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From: Nev.. on 28 Apr 2010 05:06 On 27/04/2010 7:33 PM, Lee wrote: > On Tue, 27 Apr 2010 19:20:07 +1000, Nev.. <idiot(a)mindless.com> wrote: > >> On 27/04/2010 6:53 PM, Lars Chance wrote: >> >>> The fact that he was turning when he collided with them tends to >>> indicate that speed *wasn't* much of a factor (hard to speed around >>> right-angle corners on a pushie) >> >> Really? I thought cornering speed was a function of weight, among other >> variables. Compare the speed which 125cc bikes carry through corners >> compared to MotoGP bikes as an illustration. >> > > cornering speed is a function of grip, which is entirely down to the > coefficient of friction between the tyre and the road, limited by how > far over you can lean the bike / how far over you can get the centre > of gravity of the bike/rider combination. You should be able to lean > a road pushbike on grippy rubber a fair way over, so you should be able > to get around corners pretty quick. Has almost nothing to do with > weight, the extra sideways force from momentum is exactly countered > by the extra grip from the extra mass. Which is why they put wings on > F1 cars - extra grip without using stickier rubber (that won't last > as long) Interesting. Why does a 125cc bike carry more speed through a corner than a MotoGP bike? A motogp bike has more grip, therefore should lean further. What's the difference? CoG? Nev.. '08 DL1000K8
From: Moike on 28 Apr 2010 05:51 Nev.. wrote: > On 27/04/2010 7:33 PM, Lee wrote: >> On Tue, 27 Apr 2010 19:20:07 +1000, Nev.. <idiot(a)mindless.com> wrote: >> >>> On 27/04/2010 6:53 PM, Lars Chance wrote: >>> >>>> The fact that he was turning when he collided with them tends to >>>> indicate that speed *wasn't* much of a factor (hard to speed around >>>> right-angle corners on a pushie) >>> >>> Really? I thought cornering speed was a function of weight, among other >>> variables. Compare the speed which 125cc bikes carry through corners >>> compared to MotoGP bikes as an illustration. >>> >> >> cornering speed is a function of grip, which is entirely down to the >> coefficient of friction between the tyre and the road, limited by how >> far over you can lean the bike / how far over you can get the centre >> of gravity of the bike/rider combination. You should be able to lean >> a road pushbike on grippy rubber a fair way over, so you should be able >> to get around corners pretty quick. Has almost nothing to do with >> weight, the extra sideways force from momentum is exactly countered >> by the extra grip from the extra mass. Which is why they put wings on >> F1 cars - extra grip without using stickier rubber (that won't last >> as long) > > Interesting. Why does a 125cc bike carry more speed through a corner > than a MotoGP bike? A motogp bike has more grip, therefore should lean > further. What's the difference? CoG? > > Nev.. > '08 DL1000K8 I've always assumed the 125cc bike needs to maintain higher corner speed because it has less ability to accelerate. OTOH by taking a tighter, more "V"-shaped line, the GP bike spends more time upright, and traveling at a higher speed. During the shorter time it is turning, it has a lower min speed, but due to it's braking and accelerating ability, its overall average speed through the corner zone is higher. Of course most here are aware of my deep expertise when it comes to high-performance motorcycle racing, so I may have it just a teensy bit wrong. Moike
From: Lars Chance on 28 Apr 2010 06:08 Nev.. wrote: > On 27/04/2010 7:30 PM, Lars Chance wrote: >> Nev.. wrote: >>> On 27/04/2010 6:53 PM, Lars Chance wrote: >>> >>>> The fact that he was turning when he collided with them tends to >>>> indicate that speed *wasn't* much of a factor (hard to speed around >>>> right-angle corners on a pushie) >>> >>> Really? I thought cornering speed was a function of weight, among >>> other variables. Compare the speed which 125cc bikes carry through >>> corners compared to MotoGP bikes as an illustration. >>> >> They don't have to leave clearance for the pedalling! > > I reckon bicycles have much more cornering clearance than any GP bike. > When they're not pedalling yes. -- Elsie.
From: Lars Chance on 28 Apr 2010 06:07 Andrew wrote: > On Tue, 27 Apr 2010 09:30:05 +0000, Lars Chance wrote: >> They don't have to leave clearance for the pedalling! > > You go really fast round corners on a pushie by coasting with the inside > pedal raised to the top - massively more clearance than any motorcycle on > the planet. Where on earth did you go to school that you didn't learn > that? > I'm aware of that but the fact that you can't pedal while hard cornering means that you're losing speed (compared to a motorcycle; the example Nev was using). -- Elsie.
From: BT Humble on 28 Apr 2010 06:25
Nev.. wrote: > Interesting. Why does a 125cc bike carry more speed through a corner > than a MotoGP bike? A motogp bike has more grip, therefore should lean > further. What's the difference? CoG? I'm guessing that the reason is related to the relative masses of the machinery. Maybe kinetic energy to friction ratios. BTH -- Posted at www.usenet.com.au |