I had one of these in about 1960/61 with a pair of 49D cranks. I think that the only reasoning behind them was as a supposed product improvement or that there were people (like myself at the time) who would go out and buy the latest thing whether it was any good or not. It did nothing for my speed and I didn't usually keep things long enough to wear them out. My guess is that they would be a liability if the bottom bracket threads were not perfectly aligned -- any misalignment of the bearings would lead to greater wear and friction than a ball bearing set-up.
I don't know how long they were in production, but I suspect not too long.
Nevertheless, an interesting piece of cycling history that is probably better put on show rather than hidden away in a bottom bracket.
Hugh Thornton
Crewe UK
>From: "First Flight Bicycles" <jeff@firstflightbikes.com>
>Reply-To: "First Flight Bicycles" <jeff@firstflightbikes.com>
>To: "Ray Coffey" <swampgas@usa.com>, <classicrendezvous@bikelist.org>
>Subject: [CR]Sronglight roller bearing BB
>Date: Fri, 25 Jan 2002 09:45:57 -0500
>
>I was sorting thru some older parts and found a Stronglight roller bearing
>bottom bracket. Were these common? What was the thinking behind them?
>Jeff Archer