New rubber

This week, I had the tyres on my bike replaced after they lasted just over 25000km. The last few thousand kilometres it became quite clear they needed urgent replacement.
Motorcycle tyres are round, not square like car tyres. This is because we lean over in corners and we would like to have a decent grip with the road in these situations. Especially in these situations. When motorcycle tyres get older, they square up because there's only so many corners you can insert in any road before the straights take over again. So, because, on the whole, we have to drive vertically more than we can drive leaned over, tyres wear more in the center than on the sides, leading, eventually, to squareness.
When tyres get too square, their grip with the road lessens in corners, leading to dangerous situations. Especially in wet weather and/or on dirty or badly maintained roads (of which we have plenty a supply). The last few thousand kilometres, I had to be more and more careful in corners and I could feel the rear end slipping away with an alarming increase in frequency. I could also feel when the squarest part of the tyre hit the road: from that moment on, it becomes very difficult to lean over further. Very dangerous if you have to cut short a corner!

Now, with new tyres, I have switched from a thread depth of 1.6 to 1.7mm (1.6mm being the legal minimum and 2mm being an informal safety minimum) to a whopping 4 and 6mm front and rear respectively (front tyres wear less than rear ones).
Not only have I gained grip in corners, I also got a lot more manoeuvrability again: because the contact surface between tyre and road has become smaller I can more easily steer than before.

I sincerely hope they will last at least some 20000km again, because they cost me about €450.