Buyers' Guides

Monday, 16 January 2023

Vertical Twin Wars: Bonneville vs. GPz305

“Oh-soffa-what?” I asked the Doc.

“Oesophogitis. There’s no cure. You just learn to live with it. No heavy lifting that uses your stomach muscles or your food’ll come back faster than you can eat it.”

I already knew the last bit. If my Triumph Bonneville, a 1976 T140V, didn’t start in the first couple of kicks, or I had to heave its great bulk on to the centrestand, there was a fair chance I’d throw up. That's why I'd come to the surgery in the first place.

“You'll have to change your lifestyle". I didn’t like the sound of this but he went on: “Look at you. In a year or two you'll have your bus pass. Do you intend to continue this juvenile practice of riding that overweight, overpowered antique of yours?” I nodded. He was just warming up. “Shattering the early morning and late evening peace of our village? Breaking the law every time?".  I must've passed him in his cage at some time. I nodded again.

“In your state of health it’s too heavy. It’s got to go.” I know he meant well but then he committed the ultimate blasphemy.

“If you must ride a bike why don't you change it for something lighter? One of those quiet Japanese things where you just press a button and off it goes.”

Me! The archetypal Brit with every prejudice to match. I wouldn't be seen dead on Jap iron! It then occurred to me that it might be better to stay alive with some Suzi-Yam-Hon-Kwack, or other, than die kicking a reluctant Bonnie into life.

German or Yank stuff was too heavy and expensive. Italians had style but too much temperament. I even thought about an MZ but it was no use - it had to be a Jap. I sat at the phone with the Yellow Pages open and my shopping list to hand. I was looking for something that would do the ton, weighed under 400lbs and cost about two grand, which was what I thought I'd get for the Bonnie. One of the dealers put me in touch with a customer who was Bonnie hunting. He was a nice young guy who found the exhaust note and simple classic lines irresistible. He bought the Bonnie two days later.

The dealer then said would I like to look at this little Kawasaki he had with less than 100 miles on the clock. It seemed the original owner - poor chap was about my age - had died shortly after buying the Kawasaki (nothing to do with bikes) and his family had only just put it on the market. Feeling sorry for myself over the loss of the Bonnie, and even more sorry for the guy who'd never had a chance to enjoy his new bike, I was introduced to the GPz305.

Exactly what you're looking for, the dealer intoned enthusiastically as I rolled it effortlessly on and off the centre stand, marvelling at the instant electric start. The next impression was that I was riding a highly tuned sewing machine with no exhaust note, and steering designed on some other planet. Riding over smooth roads at sub 70mph speeds, I didn’t know what I’d done to get round corners. It was like telepathy. Of all the bikes I’d ever owner or ridden I'd never met anything so easy and so completely user-friendly. And, much as I hated to admit it, it was fun!

Back at the dealers I admitted it was just what the doctor ordered but where was the ton plus performance? Had I used the gearbox and high revs? No. It was so new I'd kept it down to about 4500 revs. Then why didn't I take another spin and let it go a bit. A brief flip round the clock wouldn't do a modern motor any harm.

It was welcome to the nineties time! I discovered in a few short miles what the rest of the bike world had known for decades. Anything else I’d owned, with two wheels or four, had usually given its all by 5000 to 6000rpm. When the Kwak hit 7000rpm, a whole new world opened up. Despite its basic spec, the little motor made me feel I was hanging on to the Starship Enterprise as it moved into warp speed. This wasn’t just fun; it was exhilarating.

Next came an insanely happy few minutes during which I played tunes on the gear lever to keep the revs up where things happened. I was concentrating so much on the tacho I didn’t spot the imminent arrival of a T-junction with no escape routes. It was at that point I discovered how good the brakes were. We came to rest with the front wheel just peeping over the white line.

| felt rather than saw the glare of a frightened, middle-aged pedestrian beaming the unspoken message: it would've served you right if you hadn't been able to stop. With my heart pounding like the Bonnie on an uphill climb, I struggled to find a gear in which I could make a dignified departure. I wondered how much the irate ped could see through my visor. I wondered if he realised what he thought was an irresponsible juvenile on a speed induced high would soon be an OAP - that’s if he learns to keep his eyes on the road instead of clock-watching. I took the bike back at a more sedate pace, but couldn’t keep an ear to ear grin off my face. You've just sold a Kwak, said I. Whencanlihaveit?

