Foam-Filled vs Solid Forklift Tires

Foam-filled and solid resilient tires are both sold as answers to flats on a pneumatic-tire forklift, but they are built in different ways. That difference shows up in weight, heat, ride, mounting and what happens when the tire is done.

On a pneumatic-tire truck, the tire choice is a choice of construction: air-filled, foam-filled or solid resilient. Whether a truck runs pneumatic or cushion (press-on) tires is set by how the truck was built, not by the replacement tires you choose. Yokohama-ATG notes that some forklifts are specifically designed for solid press-on band tires, and those trucks take neither option in this guide; Classes of Forklifts and Their Tires explains the difference.

The Short Answer: Foam-Filled vs Solid

Each claim in the table names the maker that made it; where makers disagree, both views are shown.

What a Foam-Filled Tire Is

Fill maker Carlisle TyrFil describes its product as “a polyurethane liquid that is pumped into pneumatic tires to replace air with a resilient, synthetic elastomer core.” The trade calls these foam-filled tires. TyrFil sets its own product apart from what it calls standard foam fill, which it says “can vary in quality.” This guide says foam-filled, or filled, for both.

How the fill goes in, per TyrFil’s quick reference guide and weight guide:

1. The tire, mounted on its rim, is pre-stretched for 24 hours “to compensate for in-service casing growth.” TyrFil’s weight guide describes this as air pressure at the tire’s maximum rated inflation for 24 hours before filling.
2. The fill is injected through the valve stem with a fill pump.
3. The casing is vented with a needle until liquid flows out, and the hole is plugged.
4. The tire is pressurized with fill “to the recommended PSI,” laid flat, and cured for 24 to 48 hours at 72°F.

After that, TyrFil says, “further pressure adjustments are unnecessary.”

Foam-filled tire pros and cons

TyrFil sells fill, and Yokohama-ATG sells solid tires. Read each list with that in mind.

Pros, per the fill maker and the fill process:

• Flats. TyrFil says filled tires “will keep performing” despite cuts and punctures, and that its fill “eliminates flats, reduces downtime, extends tire life, and lowers maintenance costs.”
• You keep your tires and wheels. The fill goes into a pneumatic tire already mounted on its rim.
• Retreading. TyrFil says filled tires “can be retreaded up to four times without compromising performance.”

Cons and limits:

• Weight. The fill adds weight; see the weight table below.
• Damage can still end the tire. Yokohama-ATG, writing about skid steers, says a foam-filled tire is most vulnerable at the sidewall and to punctures too large for the foam, and that such damage is “catastrophic and the tire needs to be replaced. Additionally, the foam filling is also lost.”
• Hard to remove. Yokohama-ATG says the foam and tire “need to be cut off of the rim” before a new tire can go on, and that the hole made in the casing to fill it creates “a weak spot where cuts propagate.”
• Tire life is disputed. Yokohama-ATG says fill “is also hard on tires and can expedite wear,” the opposite of TyrFil’s view.

What a Solid Resilient Tire Is

Solideal by MICHELIN describes solid resilient tires as “non-pneumatic tires made from multiple layers of high-quality rubber compounds,” in three layers: a tread layer for wear and traction, a middle layer for shock absorption, and a heel layer with steel bead reinforcements for rim grip. Continental says its Super Elastic solids “are developed to fit on industrial pneumatic tire rims.” Toyota calls them solid pneumatic tires.

Toyota answers yes to replacing pneumatic tires with solid pneumatic tires, and adds that the change may slightly affect ride comfort and should be discussed with your dealer or service technician. Yokohama-ATG says solid resilients are common indoors and outdoors, in jobs such as scrap yards and demolition sites where the threat of puncture is high.

For how solids compare with air tires in general, see Solid vs Pneumatic Forklift Tires: Differences Explained. For the two ways solids lock onto a wheel, see Lock Ring vs. Click-Style Solid Pneumatic Forklift Tires.

Weight, Heat and Ride, Side by Side

Weight

Both options weigh more than the air tire they replace. For fill, TyrFil publishes estimates. Its weight guide gives the weight of the fill alone, per tire, and warns that “the amount of TyrFil needed can vary by 15 percent (+/-)” depending on the tire maker. Its figures assume TyrFil Ultra and new tires pre-stretched on standard-width rims. Used tires and drop-center wheels take more.

Solids add weight too: Solideal’s load tables do “not include the additional weight of the solid tire when converting from pneumatics.” The solid tire tables cited here (Solideal, Continental, Trelleborg) list no tire weights, and no same-size comparison of a filled tire and a solid resilient was found, so this guide does not rank the two by weight. What counts is the truck’s rating; see the data-plate check below.

Heat and speed

Solid tires build heat as they work, and heat limits how fast and how far they can run. Continental says solid tires are designed for a maximum speed of about 25 km/h or 16 mph, but that “the permitted average speed is significantly lower (5 - 10 km/h), otherwise the tire is at risk of thermal damage,” with the actual average depending on load, breaks, number of shifts and tire size. It advises letting forklift tires cool down for a whole shift whenever possible. Solideal rates its counterbalanced-truck load tables “up to 25 km/h” and says those are the maximum speeds of the unloaded vehicle.

