SU 9 x 5 x 5-SF-R

Frequently Asked Questions

Q: What is the material composition of the SU 9 x 5 x 5-SF-R, and how does it differ from the polyurethane SU 9 X 5 X 5-SF-P?
A: The SU 9 x 5 x 5-SF-R is solid industrial-grade black rubber compound (Shore A 85 ±5), designed specifically for steer wheel (front steering) duty. The SF-P is polyurethane (harder, typically Shore 95A), designed for drive wheels. Rubber provides better steering response, easier turning, and better ride quality on uneven floors. Polyurethane is harder and more durable for drive wheel traction. These are not interchangeable: use SF-R for steer wheels only and SF-P for drive wheels only.

Q: Does the SU 9 x 5 x 5-SF-R come with or without a hub assembly?
A: The base part SU 9 x 5 x 5-SF-R is the tire only without a hub. You must mount it onto a compatible 5-inch bore steel or aluminum hub using a hydraulic press. If you require the tire and hub pre-assembled together, order the part SU 9 X 5 X 5-SF-R-A (note the A suffix). The SF-R-A comes as a complete ready-to-install wheel assembly that slides directly onto the truck steering axle without additional pressing or assembly work.

Q: Can the SU 9 x 5 x 5-SF-R be used on rough outdoor surfaces or only indoor warehouse floors?
A: The SU 9 x 5 x 5-SF-R rubber compound is designed for polished concrete, sealed concrete, and smooth industrial flooring with minimal debris. The smooth flat tread profile provides no traction enhancement for uneven or outdoor terrain. You can use it on lightly textured or slightly outdoor-exposed floors, but grip decreases significantly on gravel, dirt, or heavily worn asphalt. For rough terrain or outdoor heavy use, switch to a tire with a grooved or studded tread pattern and harder compound rating.

Q: What installation tools and procedures are required to mount the SU 9 x 5 x 5-SF-R onto a hub?
A: Mount the SU 9 x 5 x 5-SF-R using a hydraulic press (minimum 20-ton capacity). Place the 5-inch bore hub on the press base, center the tire opening over the hub, and apply steady pressure until fully seated. Do not use hammers, mallets, or hand tools. Verify full seating by measuring the tire gap on both sides; it should be equal and minimal. After pressing, measure runout (radial play) with a dial indicator; acceptable runout is less than 0.050 inch. Re-balance the assembly on a wheel balancer after installation.

Q: Is the SU 9 x 5 x 5-SF-R tire non-marking, and will it discolor facility floors?
A: The black rubber compound in the SF-R can transfer slight marks or residue on light-colored or freshly polished floors, especially during sharp turns or heavy braking. It is not certified as a non-marking tire. For facilities that require certified non-marking wheels (food production, pharmaceuticals, hospitals, cleanrooms), verify that a specific non-marking grade is ordered or select an alternative material like synthetic rubber compounds formulated for zero-marking performance.

Q: How often should the SU 9 x 5 x 5-SF-R steer tire be replaced, and what symptoms indicate wear?
A: In typical warehouse operation with 16-hour daily use, expect 24 to 40 months of service life for a steer tire. Steer tires wear more slowly than drive tires because they carry less load. However, hard steering inputs and sharp turning accelerate wear. Monitor thickness monthly at three points around the tire; replace when thickness drops below 0.375 inch. Also check for visible cracks, spalling, or any loss of steering feel. If the truck pulls to one side or requires increased steering input force, the steer tire may be failing and should be replaced immediately.