Triumph Bonneville T140V

Martin Ashby's highly modified 1978 750cc Bonnie



"I built this bike from parts. Iíve had the frame for 22 years and began assembling it 19 years ago. The engine and wheel hubs are Les Harris-era Bonnie; made after the Meriden plant closed. That makes it a 1986-88 engine, or thereabouts. The original purchase price was £300 but the only part of that bike used was the frame; everything else has been bought or made since then.

The modifications are numerous, including stainless steel rims and spokes, stainless steel mudguards, billet alloy slab-yokes, stainless steel handlebars, aluminium brackets, an aluminium alloy grab-rail, cartridge oil filter, MkII Amal carbs (Harris engines usually have Mk One-and-a-half carbs), foam air filters, Norman Hyde valve gear, Norman Hyde oil-cooler, Norman Hyde rear-sets, stainless steel headlight mount, stainless steel head-steady, stainless steel pushrod tubes, LP Williams clutch conversion, Lockheed race master cylinder, braided brake lines, and all nuts and bolts made from stainless steel.


The bike has been on the road for only 15 months after a full engine rebuild. After a year, the gearbox developed a problemóthough not to the extent of preventing a trip to France to see Canned Heat. Later I discovered phosphor bronze swarf in the oil, so I split the gearbox. I then discovered the damage; 7 of the 10 gears were broken. The bike was still changing gear up to that point (under a little protest) which is a testament to the Triumph. The damage was caused by the bore hole in which the cam plate sits. It hadnít been bored to the correct depth at the time of manufacture. To remedy this, the engineers had cut




down the cam plate shaft incorrectly, which in turn prevented the cam plate from aligning correctly with the index plungeróand as a consequence eventually wrecked the gear box.

The only other problem I had was with a set of aftermarket stainless steel exhaust pipes that I had made which went on the bike when I first put it on the road last year. Because they were badly made (i.e. were not the right length and the bends were not parallel and were too extreme), it didnít allow the bike to breath properly. This caused a lack of performance which was remedied by throwing them away and replacing them with the drag pipes they currently sport. Having raised the jets from .200 to .220 the bike now runs beautifully but possibly a little loud.


Apart from the listed parts which were bought from Norman Hyde and Les Williams, and the wheels by Doug Richardson in Devon, the one-off pieces were made by my close friends Trash, Chuff, Graham and Nobbin (although the inspiration for the bike comes from our friend in Devon, Kim, and his Bonneville).

I now have a hydraulic clutch and the matching master cylinder to the hydraulic brake. An LCD speedo is on order and the next planned upgrade is the switchgear and a twin disc conversion.

As well as France, I went to Devon last year with two Norton Commandos and a Guzzi, and I use the bike all the time.

I'm really pleased with my T140 Bonnie and canít thank my friends enough for their invaluable help."


[Triumph T140 buyers guide]






Copyright Sump Publishing 2014