Riken Tyres

I have been very satisfied with these winter tyres so far, having driven around 20,000 miles on them.
They offer excellent performance in cold weather and are especially good in snow, providing dependable grip and control. I haven't had the chance to test them on ice yet, so I cannot comment on extreme icy conditions.
The tyre compound is noticeably soft, which contributes to a smooth and comfortable ride. They are surprisingly quiet on the road, with very low noise levels compared to standard winter options.
Compared to my previous Hankook winter tyres, I find these to be a clear improvement in terms of overall comfort and snow handling. My only slight uncertainty is their long-term durability and tread life, given how soft they are, but they have performed exceptionally well throughout the miles I've put on them so far.

Riken Snowtime B2 – OK performance, severe safety issue with age
Average performance and quite noisy, but acceptable for basic driving. As reported by others, tread wear was minimal. The tires were used under normal driving conditions with correct inflation pressure maintained at all times.
However, after 6 years, safety became a major issue: the tread on one tire cracked severely, exposing the internal steel belts, while another tire showed tread separation along the edge.
Decent tread life, but dangerous structural degradation over time. Replace them early regardless of remaining tread.

They are horrible, cheap tyres. The first 10,000 km were okay—nothing special, nothing good, but nothing terrible either. After that, they became absolutely horrible. They are also extremely slippery in the wet, the dry handling is bad, and I don't even have to mention the snow. Before these, I drove Michelin Pilot Sport 5 tyres worn down to around 2–2.5 mm, and I can honestly say that the Michelin tyres at 2 mm were far, far better than brand-new Riken all-season tyres, both on dry and wet roads, especially when it comes to handling.

These came freshly fitted to the car when purchased - I guess they were the cheapest tyres to get it mot'd. To summarise they were just OK in all respects, though ultimately lacking for any spirited driving - especially in the wet. Decent comfort. Biggest frustration for me was inadequate rim protection - the slightest curb encounter resulted in scuffed rims. Replaced with Goodyear Eagle F1s - no comparison really.