wheels

Wheels

Tyres

The tyres of choice are Hankook Dynapro MT (RT03) 37x12.50R17 LT. These are an 8-ply Light Truck tyre with 2 ply walls, rated to 124Q (i.e. 1600kg at 160kph), and when new are 36.8" diameter with a tread depth of 16.7 mm.

These tyres have performed exceptionally well, having great grip in all conditions and wear slowly giving over 80,000km if rotated between wheels every 10,000km.

Rims

TT30 started off with standard rims, taking Michelin XZY on-road tyres. To change to the larger Hankook tyres (and to allow much safer front brake rotors to be fitted, see brakes), the rims were changed to 17" x 9" steel rims from Gecko Wheels. These have a load rating of 2100kg.

The wheel nuts for steel rims need to be tightened to a torque of 305–375Nm. This is readily managed — using the supplied bar on the wheel nut socket spanner extended to about half a metre, a 75kg body weight on the end of the bar provides a torque of ~375Nm. For added safety a set of Wheel Nut Indicators (27mm yellow flags) are fitted for quick visual checks.

Tyre Pressures

TravelTrucks recommend running pressures across a variety of terrain as 45psi on road, dirt tracks 35psi, sand tracks 30psi and extremely soft sand down to 20psi. These agree with the calculator on the GoannaTracks' Website for SuperSingles. I have made my own version of the calculator which can be used to vary loads. Click on the example here to make your own estimates:

Tyre Pressure Monitor

I think the cost of a tyre pressure monitor is well worth it. A tyre blowout on my previous camper was expensive to repair. A TPMS can alert the driver before its too late to stop and repair the leak. This is just what happened to us when we turned around on an isolated narrow dirt track and spiked a tyre. The monitor alarmed telling us which tyre was in trouble, we plugged the leak in record time, and had no subsequent trouble.. The OBD2 TPM System is one of the better ones. The sensors screw on to the valve stems. And the receiver/display sticks to the windscreen; it is charged by a small solar cell or from a USB port. I found that a dedicated USB port is best. It has alarms for leak, over-pressure, and temperature that can be set over a wide range. Documentation is here. Note that to initiate pairing of sensors to the monitor the left button on the monitor has to be pressed 8 times to start the process. This needs to be done briskly.

The external sensor batteries are CR1632 and last for about 2 years. They are easy to change.

The pic shows the page of settings I use: psi, °C, max pressure 56 psi, min pressure 24 psi, alarm temperature 68°C.

Rims

The rims are from Gecko Wheels, have a load rating of 2100kg, and an offset of 41.5mm.

Hankook tyres and Geko rims fitted to TT30.

Geko Wheels suppy rims for TT30.

Specifications for Geko rims on TT30.

Hankook Tyres

The Hankook Dynapro MT (RT03) 37x12.50R17 LT tyres are an 8-ply Light Truck tyre with 2 ply walls, rated to 124Q (i.e. 1600kg at 160kph), and when new are 36.8" diameter with a tread depth of 16.7 mm. They weigh 38kg each, and fitted to the Geko rims weigh 60kg each. This is an increase of 11kg per wheel compared to the OEM street tyres and rims.

TravelTrucks had already relocated the diff. lock pump/mechanism to between the chassis rails behind the camper battery so there was no interference problem caused by the wider Hankook spare.

With new 37” Hankook tyres the Iveco speedometer now reads 2.0% slow and the odometer now reads 8.15% too short a distance. These numbers change as the tyres wear.

These tyres protruded beyond the front mudguards so mudguard flairs from Clark Rubber have been fitted.

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