Traxxas X-Monster Chassis

Stock is as the vehicle ships. Calculated is worked from the stock figures on this page rather than stored beside them, so the two cannot drift apart. Derived is worked out from gear tooth counts the maker publishes rather than printed as a ratio; the notes below say how. The top speed is kinematic: an ideal no-load RPM with no slip and no loss under load, so a real car is slower. Speed gearing is the taller set that ships in the box but is not fitted; swapping it in is the owner's job, and the car runs hotter on it. The maker advertises 40 mph, which is their own claim on their own conditions.

Gearing parts

Tooth counts are the ones in the specifications above. Pitch is given as metric module (Mod 1, Mod 0.8) or diametral pitch (32P, 48P). They are different standards and are not interchangeable, even where the numbers look close. Bore is the pinion’s hole, listed separately from the motor shaft (5 mm on the stock motor). Gearing in the box is supplied, not fitted: the fitted set is what the figures and the calculators use. Linked part numbers go to the maker's or official distributor's page for that part.

How these numbers were settled

A rolling chassis sold ready to run without a body.

• Traxxas's X-Series gearing chart marks a 15-tooth pinion on the 54-tooth spur as the included stock gearing and 18/46 as included gearing for higher speeds, the same chart as the belted X-Maxx.
• The parts list sets the 15-T (6487X) and 18-T (6491X) pinions and the 54-tooth (6449R) and 46-tooth (6447R) spurs in regular type, and each part page lists this chassis as a stock fitment.
• Two Traxxas documents disagree on the ratio after the spur.
• The owner's manual formula uses 8.11, but the rear exploded view shows the 7886 overdrive gear set (47T/24T) fitted in the transmission and center drive, which with the 35T/11T ring and pinion gives 47/24 x 35/11 = 6.23, the constant the belted X-Maxx manual prints for the same driveline.
• The manual's own 40+ mph on two 4S packs with stock gearing is only possible with 6.23 (about 48 mph no-load at full charge, against 37 mph with 8.11), so 6.23 is shown here.
• Stock works out at 54/15 x 6.23 = 22.43 and the boxed speed gearing at 46/18 x 6.23 = 15.92.
• The tire is the 8.6 in belted Terra Groove, from the tire part page.

Documents

• ManualOwner's manual, model 77036-4 R02 (Traxxas PDF) (opens in a new tab)Gear ratio formula
• Gearing chartX-Series gearing chart (opens in a new tab)X-Monster 77036-4 table
• Parts listParts list, 77036-4 (Traxxas PDF) (opens in a new tab)Spur and pinion gears
• Exploded viewExploded view, rear assembly (Traxxas JPG) (opens in a new tab)Cush drive and center drive, 7886 gear set

Sources

• x-monster-chassis-77036-4traxxas.com (opens in a new tab)
• Manual (PDF)traxxas.com (opens in a new tab)
• Manual (PDF)traxxas.com (opens in a new tab)
• x-series-gearingtraxxas.com (opens in a new tab)
• 77036-4_X-Monster_TQi_explo…traxxas.com (opens in a new tab)
• 7689-white-x-monster-wheels…traxxas.com (opens in a new tab)
• 6487x-15-tooth-pinion-gear-…traxxas.com (opens in a new tab)
• 6449r-54-tooth-wide-face-st…traxxas.com (opens in a new tab)
• 6491x-18-tooth-pinion-gear-…traxxas.com (opens in a new tab)
• 6447r-46-tooth-wide-face-st…traxxas.com (opens in a new tab)

Every figure on this page traces to one of these. Where they disagreed, the note above says which was used and why.

More from Traxxas

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• X-Maxx 8S Belted
• X-Maxx Ultimate
• XO-1 AWD Supercar
• XRT 8S
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• Bandit XL-5 with Battery