72 mm Reinforced Shafts 15417: An Assembly Check
Tamiya 15417 is a four-piece pack of 72 mm black, reinforced hex shafts. The official item page names Super X and Super XX as compatible chassis. That narrow statement matters: shaft length and wheel position must match the actual car, and a shaft that slides into a wheel does not by itself establish correct track width or body clearance.
Identify the shaft you are replacing
Remove the old axle with the batteries out and compare its length and hex shape with the kit diagram. A bent axle can show up as a wheel that wobbles even after the tire is seated. First rule out an uneven tire, damaged wheel hub or loose bearing; otherwise a new axle may appear to ‘fix’ a fault that was elsewhere. Keep the old part beside the new 72 mm shaft until the assembly is complete.
Fit without creating a new rub
Tamiya describes high-rigidity, carbon-reinforced shafts with black plating, but does not publish a lap-time gain. Push wheels on squarely using a proper support so the axle is not forced through the chassis at an angle. Spin each wheel by hand and watch its distance to the body, chassis and brake hardware. Compare both sides at rest and during a gentle test roll.
Check the finished car
The replacement may be dimensionally correct while the wheel is pressed to the wrong position. Measure the finished car across its widest points, including rollers, against the event's current regulation sheet. Record whether wheel runout or contact changed after installation. If wobble persists, inspect the wheel and bearing before replacing more shafts. Buy item 15417 as a documented Super X/XX replacement, not as a universal Mini 4WD speed upgrade.
Check current availability and the exact variant on the product listing before ordering.
Related reading
Frequently asked questions
Is 15417 a 60 mm shaft?
No. The official pack contains four 72 mm shafts.
Will it fit every chassis?
Tamiya's item page explicitly names Super X and Super XX; check the manual for any other build.
Sources checked 26 September 2026: https://www.tamiya.com/english/products/15417/index.html, https://www.tamiya.com/english/mini4wd/regulation.htm. Recheck product availability before ordering.