400k

[ColinJ]

h) I'm lazy and a cheapskate so I will start a ride with almost worn out blocks ...

From my experience, I can recommend not doing that!

I had V-brakes on my first MTB and was being a cheapskate with the blocks - 'Just one more ride!' I went out and was screaming down a fast rocky descent when the front blocks wore away. Too dangerous to not brake, so it was metal on metal. By the time I slowed to a stop I had destroyed my front wheel rim.

New brake blocks are a lot cheaper than new wheels!

 

[Greenbank]

I agree it's not a great idea, but it's a risk I'm willing to take given that I've got two brakes (plus leg braking). If the front brake went then I'd be ok with the combination of rear brake and leg braking (rear braking to scrub some speed off to where leg braking takes over). If the rear brake went then front brake and leg braking will do. I'd change the blocks there and then if in the hills, or at the next control if I could scrape there.

Having both brakes go on a single descent is highly unlikely (and no different from both brake cables snapping).

 

[vorsprung]

I think I took a set of koolstops from "plenty left" to "hmm, I hope the metal doesn't show" in 100km of Dartmoor Devil one time

During a wet Bryan Chapman I remember stopping a couple of times to adjust in more pad ( shimano v brake pad )

But usually before a "big" ride I will check the blocks and change them if they are worn