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Triumph Bonneville TT750 Special

Triumph 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 8.8-1 approx.
  • 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 compression.
  • 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 nuts.
  • 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 is fitted.
  • 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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