Duckstang, if you're using the Tamiya 70T Spur, then it is NOT 48p like most people will lead you to believe. Stock Tamiya uses the AV pinion set which has bigger teeth than 48p. 0.6metric pitch is closer to 48p but even then it will run choppy. I have 26T pinion for all three pitches and the Tamiya AV pinion is roughly 1mm in diameter larger than the 0.6mod or the 48p. the 0.6mod is <.5mm larger than the 48p. Might not seem like much but trust me, its enough to chew up your spur.
Only reason I have a 48p pinion is because of my blitz. Went through 3 spurs in as many months using tamiya pinions before finally getting a 48p.. 8 months of constant bashing and the spur shows no signs of wear now, even with it being wobbly(common blitz design flaw).
If you want your spur to last more than a few months of running, then stick with tamiya AV pinions or upgrade to 48p spur and pinion to get more gearing options. Or better yet 64p and run ultra smoother and even more gearing options.