Page:The Cycle Industry (1921).djvu/75

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61
CHANGE SPEED GEARS

B.S.A. Co., and the Raleigh Cycle Co., who paid attention to a three-speed hub made under the joint patents of Sturmey and Archer. Ryley, of Manchester, moved to Birmingham and began the manufacture of a three-speed hub at the New Hudson Co.'s works under the name of the Armstrong.

The three-speed hub was now an established favourite, and so rapidly did it gain favour that it was included in the specification of nearly every high grade bicycle on the market.

Armstrong's and the Raleigh Co. (Sturmey-Archer) laid down an enormously expensive plant of machine tools to deal with the gears on a commercial basis, and were able to so reduce the cost of manufacture that they had the trade to themselves. The only other change speed gear that has been retained by a cycle manufacturer is the original bottom bracket two-speed gear made by John Marston, Ltd. (Sunbeam). This is an epicyclic or sun and planet gear on the crank axle and is operated by locking or unlocking a central pinion surrounding the shaft. It is fitted as a standard article by the makers of the Sunbeam bicycle and has the great advantage that it is enclosed in a metal oil bath case and when the gear is in use the pinions revolve at slower speed than a hub gear, and are being constantly lubricated with fresh oil picked up by the chain wheel.

The production of the three-speed hub gear is now confined almost entirely to Sturmey-Archer Gears, Ltd., Nottingham, and the B.S.A. Co., Birmingham, the Armstrong gear having been merged with the Sturmey-Archer gear just before the war.

One might almost say that the production of hub gears is a special trade, because the accuracy required for the making of the parts is certainly more refined than is the case in any cycle factory where ordinary