Securing a Harley-Davidson with tie-downs or motorcycle straps is largely the same as securing other motorcycles. But, it should be noted that a defining characteristic of Harleys is that nearly all of them are heavy and big. Where an average sport bike may weigh about 400 lbs., many Harleys weigh double that. And the vast majority of Harleys are considered "big-bore" motorcycles of over 1000 cc. Big bikes tend to be heavier, so they need to be secured adequately for their weight.
Straps
Avoid using rope. Flat, nylon tie-downs are the best. Tie-downs are made specifically for motorcycles. They're recommended because you know the manufacturer has given specific thought to the needs of motorcyclists, instead of just making a general purpose strap that could be used for camping, rafting or other applications.
Front Suspension
The front suspension will probably be softer than the rear suspension. It needs to be compressed near the bottom of its suspension travel by the straps. A bump in a trailer or truck shouldn't be able to compress the front suspension further; otherwise, a bump could compress the forks enough for one or both straps to fall off. Once you have one strap snugged to each of the front forks, have one person sit on the bike and compress the front forks and another person cinch the straps as the forks are compressed. Alternate side to side, cinching a little bit at a time.
Rear
It's not always necessary to use straps that compress the rear suspension. What is important is that the rear wheel does not slide or bound around. Ideally, you'll use a trailer that has tracks or rails for your Harley's wheels. Otherwise, consider using one strap that is secured flat on the ground, perpendicular to the rear wheel, making a loop around the rear tire and rim. This will keep it from sliding, bouncing or vibrating from side to side.
Wheel Chocks
Wheel chocks are available for front and back wheels, but they are used primarily for the front wheel. Similar to a bicycle rack, they keep the front wheel upright and prevent it from turning. If you're transporting your Harley by truck or trailer often, consider buying or building wheel chocks.
Tags: compress front, front forks, front suspension, front wheel, rear suspension