Trelleborg’s material handling manual lists the strains on solids: running non-stop and high speeds build heat; long distances “prevent dissipation of heat” and “can create dangerous separation within the tire”; and repetitive cornering adds torque that makes deformation more likely.

Filled tires have duty limits too. TyrFil’s product grid recommends Flex 10, Pro 30 or Ultra 30 for forklifts on one or two shifts, but for three shifts it recommends Ultra 30, marks Pro 30 “Review operating conditions” and does not mark Flex 10. Its FAQ describes Ultra as having “enhanced heat dissipation” for severe conditions, and claims filled tires have “lower heat buildup” than solid aperture tires; the sources cited here include no independent test of that claim.

If your trucks run long distances, many hours a day or around the clock, put the duty cycle in front of the tire maker or fill maker before you choose.

Ride

Both options give up the air spring of an air tire, and the makers disagree on what that costs:

• TyrFil says its Flex 10 grade gives “Maximum Deflection Better than Air-Ride” and an “air-like ride.”
• Yokohama-ATG, in its skid-steer article, says the fill “will often become stiff and rigid as it ages, resulting in a harsh, uncomfortable ride that is inferior to the one offered by a solid tire,” and that “neither foam-filled nor solid tires will deliver the comfort of pneumatics.”
• Sentry, also a solid-tire maker, says a foam-filled tire’s ride “can be softer compared to solid tires.”
• Solid makers build ride into the tire: Solideal’s middle layer is there “for shock absorption,” and Yokohama-ATG mentions apertures in solid tires to improve ride.

How firm each one feels depends on the fill grade, the tire’s build and its size. This guide does not rank them on ride.

The Data-Plate Check (It Applies to Both)

Filling a tire and switching to solids both add weight at the wheels, so the same check applies to both.

What the federal standard says

Federal OSHA’s powered industrial truck standard, 29 CFR 1910.178, does not use the word tire. Its modification rule, paragraph (a)(4), reads: “Modifications and additions which affect capacity and safe operation shall not be performed by the customer or user without manufacturers prior written approval. Capacity, operation, and maintenance instruction plates, tags, or decals shall be changed accordingly.” Paragraph (a)(6) says the user “shall see that all nameplates and markings are in place and are maintained in a legible condition.”

What OSHA has said in letters

The six interpretation letters OSHA indexes to (a)(4) deal with strobe lights, work platforms, front-end attachments, rigging, restraints and modifications in general; none of them is about tires. In a 2004 letter, OSHA said written approval from the truck maker is required for modifications that affect capacity and safe operation, and that it would consider the lack of the maker’s approval “a de minimis violation if the employer has obtained written approval from a qualified Registered Professional Engineer after receiving no response or a negative response” from the maker. A 2002 letter adds that OSHA “might not accept an engineer’s written approval if it did not address all of the manufacturer’s safety and structural issues.” OSHA notes that its letters explain requirements but “cannot create additional employer obligations.”

So whether filling tires or switching to solids is an (a)(4) modification is a fact-specific question, and none of the letters OSHA indexes to (a)(4) answers it. It is not an OSHA tire rule.

What the truck maker and the fill maker say

Hyster’s operating manual for its H40-60XT trucks is direct: “Any change to the lift truck, the tyres, or its equipment can change the lifting capacity.” The same manual says the truck is to be rated as equipped, with the new capacity on the nameplate, and that “The type of tire and the tire pressure (pneumatic tires) are shown on the Nameplate.” It tells owners to make sure the nameplate is correct for the type of tires on the truck.

TyrFil says filling does not lower the tire’s load capacity, which “remains as specified by the tire manufacturer.” That is the tire’s rating, not the truck’s. TyrFil also says the added weight “lowers the center of gravity and reduces wheel slippage.” The truck maker’s rating on the data plate is the figure that governs what the truck may lift.

Before you fill or switch

This is FTC’s suggested routine. Steps 1 to 3 are advice, not OSHA requirements; step 4 is what (a)(4) says:

1. Read the data plate: the rated capacity, and the tire type if the plate lists one. How to Read a Forklift Data Plate shows where to look and explains that the tire line is manufacturer practice, not an OSHA-required field.
2. Check the sidewall of the tire on the truck against the plate.
3. Ask the truck maker or dealer whether the change affects capacity and whether the plate needs to change.
4. If the change affects capacity and safe operation, (a)(4) calls for the maker’s prior written approval and changed plates.

Appendix A to 1910.178, which is non-mandatory, tells operators to check the data plate for the maximum allowable weight at the rated load center; The Forklift Stability Triangle explains why. This section covers federal OSHA. States that run their own State Plans are monitored by OSHA and have to be at least as effective as federal OSHA.

