Obtaining a 23t pinion gear is not difficult if I wanted to use standard Tamiya parts, but there are a couple of downsides to this choice. The first of these is the fact that Tamiya 'AV' pinions are made of a very soft aluminium, and this means that they wear out quite quickly. I've used up several in my three TL-01 trucks over the past few years, they last reasonably well with standard 'silver can' motors but cannot really take the power of a tuned motor. They tend to wear their teeth to sharp points, and make increasing amounts of noise as they do so (also noticeable if you manually push the car backwards). They also leave grey alumimium oxide residue, which is itself abrasive, on the other (plastic) gears in the rear gearbox.
The second downside is that you have to purchase them in pairs with a one-tooth difference between them, and one out of each pair does not fit a TL-01. Therefore you have to pay extra for something you are not ever going to use.
Here are the part numbers for each of the sets that contain one gear that will fit a TL-01 (options - 19, 21 and 23t):
Tamiya 50355, 18T & 19T AV Pinion Gear Set
Tamiya 50356, 20T & 21T AV Pinion Gear Set
Tamiya 50357, 22T & 23T AV Pinion Gear Set
It must be noted that Tamiya refer to the pitch of these gears as METRIC 48 pitch, which is not the same as a regular IMPERIAL 48dp (diametric pitch) gear.
This 'AV' size was used in Manta Ray, Group C, TL01, TB01, Wild Dagger, Detonator, Vanquish, Avante2001 etc.
In reality these Tamiya gears are metric 0.6 module pitch, which do NOT mesh correctly with normal 48dp pitch gears. My understanding, having read a fair number of RC forum posts, is that 0.6 mod equates to 42 pitch, and that GPM aluminium spur gears for a TL-01 are advertised as being this size.
(For reference 48dp - imperial diametric pitch = 48 teeth on a 1-inch diameter gear, 64 pitch = 64 teeth etc.)
I cannot find any reference to Tamiya clarifying this issue - their official answer is to "only buy Tamiya pinions"!
Now to the Tamiya TL01 Speed-Tuned Gear Set (#53342 or OP-342):
These are moulded in black plastic, to easily discern them from the standard (off-white coloured) version.
Also for reference, here are the Final Drive Ratios (FDRs) for each fitable size pinion, and again for each size when used with the Speed Tuned gearset.
Pinion Gear..... Normal Ratio...... Speed-tuned Ratio
19T ................. 7.96 ................. 5.95
21T ................. 7.20 ................. 5.39
23T ................. 6.57 ................. 4.92
This is the pinion gear I've chosen to use. It is intended for use in a Maverick Strada TC/MT/XT/XB series car/truck/truggy/buggy. Its part number and description are MV22081 MOTOR GEAR 23T 0.6 MODULE:
£3.53 + £0.89 postage & packaging.
UPDATE:
You can forget all I wrote at the start of this post about needing to buy a 23t pinion. I didn't. As I realised when I came to put the gearbox into the truck the mounting holes on the gearbox (to the truck) are not diametically opposite in relation to the output shaft.
This means that a 23t pinion will not fit, even though the gearbox is fitted to the truck on the 23t mounting holes. Actually, the difference in the offset is almost exactly equivalent to four teeth on the motor pinion. So a 19 tooth pinion DOES fit here instead. And being as I already had at least one spare 19t here anyway I had no need to buy anything new (beyond the gearbox itself) at all.
Anyway I hope the following makes things a bit clearer. If you use a rule on the gearbox lining up the mounting holes (this only works on one side!) it also just touches the output shaft as a near-perfect tangent, whereas the imaginary correct line should have passed centrally hole to shaft to hole.
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