Braking distances - Cars vs Bikes

Braking distances - Cars vs Bikes

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Moose.

Original Poster:

5,339 posts

242 months

Friday 13th April 2007
quotequote all
I was having a discussion the other night in the pub with a couple of biking mates who are convinced bikes can stop in a shorter distance than cars. Now obviously this would depend on the car/bike in question, but for arguments sake we compared a Hornet 900 with my VW Polo 16v. I recon the Polo would stop in less distance due to the larger tyre contact patch, but they reckoned the bike, being so much lighter, would be quicker.

Perhaps a more average comparison would be better, say a Mondeo 2.0 and a Bandit 600 perhaps?

Anyone care to settle this argument with some facts and figures

mat205125

17,790 posts

214 months

Friday 13th April 2007
quotequote all
In the dry, the bike will stop in a far shorter distance than the car.

RichardD

3,560 posts

246 months

Friday 13th April 2007
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Performance bikes do have awesome brakes, but they are ultimately limited by being able to keep the rear wheel on the ground.



Edited by RichardD on Friday 13th April 12:23

Steve_Evil

10,663 posts

230 months

Friday 13th April 2007
quotequote all
Surely when braking you haven't got to worry at all about the front wheel being on the ground? More the opposite if the bias is a bit too much to the front, you're gonna end up with one hell of a stoppie going on and the rear lifting off the deck.

Edit: Bah, beaten to it!

Edited by Steve_Evil on Friday 13th April 12:24

mackie1

8,153 posts

234 months

Friday 13th April 2007
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I'm pretty certain a typical car and stop quicker than a typical bike but a quick search for actual bike stopping distances didn't turn up anything. A typical 60mph to 0mph stop good car will take about 45m I think.

RichardD

3,560 posts

246 months

Friday 13th April 2007
quotequote all
mat205125 said:
In the dry, the bike will stop in a far shorter distance than the car.
Do you have any times from 100mph to 0mph ?

I've got a few Autocar 0-100-0 challenge issues at home and the bikes were no where near the cars, but then I think it was tricky on the transition from acceleration to braking due to extreme weight transfer on the bikes...



Edited by RichardD on Friday 13th April 12:31

BliarOut

72,857 posts

240 months

Friday 13th April 2007
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Conveniently I've got a 900 Hornet and a 911 and I reckon I would definitely be able to pull up quicker from very high speeds in the Pork yes

excupra

6,811 posts

207 months

Friday 13th April 2007
quotequote all
RichardD said:
I've got a few Autocar 0-100-0 challenge issues at home and the bikes were no where near the cars, but then I think it was tricky on the transition from acceleration to braking due to extreme weight transfer on the bikes...

Yep, I don't know of a bike that can beat an Ultima GTR from 0-100-0 but certainly there are bikes that must be quicker from 0-100.

markh1

2,846 posts

210 months

Friday 13th April 2007
quotequote all
Did my ride drive course in the cerbera yesturday (I know its not exactly your average road car) but from 70mph to 0mph we measured a stopping distance of about 25 meters (this car has no abs)

toltec

7,164 posts

224 months

Friday 13th April 2007
quotequote all
markh1 said:
Did my ride drive course in the cerbera yesturday (I know its not exactly your average road car) but from 70mph to 0mph we measured a stopping distance of about 25 meters (this car has no abs)


That's about 2g, if I have done the sums right. Nice

mackie1

8,153 posts

234 months

Friday 13th April 2007
quotequote all
markh1 said:
Did my ride drive course in the cerbera yesturday (I know its not exactly your average road car) but from 70mph to 0mph we measured a stopping distance of about 25 meters (this car has no abs)


That's pretty good! I bet your eyes had a job staying in their sockets :P

RichardD

3,560 posts

246 months

Friday 13th April 2007
quotequote all
excupra said:
...I don't know of a bike that can beat an Ultima GTR from 0-100-0 but certainly there are bikes that must be quicker from 0-100.
Always thought it a shame that for whatever reason the Ultima factory was not included at these challenges.

Don't have the numbers now but remember a litre bike (pro rider) and the time to accelerate to 100mph was just about the same as the time to stop from said speed yikes

What I would think though is that say 150-100mph braking a superbike would brake better than many performance cars just due to the sheer bite and lack of weight ?

mackie1

8,153 posts

234 months

Friday 13th April 2007
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Random braking fact: When pulling up to a stop from it's top speed a Veyron's braking system has to dissipate around 1 megawatt's worth of energy as heat and can do it in under 10 seconds. Bugatti claim maximum deceleration of 1.3g on road tyres.

BliarOut

72,857 posts

240 months

Friday 13th April 2007
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The problem with braking hard "on the road" on a performance bike is the shocking state of repair. Although you *can* throw the anchors out hard it's very easy to hit a rut or a pothole and get into big trouble with all that force going through the front wheel. In a performance car with ABS etc you can stamp on the pedal and let the car get on with it. It takes a lot more skill (and balls) to do an emergency stop on a bike on the road.

Parrot of Doom

23,075 posts

235 months

Friday 13th April 2007
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Not a chance IMO. I've filmed cars and bikes for years, cars have much better stopping and cornering ability than bikes, because they have a much larger contact area with the tarmac.

mackie1

8,153 posts

234 months

Friday 13th April 2007
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And lower CoG thus less weight transfer.

RobM77

35,349 posts

235 months

Friday 13th April 2007
quotequote all
Yes, cars are quicker at braking simply because they brake with two tyres rather than one, and they're not limited by the vehicle trying to flip over.

I've got some figures from the 27th April 2004 Autocar magazine:

Suzuki GSX-R 1000: 100mph - 0 in 5.63 seconds
Lotus Elise 111R - 4.09 seconds
Peugeot 206 Gti 180 - 4.39 seconds
Porsche 911 GT3 - 4.00 seconds (interestingly, the raw physics suggests that a 911 obtains a 50:50 weight distribution whilst braking fully).

The bike is beaten by everything, including a hot hatch. I'm fairly confident a standard hatch would also beat the bike.

So, the 911 is 1.63 seconds quicker under braking from 100-0. Call that about a second from a typical track top speed to a typical track cornering speed, and it can be seen why bikes often fail to live up to the lap times you'd expect round a race track, especially tight race tracks with lots of braking involved.

chris71

21,536 posts

243 months

Friday 13th April 2007
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I've got limited experience of riding bikes, but I was always under the impression their stopping distances were significantly greater.

Brake discs are remarkably good at dissipating energy, so pretty soon it comes down to your ability to grip the road and of ocurse, not go over the front wheel(s). I know in theory the size of the contact patch doesn't matter, but I'm sure once you've put contact patch distortion and heat dissipation into the equation four bit fat tyres will grip better than two small (cambered) ones.

qube_TA

8,402 posts

246 months

Friday 13th April 2007
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If you do an emergency stop at high speed on a bike you risk not being able to hold on. In a car you're strapped in, it's got to make a difference.

imfinlay

3,341 posts

216 months

Friday 13th April 2007
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I think that the variance between bikes is quite large. My old Sprint ST had a crap rear brake (as in totally useless), and the front would lock up if heaved on. My new ('03) BMW has servo-assisted ABS, and with BMW's clever suspension there's not much diving going on. It stops like no bike I've ever ridden, much more like a car really. With that system on a lighter bike (K1200S?) it would be, as the Yanks say, awesome.

Ian