The 4 tools riding super fast weaving in and out across lanes behind the semitrailer down Ayliffes road at 745 this morning helped me realise why cyclists are getting sledged in the Adelaide press at the moment. Any of them could have become a smudge on the road or caused others to come to grief. Sigh.
Once you lock up, you are actually not very effectively braking, best get a bike with ABS to stop lock up or change braking style.
Unfortunately my friend didn't have much time to evaluate his braking style....he stopped just in time with his front wheel just about touching the koalas nose. The koala just sat there admiring the tread on his front wheel....didn't seem the slightest bit concerned about the whole situation.
Are you assuming the vehicle in front has come to a instant and complete stop? If not, then by the time a 10 tonne truck starts braking, 5-10m is enough to apply ones own brakes and even move to the side of the truck.. assuming one is already riding near the edge (giving a front view of impending disaster) and not sat square behind it (which would be really dumb!)...
BTW, just for reference 10m @ 36kph = 1sec! I havn't done the math for a bike, but it seems it takes the average vehicle around 3 sec to stop from this speed, once the brakelights have come on.
*addendum* just found a online calculator which would suggest one can stop a bike in 4.62m from 36kph... must try it out!
I would say there is no doubt that there is a risk associated with slip streaming trucks - but there is a risk in everything - is it a substantial risk? Does it outweigh the fun? As rossmg says it can be a calculated risk and the chances of hitting the back of a truck seem pretty remote.
WRT braking distances, the Sydney Council says this:-
Safe Speed - Be in control. Ride at a speed that will allow you to stop safely. Do you know that it can take up to six (6) metres to stop from 15 km/hr?
But with disk brakes on an ok bike, 5 metres from around 35 km/h is about right.
But you'd need up to 1/2-1 seconds reaction time, and thats 5-10m in itself! Although if I was drafting a truck as speed, I'd have the fingers curled round the brake levers already, so reaction should be less than 1/2 a sec! Thats still enough to stop by the time you get to the point where the vehicle applied it's brakes...
Just hope the car following you is as sharp!!!
Mark didn't say 'bob around a little on the road.' He said '.....super fast weaving in and out of lanes behind the semi-trailer.' I think there is a difference.
I can't work out how they were weaving in and out across lanes whilst behind the semi. Was the semi also weaving across lanes? That would have been dodgy but most semi drivers are well trained and wouldn't do that.
Was carbon fibre a factor in this, it would seem not to be too relevant, steel bikes would probably be faster downhill.
That's my query too - weaving in and out or slip streaming or ??? huh?
I wonder what Chuck Norris would do if he noticed such behaviour?
If Chuck was on a bike the semi would have been slip-streaming him,.
So what would Boris Yeltsin do?