Understanding gear ratios in a two speed gearbox

We build the motorised Gear Racer with twin speed selectable gear box! Then it was time trials over a 2m strip, some speed calculations and a look at the gear ratios.


Gear Racer with twin speed gearbox



It takes a bit of dexterity to get it together – especially after we spot some changes.


Output from the drive


Gear 1 – white lever in top position


Gear 1 selected



Gear 1 ratios: from Drive bottom left up to Load top right

Slide and lock the white lever for gear 2.


In gear 2


Gear 2 ratios


Now you can figure out which gear was the fastest over 2m!


Gear racer underside



During time trials



No parachute on this 2m strip



The Gear Racer Dragster with 2 speed box



Follow on lesson: another way to determine the gear ratios


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