4 in. BB Mecanum Wheels

$47.00 – $174.00

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The 4 in. BB Mecanum Wheel is a lightweight, slim wheel. BB stands for Ball Bearing, referring to the bearings inside of each roller that make for incredibly smooth motion. This wheel was optimized...Read More

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Product Overview

The 4 in. BB Mecanum Wheel is a lightweight, slim wheel. BB stands for Ball Bearing, referring to the bearings inside of each roller that make for incredibly smooth motion. This wheel was optimized for an FTC Chassis, such as the MecanAM Chassis. These wheels ship as an unassembled kit.

A full set consists of 2 "right" wheels and 2 "left" wheels. The "right" and "left" refer to the direction the rollers are pointing when viewing the wheel as if you're about to get run over by the wheel itself. If the roller in the middle of the wheel points up and to the right, it's a "right" wheel, and up and to the left would be a "left" wheel.

The configuration of these "right" and "left" wheels is important to a mecanum drive system! Be aware that the "right" wheel should not mean that it goes on the right side of your robot. The proper configuration would be to have the wheels create an "X" pattern when viewing your robot from above and drawing lines parallel to the rollers as viewed.

This means that a "right" wheel would be the FRONT RIGHT, and the REAR LEFT position, while the "left" wheel would be in the FRONT LEFT, and REAR RIGHT, of your robot when viewed from above. All 4 wheels are required to make a Mecanum drive holonomic system work properly.

Wheel Bores:

  • Nub Bore
    • Perfect for FTC robots
    • Compatible with Nubs as an attachment point to shafts and motors
    • A 6-32 screw is perfect for attaching to a Nub:
      • (am-1567) 1.5" for a standard HD Nub or Servo Nub
      • (am-1568) 1.5"-1.75" for an XL HD Nub
  • 1/2 in. Hex and 3/8 in. Hex Bore
    • Bore molded directly into polycarbonate center body
    • BE AWARE: these have a limited torque capacity. Recommended use in light duty applications (FTC robots or non-drive train FRC items such as an intake)

Roller and Axle Design:

The black TPU rubber roller has a durometer rating of 60A. The roller has a Polycarbonate core, and rides on a stationary brass tube.

Wheel Structure:

12 rubber rollers are sandwiched between 2 steel plates. The two plates are held together by bolting the rollers in place.

These wheels can be purchased individually as Left or Right wheels.

Individual Hardware within Each Wheel:
  • 2 - BB Mecanum Plates
  • 1 - Hub
  • 12 - Individual 4 in. Wheel Rollers
  • 24 - Axle Bearings
  • 12 - Brass Inner Sleeves
  • 12 - M3 x 0.5 in Nylock Nuts
  • 12 - M3 x 0.5 45 mm SHCS Screws


  • Nub Bore Wheels
    • For FTC Robots: If attached to a shaft or NeveRest motor, these parts are needed for each wheel.
    • Attach an AndyMark Nub or Tetrix Motor Hub directly to the Nub Bore version of this wheel.
  • 1/2 in. Hex Bore : Direct Drive
    • Simple! with a 1/2 in. hex shaft
  • 3/8 in. Hex Bore : Direct Drive
    • Simple! with a 3/8 in. hex shaft


  • Body Material, Inner: molded black polycarbonate
  • Body Material, Outer: 0.09 in. thick steel, zinc plated
  • Bolt Pattern: 6 holes (0.159 in. diameter) on a 1.875 in. diameter circle
  • Bore: Nub Bore, 3/8 in. Hex, 1/2 in. Hex
  • Diameter: 4 in.
  • Number of Rollers: 12
  • Roller Axle: Brass Tube
  • Roller Bearing Material: Steel Ball Bearings
  • Roller Durometer: 60A
  • Roller Material, Inside: Polycarbonate
  • Roller Material, Outside: TPU
  • Total Width: 1.52 in.
  • Weight: Single wheel: 0.84 lbs
  • Weight Capacity: 40 lbs per set of 4
  • Width Inset: 1.23 in.


Returns are accepted within 30 days of purchase.
View our return policy here.


2 reviews

  1. star star star star star 5 out of 5 stars

    Prefect choice for Droids and Robots alike

    Greetings Builders, My name is David Ferreira, and I recently received and tested out the 4" BB mecanum wheels on my RX droid. When I received the wheels Kit in the mail I proceeded to assemble each wheel according to the PDF doc. Each one took around 10 minutes to build with only two tools needed. Great job on making it easy :) After installing them, we tested them at a two-day Convention driving on smooth concrete as well as a low-pile commercial carpet for a total of ten hours. After the event was over I proceeded to inspect the wheels individually for any signs of wear or damage. There was none. Each roller would still free spin with no effort. A few characteristics to point out about this wheel is they seem to have an increased grip, and with 12 rollers in such a tight form factor, your speed is slightly increased due to the faster transition time from roller to roller. A few details about the Droid, RX weighs 72lbs and stands 3' tall. His wheelbase is 13 inches wide and 12 inches long. Here is a link to where you can see his performance at this particular event. https://www.instagram.com/p/Cm5hir0D4RX/ Overall I am impressed by the engineering and quality of this product. I have tested other wheels in this same form factor and all have failed for one reason or another. Whether it be the rollers breaking down or the nylon core cracking and eventually breaking away. If you're looking for a mecanum wheel built to last I would defiantly recommend the 4" BB for your robots to droid project. Happy Building David Ferriera

    D F

  2. star star star star star 5 out of 5 stars

    So smooth.

    This wheel is so smooth. Hands down the slidy-est wheel I've ever driven. Almost feels like a swerve.


    Verified Purchaser

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