Mounting and Servicing Safely

Foam fill keeps the wheel: it goes into the tire on the wheel it is already mounted on, and TyrFil’s steps then lay the tire flat on a pallet to cure. TyrFil’s weight guide assumes “The tires are mounted on standard width rims,” and drop-center wheels take more fill. A solid resilient is a new tire on a pneumatic-type wheel, with limits:

• Three- and four-piece wheels. Hyster’s manual says “A solid rubber tire that is the same shape as a pneumatic tire can be installed on a three-piece or four-piece wheel for a pneumatic tire,” and warns against changing the rim parts when one is installed: “Changes to the parts of the rim can cause a failure of the wheel and cause an accident.”
• Two-piece bolt-together (split) wheels. The same Hyster H40-60XT manual warns: “DO NOT use pneumatic-shaped, solid tires on two-piece bolt together drive wheels. Spinning may occur.” If your truck has split wheels whose halves bolt together, ask the truck maker or dealer before switching to solids.
• Lock-ring wheels. Trelleborg says its lock-ring wheels are “Suitable for resilient tires (standard and loc) as well as tubeless and tube type pneumatic tires,” in 1-, 2-, 3- and 4-piece designs.
• Click-style solids. Loc, Quick or SIT versions lock into a groove in the wheel, so they need a lock-ring-style wheel with that groove, and makers list them size by size: Trelleborg marks each resilient size STD, LOC or BOTH.
• Rim width and rim load. Solideal says to check the rim, “especially on width,” against the tire base marking, and to check the rim’s maximum load with the rim maker, because the wheel load is limited by whichever is lower, the rim’s or the tire’s.

Tire Installation Service shows FTC’s pressing options for solid tires.

Wheel work is dangerous with either choice

Hyster’s manual reserves wheel changes and tire repair for trained personnel. It says to deflate a tire completely before removing the wheel, warns that “Air pressure in the tires can cause the tire and rim parts to explode causing serious injury or death,” and says not to loosen the nuts that hold the inner and outer wheel halves together while there is air pressure in the tire. It also notes that “Lift truck tires and wheels are heavy.” Continental says mounting and demounting belong with specially trained tire professionals, and that “Serious injury and/or death may result from improper tire service procedures and improper tools.”

Do not assume fill or solid rubber takes the danger out of wheel work. In TyrFil’s process the filled tire is pressurized with fill to the recommended pressure, and the sources cited here do not cover demounting a filled tire from a multi-piece wheel. Leave it to a trained tire service.

On the OSHA side, 29 CFR 1910.177 covers servicing multi-piece and single-piece rim wheels on “large vehicles such as trucks, tractors, trailers, buses and off-road machines.” It does not name forklifts, so applying it to forklift lock-ring wheels is a reading of the rule, not an OSHA statement. A 1991 OSHA letter, written about an aircraft-type wheel, says bolt-together divided wheels are not covered by 1910.177, but that employers are still obligated to protect employees under the general duty clause.

Daily checks still apply. A filled tire needs no further pressure adjustment (TyrFil), but 1910.178(q)(7) calls for the truck to be examined before it is placed in service, at least daily. OSHA’s powered industrial truck eTool, an advisory guide that OSHA says is not a substitute for the standard, suggests checking tire condition, “including cuts and gouges, and check pressure for air-filled tires.” Forklift Tire Damage: Signs and Causes covers what to look for.

Which One Suits Your Operation

Each maker favors its own product, and no independent test in these sources settles it. These questions decide it:

• How often you get flats, and where. Both are sold for puncture-prone work. Weigh the fill’s sidewall and large-puncture limits (Yokohama-ATG, writing about skid steers) against the heat and speed limits of solids (Continental).
• How far and how long the trucks run. Continental puts the permitted average speed of solids well below their maximum and advises cool-down time; TyrFil limits its three-shift forklift recommendation to Ultra 30.
• Whether you want to keep the tires you have. Fill goes into the tires already on the wheels; a solid resilient replaces them.
• Your wheels. Hyster’s H40-60XT manual warns against solids on two-piece bolt-together drive wheels, so ask the truck maker or dealer if yours are split wheels; click-style solids need a grooved wheel, and Solideal says to check rim width and rim load for a solid.
• How permanent you want it. Yokohama-ATG, writing about skid steers, says a filled tire comes off by cutting; TyrFil says filled tires can be retreaded.
• What the truck maker says. Start with the data plate, then the maker or dealer (Hyster, Toyota).

Where to buy: solid resilient tires are in Solid & Pneumatic Forklift Tires, and air-filled pneumatic sets are in Pneumatic Forklift. For pneumatic-tire trucks, FTC’s catalog lists air-filled pneumatic and solid resilient tires; it lists no foam-filled tires and no fill service. Filling takes fill equipment and curing time, so for fill, ask your tire service or the fill maker about a dealer near you.

Frequently Asked Questions

This article is general educational information from Forklift Tire Company. It is not a substitute for OSHA-compliant operator training, a formal compliance review, your equipment’s data-plate ratings or the tire manufacturer’s specifications. Follow your data plate, the tire sidewall and 29 CFR 1910.178. Trademarks: TyrFil, Carlisle, Solideal, Michelin, Continental, Super Elastic, Trelleborg, Yokohama, Sentry, Hyster, Toyota and all other brand names are trademarks of their respective owners. Forklift Tire Company is an independent aftermarket supplier and is not affiliated with, authorized by, sponsored by, or endorsed by any tire manufacturer, fill maker, equipment manufacturer or government agency.