I have both TT-01 chassis and M05 chassis, therefore this TAMIYA (#50355) 18T, 19T AV Pinion Gear Set is a perfect spare parts. The 19T pinion is used for stock gearing TT-01 chassis, while the 18T pinion is match with TAMIYA sport tuned motor to be used in the M05 chassis. I recommend this spare part to hobbyist who have own both TT-01 and M05 chassis so that both 18T and 19T pinion is fully utilized.
These are good pinions. The quality is as expected from Tamiya, excellent. The fit and finish of the parts is as expected, brilliant. Do be aware that yes these are 48 pitch, but they are metric. These will ONLY fit tamiya vehicles equipped with 48P metric gears such as their normal electric touring cars like the TL-01 and so forth. These will NOT fit any vehicle using 48P standard. The teeth are slightly too long. Here's a very important tip, if you are going to use the 21 tooth version of this in a TA01/02 or a DF01 with a 74 tooth (standard size) spur gear, do be sure you have the notch on the motor mount pointing DOWN because it seems to work with it up, but you WILL strip out the pinion if you run it this way. I stripped out mine with a Tamiya silver can motor so it's pretty easy to strip one out. As a side thin, the 1:18 scale XTM Rage uses the same pitch on the spur and pinion. Other than that, these are really great products. I give them 5 stars easily.
Quality parts, as always from tamiya. The set comes with 2 screws, so you don't have to buy them seperately if you lost them. The fact that they are sold in pairs also makes them cheaper, which is nice, except if you need 17T and 18T for example, you would have to buy 2 sets.
These Tamiya pinion set are easy to use.. if you are got to look at getting bigger tires or changing your motor I would suggest getting a couple of sets of pinions so that you can play with different settings so that you are getting the most out of your setup without getting the motor to hot
This is a good quality part, but buyers should be aware that it is a metric 48p set of pinions. These will work very well on most (but not all) tamiya cars, but non-tamiya cars probably won't work with these. For most other makes you'll need a standard 48p, not these metric ones.
The durability of these parts is fine, not brilliant. They are light weight, but their lightness also means they wear out sooner and get chewed up easier with small stones getting in them. Even with a sealed drivetrain they will get dirty and it does chew the parts up.
One thing I like about the Tamiya pinions, their quality control is consistent. I've had other gears, including a popular American brand, and 2 pinions were identical, yet the shaft hole size in one was slightly smaller. One pinion goes on a motor just right, the other pinion is extremely tight. YOU NEVER GET THAT WITH TAMIYA PINIONS - QUALITY CONTROL IS FAR GREATER.