Repair a loose wheel by gluing thin leather or rawhide shims inside the worn hub hole, stop a cracked disc wheel by drilling a hole at the crack’s tip and pegging a batten across it, sleeve a worn axle arm with thin iron strip or a pegged hardwood sleeve, and splint a broken shaft with a sister pole. A hub bore only 3 mm oversize on a 15 cm bearing wobbles the rim of a 30 cm radius wheel by about 6 mm, so even small wear is worth fixing.
Part of Cart & Wagon Construction
Wheel and axle repair is the re-setting of loose wheels, the closing of cracks and the replacement of worn bearing surfaces on a hand-built cart.
Small Bore Wear Becomes Big Rim Wobble
A wheel on an oversized bore can tilt on its axle by the clearance divided by the length of the bearing. With assumed figures, a bore 3 mm larger than the arm and a bearing length of 15 cm (the journal length in Wooden Axle Construction):
- Tilt = 3 mm / 150 mm = 0.020 rad
- Rim movement for a rim radius of 300 mm (30 cm) = 300 × 0.020 = 6 mm
The shim thickness needed to take the slack out is half the diametral clearance: (3 mm) / 2 = 1.5 mm on each side. A longer bearing reduces the wobble: the same wear over 300 mm of bearing gives 3 mm.
What You Need
- Thin leather or rawhide, for shims (Leatherwork)
- Glue, hide glue or similar (Hide Glue)
- A drill or auger for crack-stop holes, pegs and a batten
- Thin iron strip, or hardwood, for the axle sleeve
- Cordage or wire for lashing
- A prop and chocks for lifting the vehicle
Repairs, One At A Time
Loose wheel. The hub hole has worn oversize. Glue thin leather or rawhide shims inside the hub, measured so that the wheel just turns freely on its greased arm.
Cracked disc wheel. If the crack has not reached the hub, drill a hole through the wheel at the crack’s tip to stop it propagating: the hole replaces a sharp tip with a round edge, and a sharp tip concentrates stress far more. Then batten across the crack with pegs, on one or both faces. A crack that has reached the hub weakens the bearing area, and the wheel should be replaced (Solid Disc Wheels).
Worn axle arm. Wrap the arm with thin iron strip, or build it up with a hardwood sleeve pegged in place. The arm gets bigger by the thickness of the repair, so re-fit the hub bore and re-check the clearance (Axle Box & Bearings).
Broken shaft. Splice with a sister pole lashed alongside the break, extending well past it on both sides. It is a temporary fix: replace the shaft when you can, because the sister pole carries the load only through the lashing.
Spoked wheels. For a loose iron tire, a broken spoke or a cracked felloe, see the repair notes in Wheelwright Craft. A loose tire is first tried by soaking the wheel in water for 24-48 hours, and re-setting the tire (Hot Shrinking Process) if that fails.
Method: Re-Setting A Loose Disc Wheel
Step 1: Chock and lift. Chock the other wheels, lift the axle on a prop, and remove the linchpin and wheel.
Step 2: Measure. Measure the arm and the bore; the difference is the clearance.
Step 3: Cut shims. Cut strips of leather to half the diametral clearance in thickness and the length of the bore.
Step 4: Glue them evenly round the bore and let the glue set.
Step 5: Refit the wheel and the linchpin, grease, and spin the wheel. It should turn freely, with no rocking at the rim.
Common Mistakes
- Shimming one side only — the wheel runs off-centre on the arm.
- Drilling the stop-hole off the crack tip — the crack continues past it; find the true tip.
- Leaving the lashing on a splint unchecked — it stretches and the splint works loose.
- Putting a thicker sleeve on the arm without re-boring the hub — the wheel seizes.
Safety
Lifting and propping a loaded vehicle
A cart dropped on a hand or a head while a wheel is off is the usual injury in wheel repair. Unload first, chock the other wheels, prop the axle on solid blocks and never rely on a jack alone. If a hot iron tire is being re-set, follow the water-first sequence in Hot Shrinking Process.
What’s Next
- Learn next: Maintenance & Field Repair — checks that prevent repairs
- Combine with: Lubrication & Wear — protecting the repaired bearing