Tech Info

Download Guides:


Download install instructions for pin drive wheels (.doc file)

Download Backspace Calculation Diagrams (2-page .pdf file)


Safety wiring procedure for spinners

Spinner safety clip installation

Offset to backspace conversion

Wheel Sizing
When ordering replacement wheels for your vehicle it is important to know which measurements manufacturers use when for example they advertise a 15 x 7.5 rim
These measurements are all taken from where the tire bead seats on the rim, the outer extremities of the wheel lip can actually be up to one inch wider.
Similarly the overall diameter of the wheel is larger than designated for the same reason.

Offset
Offset can be positive or negative and is measured from the centerline of the wheel to the wheel mounting face or pad where the wheel bolts to the hub flange of the vehicle.
Positive offset is when the wheel mounting face is outboard of the wheel centerline and is popular of front wheel drive / newer vehicles.
Negative offset is where the wheel mounting face is inboard of the wheel center line and is more common on rear wheel drive, older and classic cars and gives the “ sucked in” deep dish effect.
If you are in the early stages of building a replica and desire the deep-dish effect then axle width etc should be considered,  if you use a rear axle, which is too wide you will not be able to use a deep-dished wheel.
It is not recommended to change the offset beyond the limits that are recommended by the vehicle or kit manufacturer, otherwise undue strain can be placed on the wheel bearings and the steering and handling characteristics may be affected

How to calculate backspace
PLEASE NOTE ALL WHEEL BACKSPCING QUOTED ON OUR WEB SITE OR PRICE LISTS DO NOT INCLUDE THE ADAPTER THICKNESS
When quoting the specifications of our wheel range we like to refer to backspace rather than offset, as it is much easier to measure.
The diagram on this page should clarify the measurement points.
Many replica builders are looking for the largest tire which will fit into the wheel arch without fouling the bodywork or suspension. This may look good but may also overload wheel bearings, please refer to the offset section.
If you have en existing wheel rim which already fits perfectly on your vehicle and wish to order replacement wheels simply measure from the mounting face or pad of the wheel where it contacts the hub flange to the inboard wheel lip, this is the backspacing.
If you are trying to calculate which size to order, that is the width of rim and backspacing and don’t have an old wheel to measure then it is slightly more complicated.

Measure and make a note of the following dimensions
1) Distance from hub face to the point where you want the outer edge of the rim to sit in the wheel arch. If your aim I to really fill the wheel arch don’t forget to allow for tire bulge.
You will need two straight edges to measure this accurately.
2) Distance from hub face inboard to whatever would first contact a wheel to limit the backspacing, this could be a chassis member, suspension link, brake component or the bodywork, again don’t forget tire bulge.
These two measurements added together (less approximately one inch, refer wheel sizing)
Will determine the maximum width of wheel which can be accommodated.
Once the width of the wheel and tire to be used has been determined the desired backspacing can easily be calculated as shown on the diagram. 
If an adapter is used this reduces the total backspacing by .375 inch. So in other words if you need a 3.125 backspace you would need to order wheels with a 3.50 inch backspacing as the adapter is .375 thick to achieve an effective backspace of 3.125 inch.

Bolt Circle or PCD (pitch circle diameter)
If an imaginary line were drawn through the centerline of the wheel studs the diameter of the circle is pitch circle diameter or bolt pattern.
So a 5-stud arrangement with a bolt circle of 4 1/2 inches would be quoted as 5 on 4.5 or 5 on 114.3 mm. this is the most popular set up for most replica builders who are using Ford components.
A quick and fairly accurate way to measure the bolt circle on a 5 lug is to measure from center
Of stud # 1 to the outer edge of stud #3 (that is miss out stud #2)

Correct location of wheel adapters on Hub
Motor vehicle manufacturers ensure that the hub/spindle/axle /drive flange has a raised center section to help locate the wheel while the studs are being aligned and also to keep the wheel hub centric.
Whenever installing aftermarket alloy wheels it is essential that the wheel has a center hole /pilot /spigot correctly sized to index correctly otherwise the wheel will not be hub centric.
Alloy wheel manufacturers should supply spigot rings to make sure the above is complied to, otherwise the weight of the vehicle is taken just by the wheel studs which could create a safety problem, it can cause wheel studs to break under heavy loads and also create balancing problems.
Our hub adapters are designed to ensure the knock off wheel is hub centric, see below.

Fitment of Adapters
The use of hub adapters allows replica builders to use genuine pin drive knock offs without the cost of a having custom hubs manufactured.
The adapters supplied by Vintage wheels have a center spigot sized correctly to fit most standard Ford/ Chevy hubs with 2 3/4 inch spigots.
Our order forms request that the customer measures the hub spigot diameters and if it is different from the standard measurements we will resize the adapters accordingly.
The up charge for non-standard adapters varies but is typically $30 per adapter.
Do not use adapters, which are not correctly sized as described above.
Vintage wheels use two styles of drive pin lugs depending on the application.
When the adapters are installed the wheel stud will protrude allowing the pin drive lugs to be installed.
It is essential that the wheel studs are long enough to allow full engagement of the thread of the drive pin lugs but not too long as to protrude through the end of the drive pin lug.
Wheel studs used must be of the correct grade as supplied by the hub/axle/spindle manufacturer or from a reputable aftermarket wheel stud supplier.
Drive pin lugs must be installed using high strength thread locker and torqued to the manufacturers specification. The typical torque setting for a 1/2 inch x 20-wheel stud is 85 ft lb.
Vintage wheels are not the only company offering adapters for knock off wheels.
Adapters, tri wings spinners and wheels from different manufacturers may not interchange and must be checked by a certified engineer for compatibility before installation.


Brake caliper clearance
When using oversized rotors, wheel clearance can become a problem.
In order to ensure that our wheels will not foul the caliper a simple measurement can be taken to calculate the diameter of the caliper where it would contact the inside of the wheel and the set back of that diameter from the drive flange, see diagram.
Another important measurement is outboard from the caliper to where the wheel spokes may interfere. When using oversized brakes the caliper manufacturer will bbe able to supply a diagram with the above dimensions.


Tri Wing Spinners
Tri wings to be torqued using a lead hammer of around 5lbs in weight and safety wired.
The safety wire must be pulling the spinner in the direction it tightens.
Adapters and tri wings are left and right hand thread; the RH thread is fitted to the left hand of the vehicle (looking forward from the rear of the vehicle)
A small amount of anti seize compound should be used on the mating surfaces of the wheel and the tri wing.



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