How to tie down a bike:
The first thing is to ensure the trailer used has a secure perch for hooks. As the dialog continues, the exact location(s) of such perches will become clear, there are more than one acceptable position for these, but generally one set near the front, and one set on the rear. For the front and the rear, one on each side of the outboard of the trailer.
Commonly used trailers are garden trailers or flat bed trailers with wooden beds. Loading the bike on a trailer is also a concern. Some trailers, such as garden trailers usually have a rear gate that doubles as a loading ramp. Some trailers can be tilted, others lift the bike from a flat position. If a ramp is needed, a 2 x 8 will work because the trailers usually are not very high. Caution should be used if the bed of a pick up truck is going to be used. In that case, there should be at least two, preferably three persons working together to get the bike up that high. There are metal ramps that can be used, but the length of the ramp has to be tempered by the height of the truck. For example, a standard small truck such as an S-10 or Explorer can use a 6 foot ramp, but an F150 or CK1500 may require a seven or eight foot ramp.
Now for the bike. Depending on model, a Shadow (VT1100) with fuel and oil is going to weigh in at 600 to 700 lbs. A trailer should have a GVWR (the weight of the trailer plus the weight of the pay load) of at least 1,000 lbs. for a Shadow. That is a trailer that weighs in at 250 lbs., the tongue weight would be 100 to 150 lbs. This is a class I trailer (less than 1500 lbs. GVWR).
A Shadow has a wheel base of 65 inches to 66.5". However, the overall length will be from 91" to 96" depending on the accessories and model. That is eight feet. If a truck bed is used, a six foot bed will cause the bike's rear tire to rest on the tail gate with the tail gate laying down. A Shadow will fit into an eight foot bed with the gate up, a Valk will not, for example.
The Straps, what you will need:
There are varying methods and ways to tie down a bike. Each person must secure the bike to his or her satisfaction but a minimum is necessary. There are two weights used to select a strap: 1) the working strength, and 2) the tensile or breaking rating. What is being presented here is a method that has been used with success on a Shadow to haul over long distances, it is not the only solution. This method uses five straps, only four of which are actually working to hold the bike. The straps are web types, the most common and affordable, any K-Mart or WalMart will have them in the automotive section.
The bike weighs in at 700 lbs. Once the bike is secure on a platform, it will be subject to the forces of turns on the road, stops, and starts. All movements of the tow vehicle and the trailer will put stress in various directions on the bike, but primarily on the straps used to hold it down. No matter what the method, though, everyone will begin with two straps on the handle bars. I have seen bikes successfully hauled with only two straps on the handle bars, although, I would not do it, in a pinch, it will work.
I also use handle bar straps that wrap around the bars, vice tying the straps directly on the handle bars. If you use these, they can be gotten from most motorcycle shops, follow the directions and avoid binding cables, either electrical, mechanical or hydraulic. The straps have a loop on both ends, feed one end through the loop on the other end and around the handlebar at the elbow. The angle of the strap will make it settle at this point (stock bars, non stock bars may have different curves, care should be taken when attaching the straps to the bar to avoid cables).
The main tie down straps should be a minimum of 600 lbs. breaking strength, and 300 lbs. working strength. Ratchet tightening systems are preferable but friction clamps will work. Periodic checks of friction clamps will reveal, however, that the clamps will slip with age. These straps should be about six feet long. If a fifth strap is to be used as a safety strap, like I use, it should be 1500 lbs. breaking strength, that will give about a 900 lbs. working strength. This strap, if used, should only have a ratchet clamp. Straps will all have heavy hooks on the ends, but sure to select ones with a rubber or vinyl coating on the metal, ensure that the hook tip folds back to a parallel position with the shank that is attached to strap. Less than this will allow the strap to work off the hook in heavy turns.
Tying the bike down:
Attach the straps up front first. If doing this alone, attempt to sit on the bike while tightening the straps. This can be done, but is easier with someone else sitting on the bike. The front straps should be tightened to compress the front forks no more than half the travel of the shocks, a little less is OK, but about half way is the max. Full compression will damage the shocks. The idea is to have the springs in the shocks provide a tension force on the straps but still allow travel to compensate for turns and bouncing. Once the front straps are on, the bike will be stable, raise the kick stand and ensure the bike is in first gear.
If the trailer does not have a channel for the front wheel, blocking the wheel with some 4x4s may be a consideration. I for one always block the front wheel to prevent left to right movement of the tire contact point. If the trailer does not have a rigid front wall for the front tire to rest against, something such as a 4x4 block should be secured to the trailer. Make sure that the block is attached so that the straps will angle forward slightly from the bike to trailer attachment point. Failure to ensure this will allow the bike to move backward. Attaching horizontally can be done but the rear attachment become more important if a front angle cannot be achieved. This block is to keep the front of the bike moving during deceleration of the tow vehicle. Secure any loose ends of the straps. Since the travel of the bike in curves will cause slack to occur in one strap while pulling the opposite side quite tight, bungee cords may be used to take up the slack. This is not totally necessary, but if one is anal enough, it can be done.
Using the remaining two short straps, I attach the hook to a wheel spoke, run the strap up to the hub and through the wheel, then out to the trailer securing point (do this only on cast alloy wheels, not wire spokes). Do one in each direction. This set of straps are intended to stabilize the bike left right and prevent the rear wheel from hopping around from road bumps. They also tend to serve as a back up to the front strap by providing some upward stability to the bike. The important thing here is to get the rear wheel secure to the trailer, so if another set of attachment points feels more comfortable and holds the wheel, that would be satisfactory. I also recommend that if you are hauling, the rear shocks be set to 5, lower settings allow more bounce. An alternative if the bike is in a channel, is to use one strap to tie the wheel to the channel. If a channel is not available and the wheel is resting on a flat surface, take the two short straps and attach over the seat and down the opposite side to the shock mounting point, securing the straps tightly. I do not prefer this method since the risk of damage to the seat is very real. Another point is to run the straps around the lower swing arm on both sides. Again, there is risk of damage to the exhaust so be very careful. The angle on the rear straps will depend on where they can be attached to the trailer body.
The longer safety strap that should be about 12 to 15 feet long is attached to the same two securing position as the front straps and is then run through the frame at the rear swing arm joint and tightened. This strap will hold the bike if either of the front straps breaks or loosens long enough for you to stop and fix the problem.
Once the bike is secured and you are moving, STOP within 20 miles of travel and check the straps. While traveling, STOP and check the straps every 100 miles or so. One more point about hauling in a truck: The bike is unwieldy in a truck bed and will alter your braking and handling. You should slow down on curves, especially tight ones. You also should check braking when you begin to get the feel of the distance needed to stop and for God's sake, stay away from the vehicles in front of you.