Fit dual-stage foam and 1.0 inch SCX24 tires stop folding

SCX24 1.0 tire inserts decide whether a micro crawler holds its line or rolls off the rock. The fix for a folding tire is dual-stage foam. Pro-Line’s PRO616900 pairs a firm closed-cell inner ring with a soft open-cell outer, so the sidewall stays propped up while the tread still grips. A single soft foam cannot do both jobs.

Why a soft single foam lets a 1.0 inch tire fold

Picture your truck on an off-camber line. The tire rolls over onto its sidewall, the casing collapses, the tread lifts off the rock, and the truck slides down the slope.

A micro tire is tiny, and the driver’s weight advantage is gone. On a heavier 1.9 inch rig, the truck’s own mass helps press the tire into shape. A 1/24 crawler weighs almost nothing, so the insert does nearly all of the shape-holding work. Less foam volume and a thinner casing make the problem worse.

Crazy Crawler’s heavy-duty foams are built to stop the rolling effect that twists a tire and, in extreme cases, lets it slide over the flank onto the rim, per the LaserFoam 1.0 R48x17 Heavy Duty product page .

A very soft foam gives lovely tread compliance on flat rock, and that same softness is why the tire folds the moment the truck goes sideways. If your tire squats flat under the rim, rolls under on a side-hill, or wanders on a slope, the insert is too soft.

What is a dual-stage foam insert?

A dual-stage insert is two separate foams per tire. An inner ring and an outer sleeve, each cut from a different density, work together as one insert. The point is to split one hard job into two easy ones.

Pro-Line’s 1.0 inch set is the 1/24 dual stage front/rear 1.0 inch rock crawling foam, part PRO616900 . The box holds four inner closed-cell foams and four outer open-cell foams. The inner is a lightweight blue closed-cell foam. Closed cells trap air, so the ring resists crushing and props the sidewall up.

The outer is soft open-cell foam. Open cells let air move, so the tread face squashes and wraps the rock instead of skating over it. The inner ring decides whether the tire keeps its shape, and the outer layer decides how much rubber touches the rock.

Pro-Line contours the foams to match the shape of its own 1.0 inch tires. That is also why a dual-stage set can feel wrong inside a differently shaped tire from another brand. The pack lists at 56 mm height and 18 mm width, four inserts per package, and it is inserts only.

How Crazy Crawler’s LaserFoam 1.0 inserts tune a micro tire

Crazy Crawler cuts a purpose-made 1.0 inch line for 1/18 and 1/24 micro crawlers. It names FMS models, the Traxxas TRX-4M, the Axial SCX24 and the RC4WD 1/24 Trail Finder as targets, per its 1.0 inch tire insert range . It is also the one maker that publishes measured dimensions.

The LaserFoam 1.0 R48x17 Heavy Duty, product CYC150, measures 48 mm outer diameter at the serrated end, 28 mm inner diameter, and 17 mm wide. Each insert weighs 1 gram. A wider sibling, the R52x19 Heavy Duty (CYC151), is cut for the TRX-4M Defender and Bronco tires.

The design goal is stable lateral support and damping that suits a small tire, with the low flank and width keeping total foam volume down. The shape keeps firm contact concentrated in the tread area, so the tire plants on its tread rather than rolling onto its flank. On a steep side-hill, that is the difference between gripping and sliding off the rim.

Durability is part of the pitch, with the foam sold on long life and no crumbling. Still, the maker warns against leaving the inserts soaked for months. 1.0 inch inserts are a shared standard across the micro field rather than one brand’s part, so the same set covers SCX24-class wheels and the wider 1/24 and 1/18 world.

Silicone inserts vs foam on a 1.0 inch tire

Molded silicone now sits next to foam on every micro parts shelf. Silicone is a molded rubber ring rather than a cut foam, sold as a direct swap for the sponge insert.

INJORA’s 1.0 inch silicone rubber inserts for 62-64 mm tires are sold on being waterproof and temperature resistant, and on giving more sidewall support than regular foam so the tire keeps its shape. Silicone is sized by tire, not by scale, and INJORA warns that fit is not guaranteed on other brands because wall thickness varies. Softness is a choice too: INJORA offers green soft and yellow super soft, the silicone version of picking a foam density.

A LaserFoam 1.0 insert weighs about 1 gram, while INJORA’s silicone runs 11 grams each. Four corners add roughly 40 grams of low, rotating weight that also works like a small wheel weight. That helps a light truck plant, but it is still weight the truck has to carry.

Silicone wins in the wet and cold, on water crossings, and over a long season, because it does not soak up water or pack out the way an open-cell foam does. Foam still wins for featherweight builds and maximum tread wrap on dry rock. A rubber ring can also add rebound, which makes a truck bounce off a ledge instead of settling on it. One limitation: nobody publishes side-by-side climb-success numbers for the three types at 1.0 inch, so this rests on construction and owner experience rather than a lab result.

Which SCX24 1.0 tire insert should you fit?

Match the insert to how you drive rather than chasing one winner.

Fit dual-stage foam when your truck folds on side-hills and you mostly run dry rock, since it is the most direct fix for a collapsing sidewall. Choose a single heavy-duty foam like the LaserFoam R48x17 when you want lateral support at the lowest possible weight, or when your tire is not a Pro-Line shape. Reach for silicone when you run wet, cold or dusty, or when you want the insert to double as a small wheel weight. Stay with the stock soft foam only if the truck is already planted and you just want more tread wrap on flat rock.

One rule covers all of them: measure before you order. Tire outer diameter and inner width decide the insert, and 1.0 inch covers a range from roughly 52 mm to 64 mm. Buy in fours and run one type on all four corners, because mixing inserts front to rear shifts the truck’s balance in ways that are hard to unpick. Front-to-rear bias is also what SCX24 overdrive gears tune, by speeding one axle over the other for a better climb. Get the insert right and a micro crawler that used to slide off every off-camber line will start holding the rock like a much bigger truck.