This TAMIYA (#50477) 24T, 25T AV Pinion Gear Set can only occupy both 55T and 58T spur gear of the TAMIYA (#53665). I test run my TT-01 gear ratio setting (5.72:1) by installing the 58T pairing with 25T pinion gear on TAMIYA Sport Tuned Motor. Note that I am using TAMIYA semi slick tires set and full ball bearings on my TT-01. After the test run I have notice sacrificed acceleration but have high top end speed. My TT-01 runs very fast compared to stock gearing. The TT-01 sounds much quieter due to heavy motor loading and I can hear my TT-01 'cutting the wind' as it passes by me. The sound I described is very cool. I recommended this upgrade for long car park bashing or racing at large circuit.
i ordered this item from rcmart,i broke my stock pinion gear due to over playing,when i replaced it by this item the performsance went into another level,every teeth bite on the spur gear and the sound is solid.you know that the full power is going on.
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 (#50357) 22T, 23T AV Pinion Gear Set
I use the 25T for my 55T spur in my TT-01. Have the graphite chassis so installation is a breeze. Not sure about regular cassis though. Holds up good and strong. Recommend using with RS-540 motor if using stock ESC