Product Description
Rubber Press-On
Specifications: 21.000 inch diameter x 9.000 inch width (21.000" x 9.000" | 21 x 9 wheel | 21 x 9-0 | 533.40mm x 228.60mm)
Specifications
Wheel Specifications
| Outside Diameter (in) | 21.000 |
| Width (in) | 9.000 |
| Outside Diameter (mm) | 533.40 |
| Width (mm) | 228.60 |
| Drive Tire Profile | Smooth Flat |
| Material | Rubber |
Frequently Asked Questions
Q: What size is the SU 21X9X15-SF-R rubber press-on wheel?
A: The SU 21X9X15-SF-R is a 21.000 inch diameter wheel with a 9.000 inch width, which equals 533.40mm diameter by 228.60mm width. This is the widest variant in the 21-inch diameter family and provides maximum load distribution.
Q: What trucks are compatible with the 21 x 9 wheel size?
A: The SU 21X9X15-SF-R fits trucks originally equipped with 21 x 9-0 drive wheels. Verify your truck documentation lists this exact size. Do not force a 21 x 9 wheel onto a truck designed for narrower widths. Most electric pallet jacks and walkie stackers use 21 x 7 or 21 x 8; verify before purchasing.
Q: Does the SU 21X9X15-SF-R require any special installation procedure?
A: Installation is the same as any press-on wheel: lift the truck safely with proper blocking, remove the retaining ring and hub, slide the old wheel off, align the new SU 21X9X15-SF-R wheel over the axle, and reinstall the hub and retaining ring. No special tools needed beyond a wheel puller if the old wheel is stuck. Use caution when handling the 9-inch width on narrow axles to prevent side binding.
Q: Why would I choose the 21 x 9 wheel instead of a 21 x 7?
A: The wider 21 x 9 wheel reduces per-inch-of-width loading, which decreases rubber compression and wear on smooth floors. It also improves load stability on trucks designed for heavy-duty applications. However, if your truck is not sized for a 9-inch wheel, the wider wheel provides no benefit and may cause steering stiffness or axle stress.
Q: What symptoms indicate the SU 21X9X15-SF-R wheel is failing?
A: Watch for cracks radiating from the core, flat spots on the bottom that catch on the floor, rubber chunks separating, steering that pulls to one side even on level floors, or unusual noise during operation. If you see glazing or hardening of the rubber surface, replacement is due soon. Do not continue operating on failed wheels as this damages the axle.
Q: How should the SU 21X9X15-SF-R wheel be stored to extend shelf life?
A: Store wheels in a cool, dry location away from direct sunlight, heat sources, and ozone-generating equipment. Keep rubber out of contact with oils, solvents, or sharp edges. Store wheels standing on their core, not on the rubber edge, and do not stack tires directly on top of each other. Stored wheels maintain quality for 3 to 5 years if kept in proper conditions.
