1977 Triumph Bonneville T140V

Bought for around £500 in March 1982 with some 10,000 miles on the clock, I was (and remain) the fourth owner of SRJ 349R, a 1977 Triumph Bonneville T140V. ‘V' is Latin for five, the gearbox has (gasp!) five speeds and the rear mudguard has a special decal boasting of this bombshell. Yes. Frankly I've always found it sadly apt and tragically prescient that Triumph's marketing department were happy to use a dead language to promote a key feature of their flagship model.

A friend from college had owned her for the previous year so I knew both her provenance and his lack of mechanical prowess. He delivered it to Reading from Wales with my girlfriend on the back, the only major problem turning out to be less than perfect ride quality... which I fixed once I'd finished working on the bike, ho ho!

Other issues included non functioning indicators and the ignition switch not working - he'd hotwired it, a scarily simple thing to do. The ride was harsh because of a seized fork leg, due, it seemed, to a manufacturing fault - the chrome on one stanchion had raised lumps in it that I fixed by rubbing it down with wet and dry.
Mouse over the thumbnails to see the bigger picture
Harder was a drive side main bearing that had lost a couple of balls, and I've suffered holed pistons and had to get the base of the frame welded - she'd been suffering from an annoying oil leak which I'd assumed was from the gearbox. After taking it apart and finding nothing wrong I eventually spotted the crack in the base of the oil bearing part of the frame. This meant a total strip down and I got the frame powder coated at the same time - the original finish was good (and far better than that on the early T140Es - a mate had one and paint was flaking off the frame in large chunks), but the powder covered the weld and was more resistant to scratching.

The most annoying problem was low oil pressure. The oil light would start coming on at low revs and as these engines aren't renowned for their longevity it's a good idea to investigate - and sorry to dash hopes but the oil pressure sender is the most reliable bit of the lubrication system. The first time it was the timing side oil seal, a known weak point. The timing cover contains the oil way to the crankshaft, via a cavity into which you carefully slot the end of the crankshaft when you refit the cover. The cavity has an oil seal in it and eventually the lip of the seal wears a deep enough radius on the crankshaft journal to allow the oil to leak past, reducing the pressure to the crank and, especially, the drive side big end. Fix is to strip the engine, machine timing side crankshaft end down 10 thou, then fit a 10 thou oversize oil seal. This worked fine for several thousand miles, in fact until the next rebuild. After that the seal just wouldn't seat properly - in a couple of hundred miles the light would come on, and on inspection the oil seal was always chewed up. Replace seal, all would be fine for the next couple of hundred miles when the light started coming on, again. I eventually discovered it was due to the crankshaft being bent- it was running just out of true, with enough up and down movement to eat the oil seal. Possibly due to me dropping it when I was starting the previous rebuild...

Yes, in retrospect the work I did on the bike didn't always go smoothly or to plan. I managed to cross thread the gearbox mainshaft, meaning I needed a new nut every time I had to remove the clutch, the exhausts would never seat properly in the cylinder head, the end of the tacho drive unit was sealed with a 1p piece and Araldite (actually that worked well), and until I put on the Boyer she ran on second-hand coils from a Kawasaki 650, chosen because they were the right physical size, though clearly the wrong specification as she'd only kick or bump start if the battery was fully charged. So by the late 1990's she was getting a bit ratty and I wasn't using her much, having discovered the joys of my first Ducati and Hinkley Triumphs. But I never considered selling her (I've lost count of the number of times some old codger's come up to tell me how much he'd regretted selling his Triumph for tuppence three farthing in 1960something). So, in late 1999 with an indicated 48,000 miles on the clock, I decided to treat her to a total professional rebuild.

This I entrusted to my local Triumph garage, Rockerbox in Farnham, (+44 (0)1252 722973) asking them to strip the engine and gearbox, replace anything worn beyond service limits, balance the crankshaft and do any sensible upgrades thought prudent. They went through the motor with a fine tooth comb and, unsurprisingly, announced just about everything to be worn out - so cams, bearings, seals, valves, pistons and barrels and more were all replaced and a high capacity oil pump added; about the only original bits left are the crankcases and engine mounting bolts. The job cost roughly as much as the bike is worth, and I still consider it a bargain!

