These trousers promise year-round versatility for adventure and touring riders who need serious waterproofing and comfort in one package.
The Merlin Akashi Pro D3O laminated trousers have an over-the-boot fit, they’re built to take on everything from motorway miles to rough back roads — and over 3000 miles of testing in the UK and Ireland has shown exactly what they’re made of.
Fit & comfort
I opted for size medium with a short leg and the fit was spot-on. Two leg lengths are available (regular and short), and the trousers offer plenty of adjustment with Velcro tabs at the waist, below the knees and at the hem. Once dialled in, they’re extremely comfortable both on and off the bike.
Across long rides - including a 1400-mile trip to Ireland and regular 150-mile runs delivering NHS samples - they’ve never caused a moment’s discomfort. They simply disappear into the ride, which is the highest compliment I can give any pair of touring trousers.
Weather protection
A laminated waterproof membrane forms the core of the Akashi’s rain protection, and it’s proved utterly dependable. During Storm Amy’s biblical downpour across Ireland, I rode 120 miles through torrential rain and flooding - yet arrived completely dry. Every pocket stayed watertight too, confirmed by a simple tissue test that left all four sheets untouched by moisture.
Photography: Jose Mas
The trousers dry quickly after a soaking, too. Hung up overnight in a hotel room, they were bone-dry by morning - a key benefit of the laminated construction.
Cold weather performance
When the temperature dropped below 10°C, I fitted the removable thermal liner and stayed warm and comfortable down to around 5°C, pairing them with thermal long johns at the lowest points. The liner adds meaningful insulation without bulk, making these a solid winter choice.
Warm weather performance
For warmer rides, the thermal liner comes out easily and diagonal thigh vents help channel cooling air. While they’re not the most ventilated trousers I’ve ever worn, the vents gape slightly when seated, letting pleasant airflow through when riding at around 20°C.
Protection
The Akashi Pro trousers carry a CE AA safety rating, putting them on par with many top-tier laminated touring options. Impact protection comes from D3O Level 1 knee and hip armour, which is light, flexible and unobtrusive. The knee armour pockets are adjustable, though even in their highest position I’d prefer the protectors to sit slightly higher still.
Pockets
Four pockets in total - two zipped front hand pockets and two larger Velcro-closing thigh pockets - give plenty of practical storage. They’re all genuinely waterproof, which is reassuring when you’re carrying a phone, wallet or paperwork through heavy weather.
Durability
After 3000 miles in everything from motorway drizzle to storm-force rain and Irish backroads, the trousers still look like new. There’s no wear, chafing or damage, and all zips and adjusters work as they did on day one. They feel built to last many more seasons of demanding use.
Final thoughts
The Merlin Akashi Pro D3O trousers have impressed across every mile. They’re comfortable, flexible, and reliably waterproof — a genuinely all-season option for touring, commuting or adventure riding.
They also fit over the Alpinestars Tech 7 Enduro Drystar boots I reviewed at the same time, so I'd expect them to fit over the top of virtually any motorcycle boot.
Matched with Merlin's Akashi jacket they form a versatile laminated suit, and you can read my review of the jacket here. On their own merits, these trousers deliver excellent comfort, performance and protection at a very fair price.
