NachaLuva
Product Developer
After some researching on wheel spacers I've found some useful info.
First is that several car manufacturers have spacers as optional OEM equipment, eg Porshe.
If offered as OEM, spacers (of the correct type) ARE legal in Australia.
Spacers need to be the bolt on type. Ie, they bolt to the hub using the OEM studs & have high tensile bolts pressed into them for the wheels to bolt onto.
Spacers need to be hubcentric, ie, have a protruding lip that locates the wheel exactly in the centre.
Now we get to some controversy...are the hub centres actually weight bearing or do they merely locate the wheels, ie, keep them exactly centre while torquing the studs?
The argument is that by torquing the studs to 100Nm each, the force holding the wheels to the hubs is in the order of an order of magnitude greater than the force that can be applied to it. Ie, one calculation was ~30t of clamping force. The max load might be as much as 3t if the wheel were to hit a severe bump, so only 1/10 of the clamping force. This means that the studs are not under a shear force (if the studs are correctly torqued) only a tensile force.
This leads me to think that the hub centres are not weight bearing, instead their purpose is to locate the wheels centrally so there is no vibration.
However I do not like the idea of my wheels falling off! So I am playing safe by making sure my spacers are bolt-on, hubcentric with the correct size bore & high tensile studs (mine have grade 10.9 studs) :biggrin:
I have a question though...the manual says 66ft-lb (90Nm) yet I've seen it elsewhere as 74-89ft-lb (105-120Nm). So what is the CORRECT torque for subaru wheel studs???
First is that several car manufacturers have spacers as optional OEM equipment, eg Porshe.
If offered as OEM, spacers (of the correct type) ARE legal in Australia.
Spacers need to be the bolt on type. Ie, they bolt to the hub using the OEM studs & have high tensile bolts pressed into them for the wheels to bolt onto.
Spacers need to be hubcentric, ie, have a protruding lip that locates the wheel exactly in the centre.
Now we get to some controversy...are the hub centres actually weight bearing or do they merely locate the wheels, ie, keep them exactly centre while torquing the studs?
The argument is that by torquing the studs to 100Nm each, the force holding the wheels to the hubs is in the order of an order of magnitude greater than the force that can be applied to it. Ie, one calculation was ~30t of clamping force. The max load might be as much as 3t if the wheel were to hit a severe bump, so only 1/10 of the clamping force. This means that the studs are not under a shear force (if the studs are correctly torqued) only a tensile force.
This leads me to think that the hub centres are not weight bearing, instead their purpose is to locate the wheels centrally so there is no vibration.
However I do not like the idea of my wheels falling off! So I am playing safe by making sure my spacers are bolt-on, hubcentric with the correct size bore & high tensile studs (mine have grade 10.9 studs) :biggrin:
I have a question though...the manual says 66ft-lb (90Nm) yet I've seen it elsewhere as 74-89ft-lb (105-120Nm). So what is the CORRECT torque for subaru wheel studs???
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