Pre-Unit Triton

[AdamR92t]

As I mentioned building a Triton in my introduction post, I figured that I should put a build thread up.

This was always planned to be a long build but it does seem to be getting closer.

Basic spec for those interested;

Wideline featherbed frame
Ceriani GP replica forks with minivation yokes.
Hemmings wide swinging arm.
230mm grimeca 4ls and triumph conical hubs built into 18" flanged excel rims.
Alloy 5 gallon manx tank and central oil tank.
Alloy hump seat
650 pre unit engine with 9 stud twin carb head, newby belt drive and clutch with a triumph gearbox.

Still plenty to do and even more to still make, I'm hoping that my new to me Tig will help with some of this, otherwise I have a myford S7 and small mill to move things along

 

[Rannsachair]

Looks great, all the right parts. I run an almost standard T120:

A guy in the next village has this one ( at Ardrishaig show last year)

And a friend of mine runs this 500 he has had since the 70's.

Good luck with the build.

 

[ms08]

Silly question maybe but why was the Triumph engine favored over the Norton or was it a just because you can.....

 

[oldbikedavey]

Silly question maybe but why was the Triumph engine favored over the Norton or was it a just because you can.....

Noticeably more easy to tune, and easier to work on.

 

[redlig]

The ultimate classic cafe/ real racer! (special)

 

[Rannsachair]

Silly question maybe but why was the Triumph engine favored over the Norton or was it a just because you can.....

As @oldbikedavey says plus folk wanted a fast 650: Norton never started making one until the early 60's whereas Triumph made one from 1949 in relatively high numbers. So in the early 60s a Norton 650 was an expensive new bike whereas a Triumph 650 engine was the cheapest way to get performance in the fine handling Norton featherbed frame. The Triumph engine was well developed by this time with lots of tuning options too, so was the natural choice. That was my understanding of why folk started making them from folk who did it in the 60s.

 

[redlig]

As @oldbikedavey says plus folk wanted a fast 650: Norton never started making one until the early 60's whereas Triumph made one from 1949 in relatively high numbers. So in the early 60s a Norton 650 was an expensive new bike whereas a Triumph 650 engine was the cheapest way to get performance in the fine handling Norton featherbed frame. The Triumph engine was well developed by this time with lots of tuning options too, so was the natural choice. That was my understanding of why folk started making them from folk who did it in the 60s.

650 non unit were the best option especially if you could bury the remains somewhere like a concrete driveway so rumour had it. Wink wink say no more say no more !!

 

[redlig]

Mated to a BSA RRT2 gearbox but if you were really smart a BSA RRT box was better as it had a lower first gear which got you off the line quicker . Both engine and gear box run on the mandatory Castrol R40.

 

[tom2207]

who made the tank , looks smart

 

[AdamR92t]

@ms08 apparently there were quite a few featherbed frames kicking about back in the day after racers took the manx engines out then, triumphs do seem to be easier to tune and the engines were plentifulm

@redlig went triumph with mine but my DBD has the rrt2 box, it makes riding in traffic a pain but great on the open road.

@tom2207 a guy named Gordon Scott made both tanks and seat unit, very happy with them (Gordon is on the Triton Facebook group)


I'm currently working on the headsteadyive already started one although I suspect I'll likely have another go now that I've got the Tig to weld it rather than bolt it together

 

[redlig]

I proddy raced my 650ss Norton and discovered a weakness in a conrod at a meeting at Cadwell park in '66 so bought a Goldie engine to put into the SS rolling chassis but was then offered a Greenwood ' tuned' Pre unit Bonnie engine in a complete Manx rolling chassis , as per foto. eventually discovered another weakness in a Bonnie rod . Sold the lot and bought a new model Suzuki Hussler . Instant success ( at club level ) and RELIABLE.
What caused the apparent hole in the upper frame tube?
Suck eggs time . If you don't already know the secret to an oil tight triumph is good breathing to reduce the internal pressure .

 

[tom2207]

I proddy raced my 650ss Norton and discovered a weakness in a conrod at a meeting at Cadwell park in '66 so bought a Goldie engine to put into the SS rolling chassis but was then offered a Greenwood ' tuned' Pre unit Bonnie engine in a complete Manx rolling chassis , as per foto. eventually discovered another weakness in a Bonnie rod . Sold the lot and bought a new model Suzuki Hussler . Instant success ( at club level ) and RELIABLE.

and so ended the British bike industry ...

a few others discovered the same thing .

 

[waddycall]

Silly question maybe but why was the Triumph engine favored over the Norton or was it a just because you can.....

I’m very slowly rebuilding a Norton 500. The cranks are weak as they are cast steel rather than forged. The heads are also made with the valves at an angle which makes head work more difficult.

 

[redlig]

and so ended the British bike industry ...

a few others discovered the same thing .

In the early 70's I was working as a M/C mechanic and one of our customers was a courier for a local newspaper and was provided with 2 off 500cc Triumph's which took in turns to require a total engine rebuild .one in one out eventually they were replaced with one Hussler which only needed routine maintenance , hence my choice of a comp bike.
Never could understand how I came to be a Sales Rep for NVT in their dying days .

 

[Rannsachair]

In the early 70's I was working as a M/C mechanic and one of our customers was a courier for a local newspaper and was provided with 2 off 500cc Triumph's which took in turns to require a total engine rebuild .one in one out eventually they were replaced with one Hussler which only needed routine maintenance , hence my choice of a comp bike.
Never could understand how I came to be a Sales Rep for NVT in their dying days .

When I ran a Triumph 500, I managed around 50,000 miles until a full engine rebuild: rebore, crank regrind etc. was a single carb bike, so perhaps less stressed. Was high maintenance when commuting for oil changes, greasing bearings etc.

 

[RichardM]

Back to the Triton, 4 speed I assume, if you can find a T150v gearbox for the right money, it should slip straight in. Just a bit of clearance work for the selector cam at the index boss needed.

 

[AdamR92t]

Yes 4 speed,
I wouldn't mind a 5 speed but unfortunately right money prices don't come around too often.

@redlig had me puzzled for a moment there, it's black tape

No recent progress I'm afraid, too busy welding the Old man's P4 rover

 

[brightspark]

Silly question maybe but why was the Triumph engine favored over the Norton or was it a just because you can.....

the triumph engine is better than the norton engine but the norton frames better more rigid than the triumph so you have the best of both

 

[graffian]

Yes 4 speed,
I wouldn't mind a 5 speed but unfortunately right money prices don't come around too often.

@redlig had me puzzled for a moment there, it's black tape

No recent progress I'm afraid, too busy

Just stuff the five speed internals from a T140 or trident in and it all works. My harley 45" had a 5 speed slickshift box.

 

[badabec]

Early 70s, my physics teacher had a Norvin. Often had L plates as he was teaching his girlfriend to ride.