What bike is Whitney Straight sitting on?

Forgive me for posting what is clearly not a motorcycle racing image, but the young man astride the bike certainly is a motor sport personality – it’s Whitney Straight, at Dartington Hall in about 1926.

I’m looking for help in identifying the bike. What is it, and what sort of performance would it have had?

Any help will be acknowledged in the Whitney Straight book I am working on.

Rgds

Paul

Strict copyright Dartington Hall Trust Archive

I believe this to be a Dunelt.

They built a 500cc and a 250cc two stroke which had a double diameter pistons thus the two exhaust pipes.

This might be a 1926 250 K

I think you are right, well spotted - a look around this website might provide confirmation :- http://www.dunelt.se/index.html

Gentlemen, many thanks for the swift response, much appreciated.

Paul

Edited by P0wderf1nger, 07 May 2014 - 18:54.