At this stage, it hardly seems fair to compare the 18 year old lump of British brawn with nearly new Jap technology, especially as the Bonnie was losing Brownie points like Group Four loses prisoners. The Kwack was winning all ways - ease of handling, at rest or on the move; it’s half the size engine almost as quick but no vibes, all on unleaded petrol. An added bonus was 76mpg as opposed to the Bonnie’s 53mpg on four star. Modern brakes and lights were superior. Starting was child’s play.

And there’s no way any Bonnie’s going to be as reliable as a practically brand new machine. But instant infatuations can have short honeymoons. By the time the GPz went in for its 500 mile service the Bonnie was pulling back a little lost ground... although the acceleration of the two bikes was similar - sub wheelie, but more than good enough to deal with average traffic - that vital surge from 50 to 70mph was always instant with the Bonnie. All you do is open the throttle. By the time you’ve dropped a couple of cogs on the Kwak the gap might have gone and the sparkle definitely goes if you're carrying a passenger, whereas the Bonnie didn’t seem to notice the difference. What I really missed was the low down grunt and that reassuring bellow from the exhaust.

But it’s nice not to have vibes as the limiting factor on top speed.  The sheer lightness of the GPz, one of my reasons for buying it, can become its worst enemy. Every little breeze deflects it from the straight and narrow. I soon began to miss the way the heavier Bonnie sat on the road, especially at speed (at least once a set of TT100s was fitted). Hit a coarse surface, like newly laid gravel, and the Kwak’s uncannily light steering disappears. Suddenly, it’s like tiptoeing on eggshells. The front wheel takes on a life of its own and feels liable to go anywhere without notice. The only solution is to hold your breath and keep the bike straight up until the terra became firmer. The Bonnie didn't like loose gravel either, but at least l felt I was still in control On the sort of long, sweeping 70mph plus bend we all know and love, there’s a whole lot of twisting goes on at the GPz’s back end. At least that’s what it feels like. I haven't figured it out yet but the chassis looks too solid to twist.
Perhaps better tyres would fix it.

The smooth belt drive seems a gem of an idea. Expensive to replace but lasting three times as long as a chain. On a motorway, which I find boring, it’s swings and roundabouts. The Kwack sits there quite happily at 75 to 80mph but gets blown about whereas vibes spoil life in the fast lane on the Bonnie. It’s worth saying that, like the poor, the Bonnie’s vibes will always be with us but are no worse that those regularly reported in the UMG, and elsewhere, on big, old Japs. They can, however, be greatly reduced by spending a quiet Sunday afternoon synchronising the fall of the carb slides into just one click as they hit the bottom - I’ve no idea why but a pair of new tyres also seemed to smooth out my Bonnie.

Regarding this strange business of image and owning a glamorous piece of history, the GPz305 comes nowhere. I’m totally ignored. And never again will I be as proud as when a lovely old fella shook me by the hand and thanked me for keeping such a beautiful old bike on the road. Turned out he’d been one of the Meriden workers and he gave me loads of useful tips. Altogether now... awww!

If this seems an odd way to enjoy biking there are thousands of like-minded souls who prefer to drive about in troublesome old MGBs when the same money would buy and run a faster, more reliable GTi. They probably like antique furniture, too. It takes all sorts. If anyone’s being seduced by all this sentimental talk - be warned: Bonnie ownership’s an expensive and mixed pleasure. If you're determined, buy the best you can afford. Avoid hybrids, they’re a lot of trouble and don't hold their value. Around two grand gets you one that's well sorted. Even then, keep £500 back as a contingency fund.

Three years running cost me £1500, including a £600 gearbox rebuild. A properly rebuilt Bonnie doesn't leak oil and I’ve a clean garage floor to prove it. Electrical problems do happen. It's worth changing any one or all of the three electrical switches at the first sign of trouble. The oil light switch (everything dies if it fails), the ignition switch when badly worn causes erratic running which is difficult to diagnose, and the handlebar cluster drivers you bonkers if you try to repair it. Even the metal seat base can short out the electrics over rough roads!

So which costs the most? GPz servicing's cheap, fewer parts will be needed, excellent economy in the short term it shouldn't cost much to run. But the Bonnie retains its purchase cost much better, I expect to lose a grand when I sell the Kwak. The GPz is loads of fun but being a sentimental old slob I'll never learn to love it, not like the unreliable but beautiful old Bonnie.

Stan Barrett