Taichi RSJ340 Explorer Air adventure motorcycle jacket

Straight answer: ordinary mesh is a flat sheet with holes. Three-dimensional mesh is two mesh faces joined by upright fibres, leaving a gap a few millimetres deep between them. The chest and back of this jacket use that construction.

That gap does two things flat mesh cannot. First, it holds the outer face off your back, so when you lean against the seat or wear a rucksack the air still has a path instead of being pressed shut. Second, it keeps its shape when soaked in sweat, so the jacket does not cling to your skin the way a t-shirt does.

You notice it most at a red light. Flat mesh does almost nothing standing still, because no wind is passing through the holes. The three-dimensional structure still holds its gap, so heat has somewhere to rise instead of pooling between fabric and skin.

The inner sleeves are mesh too, but flat mesh. Sleeves need to stay thin so the elbow bends easily, and the inside of the arm always has air moving over it once you are rolling, so it does not need the thicker structure.

Straight answer: four soft protectors rated CE level 2 are fitted at both shoulders and both elbows. The back carries a foam pad. The chest is left empty with only a mounting point.

Level 2 at this price is worth noting. The European scale for limb armour has two tiers, and tier 2 allows less force through the pad than tier 1. Most mesh jackets at this money carry tier 1 only. These are the soft type, so they still bend with your arm rather than sitting like a plastic plate.

The foam at the back is not armour. It is damping padding, not tested to the protector standard. Anyone covering distance or riding hard should replace it with a proper back protector in the existing pocket. RS Taichi sells three that fit: the TRV101 at CE level 1, the TRV094 at CE level 2, and the TRV044.

Chest armour is a separate purchase. The jacket has snap buttons ready for a chest plate and RS Taichi lists several that fit. The chest is what meets the handlebar or the road in a forward fall, so if the budget stretches to one extra piece only, take this before the back protector.

Straight answer: the jacket is not waterproof, but the flapped pocket at the waist is. That is where documents and a phone go when rain arrives mid-ride.

Why one pocket is worth mentioning: a mesh jacket is going to get wet and the rider accepts that. What is not acceptable is soaked vehicle papers or a phone full of water. One sealed pocket on an open jacket solves exactly that problem.

Arms and waist have adjusters to stop the fabric flapping. A loose mesh jacket at highway speed sets the sleeves and hem hammering, which is both noisy and tiring on the shoulders. Cinch the adjusters and the jacket sits close and the wind noise drops noticeably. Riders skip this detail in the fitting room, because standing still it feels like nothing.

Reflective panels sit front and rear. Most jackets only carry them at the back, aimed at headlights behind. The more dangerous situation on Vietnamese roads is a vehicle pulling out of a side alley, and there the panel that saves you is the one on the front.

Straight answer: RS Taichi makes six men's sizes from M to 4XL and two women's sizes, WM and WL. BigBike stocks all eight, in all three colours.

The women's sizes differ in proportion, not only in numbers. Look at the chart below: WM runs 83 to 88cm at the chest but 89 to 94cm at the hip, so the hip is wider than the chest. All six men's sizes are the other way round, chest always wider than hip. That is why a woman in a men's M finds it tight at the hip and loose at the shoulder.

RS Taichi cuts to a Japanese fit. That runs closer than European gear at the same size letter, and Vietnamese riders usually land on the maker's M or L, the first and second sizes in the range. There is no S for this model.

Quick method: measure your chest at its fullest and read it against the chart. Between two sizes take the larger one, because mesh does not stretch and you still have a base layer underneath.

Take the RSJ340 if you want an adventure-cut jacket for hot weather, want high-tier shoulder and elbow armour from the box, and accept carrying a rain shell rather than buying a waterproof jacket.

Matching trousers: the RS Taichi RSY269 Kompass Air is the trouser from the same line, in the same mesh and the same adventure cut.

For days of riding in rain take the RS Taichi RSJ729 Drymaster Kompass, which swaps the mesh for a waterproof membrane.

For city use at less money look at the RS Taichi RSJ351 Air Flight, a short bomber cut that runs cooler and wears more easily every day.

If you want a chest plate in the box look at the RS Taichi RSJ342 Quick Dry Racer, which includes a hard chest protector.

Buying at BigBike: genuine stock, a 12-month warranty on manufacturing faults, nationwide delivery with cash on delivery.