Checking motorcycle chassis wear
Wear affects the chassis: brake discs or calipers, fork tubes, two wheel and steering column bearings, swing arm rings or needle cages. Here's how to assess chassis fatigue ... and what repairs to consider.
Difficult level:
easily
Equipment
– Car jack or motorcycle workshop stand without center stand.
– Lubricant in a can, tube or aerosol.
– Bomb lube/penetrating/water repellent like WD 40, Motul’s Multiprotect, Ipone’s Protector 3, or Bardhal’s multipurpose lube.
1- Check the steering column
While stationary, lift the front wheel off the ground and shake the fork legs (photo A). Together it's easier. Without a center stand on the side, use a car jack under the frame at the front right to raise the front wheel. When you put your hand on the triple clamp, you will feel the play, which is also felt when driving, on the brake: you feel a sharp click in the steering wheel. Tightening the steering column nuts should eliminate this play. Make sure the steering is free of attachment points (photo B). It is easier to drive by lifting the front wheel off the ground. The fork must rotate freely, which will not happen if the raceways of the balls or rollers on the bushings are marked. We say the steering is "blown up" and all that remains is to replace the bearings. Everyone knows that fork oil seals can leak, but few people know that the fork tube (photo C) wears out with the accumulation of kilometers. Admittedly, this is a slow phenomenon, but for good reason most forks have tube guide rings in the legs that are replaced when worn.
2- Check wheel bearings
Adjusting the backlash of the rear wheel bearings is not a luxury, especially on a powerful sports car. They can get tired from 40 km. The front wheel is not affected by the traction force of the engine, but play will eventually occur. Hold the splint with both hands (photo A), one at the top and the other at the bottom. It's easier with a center stand. Pull on one side, push on the other side perpendicular to the wheel, reverse force. If they are in good condition, the play is invisible. If you feel any slack, you need to replace the bearings to fix the movement problems. If you delay, it will become a security issue. To be sure, we remove the wheel, manually check the bearings: if they need to be replaced, then they definitely “catch” and do not spin.
3- Check the swing arm play.
With one hand, firmly grasp the rear wheel, and with the other, place between the passenger footrest and the swingarm. Shake vigorously. If you feel any play, lower the rear wheel and grab the swingarm with both hands to shake it. Then you will feel great if it moves around its axis. The play in the swingarm axle is very bad for handling. Mounted on ring or needle bearings, repairing it is no easy task. It is not difficult to remove the axle if it is not seized. The biggest difficulty lies in removing the rings or cages of the needle bearings mounted in the arm.
4- Check the brakes
Everyone knows that brake pads wear out and need to be replaced. Brake disc wear also exists, although it is slower. The discs become hollow and beyond a certain thickness must be replaced for safety reasons. The minimum thickness is usually indicated by the manufacturer. If you go too far, cracks may appear from the ventilation holes (photo 4 a opposite). It is absolutely dangerous there. Imagine a disc breaking when you brake hard! Brake calipers also need proper maintenance. When pushing the pistons back to install new pads, they must be cleaned. Otherwise, the pistons will jam, they will not move back. Push the bike with your hand, brake, then release if it still slows down, this is due to jammed calipers (photo 4b below).
5- Prevent jamming
The phenomenon of sticking screws and nuts, wheel axles, engine axles, pipe fittings and exhaust pipes is relatively unknown to DIY enthusiasts. However, it is not sad to remove a jammed axle. Sometimes the operation is not even possible. When you yourself service a motorcycle that you ride in any weather, the precautions are simple. On all dismantled screws and on all axles, traces of oxidation are removed using a candle brush and iron wool. Apply a thin coat of grease or spray such as WD 40, Motul's Muttiprotect, Ipone Protector 3 or Bardhal Multi-Purpose Grease before assembly.
Equipment
– Car jack or motorcycle workshop stand without center stand.
– Lubricant in a can, tube or aerosol.
– Bomb lube/penetrating/water repellent like WD 40, Motul’s Multiprotect, Ipone’s Protector 3, or Bardhal’s multipurpose lube.
Etiquette
– Continue driving with HS wheel bearings: if the ball cage breaks, the wheel will seize up and fall off.
– Do not replace a cracked brake disc.
