How fast

[classic33]

could you stop from over thirty mph on a wet cobblestone road. Also what distance do you think you'd need.

I ask because there is a regular on a bike, who appears to feel that what he does harms no-one. He'll fly down one road, pedestrianised, across another with no regard for others. Mounts the pavement, before flying off down the pavement out of sight.

He can't however seem to be able to ride back up.

 

[montage]

20-30 metres? Not entirely sure, but need to take into account tyres, brakes, if you are feathering the brakes etc.

Sounds like this guy needs a telling off.

 

[RedBike]

If I'm doing 30mph on wet cobbles using a road bike then I'm clearly unable to stop. I don't think I would want to be going that quickly. The vibration would be horrific.

The MTB should hanker up pretty quickly. The trouble will be modulating the front brake so that the front wheel doesn't just wash out. I would expect a good 10m or so + reaction time though.