How do I know if I’ve refilled my shocks properly? I’ve heard the shaft should
pop back out after you compress the shock. Is that true? How far?
;e amount that the shock shafts “pop out” after being compressed is called
“rebound,” and to be clear we’re talking about compressing the shocks with the
springs removed. ;e amount of rebound depends on the amount of oil in the
shock. First and foremost, you want to be sure you don’t have too much oil. It’ll be obvious
if you do, because you won’t be able to compress the shock shaft fully (or, it will be hard to
compress fully, then shoot back out quickly when released). If you run the shocks with too
much oil in them, you’ll either pop the cap o; or blow out the shock seals. If overfilled, just
loosen the shock cap and compress the shaft, then tighten it when the shaft is about 5mm
of fully compressed. ;e shaft should now compress fully and easily, then rebound slightly.
Racers can obsess over this, painstakingly making certain each shock rebounds the same
amount, but if you’re just fun running it’s hardly worth worrying about.
Above: If you can’t fully compress the
shock, it has too much oil inside of it.
Left: To bleed the shock, loosen the cap
and compress the shock shaft. Do this
over a towel to catch the oil that bleeds
Right: Losi’s Shock Matching Tool
(LOSA99170, $35) makes it easy to
match your shocks' damping.
What’s the di;erence between “ 48 pitch” and “metric 48
pitch” gears, and how can I tell what’s in my car?
A gear’s pitch refers to its tooth size. ;e smaller the
number, the bigger the tooth. In RC, we most typically
see 32 pitch (common in high-power vehicles), 48 pitch
(most 1/10 scale), and 64 pitch (generally seen only in pan
cars). Each of these has a metric equivalent, or at least a
rough equivalent. ;e correct term for the tooth size of
metric gears is “module.” A 0.6 module gear is referred to
as “metric 48 pitch” but is actually 42. 3 pitch. Standard 48
pitch and “metric 48” pitch gears will not mesh together
properly. Competition cars typically have standard 48
pitch gears, while sport cars from Tamiya and Kyosho are
generally metric pitch.
As for telling metric and standard pitch apart when
uncertain, the best thing to do is check your manual and
the gears themselves for any labeling that indicates
metric or standard pitch. If that doesn’t provide the
answer, try meshing the gear with another pinion or spur
that you do know is standard or metric. If the gears mesh
smoothly, you’ve got a match. If the mesh feels notchy,
you’ll know you’re mixing metric and standard pitch.
Both of these gears have 21 teeth;
the silver gear is “metric 48 pitch”
and is noticeably larger than the
standard 48 pitch gear.
Tamiya cars and trucks,
like this TT-02B, typically
have metric gears.