In combination with the spur gear, the pinion gear makes your car!!! The 22T it's the stock pinion for the TA05 - it comes along with the kit - and it is the best for it!! Either you're drifting or racing it is all you need!!!!
Purchasing this pinion gear set, along with a set of spur gears for your chassis is a great way to improve acceleration or top speed of your RC car. I purchased every pinion gear from 19t to 25t for use in my TT-01, as well as the 55T and 58T spur gears. Using these gears has allowed me to perfect my gear ratio for my style of racing and the motor that I use.
I recommend you also purchase other pinion gear sets just like i did:
Tamiya (#50356) 20T, 21T AV Pinion Gear Set
Tamiya (#50477) 24T, 25T AV Pinion Gear Set