Tamiya 11mm Ball Bearings (2pcs.)(15345)

A pair of 11mm outer-diameter ball bearings for Mini 4WD rollers, Grade-Up Parts No.345. Like Tamiya's other bearing sets, these replace a roller's stock bushing to cut rolling friction against course guardrails, helping maintain speed and reduce wear during a race. The larger 11mm diameter suits rollers built around this bearing size rather than the smaller 9mm version.

• Outer diameter: 11mm
• Thickness: 4mm
• Quantity: 2 ball bearings
• Includes 4 brass bushings and screws for mounting

This 11mm, 4mm-thick bearing is the larger of Tamiya's two everyday roller-bearing sizes; the smaller 9mm, 3mm-thick version is sold separately as Grade-Up Parts No.344 for narrower roller barrels. An 11mm roller covers more guardrail per rotation than a 9mm one, so it sees proportionally more sustained rolling contact during a race -- exactly where a stock plastic bushing, which slides against its shaft rather than rolling on it, tends to heat up and stiffen over a run. The four included brass bushings double as axle sleeves, so the bearings mount without needing a separate axle purchase.