The diamond frame was not without rivals in the early days of the safety bicycle. Its principal competitor was the cross frame, which got its name because it typically had a main beam (linking the steering head to the rear wheel) intersecting at approximately 90º with the seat tube (which extended downward to the crankcase). Because of its open design, manufactur-ers of cross frames didn’t have to make separate models for men and women. However, the height of the main beam was more of an impediment to a skirted rider than most ladies’ deriva-tives of the diamond frame.
Lawson’s Bicyclette of 1879 had a cross frame of a sort. More cross-frame machines be-gan to appear about four years later: the Marvel in 1883, the Pioneer in 1884, the BSA safety bicycle in 1885. The Premier, introduced by the Coventry firm of Hillman, Herbert & Cooper’s in 1886, was more sophisticated, and elements of its design were patented (British patent
1,775 of 1886). The steering was self-centered by a spring and chain slack was adjusted by tensioning a stay linking the bottom bracket to the main beam. The Premier was popular for several years.
Dan Albone’s Ivel cross-frame machine, introduced shortly after the Premier, was, in con-trast with most other early safety bicycles, fairly easy to ride in the “no hands” style. In 1886, George Pilkington Mills, an engineer as well as an athlete, broke the 50-mile and 24-hour re-cords on an Ivel. Mills worked for Albone before joining Humber and later Raleigh.
In 1888, Starley & Sutton briefly made a cross-frame machine; it was not commercially successful. The following year, M. A. Holbein, riding a Hillman, Herbert & Cooper cross-frame bike, broke the 24-hour record, covering 324 miles (RRA 1965, 40). But by that time, Wil-liam Hillman had already patented his own “diamond-shaped frame” (British patent 16,736 of 1888). The stronger, more fully triangulated diamond frame had already made its mark, and cross-frame bikes began to disappear from manufacturers’ catalogs.
Some “semi-diamond” designs combined elements of the cross frame and the diamond.
One such was the 1889 Starley & Sutton Universal Rover, a safety bicycle that was relatively cheap by that company’s standards. Like a closed diamond, its frame had a rear triangle formed by the seat tube, the chain stays, and the seat stays. But like a cross frame, it had a main beam between the seat tube and the steering head. In common with the Ivel, it had a thin tie between the front of the main beam and the bottom bracket.
From time to time, cross frames made a comeback. The American Compax, designed in 1937 by Albert Rippenbein of New York (US patent 2,211,164 of 1940), had a cross frame, as did several designs of the late 1940s and the early 1950s, including one produced by Dilecta of France, two prototypes built by the British cycle mechanic Jack Lauterwasser (prompted by the postwar steel shortage), and a widely publicized prototype built by Sir Alliott Verdon Roe, the aeronautical engineer who founded the Avro and Saunders-Roe aircraft companies. The German Hercules HK, introduced around 1958, had a cast aluminum cross frame. All these machines had wheels of conventional size. However, from the 1960s on, cross frames and other open frame designs were more commercially successful when used on small-wheeled bicycles than when used on larger ones. Some open designs (such as the H frame used on Raleigh’s 20 series) had a standard rear triangle, with seat stays and chain stays. The lazy F, typified by the early Moultons, had a main beam so low that the bottom bracket was directly mounted on its underside. In both of these cases the name “cross frame” is inappropriate, as the seat tube and main beam don’t cross to any great extent. There were also many U frames, with a single curved tube forming the seat tube and the main beam. (U-frame bicycles for women had been produced in 1895 by Reichstein Brothers in Germany and by Humber in England.) Many of these open frame designs—cross frames, H frames, U frames, lazy Fs—
used gussets, struts, or stays to brace the main beam to the head tube or the seat tube.
Figure 5.9 Above: An 1887 cross-frame Rudge with bridle-rod steering (Alan Osbahr). Middle: A cross-frame Ivel (R. John Way). Below: An 1889 Universal Rover (catalog picture).
Simple cross frames of the 1880s, such as those of the Ivel and the Premier, should not be confused with more complex later designs—also called cross frames—that were more like reinforced diamond frames. The best-known example of the latter was the Raleigh X frame, created by George Pilkington Mills after he left Humber to join Raleigh. Although Raleigh had produced something similar a few years earlier, the X frame featured prominently in the com-pany’s advertising from 1901 until the 1920s. Mills observed that a large men’s diamond frame wasn’t fully triangulated, owing to the length of the head tube. His X-frame design remedied this by sloping the top tube forward and down to the point where the down tube and the head tube met, introducing an additional tube linking the bottom bracket to the top of the head tube, and making the additional tube intersect the sloping top tube.
Raleigh used the name Modèle Superbe for most of its X-frame bikes. Various other mak-ers copied the design. There was also a ladies’ vmak-ersion; it maintained the step-through feature of the ladies’ diamond frame, but instead of the normal sloping top tube above the down tube it had two intersecting tubes. X frames were, according to Professor Sharp, “appreciably more rigid than the usual diamond frame.” But they were also heavier and much more expensive.