1/10 Basher Monster Truck

Traxxas Stampede XL-5 (Brushed / RTR) Gearing Guide

Internal transmission ratio: 2.72 · Recommended spur: 90T · Suggested motor class: Titan 12T brushed (stock XL-5 RTR)

Traxxas Stampede XL-5 RC Gearing & Optimization Guide

Optimizing your gear ratio is one of the most effective ways to balance speed, torque, and electronics longevity in your Traxxas Stampede XL-5 (Brushed / RTR). The relationship between your pinion gear (attached to the motor) and your spur gear (attached to the transmission) dictates how hard your motor has to work — and on a 1/10 basher monster truck platform with a 2.72 internal transmission ratio, even a single-tooth pinion change shifts your final drive ratio by 3-5%.

The Traxxas Stampede XL-5 is the brushed RTR monster-truck configuration, wearing 2.8-inch tall tires driven by the Titan 12T 550-size brushed motor. The combination of a heavy tire and a low-turn brushed motor makes over-gearing the single fastest way to cook brushes and glaze the commutator, which is why the stock 7-cell Ni-MH baseline is the correct starting point for any XL-5 owner.

Basher & Monster Truck Durability Notes for the Traxxas Stampede XL-5

Heavy landing impacts on a platform like the Traxxas Stampede XL-5 routinely bend motor mounts out of parallel with the spur, which is the single fastest way to strip a 48-pitch spur gear mid-session. After every big air session, sight down the pinion-to-spur mesh and confirm the motor plate has not shifted — a mount that has moved even half a millimeter will chew teeth within a pack. Just as importantly, check your center differential fluid thickness on a regular schedule; on high-power basher drivetrains the center diff is what manages extreme power distribution between the front and rear axles, and thin or contaminated fluid lets the light end spin up under throttle punch, spiking motor amp draw and cooking spur teeth from the inside out.

🛠️ Essential Tools Required for Gearing Changes

  • Hex drivers (1.5mm, 2.0mm, or 2.5mm depending on the Traxxas Stampede XL-5 variant)
  • Paper strip (for setting precise gear mesh)
  • Infrared temperature gun (crucial for monitoring motor heat after each run)
  • Threadlock (for the pinion gear grub screw)
  • Pinion gear puller (recommended when swapping gears on a hot motor shaft)

📋 Comprehensive Gearing & Temperature Guide

1. Understanding Pinion vs. Spur Gear Adjustment

Changing your gears alters your final drive ratio. Installing a larger pinion gear or a smaller spur gear increases top-end speed but increases the load on the motor, causing it to run hotter. Conversely, a smaller pinion or larger spur increases torque and acceleration while lowering top speeds and keeping your motor cool. On the Traxxas Stampede XL-5, this trade-off is amplified by the fixed 2.72 internal ratio — small external changes have a direct thermal consequence.

2. How to Set a Perfect Gear Mesh

Improper gear mesh will quickly strip your spur gear or bind your drivetrain.

  1. Loosen the motor mount screws slightly.
  2. Place a small strip of standard notebook paper between the pinion and spur gear teeth.
  3. Press the gears tightly together and tighten the motor mount screws.
  4. Roll the paper out. The paper should have clean, crisp crinkles without ripping.

Recommended Pinion & Spur Chart

All combinations use a 90T 48-pitch spur. FDR is calculated as (spur ÷ pinion) × 2.72 internal ratio.

PinionSpurFDRTypical Use
13T90T18.83High-bite carpet / tight indoor
14T90T17.49High-bite carpet / tight indoor
15T90T16.32High-bite carpet / tight indoor
16T90T15.3High-bite carpet / tight indoor
17T90T14.4High-bite carpet / tight indoor
18T90T13.6High-bite carpet / tight indoor

Understanding Pinion & Spur Gears

Stock XL-5 Stampede ships with a 15T pinion / 90T spur. Bashers running hot summer sessions on brushed power should drop to 14T to keep the Titan under thermal limits — dropping below that starves the motor of RPM and makes it lug in soft dirt.

Rollout Targets

Stock XL-5 Stampede rollout with 2.8 monster tires sits near 3.4 inches per motor revolution. On grass and loose dirt this is fine; on smooth pavement the tall tires balloon and effective rollout climbs, which shows up as extra heat in the Titan motor after even a short session.

Motor Temperature Management

Titan 12T brushed motors on the XL-5 should stay under 180F (82C). If the motor is running hotter than the ESC, the brushes are likely worn or the comm is glazed — clean the commutator every 4-5 packs and swap brushes at 2mm length or below.

