Mole wrote:
Just as an aside (sorry for the thread drift) does anyone have any accurate figures for stopping distance in the dry from (say) 20 or 30 MPH for a pushbike? An "average" road one would be nice, but just to get us in the ball park, any pushbike at all, with any kind of brakes. Just curious.
And tonight's quick test concludes that i need a better data logger (or at least to turn smart logging off).
Road bike, standard brakes/pads on alloy rims. Dry smooth tarmac.
At limits of rear wheel locking.
Stop 1: 7.96mph to 0, 3seconds = 1.18 m/s/s = 5.3m
Stop 2: 8.65mph to 0, 6seconds = 0.64 m/s/s = 11.598m
Instantaneous speed at start of stop was faster, but not recorded so taken first point during the stop. Second stop was definitely longer distance but not as much as half the rate / twice the distance!
Best I can do on this device is 1sec log interval. Wonder if the vbox from work will run off a few AA batteries
OOoo thanks, I missed this one! Was that using the front brake as well? Seems to be quite a difference between the two stops though. I have to say I'm surprised at how long it took to stop. That's only (about) 0.1G deceleration of you (sort-of) average the two. I'd be looking at MUCH better than that in a car (maybe 0.7G)? I have to say this bears out my own observations that pushbikes are AWFUL at stopping. It's probably not been an issue in the past where they rarely did more than about 20MPH, but now they can go quite a bit faster, I'm wondering whether we need to introduce some sort of minimum requirement? On downhill stretches, my cheap mountain bike will easily get up to 30 MPH (and I'm quite fat) so stopping it is quite a feat!
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