suicyclists again
in [Cars]
|
Prev: Hoover Dam Bypass and Vegas notes
Next: Illegal mexican with "suspended drivers license" pleads "no contest"to murdering 4 year old white girl.
From: DanKMTB on 10 Jul 2008 17:13 On Jul 10, 5:03 pm, gpsman <gps...(a)driversmail.com> wrote: > On Jul 10, 4:35 pm, Brent P <tetraethylleadREMOVET...(a)yahoo.com> > wrote:> > > > I was going by feel trying for the edge of lock of the rear wheel. > > <s p i t t a k e> > > The rear tire offers little if any braking, Sparky. For all practical > purposes it does not exist since it won't be in contact during maximum > braking. > > > The other times I got > > lock and backed off so I wouldn't fall or skid the tread off the tire. > > It probably hasn't occurred to you that you don't know how to ride a > bike. > > > I > > was in my normal upright riding posistion. I don't like riding in the > > drop. > > CG has to be low and rearward for maximum braking effect. > > You couldn't more obviously have less of a clue how to ride or stop a > bike. > ----- > > - gpsman All these comments and no guess on my stopping distance?
From: Matthew T. Russotto on 10 Jul 2008 17:19 In article <1493ccb8-1ead-4dde-8d4d-eb3c56820fb0(a)p25g2000hsf.googlegroups.com>, DanKMTB(a)gmail.com <DanKMTB(a)gmail.com> wrote: > >I won't bet $100, since I'm not in the position to lose it and I'm not >that sure. Like I said, I think I can, I'm not sure. Smart move. >The initial >deal was is a bicycle capable of stopping as fast as an average car >from 30MPH. The brand new cars I found on Edmunds were mostly 33-35 >feet from 30MPH. That leads me to believe average car (most cars have >worn tires, many are older, not all brakes are brand new, etc) is more >like 35-38, but I'll stick with 33-35. Call it 33, there's no way to >claim an "average car" can stop faster than that from 30MPH, agreed? Sure. I think it's still impossible to stop a bike faster than that too. But I wouldn't be as willing to risk the C-note as for the sheer impossibility of 30 feet. >it (although with less fervor than before). Also, you mentioned road >bike. I am planning to execute my test on a mountain bike, since it's >the only one I have with gears, and as such the only one I have that >can reach 30MPH. Does this change your opinion of my test, or make it >seem more likely? The extra tire shouldn't matter since I won't be >skidding the front wheel regardless, it's simply a matter of how much >brake can I apply without going over the bars and how fast will that >stop me. A mountain bike with knobbies on pavement should be worse than a road bike on pavement. With slicks, no big difference. >and the tape measure I'll be stopping alongside. I guess we=92ll have >to settle for a gentlemen=92s bet, with my word I=92ll be honest and you >reserving the right to call bullshit on my stopping distances if you >so choose. I think you'll be surprised. -- There's no such thing as a free lunch, but certain accounting practices can result in a fully-depreciated one.
From: Arif Khokar on 10 Jul 2008 17:23 DanKMTB(a)gmail.com wrote: > On Jul 10, 4:59 pm, Brent P <tetraethylleadREMOVET...(a)yahoo.com> > wrote: >>> Why would the distance increase once the rear wheel is lifted? At >>> that point hasn't the front wheel taken any extra braking force the >>> rear could have applied? >> To put it simply and crudely, because you're not going to want to plant >> your face in the pavement. > I am of the impression you've achieved maximum braking when you've > fully unweighted the rear tire. I can comfortable stop on the front > wheel alone, rear wheel hovering. As you apply the front brake, you increase force to the point that the rear wheel starts coming off the ground. Ideally you would want to keep the application force constant at that point, but in reality, it's hard not to decrease the amount of force applied. That in itself would increase braking distance to some extent.
From: DanKMTB on 10 Jul 2008 17:26 On Jul 10, 5:19 pm, russo...(a)grace.speakeasy.net (Matthew T. Russotto) wrote: > In article <1493ccb8-1ead-4dde-8d4d-eb3c56820...(a)p25g2000hsf.googlegroups..com>, > > DanK...(a)gmail.com <DanK...(a)gmail.com> wrote: > > >I won't bet $100, since I'm not in the position to lose it and I'm not > >that sure. Like I said, I think I can, I'm not sure. > > Smart move. Fair enough. > >The initial > >deal was is a bicycle capable of stopping as fast as an average car > >from 30MPH. The brand new cars I found on Edmunds were mostly 33-35 > >feet from 30MPH. That leads me to believe average car (most cars have > >worn tires, many are older, not all brakes are brand new, etc) is more > >like 35-38, but I'll stick with 33-35. Call it 33, there's no way to > >claim an "average car" can stop faster than that from 30MPH, agreed? > > Sure. I think it's still impossible to stop a bike faster than that > too. But I wouldn't be as willing to risk the C-note as for the sheer > impossibility of 30 feet. What's your guess on the stopping distance? It does have knobbies, by the way. I still think the limiting factor will be not flipping as opposoed to traction, so I don't think it'll make much of a difference. > >it (although with less fervor than before). Also, you mentioned road > >bike. I am planning to execute my test on a mountain bike, since it's > >the only one I have with gears, and as such the only one I have that > >can reach 30MPH. Does this change your opinion of my test, or make it > >seem more likely? The extra tire shouldn't matter since I won't be > >skidding the front wheel regardless, it's simply a matter of how much > >brake can I apply without going over the bars and how fast will that > >stop me. > > A mountain bike with knobbies on pavement should be worse than a road bike on > pavement. With slicks, no big difference. I'll be on knobbies. I don't forsee skidding the front, so I don't expect much of a difference. > >and the tape measure I'll be stopping alongside. I guess we=92ll have > >to settle for a gentlemen=92s bet, with my word I=92ll be honest and you > >reserving the right to call bullshit on my stopping distances if you > >so choose. > > I think you'll be surprised. I very well may be. That's the fun of experimentation.
From: gpsman on 10 Jul 2008 17:34
On Jul 10, 5:13 pm, "DanK...(a)gmail.com" <DanK...(a)gmail.com> wrote: > > All these comments and no guess on my stopping distance? 25mph... <30', probably closer to 25. ----- - gpsman |