QS205 Spoke Sizes, Rim Sizes, and Wheel Lacing for ONYX RCR 72V

This reference covers ONYX RCR 72V wheel lacing, front spoke dimensions, QS205 rear spoke and nipple dimensions, and rim choices. Spoke dimensions describe the listed wheel/motor combinations; a different rim, hub, or lacing pattern requires its own fit verification.

For tire selection and clearance, see Tires and Fitment for ONYX RCR 72V.

Spoke Patterns (Cross vs Radial)

Cross-Laced Spokes

• Spokes cross each other (2-cross, 3-cross, 4-cross)
• Handles hub motor torque
• Better braking force support
• Even stress distribution
• Long-term durability

Best for:

• Hub motors
• Disc brakes
• Heavy batteries
• High power builds
• Off-road riding

Radial-Laced Spokes

• Straight from hub to rim
• Lighter
• Slight aerodynamic benefit
• Poor torque handling
• High hub flange stress

Best for:

• Front wheels without disc brakes
• Low power bicycles

Verdict

For ONYX hub-motor wheel builds:

Use cross-laced spokes. Prefer 3-cross or 4-cross for maximum strength.

Rims (17" and 18")

The correct rim width depends on the tire, motor, dropout width, and swingarm configuration. Wider rims listed here should not be interpreted as direct-fit options for a stock RCR or CTY2.

Common aftermarket options:

On RCR and CTY2-style 150mm dropout rear setups, the widest rim I have personally recommended and used is 2.5". Wider rims belong to different motor, dropout, swingarm, or custom wheel configurations and should not be treated as universal RCR/CTY2 fitment.

On larger 200mm dropout setups, I have used rear rims as wide as 3.5".

Spokes - Front (17" wheel)

Specifications:

• Length: 185mm
• Diameter: 3.0-3.18mm
• Count: 36
• Nipples: Included

Spokes - Rear (QS205 motor, 17" wheel)

Specifications:

• Length: 105mm
• Diameter: 3.0-3.2mm
• Count: 36
• Type: J-bend

Nipple sizing:

• Middle: 4.7mm
• Top: 5.7mm
• Head: 8.7mm
• Rim opening: 4.5mm

Rim Width vs Tire Width

Rim width and tire width are different measurements. A 4" tire does not require a 4" rim. The tire’s section width is normally wider than the rim it is mounted on, so rim width alone does not determine the maximum tire width.

The original ONYX RCR and CTY2 use the same wheel dimensions front and rear: 17 × 1.60" laced rims with 3.00-17 tires on both wheels. In other words, both bikes use a 1.60" rim with a 3" tire at the front and rear. This is a good example of why rim width and tire width should not be treated as the same measurement.

On 150mm dropout RCR and CTY2 setups, 1.8", 2.1", and 2.5" rear rims can be used depending on the tire and wheel build. The widest rim I have personally recommended and used on these 150mm setups is 2.5".

For wider 72V RCR and CTY2 rear setups:

• 2.5" is the widest rim I have personally recommended and used on 150mm dropout builds
• A 2.5" rim can support substantially wider tires than the rim itself
• 4" is the widest rear tire I have personally used without additional modifications
• Tires wider than 4" should be treated as modified fitment and may require extended swingarm plates

I have also personally run tires on 1.60" rims that are wider than what would normally be recommended for that rim width, and they have worked for me. However, physical fitment and recommended fitment are not the same thing. A tire may physically mount on the rim while placing the tire outside the manufacturer’s recommended rim-width range. It may also mount successfully but still create clearance problems on the bike. Rim compatibility, mounted tire profile, and bike clearance should therefore be evaluated separately.

A 2.5" rim is not required simply because the goal is a wider tire. The tire should be selected first, followed by a rim width within that tire manufacturer’s recommended range. This is the recommended approach, not a statement that wider tires cannot physically be mounted on narrower rims. I have run wider tires on 1.60" rims successfully, but those combinations should be treated as experimental fitment when they fall outside the tire manufacturer’s specified rim-width range.

Nominal tire width also does not guarantee actual mounted width. Two tires labeled as the same size can have different installed widths and profiles depending on tire construction and rim width.

Always verify:

• Actual mounted tire width
• Sidewall and tread clearance
• Chain clearance
• Wheel and motor centering
• Swingarm clearance
• Clearance throughout suspension travel

Knobby and dual-sport tires can require more clearance than street tires with the same nominal width. Tread blocks can become the limiting clearance point even when the tire’s nominal section width appears acceptable.

For a stock 72V RCR or CTY2-style 150mm setup, I consider approximately 4" the practical upper range based on configurations I have personally used. Wider configurations are possible with modifications, but should not be treated as universal bolt-on fitment.

The 80V ONYX uses a different rear-wheel configuration with substantially more available width. We use a 4" tire on the 80V, and 4.5" configurations also exist. Those dimensions should not be used to determine fitment on a 72V RCR or CTY2.

Rear rim options are also limited by the motor and swingarm configuration. The RCR/CTY2-style 150mm dropout setup has substantially less available width than a custom 200mm dropout setup. On larger 200mm configurations, I have used rear rims as wide as 3.5".

Rear Swing Arm Compatibility

The stock ONYX rear swingarm supports a wide range of tire sizes and riding styles, but has defined clearance limits that must be respected.

• Supports approximately 4" rear tire width depending on the specific tire, rim, and available clearance
• Maintains front-end stability under acceleration

Limitations:

• Less comfortable for passengers due to shorter wheelbase
• Becomes more sensitive at higher power levels beyond stock
• Nominal tire size alone does not guarantee clearance

ONYX has developed wider and extended swingarms:

• Increased rear clearance for larger tires
• Extended wheelbase improves stability
• Better suited for passengers and heavier loads

Four inches is the widest rear tire I have personally used on the 72V RCR without additional modifications. This should not be interpreted as a universal guarantee that every tire labeled 4" will fit. Actual mounted width and clearance must still be verified.

Rear tires wider than 4" should be treated as modified fitment. Extended swingarm plates allow additional clearance and can support wider configurations.

Rear Swing Arm Tire Compatibility

Rear Swing Arm Rim Compatibility

For RCR and CTY2-style 150mm dropout setups:

The 2.5" rear rim is the widest size I have personally recommended and used on the 150mm setup. Wider rims should not be assumed to fit the same configuration.

Larger 200mm dropout and custom swingarm setups provide substantially more space. I have used rear rims as wide as 3.5" on those configurations.