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26 • DRAG SLASH
Motor and Gearing
The model is equipped with the Magnum 272R Transmission. One
of the more significant advantages to the 272R transmission is the
extremely wide range of available gear ratios. It can be geared low
enough to run an extremely hot, modified motor. A higher kV motor
should be geared lower (higher numerically) than a stock motor
because it will reach its maximum power at higher rpms. A higher
kV motor that is geared incorrectly can actually be slower than a
correctly-geared, stock motor. Use the following formula to calculate
the overall ratio for combinations not listed on the gear chart:
If you are worried that you might be over-geared, check the
temperature of the battery pack and motor. If the battery is
extremely hot, and/or the motor is too hot to touch, your model is
probably over-geared. If you are not able to run your model for at
least four minutes before the battery dies, then change to a lower
gear ratio. This temperature test assumes that the model is close to
factory stock weight and operates freely with no excessive friction,
dragging, or binding, and the battery is fully charged and in good
condition.
The model is equipped with a Velineon 3500 motor. The gear
combination that comes stock on each model provides good
overall acceleration and top speed. If you want more top speed and
less acceleration, install the included high-speed gearing (more
teeth). If you want more acceleration and less top speed, use a
smaller optional (not included) pinion gear.
The included high-
speed gearing is intended for use with a 2s LiPo battery on race
day. Using this high-speed gear for other types of driving may
overheat the motor, speed control, or battery.
Gearing Compatibility Chart
The chart to the left shows a full
range of gear combinations. This
does NOT imply that these gear
combinations should be used.
Over-gearing (bigger pinions,
smaller spurs) can overheat
and damage the motor and/or
speed control.
ADJUSTING YOUR MODEL
# Spur Gear Teeth
x 2.72 = Final Gear Ratio
# Pinion Gear Teeth
• Good Acceleration
• Good Speed
• Normal Conditions
22-Tooth Pinion
76-Tooth Spur
• Drag Racing
• Short Distances
• High Top Speed
29-Tooth Pinion*
76-Tooth Spur
*optional included
Recommended Gear Range
Stock Gearing
Included optional gearing,
for high-speed running only
Not recommended
For high-speed runs only, not recom-
mended for use with NiMH batteries.
High-current LiPo batteries required.
For high-speed running only
Spur Gear
Pinion Gear
76
83
86
90
15
-
-
-
-
16
-
-
-
-
17
-
-
-
14.39
18
-
-
13.00
13.60
19
-
11.89
12.32
12.89
20
-
11.28
11.69
12.24
21
-
10.75
11.14
11.66
22
9.38
10.25
10.63
11.12
23
8.97
9.82
10.17
10.63
24
8.62
9.41
9.74
10.20
25
8.27
9.03
9.36
9.79
26
7.94
8.67
9.00
-
27
7.64
8.35
8.67
-
28
7.37
8.05
8.35
-
29
7.12
7.78
8.08
-
30
6.88
7.53
-
-
31
6.66
7.29
-
-
32
-
7.04
-
-
33
-
-
-
-
34
-
-
-
-
35
-
-
-
-