"You get no sensation at all of gears changing," Mr. Sanfilippo said.

It incorporated synchromesh cones, but these did not wear well and gear changing still required drivers to adjust engine to road speed.

A four-speed transmission was fitted with an optional free wheel mechanism allowing "clutchless" gear changing.

With three passengers in the front, the middle one did all the gear changing.

The rasp of gears changing as the bus cornered was deafening.

A small motor, assisted by some old-fashioned pedaling, does the gear changing.

Prior to 1937 this was the only permitted form of gear changing on the Tour de France.

Transmission was a three speed "T-Bar SelectShift Cruisomatic" unit, allowing a choice of manual or fully automatic gear changing.

Whereas the transmission on the rear wheel drive Primus was controlled using a floor mounted lever, gear changing on the front-wheel drive Trumpf was achieved using a column mounted lever.

Newer bicycles with derailleur gears use bushingless chains which flex, making gear changing possible.