⚠️ Critical Safety & Temperature Warning

Always use an infrared thermometer to check your motor and ESC temperatures during a run. RC electric brushless motors should never exceed 160°F (71°C). Exceeding 180°F (82°C) risks permanently demagnetizing your motor rotor and frying your Electronic Speed Controller. If your Traxxas Stampede XL-5 is running above these thresholds, you must "gear down" by installing a smaller pinion gear immediately, improve airflow with a larger motor fan, and inspect the drivetrain for binding.

Calculate a custom FDR for your Traxxas Stampede XL-5

The link below opens the calculator with Custom / Other Chassis pre-selected, the Traxxas Stampede XL-5's internal ratio of 2.72 and its recommended battery of 7-Cell Ni-MH (8.4V) already set — just plug in your pinion, spur, motor, and tire to see top speed, runtime, and FDR for your exact setup.

🔧 Brushed Motor Maintenance for the Traxxas Stampede XL-5

Brushed motors on the Traxxas Stampede XL-5 are wear items — the carbon brushes, springs, and copper commutator all consume themselves as the truck runs, and 90% of "my truck feels slower" complaints on a brushed RTR trace back to worn brushes or a glazed comm rather than a bad pack or the wrong gearing. Build a five-minute inspection into every 4-5 pack cycles and the stock Titan-class motor will outlast most bearings on the truck.

1. Inspect the carbon brushes

Pop the brush hoods off the endbell and pull the brushes out with a pair of tweezers. New brushes on a 540-size motor are roughly 6-7mm long. Once they wear below 2mm the spring can no longer keep firm contact with the commutator — you get arcing, hot brushes, and a sudden drop in top-end speed at the same gearing. Replace brushes as a pair, never just one, and always with the motor cold.

2. Clean the commutator

A glazed or dirty commutator shows up as reduced pulling power at low speed and a burnt-electronics smell after a hard pack. Remove the brushes, blast the commutator surface with a can of dedicated motor spray (never brake cleaner — it attacks bearing seals), then run a comm stick lightly across the copper segments while spinning the shaft by hand. The copper should come back to a bright, uniform pink; any dark spots or grooves mean the comm needs a true-up on a comm lathe or a motor replacement.

3. Check brush spring tension

Weak springs cause the brushes to bounce at high RPM, which shows up as an intermittent power cut on straights. Compare the spring compression side by side with a spare — if one is noticeably shorter or softer, replace the pair.

4. Break in new brushes properly

After a brush or motor swap, run the truck on a stand (wheels off the ground) on a 6-cell Ni-MH pack for 2-3 minutes at low-to-moderate throttle. This seats the new brush face to the commutator profile before you subject it to full stall torque on a rock face or bash pack.

Rule of thumb on the Traxxas Stampede XL-5: if top-end speed drops noticeably at the same gearing and pack, inspect the brushes and commutator BEFORE you assume the motor is dying — 8 out of 10 times it is a $6 brush set, not a $35 motor.

Ni-MH vs. LiPo on the Traxxas Stampede XL-5

Running a traditional 7-Cell Ni-MH (8.4V) nickel pack on the Traxxas Stampede XL-5 behaves very differently from a modern LiPo of similar nominal voltage. Ni-MH cells sag noticeably under load — a fresh 7-cell 8.4V stick pack measures closer to 7.2-7.6V once the trigger is pinned, which lowers real-world motor RPM and top speed by 10-15% compared to a 2S LiPo bench number. This voltage drop also means the ESC pulls higher current to hold speed, so brushed Titan-class motors on Ni-MH actually run hotter per lap than the same truck geared identically on a 2S LiPo, even though the pack voltage looks lower on paper.

Weight distribution changes too: a 6-8 cell Ni-MH stick or hump pack weighs roughly 380-460 g, versus 220-290 g for a comparable 2S/3S hard-case LiPo. On a short course truck or stadium truck like the Traxxas Stampede XL-5, that extra ~150 g sits low and rearward, softening the chassis' pitch response and loading the rear tires harder on corner exit. Bashers converting from Ni-MH to LiPo almost always need to add a tooth to the pinion (to compensate for the lighter, punchier LiPo delivery) and re-check motor temps after the first pack, because the same FDR that was cool on nickel can heat-soak on a high-C LiPo.

Rule of thumb: on Ni-MH, target motor temps 10-15°F cooler than the LiPo maximum listed above — the sustained current draw is higher, and nickel packs are less forgiving of over-gearing before they thermally cut out.

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