Regular wheel maintenance is necessary to maintain the appearance and safety of the vehicle. Special attention must be paid to the rim edge in order to keep the joint tight and to prevent rim from damaging the tyre.
When driving, the tyre is constantly rubbing against the rim flange and finally produces a sharp edge. The edge condition should be checked every time the tyre is changed. Only Alcoa® Wheels Dura-Flange® rims have special protection against this type of wear, and the edge has a two-year warranty without mileage limit.
The edge sharpening is particularly affected by corrosive detergents, heavy loads, low tyre pressure and moving cargo weight from one side to another. Also avoid using too narrow wheel size.
An excessively sharp edge may damage the tyre when it is removed from the wheel.
Sharp edges can cut the long shavings of rubber from both sides of the tyre. This can cause air to leak. Sharp wheels should not however be scrapped without further inspection. A properly maintained wheel can still continue to serve for tens of thousands of miles.
To estimate sharpness, you should bevel the rubber-coated wood back against the rim edge. If the edge cuts the rubber, the rim requires immediate maintenance.
Use caution when removing the tyre
When you notice a sharp edge, lubricate the contact surface of the tyre and rim using e.g. Alcoa HubGrease. Gently remove the tyre from the wheel.
Check all wheels at each tyre change for proper contour of the open side of the rim. The following inspection technique only applies to dual or disc faced wheel.
Place the long edge of a carpenter square across the center of the disc side of the wheel. Extend the short leg across both rim flanges of the wheel as shown in pictures. Repeat this process at four equidistant points around the wheel. The short leg should touch both rim flanges at each point. If a distance greater than the thickness of a credit card (0,76 mm) appears between the short leg and the rim flange, the wheel should be permanently removed from service and scrapped. Otherwise, the edge can be checked with a wear gauge tool and if it passes the test, may be grinded and returned to service.
Picture 1. Use of a carpenter square for rim measurement. On the right a credit card can be placed easily between the square and the wheel.
Alcoa Rim horn wear gauge
Rim edge sharpness can be removed by grinding. Alcoa rim horn wear gauge (Picture 2) can easily see if the edge is still high enough. When the metal is no longer sufficiently grinding, the rim is exhausted and should be deactivated. Your Alcoa wheel interpreter is free of charge from Milcoa.
Picture 2. A rim wear gauge is placed on the edge. A) Sufficient material left for grinding B) Still OK, the daylight can be seen under C) The wheel has to be scrapped.
Sharpness removal
The sharp edge can can be removed with a file or grinder. If you are using a grinding wheel, protect yourself from noise, sparks and metal chips. Wear safety glasses, gloves and hearing protection. Only remove a necessary amount of metal to eliminate the sharp edge and avoid gouging the wheel. Be careful to make the edge as uniform as possible. Finally, check the flange area for a sufficient height with a wear gauge. If the entire circumference has sufficient edge to support the tyre, the rim can be returned to service.
For more service instructions, see the Alcoa Wheels service manual, which you can request at info@milcoa.fi. Online info available in Service manual section 13g.
Video Guide for removing a tyre: How to mount and dismount Alcoa Wheels.