(This article originally appeared in the March 2003 issue of TWMX. Have you subscribed yet?)
A few years ago seat bouncing used to be a method that only a handful of experienced pros used. The technique was reserved for the skill levels of Supercross heroes like McGrath, Emig and Ward. These days, without a good seat bounce in a racer’s bag of tricks there’s no way that they could even be competitive, not to mention safe on today’s increasingly technical Supercross tracks.
Mostly used on tighter courses with tons of jumps, the seat bounce is employed to propel a racer over an obstacle such as a double or triple jump when there is little room to muster up speed. By sitting on the seat and twisting the throttle, the rider loads the rear shock through a combination of his own weight and torque from the engine. The shock responds by using its coiled-up energy to bounce the rider up and over the obstacle that lies ahead.
This month, MotoworldRacing.com team rider Andrew Short rendered his services to the readers of TWMX. Andrew’s a Colorado boy that began his racing career at the tender age of six. Now all grown-up and racing pro, Andrew will be contesting a 125cc Supercross title while racing selected 250cc events in this year’s AMA/THQ Supercross Series. Our shoot was at the newly redesigned Suzuki test track in Corona, California. Be advised that this is an advanced move and beginner riders should work up to something as advanced as the seat bounce. Here are some of Andrew’s tips …
Get Over It
“Though I will focus primarily on the 125cc class this year, today I will be on my RM250. Even with the extra power of the 250, I have my bike in first gear as I go over the roller preceding this double. As I go through the mechanics of the seat bounce, note that I have my finger on the clutch through the entire jump. This particular part of the track has a roller before the double I am seat bouncing. This adds a degree of difficulty because speed is limited for the jump.
“As I feel my rear wheel get over the roller I start to approach the take-off of the jump, adjusting my body to where it should be for maximum spring. On this jump, I sit in the middle of the seat. At this point I am grabbing the throttle and easing the clutch out at the same time.
Once in the air, I un-weight the seat and aim the front end where it needs it to go. As I am in the air, I am spotting the landing. Landing smooth when you’re in a section with numerous obstacles is important because you need to keep your momentum moving forward. Now you’re set to accomplish the next obstacle on the track.”
“One thing you want to watch out for is throttling off the face of a jump. If you’re not sitting back far enough on the seat, the bike will tend to take off with the front end high. By pulling in the clutch and tapping the rear brake, you can add weight to the front of the motorcycle by stopping the gyroscopic effect of the rear wheel; this should help to bring the nose down. On the other hand, if you’re sitting too far back on the seat the bike will go into endo mode, where your front wheel drops on you. The way to correct this is to give the bike more throttle. The spinning weight of the rear wheel will pull the back end of the bike down.”
Shift Your Weight
“The seat on a motocross bike acts like a pogo stick: The further back you sit, the higher your bike will spring you. The more forward you sit, the less spring you get. Be careful to adjust where you are sitting according to the speed you have going into the obstacle. Another rule is that the faster you are going, the further forward you will want to sit. The slower you go the further rearward you must sit. This will provide for additional leverage. Also, be aware that the higgher you go the more airtime you get, and the additional time spent in the air will increase seconds on your lap times. The idea is to get the least amount of air while still getting over the jump clean. The more times you practice the technique the better of a feel you will get for it, and soon you’ll be able to gauge your speed for the appropriate air time.”