Excessive tire wear, and/or cupping, is a problem that most motorcyclists experience over time. Too often this is simply the result of failing to maintain proper tire pressure. However, this is far from a complete answer.
Cupping is a phenomena that is absolutely normal! Excessive cupping or excessive wear on one side of the tire as compared to the other is not.
There are at least seven causes of cupping and/or uneven wear in the front tire other than tire air pressure:
- Most roads are banked away from the center. Thus, if you ride vertical, the side of your tire closest to the center of the road wears more.
- Your tires 'scuff' when you force a speed change with them. The rear tire scuffs when you accelerate and when you brake (and every time you ride in a direction other than straight ahead.) Thus, it tends to have even 'cupping' as compared to the front tire (which scuffs when you brake but not when you accelerate.)
- While alignment is not usually a problem with motorcycles - it can be.
- Carrying an unevenly divided load (all your tools, jumper cable, etc.) in one saddlebag can result in your riding the bike other than vertical most of the time.
- Setting your TRAC (anti-dive) unequally can easily cause uneven tire wear.
- If one of your front shocks is defective you will experience uneven tire wear.
- Excessive use of the front brake will result in excessive cupping.