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
The Troutbeck School 