Head Stem Bearings Size (1938 Triumph 350cc)

[Bennetts Custom]

Hey guys, looking for some head stem bearings for my 1938 Triumph 350cc pictured below. Hoping someone can help out with what size they are?

Cheers,
Ben

 

[Greyfell]

Lovely!

 

[Rudie]

The balls are part number S70-4 - 3/16" o.d., same as used in the 57-66 unit 350 and 500. Unfortunately, the pre-WW2 350 (and 250) used only 22 balls in each race whereas the unit 350/500 used 24; the pre-WW2 cups and cones are a smaller diameter than the unit 350/500 ones.

 

[speedrattle]

i am ignorant of these old things. is that the original gearbox? was this a board track machine?

more pictures, please. its beautiful.

 

[Rudie]

i am ignorant of these old things. is that the original gearbox? was this a board track machine?

Cannot say I am particularly knowledgeable but, ahead of another post from the OP with more information, I would say the bike was probably originally a Tiger 80, the gearbox appears to be original, Triumph did not produce board track racers.

The singles (both SV and OHV 250, 350 and 500) were inherited from the original Triumph company when it sold motorcycle manufacturing rights to Ariel and Ariel owner Jack Sangster set up the Triumph Engineering Company.

Sangster put Ariel employee Edward Turner in charge of the new company. To generate additional income while he (Turner) developed what became the Speed Twin, he had the idea of fitting the OHV versions of the singles with chrome plated tanks, high level exhausts, a few other changes and calling them Tiger 70, 80 and 90 respectively, the figures referring to the top speeds.

These singles lasted until November 1940, when Coventry was blitzed. The original Triumph factory was close to the city centre, was completely destroyed, with manufacturing machinery and drawings. The twins were rescued by a combination of British government grants and Triumph employees collecting drawings copies from suppliers but the singles were not.

 

[sikatri]

Beautiful motorcycle! Looking forward to reading about the restoration/rebuild!

 

[speedrattle]

more pictures please.

does it run?

 

[Max Burke]

Hey guys, looking for some head stem bearings for my 1938 Triumph 350cc pictured below. Hoping someone can help out with what size they are?

Cheers,
Ben

G,day Ben What you have is a 1940s 3HW army machine made up as a make believe racer. The engine is similar to a 3H but with an entirely different cylinder head. First didgit of the engine number will tell you its year. For the amount of riding that it will get take the balls out of the pitted cups and form up two rings out of bronze welding rod to take the place of the balls. Max Burke. Riding 67 years.Nulkaba 2325 Au