Safety is the primary reason to wear a motorcycle jacket. It is meant to keep the blood and flesh inside the skin more than it is meant to protect you from the heat, cold or rain. So ideally, you want as much protection as possible. Think Iron Man. But the more bulky a jacket gets, the harder it becomes to live with because at some point you're going to have to take it off and cart it around or try to shove it into a bag.
So at it like this. Ninety nine percent of you are not going to use the jacket at outrageous speeds because you're riding on the street or the highway and not the racetrack. So you need a blend of reasonable protection and portability, in that order.
You ascertain the safety aspects of a motorcycle jacket substantially from two angles. First, the less important of the two is visibility. Being seen is a big part of not having an incident so do not discount it. Cheap motorcycle jackets tend to be black in color – I cannot explain this phenomenon. But black also means you will not be seen, especially in the night
Next thing to consider is convenience. This is important because if the motorcycle jacket isn't convenient, then chances are, you will simply not use it. To me there are three crucial things to convenience, I'll discuss there in order.
WeatherThe biggest issue with riding in Thailand is that our weather is not always great for riding and varies somewhat. Parts of the year the South of Thailand and Central Thailand, like Bangkok, are easy to ride regions always hot and tropical temperature. And sometimes it rains as well. This means a mesh jacket and a rain suit is usually enough to get you through the year. But in the upper North of Thailand where it can be hot, and the temperature can also drop sometimes near frezing and not forget that it also can rain, it gets harder to gear up correctly...
Mesh materials are a relatively recent phenomenon but they've rapitly becaome my go-to-solution for riding in Thailand and Southeast Asia. I've crashed in them too, repeatedly, so I know that the protection is good enough for street speeds. Look for large mesh panels or all-mesh construction so that the mesh is placed where the wind normally hits you – like in the chest. Also check that there is mesh at the back because the wind that enters the jacket also has to leave otherwise the jacket will simply balloon and feel uncomfortable. Current mesh jackets tend to have stronger materials over the impact areas – like the outside of the arms, over the shoulder and across the top of the back. These are good idea because they allow the jacket to breathe while offering more protection when you come off the motorcycle.
For my next motorcycle jacket, I'm seriously looking at a mesh and leather combination that I think will be great for my daily use. The best mesh jackets come with rain and warm liners that you can use to extend the usability range of the jacket by adding/subtracting layers.
Vented jackets use more impermeable materials than mesh to construct the jacket and then insert vents that you can zip open for ventilation. These are warmer than mesh but also more versatile. With a rain liner or a warm liner or both, and the vents closed, these jackets can handle some pretty cold conditions while remaining usable in our tropical conditions. How to evaluate the zip-vented jacket? Start by looking at the armor placement, quality etc. Then look at the zip quality and the vent placement. Waterproof zippers, ideally branded (YKK zippers is a good sign) are best. Some vents have a velcro tab that can be used to hold the vent open. This can be useful. Then comes the placement of the vents. I've a jacket that places vents on the forearms which seem to do absolutely nothing. But usually vents on the chest and shoulder with exit vents at the back are best. Try and aim to have the largest rear vent you can find. Too small and your jacket will balloon.
Waterproof jackets are a whole different thing. These will usually have a membrane or coating inside with taped seams to prevent water ingress. Note the membranes last longer than coatings if you're careful. These jackets are usually tremendously warm and often bulky and that means they're more troublesome off the motorcycle in Thailand when you're just waling around...
Off the MotorcycleThe most protective jackets can also be the bulkiest. The off the motorcycle angle isn't the central issue in buying a motorcycle jacket but you should keep it in mind. If the jacket is a major hindrance off the motorcycle, you will be tempted to not wear it when you go out knowing you'll eventually park the motorcycle and spend quite a while off the motorcycle.
Keeping It GoingYes, motorcycle jackets need maintenance, I hate leather in Thailand because it tends to go mildew-ey in the rain when it's not really in use. In that sense, textile is easier to live with because you can throw it in the washing machine and it comes out sparkling clean. If you've got a leather motorcycle jacket, buy some neutral upholstery leather nourisher/polish but cheaper. Try it on a small inside patch of leather to see its effect on the color of the jacket before actually using it on the exterior.
Motorcycle jackets tend to last forever due to their naturally strong construction and wear resistant materials. This means replacing a motorcycle jacket is a matter of needing a change because you're outgrown the jacket – either in fit or style. If you've fallen and damaged materials, obviously, get a replacement.