Pre-unit - unit - what year?

[Big Dave]

What year did Triumph change to unit construction ?

Bonnevilles?

[muzz]

1963 All 650s, (including Bonnies, Tbirds, TR6, Trophy) are built with a new unit construction engine/gear box.

[Big Dave]

1963 All 650s, (including Bonnies, Tbirds, TR6, Trophy) are built with a new unit construction engine/gear box.

Thanks. I'll post a link when I get the page done.

[Paul in NZ]

You are kidding me right???? You ARE the defender of all things Triumph???? Right?? (sigh) Please tell me you are not re writing Triumph history????

First 'unit' was really the Triumph 'terrier' 150 in the early 50's (became the 200cc 'Cub' later..

First unit twin was the 3TA known as the 'Twenty One' 21 cubic inches and twenty one years since triumph rose from the ashes of the depression...

500cc unit twin (5TA) in 1959. Pre unit T100 (all alloy 'sports' Tiger 100 solidered on for a bit using up bits as really the first unit 500's were - um - pretty lame. Later versions were rather good.

First unit construction 650cc twins appeared in 1963.... They were not cough - acually - very good.... But, they solve a few of the issues the pre units had (like the dreadful 8 stud alloy head.)

If you want, We can detail all the stuff Doug Hele and co did to make them fabulous???

Or if you are really keen about Bonnevilles I can tell you about meeting Jack Wilson at Big D Cycles??? Jack built the bike that set the record at Bonneville that gave the bonne it's name... If you think Burt Munro was a character.... (he was, met him too) Jack was super dooper organised and a freaking genius that never got the recognition he deserved outside the USA. There he was a Triumph God (and a bit of a bastard if he didn't like ya but he took a shine to me and treated me really nice...)

This would be - gawd... Late 80's a couple of years befoe he died.. Just after the Hinkley triumphs first made it to the USA. Yes - that was probably where the bike was built and yes I saw the dyno it was developed on and all the bits left from 'erm' development, before the final bits were sent off to the UK and the national Motorcycle Museum...

If there is a mecca for triumph in the USA and the true birth place of the Bonnie, it is Big D Cycles in Dallas Texas....

[pete376403]

That last pic is gonna get Motu excited

[Paul in NZ]

That last pic is gonna get Motu excited

Thought it might - wanna tell me why it's extra special?????

[Paul in NZ]

These should have him frothing then....

The T120TT was in the car park and no - its NOT restored, just never used, note the 1 year only white grips still on the bike... GAH!

[Brian d marge]

That last pic is gonna get Motu excited

not just Motu ..track master?? ...

anyway i can vouch or the terrier and the 3ta, had both also rode around France on a 74 T140.

he was good at design , but In moved on top better things and bought the Enfield ..

Stephen

ps I think they called the Terrier a semi unit construction ...might be wrong though

[Big Dave]

Just checking I had the correct images.



http://kiwirider.co.nz/jenkse/jenkse.html

[Big Dave]

it is Big D Cycles in Dallas Texas....

Dig es vous upon this.

Autographen Stormy Mangham.

The Davian way is wide.

[Paul in NZ]

not just Motu ..track master?? ...

Its a very special one - experimental, lots of magnesium and an exotic frames.

[Motu]

The first unit twin was the 3TA,then the 5TA.These are what the 650 unit should of been.The gearbox design was taken from the Terrier/Cub,which grew into the BSA singles,and ultimately the B50.It would be called a cassette gearbox these days - you assembled it outside the bike,then slipped it in the crankcase.The engine was tidied up,still using twin cams and rocker boxes - but in a design that worked. The 650 was just the pre unit fitted into unit cases.Same gearbox (but with needle rollers),same clutch (but with duplex chain) Same engine,but with a better cyl head (same head,just wider stud pattern).The only real innovation was the exhaust camshaft driven ignition.

In the late '60's and '70's us guys riding preunits would fit all the unit stuff on our old shitters - because it would all fit.Unit cranks,unit cams,whole 9 stud top ends....you could even fit a 5 speed into a preunit case.

But the BSA unit 650 was a complete resign - all new,all improved.No more leaky rocker boxes,a cassette gearbox,triplex primary.Why didn't Triumph take the chance to improve the design instead taking the easy way out?

[Motu]

Dunno if the flattracker is a Trackmaster or a Champion,but I'd say Trackmaster because Paul is going along with that.59? The number doesn't ring a bell....but I could be getting embarrassed on this one.I think the flattrack Triumphs were probably the fastest Triumphs ever built - they were super light and pushing out as much hp as they could.

[200BUSA]

1957 first unit construction twin the 350cc 3TA. The 500cc was 1959. 1960 brought the T100A unit construction. T he 650 continued with its separate gearbox until 1963 when the bigger unit construction engine was introduced. i have a nice Triumph restoration book with all info on Triumph Twins upto 1972. Great book.

[Ixion]

Need to be careful about years. Typically new models were released at the Earls Court show (which replaced the earlier one at Olympia, a more important event) ,late in the year.

But , almost always, there were not actually any of the new models available for actual sale (and if the punters at the show didn't bite, maybe never would be!).

In other words, model years didn't follow the calendar. The first Bonny was seen at Earls Court in 1958, but production didn't actualy start until 1959.

Similarly, technically the unit 650 can be dated 1962, it was *theoretically* available after its release in October that year. I doubt any production models were available before 1963.

It was very common back then for the motorcycling press to carry letters lamenting that wonderful new models were still unseen up to six months after their first sighting. I recall an article in one of the rags slating Honda severely because a year after the announcement of the CB750 the only person to have actually succeded in buying one was Rollo, Earl of Denbeigh. And only because he was a director of a large motor sales group.