Maintenance - Major Service

15. Check the wheels and wheel bearings

Wheels

Carefully check the complete wheel for cracks and chipping, particularly at the spoke roots and the edge of the rim. As a general rule a damaged wheel must be renewed as cracks will cause stress points which may lead to sudden failure under heavy load. Small] nicks may be radiused carefully with a fine file and emery paper (No 600 - No 1000) to relieve the stress. If there is any doubt as to the condition of a wheel" advice should be sought from a reputable dealer or specialist repairer.

Each wheel is covered with a coating of lacquer or paint to prevent corrosion. If damage occurs to the wheel and the finish is penetrated, the bared aluminum alloy will soon start to corrode. A whitish gray oxide will form over the damaged area, which in itself is a protective coating. This deposit however, should be removed carefully as soon as possible and a new protective coating applied.

Check the lateral run out at the rim by spinning the wheel and placing a fixed pointer close to the rim edge. lf the maximum run out is greater than 0.5 mm (0.02 in) the manufacturer recommends that the wheel be renewed. If warpage was caused by impact during an accident, the safest measure it to renew the wheel complete. Worn wheel bearings may cause rim run out. These should be renewed.

Note that impact damage or serious corrosion has wider implications in that it could lead to a loss of pressure from the tubeless tires. If in any doubt as to the wheel's condition, seek professional advice.

Front wheel bearings

Support the machine on its center stand on level ground so that the wheel to be examined is clear of the ground (wedge a wooden block or similar under the sump to raise the front wheel). Grasp the wheel firmly at top and bottom and attempt to rock it from side to side about its spindle; if any play is discovered, the wheel bearings must be renewed. See Chapter 9 - Wheels & Brakes.

Rear wheel bearings

Support the machine on its center stand on level ground so that the rear wheel is clear of the ground. Grasp the wheel firmly at the top and bottom and attempt to rock it from side to side about its center. If any play is discovered the machine should be taken to a BMW dealer for the bearings in the final drive to be checked. Note that there should be no discernible endfloat (axial play) at the wheel hub.