Safeties with special diamond frames

A lot of special or experimental frames have been built. Double tubing was supposed to add strength, but in reality it only added weight.
These were almost experimental models, but some were very succesful !

 Rudge, c 1890
 Rudge c. 1891-92
 HHC model F c. 1889
 Victor Model C 1892
 Humber no.5 1889
 Columbia model 27, 1893
Columbia model 39, 1893
 Sparkbrook no.1 c. 1888
 Rochet modele B
 Hurtu c 1890