The Pre-1941 Triumph Motor Cycle Pages

1933 Model XO

1934 Model XO 5/5

Following the two-stroke Model X Triumph decided to produce a more 'refined' overhead valve machine, and this was logically designated the Model XO and was catalogued for 1933; the Models X and Z being discontinued at the same time. With an inclined cylinder with cooling fins mounted horizontally in line with the direction of travel, and oil recirculated from a crankcase oil reservoir, the little 147cc Model XO engine was a masterpiece of 'minature' engineering at that time. This had been Triumph's smallest four-stroke engine, and it was overhead valve 'to boot'! Not only did the engine look good, but so did everything else about the machine. The original Model XO proved to be very popular and by 1934 there was also a sports version, as well as larger 174cc models. The original 147cc versions became Models XO5, while the 174cc models were XO7. It was a shame that it was not contined following the introduction of Val Page's 1934 machines, and thereafter the smallest available machine was 250cc.

Brief Specifications and Variations

Catalogued for 1933 and 1934.

1933 - Model XO.           147cc 4-stroke ohv. 56.6mm bore X 59mm stroke.
1934 - Model XO5/1. Standard model. 147cc 4-stroke ohv. 56.6mm bore X 59mm stroke.
........ - Model XO5/5. Sports model.         147cc 4-stroke ohv. 56.6mm bore X 59mm stroke.
........ - Model XO7/1. Standard model. 174cc 4-stroke ohv. 61.5mm bore X 59mm stroke.
........ - Model XO7/5. Sports model.         174cc 4-stroke ohv. 61.5mm bore X 59mm stroke.

A three-speed gearbox was standard, with a four-speed box available as an optional extra.

Electric lighting, legshields and lifting handle were standard, except on the Sports models which had no legshields.

I do not currently have enough details from surviving machines to be able to give a more accurate estimation of production figures, but it would appear to be between 1,500 and 2,000.

I have knowledge of surviving, or had been, Models XO in Argentina, Australia, Britain, Denmark, Germany, Holland, Ireland, Italy, New Zealand and South Africa. There is also one in a museum in America but it would not have been originally sold there, due to American restrictions on imports in order to protect their own motor cycle industries.

For more information you really need to read the booklet I have written which includes these models.

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