What is motorcycle suspension sag and why is it important?
Suspension sag is the amount your suspension compresses under the weight of the rider and gear. Proper sag ensures your suspension operates in its optimal range, providing better traction, comfort, and handling by keeping the bike balanced and allowing full use of suspension travel. See also our Motorcycle Chain Length Calculator.
How do I measure sag on my motorcycle?
To measure sag, first measure the suspension length with the bike unloaded (free sag), then with you seated in riding position (race sag). The difference between these measurements is your sag. Use a tape measure from the axle to a fixed reference point on the bike.
What's the difference between front and rear sag settings?
Front sag typically ranges from 25-30mm or 20-25% of total travel, while rear sag is usually 25-35mm or 25-30% of travel. The exact settings depend on your bike type, weight, and riding style, with track riders often using less sag for sharper handling.
How does riding style affect sag settings?
Track riding requires less sag for quicker steering and better feedback, while touring riders need more sag for comfort over long distances. Off-road riding often uses more sag to handle rough terrain, and street riding falls somewhere in the middle for balanced performance. You might also find our use the Two-Stroke Premix Calculator useful.
What should I do if my sag is incorrect?
If sag is too little, increase preload by tightening the preload adjuster. If sag is too much, decrease preload. If you can't achieve proper sag with preload adjustment, you may need different spring rates - stiffer springs for heavy riders or softer springs for lighter riders.
How often should I check my motorcycle's sag settings?
Check sag settings whenever you change riding gear significantly, after suspension service, or if handling feels off. It's good practice to verify sag at the start of each riding season or after any suspension modifications or repairs.
Can incorrect sag damage my motorcycle?
While incorrect sag won't immediately damage your bike, it can cause premature wear of suspension components, tires, and other parts due to poor handling characteristics. Proper sag helps ensure your suspension and bike geometry work as designed by the manufacturer.