[650]

Sounds like old tyres to me. A wet garage floor isn't going to cause you to lock up and drop the bike when on the way back from a ride. Think about how much petrol slime you're picking up when sticking petrol in the bike. It's gone within a few meters of riding.

So I say check the tyres code, it lets you know the age.

Another thing, braking isn't just dependent on your calipers - the amount of fork travel, pad temp (I'm assuming they're HH sintered, something people seem to obsess over - that gives zero benefit on the road and arguably detracts from braking ability in anything other than optimal ambient temperatures and almost traffic free riding), Tyre temp and quality all play a part.

But start with the simple stuff.