Bonneville TT750 Special
What we have here
is a VERY special motorcycle. Built as the ultimate
track bike it has the very best components in
all areas. From the Metisse type frame with
Cerriani forks to the high spec running gear
and engine, this really does have the best of
everything. One of 5 built by Dave Whitfield
of P&M in London it sadly has to be sold
as I am moving out of my commercial premises.
The engine is T120 based with an all alloy 750cc
top end, 5 speed gearbox and Bob Newby transmission.
The bike is ‘F’ registered meaning
it is tax exempt and it is currently SORNed.
To build from scratch to this spec would reputedly
cost in the region of £14,000.
TT750 Special details;
- Crankshaft has been tuftrided and rebalanced
to a factor of 82%. The crank has been drilled
through from the left-hand side to allow the
use of a flap valve for crankcase breathing.
- Conrods are Carrillo.
- Pistons have been weight matched, the valve
pockets have been deepened to give more clearance
with higher lift cams. Compression ratio is
- Cylinder block is all alloy with Nicasil
liners and stainless steel studs.
- The cylinder head has been gas-flowed at
P&M, fitted with Colsibro valve guides
with seals on the inlets, both faces have
been machined. Lightweight P&M valves
are fitted, being closed by R&D springs
and Titanium retainers, valves are fitted
with lash caps. There are no gaskets fitted
at the head or cylinder base faces to raise
- Camshafts are Megacycle (510-15, JOMO 15’s).
Tappets have been lightened and reground to
1 1/8” radius. High strength push-rods
run inside alloy tubes. Seals are as a Triple.
Camshaft pinions have been lightened and tuftrided.
Copper rocker box gaskets are used.
- The rocker box faces have been skimmed
to clean up, faces of covers have been lapped.Rocker
arms have been lightened and highly polished.
Mushroom adjusters are used with lightweight
- Gearbox is standard Triumph 5-speed. 18-tooth
gearbox sprocket, which has been thinned down
on the inside face to allow the use of ¼”
final drive “O” ring type chain.
- Redline gearbox oil is used.
- Transmission is by Newby clutch and belt
drive, gearbox main shaft has been re-machined
to align the pulleys.
- Oil circulation is by Morgo plunger type
pump, oilways in the crankcases and crankshaft
have been opened up. Filtration is by a spin-on
filter fitted in the scavenge line. Oil capacity
is approx 4 ½ pints, level sight in
right-hand side cover.
- Ignition system is Digital Boyer with single
double-ended coil. NGKB7ES plugs are used.
Full advance is at 38 degrees.
- Charging is taken care of by a Lucas single
phase alternator with a Boyer powerbox controlling
output. The battery is a 3 amp hour type,
with a 15 amp fuse in the circuit. Both handlebar
switches are Honda items.
- Carburation is by AMAL MkII 32 mm on a
Kawasaki rubber mount. The carb is fitted
with a chrome brass slide. A K&N air filter
- The exhaust system is a 2 into 1 made from
stainless steel by Rob James. Silencing is
by a White Brothers “E” series
can which has adjustable baffles.
- Rear suspension units are Falcon
- Braking by AP Racing master cylinder and
single caliper (provision for second caliper
on RH fork slider).
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