Wednesday, 17 December 2014

Triumph Bonneville vs. BMW R80

Owning both a late T140 750 Bonnie and a BMW R80/7 might seem like a strange choice but there's nowt so queer as folk... Both bikes were accidental purchases. I just happened to be flicking through the ad's in MCN, as you do, when I saw the Bonnie. A runner needing an MOT for £600. I was in two minds. It was cheap enough but my past experiences of British bikes weren't too enjoyable. I tossed a coin and hit the phone.

The owner's command of English didn't go beyond grunting. After half a dozen attempts I had the address. I tossed the coin again and cursed. The bike turned out to be more together than the owner. Had electronic ignition, a sweet sounding pair of sixties silencers and didn't drop any oil. The chassis was a little battered and rust sprouted from shock springs, the odd bits of chrome and the chassis. Nothing that looked like it was going to collapse, though. I offered £500, the owner grunted and the deed was done.

Having arrived on the BMW, I then had the problem of getting two bikes home. In the end, I let the past owner ride the Triumph and gave him a lift back. It was immediately evident that he only had a minor grasp of clutch/gearbox coordination. Or the transmission was shot...I had another blast but it was smooth and precise under my control, but then I'd become used to the BMW's clunk-click, half a foot lurches and a rising rear end that could go wild enough to give me a good kicking in the kidneys. In contrast, the Triumph's gearbox was a paragon of virtue, a perfection of engineering, etc.

This was the immediate difference between the machines. The next was ease of handling. Here, the Triumph won out again, being lighter, narrower and easier turning. It was also more stable at 70mph plus speeds and didn't mind if I changed my mind half way through a bend. Where a change of line on the BMW involved a good chance of riding off the road, the Triumph only objected when it ran out of ground clearance, with the stands digging in ferociously. Rather odd, that the Beemer, with those bloody big jugs sticking out, could be thrown over as far as the Triumph, until I'd modded the stands.

The BMW won out on long tours. Not only was the Triumph's riding position rather odd - neither comfortable in town nor on the open road - but the engine buzzed out the vibes at 80mph where the BMW smoothed out and had a most relaxing stance. The taut, short travel suspension on the Triumph rumbled a little even on smooth motorways whereas the BMW's tuned out all but the most vicious of road shocks.

Everything about the BMW - its general build quality, the size of its fuel tank, its history, etc - gave the impression of being able to eat up huge mileages without any worries whatsoever. Whereas everything about the Triumph was against it, its reputation, vibration and build quality made me think twice before slinging a leg over the bike and heading off into the sunset. This is unfair to Triumph twins, I soon learnt that it all depended on how well they'd been rebuilt and how well they were treated.

After cleaning up the Triumph's chassis, polishing to a reasonable sheen, I couldn't find much wrong with the OHV twin. Despite its owner's lack of competence - he probably hadn't touched it and therefore done no serious damage. The mileage on the clock was only 18,000, compared to 74,000 miles on the BMW, but the Triumph had six past owners! Either the clock was lying or the owners hadn't been keen on riding any distance.

One reason for that was the size of the engine. 750cc's of straightforward vertical twin engineering equals loads of vibration and potential hassle. It's an old song, if you want simplicity, narrowness and lightness then these old style twins are ideal. But the price paid is omnipresent vibration as the complete lack of primary balance - basically two cylinders pounding up and down side by side - is only mitigated to a degree by careful matching of the frame dynamics to the engine's characteristics.

The Beemer doesn't actually vibrate as in putting out a buzz but it does rumble at high revs and shakes in the frame at low revs. 40 to 100mph, though, it smooths out very nicely, more a suggestion of the engine working away than the nasty thrumming put out by the Triumph above 75mph. Come 90mph, a serious stiff upper lip was needed to survive but it seemed to smooth out slightly at 100-105mph before going into an absolute frenzy. Its smoothest range was 55 to 70mph whilst the best power delivery was from 65 to 90mph (non-standard exhausts and air-filter, stock bikes are somewhat more somnolent).

Up to 90mph, the Triumph was the faster accelerating of the two, helped along by being able to snick up the gearchange at a rapid rate rather than the clunk-pray-click-swear-clunk on the BMW, but I had little inclination to hold a decent velocity on the Triumph. A continuous 70mph trawl was about all I'd want to do - boring and not particularly comfortable.

Much more fun on the back roads, though, as it could be hurled through the bends and slung around to my heart's content - so much fun that the vibes faded into the background. The Beemer wasn't bad once used to its ways - it wasn't the kind of machine to sling a leg over and let rip with the throttle without any thought as to how it should be handled. Very careful throttle work needed to make sure it didn't turn into a rocking horse, no way it would easily change from the selected route.

It takes a good 2000 miles to become used to the BMW's ways. Once re-educated by the Bavarian beast, it could be ridden in a fast, fluid manner that was so relentless that despite its lack of sporty specification would cover distances more rapidly than most bikes. The further you wanted to go the better the BMW became.

A pattern soon emerged. If I wanted some fun, a short hack through the country lanes or A-road hustle, then the Triumph was the natural choice. Any kind of serious distance, the BMW was the only option worth considering. Both did around 60mpg, needed an eye kept on the oil level and felt safe on wet roads. The BMW needed its valves done every 2000 miles, much easier to get at than the Triumph's which wanted attention every 400-500 miles. Carb balancing was another matter, the BMW's needing a fiddle every 250 miles (obviously a bit worn, ignore them and the engine would try to shake itself out of the frame at low revs). The Triumph's would last for 500-600 miles but took twice as long to set up. Also the Triumph's chain was a major pain, needing attention every couple of hundred miles. I'd forgotten how much hassle they were after the BMW's shaft.

I've done 9000 miles on the Triumph without any major hassles, suggesting that at some point it'd had a good rebuild. Overall, I've done 68000 miles on the BMW with just the regular servicing but I tend to ride it in its optimum speed range and never really thrash the engine - it just doesn't feel right. I doubt if the Triumph will do that kind of mileage without several expensive rebuilds, especially as I like to rev it out in the tighter curves. Already, from cold there's a disturbing ringing noise from the top end!

If I could have the BMW's long-legged nature in the Triumph's form factor without any of the vibration, the perfect bike would emerge! Unfortunately, I can't. I must say that the Bonnie was bargain priced - a good R80 going for three times that - and any time I want to sell it I won't have any problem making a nice profit. Spares are readily available for both models, the Triumph stuff cheaper but of a somewhat variable build quality - one guy I know had terrible problems with pattern valves and springs! I'm quite happy to keep both for a while; a nice contrast in motorcycling experiences.

Terry Osborne