I’m intrigued how different frame sizes affect the profile of a ‘Truss Frame.’ A shorter headstock means a more shallow angle, as you can see by comparing this 22″ Lovell Diamond Truss Frame (on the left, above) with the 24″ the Lovell Diamond Truss frame opposite.
The Iver Johnson catalogue illustration above presumably shows an 18″ or 20″ frame.
A truss is an extra support: the description ‘truss frame’ is very general, and can include an extra bracing tube anywhere within the frame diamond. The Lovell Diamond Truss Frame Roadster first appeared in the company’s 1909 catalogue. The design was already in use in England; the 1906 Helical Royal Premier, below, has an even more accentuated truss tube than the the Lovell Diamonds due to its large 26″ frame.
1920 Lovell Diamond Truss Frame Roadster
Frame No 320812
Iver Johnson originally manufactured Lovell Diamond bicycles, and they bought the Lovell Diamond company in 1900.
Iver Johnson’s Truss Bridge was the world’s market leader for a truss frame. So did they introduce another braced-frame bicycle to capitalise on the success of the Truss Bridge? Or to provide a cheaper alternative?
Cycle manufacturers were fiercely protective of their trademark designs. No other company sold a truss bridge bicycle until Iver Johnson’s patent expired in 1917, at which time Columbia, Schwinn Harley Davidson and other makers’ ‘Arch Bar’ bicycles suddenly appeared. (Note that, even then, no other company used the term ‘Truss Bridge’). This suggests that Iver Johnson had a powerful litigation team ready to act against any competitor.
The style used by Iver Johnson for the Lovell Diamond Truss Frame was already in use in England. Lovell Diamond was not a major company, and promotion and sales of this model was minimal compared to Iver Johnson’s flagship Truss Bridge. There are now only a few surviving examples.
My personal opinion is that Iver Johnson introduced this style into the Usa and registered it to prevent other companies introducing a similar ‘Truss Frame’ to compete with their Truss Bridge.
1912 LOVELL DIAMOND CATALOGUE
1912 LOVELL DIAMOND (22″ FRAME) v 1920 LOVELL DIAMOND (24″ FRAME)