Oil In Frame Triumphs - A Potted History
Written by Martin Peacock   
Monday, 03 April 2006
Martin’s 1972 TR6R with a view over Weardale
Martin’s 1972 TR6R with a view over Weardale (Click any Image to Enlarge)

When I got back into old bikes a scant two years or so ago, I did lots of research, well some anyway, leading in the general direction of a ‘50’s or 60’s 500cc parallel twin and preferably a product of BSA or Triumph.  In the end, I bought the bike that just looked right.  What I did not know at the time was that I was buying an oil in frame Triumph, a bike representing the dark side of BSA - Triumph history and one that few had a good word for. 

This struck me as strange because my experience was that my particular bike ran and handled well, stopped reasonably well and presented few problems.  But there’s more to it than that and in the interests of truth, justice and a good chuckle, I’ve put together a potted history of the ‘oily frame’ development.  Of course I am not a “noted expert,” not even a ‘vaguely mentioned somewhere in the footnotes expert’ so do not expect a definitive work here.

Even allowing for my minimal research, there wasn’t much written about the oil in frame Triumphs.  The little I did find was mostly in the nature of “what-were-they-thinking???"  Even now, you will find little favourable opinion among the pundits and sellers of c1970 bikes often state "pre oil in frame" lest the merest whiff of Umberslade damages their price tag.  On the other hand, those that own and ride them worry less about the history and enjoy the bikes for the excellent machines they are. 

Twin Clocks

To be fair, the early history is pretty dire and usually put down to the misguided efforts of woolly minded marketing people and corporate bean counters.  As such, the frame is inextricably tied to Umberslade Hall , the corporate money pit dug in a desperate attempt to catch up with the Japanese – perhaps to bury them!  No doubt the men in suits deserved the jeers but consider what they were up against in the late ‘60’s: for despite selling every bike they could produce, the writing was on the wall for BSA - Triumph.  Japanese bikes were showing that poor reliability, oil leaks and vibration could be all but eliminated by good design and modern manufacturing.  Worse, the old designs were expensive and time consuming to produce and let’s not get into industrial relations at that time.  So, given that Triumph’s remaining edge was that British bikes still enjoyed their superior handling, you have to wonder why they ploughed a fortune into a new frame!

Looking closer and after enjoying a good chuckle at this apparently supreme example of management by numbskulls, there really was ample justification for a new frame.  Indeed, anticipating the need for change may have been seen as visionary or at least brave had they not so thoroughly bungled its production.  It was a necessary decision that went beyond marketing whims and keeping the accountants happy.  Forget the Japanese; at that time BSA - Triumph were literally having to play catch-up with Norton’s Commando.  And so it was that, despite continued success in the US market with the TR6 'desert sled' and much loved Bonneville, a makeover was way overdue. 

Much was riding on the new frame, going well beyond presenting something "new and improved" to stand against Japanese quality and innovation.  Most importantly the new frame was to cut costs both in its own right and through shared use on the Triumph and BSA 650 ranges.  Of course Triumph’s problems weren’t going to be solved with a new frame alone and to be fair; BSA - Triumph was also sinking considerable if misdirected effort into new engine development.  In fact so many resources were put into the stop-gap Triple engine that much of the 'X' frame development went to the safe hands of an outside consultant -- Rob North.

Triumph engineer Brian Jones, later to become Chief Engineer, first penned the design.  This was taken up by Dr. Stefan Bauer, a former director of engineering for Norton during the Commando's development.  At the time it was a big step forward.  The new and first all-welded frame had a slim, modern look.  Its Ceriniani style front forks were mounted on tapered rollers and gave 6.5" of double damped movement.  True, the conical hub brakes were of dubious merit but the new look was well received in the USA if less so in a UK market saddled with the Ogle styled “breadbox” tank.

The Airbox

Unfortunately the weak electrics and second-rate switchgear were retained but the new frame had important, practical benefits.  One was that getting rid of the oil tank made room for a large, cast aluminium air box and large air filters.  This reduced induction noise as required by the US regulations but the new megaphone silencers though quieter than the old Burgess units, still gave that essential parallel twin sound.  Less impressive were the plastic air filter covers that so clearly belonged to the cost cutting side of the plan.

For Triumph though, the devil was in the details.  The duplex design featured a 4" tubular backbone that provided strength, stiffness and somewhere to put the oil.  This should have provided better cooling through increased oil capacity but moving the filler cap from the headstock to the seat nose cut the oil reservoir by half.  Serious though it was, this problem faded into insignificance (unless you happened to be racing across the Mohave Desert) compared to months of delay before the Umberslade boffins and bureaucrats delivered the vital production drawings.


Triumph workers could still make engines though and these were assembled and stockpiled for the day when the new frames arrived.  The marketing folk and dealers did their best to hang on to anxious customers for the new, 1971 models by promoting the new generation of bikes as “worth the wait.”  Sadly this only served to increase the level of disappointment when they finally arrived.

Production quickly resumed when the new frames came in but the engines wouldn't fit without removing and eventually redesigning the rocker covers.  Worse still, the new frames raised the seat height to an Alpine 34.5" and the bikes were five months late for the all important US market.  When they finally did arrive, the continuing build problems such as leaving weld debris in the oil reservoir, cracked welds and the way-too-tall-seat plagued what could have been a continuing success story.

Front Brake

Another nail in the Meriden coffin yes but what is generally lost in all the gloom and general derision is that OIF bikes ride and handle very well indeed.  The worst criticism I have found in terms of their handling is grounding of the centre stand.  Well as far as I am concerned, something has to ground sooner or later and in my case, getting the stand down is firmly in the “later” category and not a problem for the everyday rider.  Most of the problems were fixed in '72 bringing the seat height down to a more reasonable 31" and providing improved handling.  In fact the much maligned 'oily frame’ enjoyed a further ten years of production with highly rated bikes like the T140 in its many forms.

Today the electrics and even the brakes will work well given some attention and modern parts.  For many Classic riders the OIF Triumphs provide affordable fun and performance.  Many rate the T140 as a top notch classic ride and my TR6 never fails to remind me why Triumph, for so long, really did sell every bike they could make.

This article was first published at http://www.realclassic.co.uk. Reproduced with permission from the author.