[Tigers] Replica Libre/Libra wheels

[Steve Laifman]

Jerry,

It isn't "torque" that holds the wheel on to the car, but the total 
clamping force.   The diameter of the root of the stud threads, the 
number of studs/wheel, and the bearing area of the lug nut seat dictate 
the clamping force required.  Whether the wheel can take it depends on 
the design.  I recall that the Triumph TR-2 was required, for racing, to 
have a load plate over the studs to prevent the wheel center from 
tearing out.

The Tiger has thicker wheels in that area than the Alpine then proceeded 
it. Later "homogulated" to reduce stocking parts.

The clamping force can be measured with some sophisticated strain gauges 
in special instrumented washers, but that's a little much for a 
production car.  I recall my Jaguar Knock-Offs mounting torque was "a 
good fitting with a rawhide hammer, followed by a goodly thwack with a 
copper one. (Came with the car!)

The actual clamping force required in the stud is translated to the 
installed torque of the wheel nuts for each application so that a garage 
or owner can tighten to the required clamping force.

If you have bigger stud diameters, and/or more of them, that number can 
vary, and does.

I have used a Snap-On Torque Wrench, set to 50 pounds F, to correctly 
clamp the wheel to the car.  An alloy wheel needs to withstand that 
clamping tension and not crack.

Your Panasport wheels are very well made, and can stand the compressive 
load required.  Not so good wheels could crack in the stud holes.

BTW, this is the reason that factory tire wrenches seem short.  That is 
to prevent the Gorilla in us from exceeding the force, and maybe 
breaking something.

Steve

Steve Laifman

Editor

http://TigersUnited.com



Jerry & Maureen (Mo) wrote:
> List
>
> I found it interesting on that website, if you go to "FAQ & Tech", it shows
> 7/16 lugnuts to be torqued to 55-65 lbs. The Tiger Shop Manual shows 48 lbs.
> that I always thought was quite low.  I'm a firm believer of proper torque
> settings, but now I think I'll go up a few more lbs.
>
> Jerry Christopherson
> 9473187