This is by no means an exhaustive list of steps for long term motorcycle (or car for that matter) storage, but a few tips I have picked up along the way.

When a motorcycle is put into storage it will often remain in the same position for extended periods of time. This is not the intended purpose from factory though and as such the tyres and suspension will not thank you for it.

Tyres

Tyres tend to lose pressure through the winter months and under inflated tyres are more likely to get flat spots. If the pressure drops significantly then the side walls will tend to crack if they are left sitting on cold concrete.

Once a tyre has been affected by either a flat spot or a crack then it should be replaced immediately. Both problems are a major hazard that could lead to dramatic tyre deflation at speed or big blow outs. Often this will lead to the bike continuing down the street on its side.

Suspension

Although it is not a significant issue in my experience or research it also makes sense to unload the suspension so that it can relax for the duration of the storage. This might help to prevent spring sag, but I am unaware of any other benefits.

Suspension is basically comprised of oil, springs and seals. Seals are made of rubber and when not in use rubber stiffens and becomes brittle, which can cause cracking and seal failure.

Replacing fork seals is a reasonably time consuming process and therefore can be an expensive trip to the dealer if you are not doing it yourself.

The best way to avoid this issue is visit your motorcycle every fortnight or so, sit in the saddle and drop the bike off of the stand. Now it may sound odd but you need to have a good bounce on the bike to cause the suspension to compress and extend a number of times. This puts seals through their paces so that their propensity to stiffen is reduced.

I find the easiest way to get the forks to travel nicely is to rock the bike back and forth applying the brake firmly as the bike comes forward. If there is more than one person present you can have them push down on the head stock as you sit on the bike to stabilise it.

Another tip is to add little fork oil to your fork stanchions so that your seals remain a little more protected. I like to add some onto the stanchions before I attempt to bounce the bike as mentioned above. Avoid WD-40 as it can swell rubber seals and if it penetrates the seal it can mix with the oil in fork and thin it reducing damping.

Stand Solutions

If your motorcycle has a centre stand then you can make use of it to avoid both problems. With be bike on the stand the rear wheel will clear the ground, which leaves you the simple task of propping the front wheel off of the ground.

A lot of modern bikes do not come with centre stands to improve ground clearance, but there are solutions such as the Superbike Stand from abba. Other options include the Bursig and the Becker-Technik Motorbike-Lifter. I am using an abba stand myself, but the Becker-Technik does look like a nice alternative.

If you just want to get the wheels off the ground then you can use a pair of paddock stands, but this will not take the pressure off of the suspension. A couple of paddock stand options include the Venom Headlift Paddock Stand, Genssi Motorcyle Pro Front & Rear Stands or MOTO-D Front & Rear Paddock Stands.

Flooring Solutions

Seems like too much effort? Then you should at least consider putting the bike a sheet of timber or chipboard to help protect the tyres from the cold concrete. Some people have also used foam or rubber tiles under the bike. Like these NT interlocking rubber tiles for example.

You will still need to move your bike or rotate the wheels regularly so that the tyres do not develop flat spots.

The essential information to take away from this is that your bike does not like being stationary and it should be kept off of its wheels.