She's only done a couple of thousand miles since (long gone are the ‘ride her every day' days), I keep the revs (mostly) no higher than 4,000, about 70mph in top, and so far she's shown no sign of blowing up. Handling is still OK and on twisty A roads that, and the acceleration to 70, is good enough to embarrass quite a few much younger sports 600. And even parked up I still reckon she's one of the best looking Bonnevilles ever. My favourite.

Which freed it up a treat, trouble now was the fork seal wouldn't, err, seal. This I sorted by installing some ‘everlasting' fork seals - rather than being wedged into the legs they float in them, the pressure of the oil forcing them out and tight as the forks are compressed. They were my last resort before forking out for a new stanchion, and somewhat to my surprise they actually worked, and do so to this day. The electrical problems were easier to fix - just taping up bare wires and improvising with a bit of tin in the indicator switch solved them all.

She came to me as US spec, high bars and an unfeasibly small tank - range about 100 miles. And less than 10 miles on reserve, as I discovered the first time I had to use it. Records say she was sold direct into the UK and I've no idea if she left the factory with the US bars, cables and tank, but despite the impracticality I find the looks appealing (these days she out poses Harleys). The tank range isn't a disaster - we toured two up around northern Scotland and did a 2,000 mile tour around Sweden, never having to panic about fuel. And neither time did she let us down - a flat battery and a broken speedo cable were the only problems on either trip. Mind you, the broken speedo cable nearly wrecked the Swedish trip. We were pulled coming out of some little town on a clear and empty road and got written a ticket for doing 79kph in a 40kph limit. Not best pleased I was relating the story to the people we were staying with, who congratulated me on my good luck. I questioned their concept of ‘good luck', and they explained that Swedish speeding penalties came in three tiers - a fixed fine for up to 20kph over, a bigger one for up to 40kph over... and 21 days in clink for any higher speeds.

Other than that I've never been done for speeding or any other infraction on her. After the flat battery experience I rewired the lights through the ignition (main and parking lights were directly wired to the battery when I got her, which I think was standard). A bonus was the rear bulb unit being rubber mounted as a (surprisingly effective) counter to the ferocious vibration; this means it has a dedicated earth lead, so I took the opportunity to extend and run it through the three way light switch, in place of the parking light, itself even less use than as standard now it needed the ignition to work. Sacrificing the parking light for a rear and brake light cut-out was a good trade-off - very useful for those occasions when I needed to disappear quickly.

I was in my mid twenties when I got her and did a lot of miles in the first ten or so years - I had a Honda 400/4 as well (which had about the same performance as the Bonneville) and a Laverda Mirage for about 6 months until I wrote her off, but the Bonnie was always my favourite (and still is). She handles OK (ground clearance could be better), lots of low down torque and with peashooter pipes in place of the standard ‘cigar' silencers she makes a lovely noise. Instrumentation is good (check out the cute NVT badged speedo and tacho by panning the image below), front light accepts a halogen reflector and bulb, the indicators work well and are a must for modern traffic. Left foot gear change means no acclimatisation issues when I switch to and from more modern machinery. Overall she's a good mixture of traditional character and modern convenience.

The main weakness (other than the prehistoric design) was the rear wheel - spokes kept breaking. This was obviously recognised as a problem by Triumph because the later T140E models had heavier gauge spokes. The first step I took from keeping her ‘standard' was to replace that wheel with one from a T140E, and presto, no more breaking spokes. The other significant change, though stupidly not made until I'd had her for many years, was to install a Boyer Bransden electronic ignition. It transformed the running - I'd spend an hour or so setting up the old contact breakers and she'd run great once I'd tightened the various bolts... but in a hundred miles she'd be vibey, take more than two kicks to start and not tick over cleanly. The Boyer is truly fit and forget and gives a reliable 900 rpm tick over. Other sensible stuff I've done is fit an external oil filter and a Norman Hyde oil cooler. The former hangs discreetly down from the oil tank in front of the rear wheel, the latter mounts between the two front down tubes and looks pretty neat. Other than the obvious advantages these give - cooler, cleaner oil - they also up the overall capacity by about half a pint, which is significant given she only holds about 4 pints as standard.

She did go wrong pretty frequently though, largely due to the whole bike being overstressed - during high speed use she'd vibrate like a jack hammer,
great for female pillions but not for the engine or ancillaries. So she taught me a lot about rebuilding engines. Well, tried. Head gasket blowing between the two barrels stranded me once - she'd suddenly gone down a bit on performance then wouldn't start after I'd stopped for fuel, annoying but not too difficult to fix once home.