I have long been a user of all types of motorcycle tankbags. From combined tank covers with attachable tank bag like the ‘Bagster’ system, to various magnetic bags.
Many sales people won’t know what works best. Quite often they don’t even commute, let alone tour on motorcycles so really have little experience with the positives and negatives.
Firstly I will start with the ‘Bagster’ option. I tried one of these for around 9 months but found it to be inferior when compared to a good magnetic bag. The tank cover that is required to be fitted to the bike in order for the Bagster to be affixed is marketed as being attractive. This is normally colour matched to your bike but personally they are not to my taste. You purchased a thoroughbred so why make it look like a donkey?
These are also sometimes given a sales pitch that they scratch your tank less than a magnetic bag. I have found the opposite to be true in Australian conditions.  In any sort of dusty conditions particles can get under the tank, the cover then rubs against the dirt and your tank with obvious results. You have to take the tank cover off and wash both it and the tank regularly to prevent this.
Now to my favourite, the magnetic option.
Seldom have I seen a magnetic bag scratch a tank. I have covered hundreds of thousands of kilometres with a magnetic tankbag fitted to various motorcycles.  On long trips I use the tankbag to hold my laptop computer and camera gear.
I once used a small and cheap Branchi item that I found to be probably the best value for money motorcycle accessory I have ever purchased. After probably a hundred thousand kilometres it finally gave up the ghost and started to split its sides. Impressed.
I replaced it with a new ‘Hustler Twin Sprint’ bag. This is a much bigger option than the Branchi. It is quite small when only the lower compartment is used but can hold stacks of gear when the top part is fully extended.
The Branchi proved to be waterproof but as a habit I normally stick all my gear in plastic bags when it is raining heavily anyway. The Hustler has its own plastic cover that can be put on the bag when the rains come so there are no problems there.  Â
Of course a tankbag is also good for commuting or popping down the shops to grab a few things. The picture at the extreme bottom of the page shows how much shopping I squeezed into the tankbag on a shopping tripÂ
Tankbags in general do not interfere too much with the handling of the bike and are the easiest of all storage systems to either put on or pull off. With a magnetic bag it is as simple as picking it up or putting it down as the magnets do the work of attaching the bag. This may worry some but even on the most spirited of rides I have never had a problem with a bag moving around at all, this includes some very fast wheelies and lots of scratching.Â
The only time the bag can be annoying is when going faster in a straight line than you maybe should, here the bag prevents you from getting right down below the bubble with chin on tank and thus exposes you to more windblast. I once had the magnetic tankbag on stuffed full with laptop etc. while riding a Hayabusa pretty much tapped, took a while for the neck muscles to get over that one.
In summary the tankbag can be your most versatile friend if you use a bike everyday or even for weekend jaunts.  Well designed tankbags normally include a waterproof cover, carry strap, clear map reading pocket, change/key pockets and some even convert into a backpack. Versatility is the key. Â
Racks are much less attractive and much harder to remove or fit. Backpacks are great but not good to have on your back in the case of a crash where you are in for a hard landing. If you land on the bag it can put a great deal of stress through your spine. Tankbags normally also have a clear top section where you can put your map so you can glance at it while riding and a couple of external pockets to keep your wallet, house keys or spare change for those annoying tolls that they have on the East Coast. Easily the most practical way to carry things on your bike. Â
As an added bonus, on long trips when your wrists are aching, you can lean on the tankbag and take the weight off your wrists.Â
Prices for magnetic tankbags range from around $70 for the cheapest items, through to over $200 for a top of the range item.