Spa Treatment...part two
The Triumph-Greeves hybrid continues
John Newman
The build involves the coming together of a Triumph Trident engine unit with a Greeves Scottish frame, and all the attendant problems an 'arranged marriage' of this nature has to involve. Not only that but they had to give some attention to a couple of customer bikes that would also be making the journey to Spa.
I'd called into the workshop on a couple of occasions and their endeavour seemed to be making positive progress towards to the first important goal: when the engine could be fired up. I exchanged texts with Andy on 12th May to ask how near the bike was to that moment when they would hear the three cylinder exhaust note for the first time. The following day was going to be dedicated entirely to the engine firing stage of the build, and Andy pledged they would not be going home until it happened.
The best-laid plans
Like any good motorcycle workshop in the spring period, Andy's business,
Mollspring Motorcycles, is busy. As a consequence, he and Nick had been distracted by customer requirements, and when I arrived mid-afternoon Nick was working on the under seat electrics and Andy was filling the oil tank. There didn't seem to be too much point in me hanging around distracting them, so I agreed to visit again in a couple of days.
The bike now looked more like the complete motorcycle. It had been dismantled and the frame, forks and oil tank had all been powder coated and re-assembled. Andy and Nick had to cut away some more of the frame in order for the carburettor linkage to fit. This is just one example of the many problems they've had to resolve as the build progressed. Because the Trident engine fills the frame, the routeing of oil pipes from and around the oil tank, breather assembly and oil cooler has needed careful installation. Also, they have yet to fabricate mountings for the oil pressure gauge, rev counter and speedometer.
When I returned to the workshop Andy and Nick were in sombre moods. The kick start return spring had snapped, but they were able to get access to a set of start rollers to fire the engine for the first time. They reported that it sounded great, oil pressure was okay and the extended gear linkage allowed Andy to move through the four-speed gearbox smoothly. But when they had started it again the following day a major problem occurred.
Time was not on their side...
The Triumph Greeves, plus three other Spa-bound bikes, were booked into a dyno workshop on the 26th so that they could ensure the motors were in the right tune and gearing for their riders to get the most out of them at Europe's premier classic bike meeting, on a circuit that encourages maximum performance linked with rider skill over the 7.04 kilometers that wind through the Ardenne forest.
How to start your Triumph/Greeves when a kickstart, rollers, or electric start is not available?
Take one Honda Dream 250 and place on centre stand. Start the motor and engage first gear. Back the Tri/Greeves rear wheel onto the Honda, engage fourth, rev the Honda to spin it up. After a few seconds of heart in mouth the Tri/Greeves fires, but oil pressure drops alarmingly. Stop engine and take off the clutch side and oil pump. Discover that oil is leaking into the clutch too.
This had caused the sombre mood in the workshop. It's an understandable reaction to imagine the worst scenario. Other problems become magnified. The time schedule becomes an insurmountable obstacle. All the hours and positive work and problem-solving thus far dissolve into the current predicament. There is no Plan B, they may have to get into the engine's innards.
A text message from Andy:
They have the bike running again and have ridden it round the industrial estate.
When I drop into the workshop the following day, smiles and confidence have returned. The oil pressure drop was a result of frothing. This can happen when there is an accumulation of small bubbles of air, and one of the symptoms is the reduction of lubricating property. Easily sorted...top the tank to capacity. Oh, and they'd identified the clutch leak problem too, got the timing spot on, and tuned the carbs. Though pending the dyno test they may replace the older Amals currently fitted.
In
part one it was speculated that the Greeves leading link forks may not be sturdy enough to cope with the additional weight of the Trident unit, but Andy said that it felt okay in the limited steering and braking space this first 'road test' allowed. The bike will have an MOT and insurance, so before the dyno session, they will identify a stretch of road to gain some idea of how it might behave on track.
Gearing is quite high with the bike wearing a 20 tooth front sprocket and a 52 tooth on the rear wheel. Mathematic calculations indicate a top speed of 136.5mph at 7,500 revs in fourth. A definite case of optimistic calculus we all agreed.
In part three we'll report on how all the Spa bikes shape up when they're exposed to the dyno, and in part four we'll be at Spa, where magnificent classics and fabled riders take to the track on historic racing solos and sidecars; the sounds of which will echo across the Ardenne valleys.
Comments
27/05/16 Looking good
31/05/16 Nice one John