One of the interesting projects I was involved with at Meriden was the eight valve head for the TSS. This was based on Weslake's design but went a little bit further because we had the opportunity to improve the crankshaft in line with the increased power. The design included much stiffer crank with bearings that were a bigger diameter and slightly narrower. I made the conrods offset so the cylinders could be centred further apart in the sleeved alloy barrel.
When production began I did some time on the assembly line fitting the rockers to the new heads. There were tales that some of the heads were poorly cast and leaked oil because thay were porous. I didn't see any signs of that.
I was so impressed with the TSS that, when Harborough Bike Centre had a second hand one in, I bought it.
The TSS also had the electric starter and the tandem valve oil pump. The oil pump was a good idea because although the original piston design was very efficient, if a bit of muck lodged in the single ball valve it would stop it working. With two valves there was hardly any chance that both valves would be held open at the same time so the 'good' valve could pump the 'open' valve clear of muck.
The electric starter also worked a treat. I cannot claim any credit for its development. When the prototype was tried it worked fine but the Bonnie it was on kicked back and stripped gear teeth off. Brian Jones asked me to redesign the gear train with stub tooth profiles. I spent hours going through the calculations of the whole gear train, altering diameters and centre distances and trying to get my calculations to give the same answer twice in a row, without much success. When I came in the next morning Brian had a sheaf of papers with all the dimensions laid out. He had phoned an ex-Triumph man who was working at Massey Ferguson who had put it through the company computer. I think that is when I realised where the future lay!
Although the head was not porous I did have a lot of trouble with leaks from the head and there was evidence of head leak between the cylinders. Because the cylinders were so close together the head wasn't sealed by the usual gasket. Each cylinder was sealed with a Cooper ring. This is a metal O ring that sits in the recess made by the top of the cylinder liner.
The problem was my fault.
When I dimensioned the lead in chamfer on the alloy barrel for inserting the liners I must have set the tolerence too big. Tightening the head down could press the liner further into the barrel and spoil the pinch on the Cooper rings. I had to have the top of the barrel skimmed to get it to seal.
By the mid 80s I was beginning to suffer from arthritic hands after a number of breakages. I could still manage the Triumph clutch. When I took the CX500 on a photo shoot with RMTS manager Ian Tremelling on his Thunderbird, Ian suggested that we swap bikes halfway. As I was about to set off on his Thunderbird Ian yelled for me to stop. "Your clutch cable has broken!" he shouted, squeezing the clutch lever open between index finger and thumb. "No it hasn't," I laughed, "It's not a Triumph clutch."
There was a rumour put about that RoSPA were anti-motorcycling. I would patiently point out that this was not true. I rode a Trident and a TSS. Assistant Director Ron Bryan rode a pre-unit Bonnie and Ian Tremelling rode a Thunderbird and a Trident. "It's not that we don't like motorcyclists," I explained "We just hate the bastards who don't ride Triumphs!"
The thing that really caused problems was the TSS twistgrip. Although there were only two carburetter slides to pull open, the springs must have been out of sidecar forks. On wet days I just couldn't stop the twistgrip slipping closed. To give some assistance against the carb springs I threaded a pipe bending spring through the inside of the handlebars and pegged it under the left hand grip. I then twisted the right hand end of the spring clockwise and spigotted it to the twistgrip. It didn't open the throttle on its own but it gave some assistance against the carb springs.
I used your method of reducing the weight of the throttle by fitting a light 12mm coil extension spring. It works a treat!
The TSS was light, had lots of grunt and the electric start worked on the button, but it didn't have the smoothness and speed of the Trident. When I moved house, sadly it had to go.
- Joe Virgona
Use the Contact Centre to be put in touch with Joe so you can swap sorry tales of leaky heads.
Here is someone who did ...
I have just completed a full rebuild of a completely original 1982 TSS which has done 5985 miles since new. With the exception of an oil pressure gauge, stainless steel valves and hardened valve seats, this machine is standard.
- Bryce Bathe
- Bob Stewart
Yep, sounds like a genuine TSS. Try wiring the starter off the grid.
1983 TSS Triumph is an excellent design in looks. The home version square tank look and with the black and red paint and gold pin stripe. The only flaw is that engineering reports were not published to remedy the problems.
- Joe Virgona
Always fascinated by Triumph at Meriden