Update: I'm now pretty sure it is a Boisis, and not a Barra

Nicola Barra ~1938?

frpm the M-Gineering study collection
(c) 2011

Before WO2 framebuilders in France built sophisticated bikes which even now look modern. The aluminium frame shown below is a nice example.  Handbuilt , welded by hand with oxy-acetylene, equpiped with novel cantilever brakes and with great details Builder is Nicola Barra, who first worked on his own, during the war for Garin, and after the war again for himself. This is an early one, later post war bikes have the framenumber on the headtube.


barra

Overview of the mixte frame.  1400 grams as shown with headsetcups, rearbrake, seatcollar and BB cup


barra

seatcollar

barra
To provide clearance for the narrow cranks l (Stronglight 49D with Rosa chainwheels (48-32)  the lefthand chainstay is indented as well


barra
The originale cantilever. Pivots around the bolt, which isn't the best of idea's: It increases the chance of the bolt loosening


barra brake
The brakepivot on the fork, with the hole for the returnspring
barra brake
The brake in pieces The pivotbolt clamps the washer with the lip, which catches the brakearm before this hits the frame

barra
Try welding this with a torch


barra
Rear dropouts with the original cotton insulated wire. The frontfork is stamped 111 too

barra
Steerer with extension for the external clamping stem


barra
Front dropout. And yes that is a crack, but you should see the other leg! (frame isn't my size anyways ;) )

barra
Twin plate crown shows how the fork was constructed. The topplate is welded to the forklegs, the lower plate is attached to the steerer. Next the subassemblies are slid together, and welded where accessible.


barra
Many ventholes, not only convenient for the wire, but also necessary to wash out all the corrosive  flux


barra dimensions
The dimensions of the 52,5cm frame. It is the most flexible frame I've had the pleasure of of putting on the alignment table: 40 Nm/degree, while a Columbus SL etc would be closer to 80 ;)


Literature

Raymond Henry, : Nicola Barra, French Frame builder, Proceedings 12th International Cycling History Conference
Bicycle Quarterly Summer 2008 issue