How to Choose RC Wheels and Tyres That Fit: Hex, Diameter and Offset

A wheel can be the right advertised size and still fail to fit your RC car. Check the tyre-to-wheel connection, wheel-to-axle connection and clearance around the vehicle separately. “For 1/10 crawlers” or “1.9-inch” is a useful starting description, not a complete fitment specification.

Wheel diameter is not tyre height

Common crawler sizes such as 1.0, 1.3, 1.9 and 2.2 inches usually describe the wheel/bead size. The tyre's overall outside diameter is a separate measurement. Two tyres for the same nominal wheel size can have different heights and widths, changing body clearance, gearing and steering load.

Check the bead and mounting method

A tyre and wheel need matching bead diameter and compatible bead shape. Beadlock wheels clamp the tyre bead mechanically; glue-on wheels retain the tyre using the specified adhesive and preparation. Do not assume every tyre in a nominal size fits every beadlock design. Confirm whether inserts are included and whether the listing is wheel-only, tyre-only, a mounted assembly or separate components requiring assembly.

Measure the axle connection

Measure the wheel hex across its flats and compare it with the wheel recess. Also check the axle-bore diameter, hex depth, drive pin arrangement, axle thread, retaining nut and available thread engagement. A wheel that sits on the hex but cannot be secured correctly is not a fit. An adapter adds further interfaces and may alter track width.

Understand offset without relying on a label

Offset changes where the wheel and tyre sit relative to the hub and vehicle. Manufacturers may describe offset and backspacing differently, so compare drawings and mounting-surface measurements rather than a positive or negative label alone. A wider stance can change steering geometry, bearing loads and body coverage; extra width is not automatically an improvement.

Test clearance through the full movement

1. Check the rim's inner clearance around steering knuckles, portal housings and links.
2. Turn the steering fully in both directions.
3. Check tyre-to-body and tyre-to-bumper clearance as suspension compresses and articulates.
4. Inspect the inside sidewall near suspension links and shock mounts.
5. Confirm the wheel spins freely and the retaining hardware seats correctly.

Do the mechanical checks with power disconnected. Do not solve binding by tightening the wheel nut harder or reducing necessary thread engagement. If spacers or different hardware are proposed, confirm their specification and suitability first.

Think about load as well as size

A larger tyre changes the effective gearing and can increase motor load. Heavier wheels add rotating mass and can place additional demands on the servo and drivetrain. Choose gearing and operating limits from the vehicle and power-system manuals, then monitor a short initial test. Do not copy another vehicle's pinion recommendation simply because both use the same tyre diameter.

What to send before ordering

Send RC MEGA the exact vehicle model and revision, photographs of the hub and current wheel, measured hex size, current tyre diameter/width and the product you want to fit. Mention changed axles, portal conversions or existing spacers. Keep the original hardware until the replacement has been checked.

Browse wheels and tyres and read crawler upgrade priorities. A linked product or familiar model name is not a substitute for matching these measurements.

Manufacturer references

Pro-Line's Impulse wheel specification lists wheel size, hex and specific applications separately. The Pro-Line removable-hex chart illustrates offset choices within that particular system. The Traxxas model 70054-8 manual discusses tyre-size and gearing considerations for that model.