Langster / Langster Pro / Langster Steel

well, compared to the days i was riding bmx 23c feels like breaking everytime when i jump a curb ;)

that's what i said, i still like the frame (stickers removed) but not the components.

maybe it the tyres then, but somehow when it rains the bike it sooo slippery

700x23C is a fast road tyre size designed for low rolling resistance / high speed. They're not designed for bump absorption - you'll have to do a lot more of that with your legs.

To be honest, any road tyre is going to be slippery in the wet on drain covers and white lines. I saw a guy go epicly sideways on a Boris Bike last week because he was unfamiliar with this particular branch of physics. But if you're slipping on normal asphalt then some better tyres are definitely in order.