Traxxas X-Maxx 8S Belted

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. 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

This belted X-Maxx is geared differently from the earlier X-Maxx 8S (77086-4).

• Its product page lists 'Overdrive gearing pre-installed', the rear exploded view shows the 7886 overdrive gear set (47T/24T) fitted, and the owner's manual formula is spur / pinion x 6.23 rather than 8.11.
• Traxxas's gearing chart for 77096-4 marks a 15-tooth pinion on the 54-tooth spur as the included stock gearing and 18/46 as included gearing for higher speeds, so the 46T spur and 18T pinion ship in the box but are not fitted.
• 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 truck as a stock fitment.
• 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 8.4 in belted Sledgehammer, from the tire part page.
• The manual quotes 40+ mph on two 4S packs with stock gearing and the product page 50+ mph with the included speed gear; both sit at about 75 to 85 percent of the no-load speed these ratios give.

Documents

• ManualOwner's manual, model 77096-4 R04 (Traxxas PDF) (opens in a new tab)Gear ratio formula p. 28
• Gearing chartGearing chart, 77096-4 (Traxxas PDF) (opens in a new tab)
• Gearing chartX-Series gearing chart (opens in a new tab)X-Maxx (Belted) 77096-4 table
• Parts listParts list, 77096-4 (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-maxx-77096-4traxxas.com (opens in a new tab)
• Manual (PDF)traxxas.com (opens in a new tab)
• Manual (PDF)traxxas.com (opens in a new tab)
• Manual (PDF)traxxas.com (opens in a new tab)
• x-series-gearingtraxxas.com (opens in a new tab)
• 77096-4_X-Maxx_TQi_exploded…traxxas.com (opens in a new tab)
• 7871-black-x-maxx-wheels-be…traxxas.com (opens in a new tab)
• 7870-x-series-belted-sledge…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.

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