-bearing boss and stiffeners to the crankcase mouth. They also included the required off-set to allow for the AMC chain-line used.
Alan also made his own drive-side crankcase halves. As you would expect from a joiner, the patterns were made of wood and included a larger main-bearing boss and stiffeners to the crankcase mouth. They also included the required off-set to allow for the AMC chain-line used.
The crankcase
half was machined to house two main-bearings, in order that the extended main-shaft
was properly supported. An over-sized 1 ¼” main-shaft was fitted the drive-side
flywheel and larger roller bearings used. The engine shock absorber was no
longer necessary as the AMC clutch incorporated a cush drive.
Partially machined crankcase |
As the bike
was further developed it became increasingly competitive, even at National
level. A queue of riders willing to put their leg across included:- John Beney,
Trevor Beharrell, Bill Clark, Wally Dawson, Tony Myers, Dave Saville and Alec
Swallow.
Bill Clark and Coultas Special |
Some more links related to Alan's racing bikes:
The Coultas Velocette - Part 1
Coultas 4 valve racing Velocettes
Coultas Velo in winning action
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ReplyDeleteVelocette is truly impressive and vintage motorcycle . The bike have a remarkable Motorcycle Fairings Kits and design for both performances and aesthetics. Thanks for sharing!
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