PROJECT TRIFIELD
Rick twirls his spanners at a special kind of special
This is my partner Judy’s Trifield, built with my dad’s help in the mid-’90s as a longer-legged option to her 250cc Royal Enfield Continental GT. “The GT was great fun but wasn’t very reliable and
I had problems with the gearbox. I’d had Triumphs before, so building a Triumph-powered GT seemed to be the perfect solution. But unfortunately that brought problems of its own...” she recalls. The generally smooth 500cc Triumph engine vibrated badly in the Enfield frame, blowing bulbs, breaking brackets and making it tiring to ride. Engine balance is calculated for the standard frame, so smooth engines can be much rougher in a different chassis. The end came 15 years ago, when the vibes suddenly got much worse accompanied by a lot of noise. The crank had broken, but which came first – the crack or the vibration?
When the bike came into my life, I was moving around the country and it wasn’t until 2015 that I managed to rebuild the motor. Incredibly, there was no other damage and I had a spare reground crank ‘in stock’. Comparing the two revealed the original had been balanced for a 350, offering another explanation for the shakes. I fitted the engine, but there were other problems – mainly a rotted exhaust and leaking tank.
The race-style GT tank is a crowning feature, but made of glassfibre it’s easily dissolved by ethanol in modern fuel. Sealant may offer a cure, but has to be done before it gets near ethanol; even then, unless you get 100% perfect internal coverage (surprisingly difficult), you’re wasting your time and with ethanol content set to rise the problem may still recur later.
We do have an alloy tank for the Trifield, which Judy commissioned from the late Terry Baker before the blow-up, but we’ve had to use it on her Continental GT. Terry’s daughter Aline has carried on Terry’s business (TAB2 Classics, 01974 821469) so we could get another, but the cost of a hand
made tank reflects the work involved and is easier to justify for a Gold Star or Triton. For a time, I thought about sharing the tank we have between the two bikes, then took a chance and bought the secondhand tank shown above. But despite the transfer it’s a Triumph tank and too long to fit.
So the Trifield went back in the shed and joined the end of a very long queue for workshop time...
Still, this has been a year for queueing and the Trifield has finally reached the front. A mate turned up a pair of new old stock pipes for a bargain £20, which focused the tank as the only real problem.
Thinking about it, the engine rebuild had cost next to nothing thanks to my stock of spares from way back, so we decided to bite the bullet – well, Continental – and order one of TAB2’S replica GT tanks. This time it’ll be unpolished, ready for painting red for Judy’s GT, so the polished tank can finally go on the Trifield. With that decision made, I was keen to tear into the job.
IF I THOUGHT ordering an alloy tank marked the end of my problems, I was wrong. The idea here is to get the bike back on the road this year, but everything I unbolted threw up yet another problem.
I needed to take off the oil tank to wash it out... which revealed a split mudguard. I took off the shocks for painting... and found broken chainguard brackets and a rear brake anchor that made it stupidly difficult to remove the wheel. After levering the wheel out to devise a better system, I noticed the anchor slot in the fork end was distorted, plus a bent pillion rest bracket, so now the swingarm had to come out. That drew my eye to the motley selection of spacers for the rear engine plates; why not take the engine out again and sort that – then if I strip out the front end I can repaint the frame... aaaargh!
This is how repairs sprout legs and run away with your time! Common sense says we still don’t know if the vibration is cured; if not, the engine will have to come out anyway – forget the engine plates. But my fussy side had my spanner hand twitching like a drinker trying to resist the bottle.
Specials are always a compromise; the bits weren’t made to fit together and they don’t. If you have the right equipment, it’s much easier to make a ‘factory job’ of your builds – but you also find it harder to let things go. I want the bike on the road this season, so I employed a rule that kept me sane while welding up old cars: keep cutting out rot till you meet sound steel, then weld your way back. The next rotten patch is another job for another day, otherwise you can end up out of your
depth in time or even enthusiasm.
With some structure imposed, I decided to concentrate on the back end first. Next month I’ll start on the front and work back to the middle – which, being the rebuilt engine, shouldn’t need much. All being well, that should see it finished – much quicker than attempting a restoration.
Phew! That was close – I nearly took a swig out of that bottle!
Will I stay on the wagon? Let’s see...
‘EVERYTHING THAT I UNBOLTED THREW UP ANOTHER PROBLEM’