Adjusting Rear Spring Preload

While I'll bet that most cruiser riders don't buy bikes for their razor-sharp handling prowess, that doesn't mean basic suspension adjustments should be overlooked. If nothing else, most bikes have some provision to adjust the rear spring preload. Some riders intuitively feel that these adjusters can be used to stiffen or soften the spring, but sorry, that ain't the way it works. The suspension may feel stiffer when preload is increased, but that's because adding preload compresses the spring, so it takes more pressure to move the suspension any further. Adjusting preload simply determines the motorcycle's ride height.

Ride height is intertwined with sag, a subject too deep to cover here. Suffice to say that it's one of the prime ingredients in the handling stew. Basically, when ride height is overly high there is too little sag. The bike rides near the top of its suspension travel, it's stiff, uncomfortable, and if you're vertically challenged you may have trouble reaching the ground. If the ride height is too low, there is too much sag, the bike tends to move around on the suspension more than it should and the hard parts drag, a problem exacerbated by cruiser styling and the addition of a passenger and luggage. In general, most bikes are set with the preload on the low side for solo use. Turning it up a notch or two often firms up the handling, and of course any time a passenger is on board the preload needs to be adjusted upward to compensate for the added weight. Take some time to experiment with preload and learn how each change affects handling. Once you understand what's happening you'll be able to tailor the ride to your liking, rather than just accepting it.

How-To: Bolt-On Suspension Mods.