Chop It and Drop It!

Lowering The Front End

First and foremost, a general rule: Never lower the front end without lowering the rear. You can lower the rear without lowering the front, and what this does is give the bike a more chopper-esque effect. Think of the bike as a triangle, with the flat line at the bottom being your wheelbase and the one angled side being the tank/seat and the other being your front end: as you tilt the rear portion downwards the rake (angle of your steering axis/fork tubes) becomes less steeper in retrospect to a perpendicular line to the ground, thereby increasing the angle in relation to the perpendicular axis.

But if you just lower the front end while leaving the rear stock,you now unbalance the bike the wrong way. This impairs the bike's braking ability, as the bike will dive forward under hard braking, and to have the bike in an already "diving forward" position places even more stress onto the front when braking, and a loss of control is more probable under these conditions (especially if braking while in a turn or curve). We'd all like to avoid any unneccesary "nipple surfing" so abide by this one...

There are several methods to lowering the front. The least expensive (actually it's free), assuming the design allows for it, is to drop the fork tubes through the triple trees, but this doesn't really look too appealing with an inch or two of fork tube jutting up from your custom's upper triple tree and through the handlebars...

The most popular method is swapping the coil springs inside the fork. You'll want to consider progressively wound springs over constant wound springs, as the progressively wound coils get stiffer as they compress as they use the softer coils first. (see Fork Lowering Illustration 2)

Some bikes come with pre-load spacers that compress when the fork springs an inch or more when unloaded. Shortening this spacer drops the front end of a bike an amount roughly equal to what is removed from the spacer. Be careful not to go beyond the point where there is minimal pressure on the spring when the suspension is fully extended (see Fork Lowering Illustration 1). If you go beyond this point, your bike will be effectively "springless" when the front end extends completely, as when the front wheel drops into a dip in the road at speed. Not a nice scenario...

One final note about front end lowering, make sure your fender (or tire if no fender) does not make contact with the lower triple clamp when the suspension is fully compressed. If it does it will lock up the front wheel while in motion over bumps and other obstacles that would be better off tackled with a free spinning wheel.

Lowering The Rear End

Lowering the rear is typically what many riders need, since lowering the rear end also lowers the seat height, making it easier to flat-foot a bike at a stop. If you've ever found yourself on a too-tall machine at a slippery intersection, you know you'd trade in all the shiny chrome in the world for more secure footing.

Probably the best method is shorter shocks or shorter mounting clamps on the shocks. Just make sure the shorter shock is designed for your particular model, as they need to be able to sustain the mass of the bike to work properly. This means you don't want to lower your big tourer with a pair of 250 Rebel shocks that are 2" shorter than yours; those shocks are meant for a 300 pound bike and will turn your touring machine into a bottomed out hardtail...the same holds true with shorter shocks from a larger machine installed on a smaller one, a shock made for a 600+ pound bike won't be compressing much on a 300-400 pound bike.

LEVER RATIO: A shock's lever ratio is determined by the angle at which it is mounted. To better understand this, picture a bike's rear suspension: including the swingarm pivot, rear shock lower mount, and the rear axle. Now imagine the rear wheel moving through it's travel, which describes an arc, and draw that arc. The distance the rear axle travels is most often greater than the distance traveled by the shock's lower mount. At the extreme, the shock mount might move about two inches versus the rear axle's four inches. (see Rear Lowering Illustration 2)

This means there is no simple formula to lowering your rear end, it's not as simple as "I want to lower the rear by 2" so I'll buy 2" shorter shocks." On a bike such as the Honda Valkyrie, the lever ratio is 1.5:1 so a 1" shorter than stock shock will lower the bike an inch and a half. Most bikes have a ratio greater than 1:1, and on a mono-shock type bike (such as the 650 V-Star or VT-600 Shadow) the ratio can be anywhere from 2.5:1 up to near 4:1, so to lower a bike like this the shock won't need to be as short, 1/4" shorter shocks will drop an inch on a 4:1 ratio bike. Probably the easiest bike to do the math on is the FLH Harleys, they are pretty close to 1:1 lever ratio.

Aftermath Of Lowering

Lowering a bike lowers its center of gravity, so it will handle better in some circumstances. It also lowers its ground clearance, so this mod both helps AND hinders your handling characteristics. Things you used to clear before such as speed bumps or curbs may now become a problem. Your lean angle is also narrowed so if you drag pegs on occasion you'll be be doing so more frequently...and if you've dragged solid parts in the past such as pipes or sidestands you may want to really consider what you're getting into.

Another item you'll discover on your newly lowered machine is the comfort, you've given up travel so the suspension is now stiffer (or your pre-load will need to be adjusted accordingly to prevent bottoming out).

Also noteworthy is the lowered bike's load capacity. Two up touring won't be an option on a lowered bike, the additional weight on the rear will cause the bike to bottom out easier.

One more consideration, when lowering you may have to modify or swap out the side stand. A bike that sits too low on it's OEM kickstand will lean in a near upright position when parked, and this is rather precarious for comfort and ease of mind.

Editor's note: Beginners should take great care with any bike modification and strongly consider consulting a professional or their local motorcycle dealer.