Better Brakes, Car or Bike??

[Gridlock]

With a high performance bike the high CG and resulting weight transfer forward are surely the limiting factors in hard braking. I.e. you can do a 'stoppy' before the front tyre starts to skid.

Never seen a car do that!

YouTube - Car Stoppie

Ask and ye shall receive...

Bit of cadence braking involved though.

 

[renault12ts]

...probably no shock absorbers either...

 

[martin_a]

My Blackbird has linked brakes but not ABS (i don't think) so stoppies are a no no really.

Braking performance is good, i'm not really sure what would win. I'd certainly take the car in the wet but today most cars have ABS which obviously helps a lot. Without ABS there is a lot more skill involved. Assuming neither had technical aids then I'd think bike, against a decent ABS car, possibly the car.

5m.

 

[NormanC]

It would be interesting to see where the braking points are and what the straight and corner entry speeds are for different vehicles on the same circuit.

Absolutely!

Didn't EVO magazine do some tning like this a couple of years ago? Anybody remember?

Edit:- Link here suggests cars beat bikes. www.evo-me.com - Car Group Test: Bike v Car

with quote "proving the obvious - that our cars are better than any road bike - or race bike."

 

[Bellow]

Autocar had a video of Caterham and Ducati on a circuit. Can't remember which braked better but seem to remember the Caterham getting round quicker.

 

[BTB 500]

You don't really do a stoppy unless you encourage it on a bike. (usually by a sudden increase or by shifting your weight). That said, look at the GP boys when they brake into a corner and the back wheels are often a centimetre or so in the air - actually, thinking about it, so do many cars (thinking of saloon car racing).

Yup it was the racing bikes I was thinking of, where presumably they are trying to slow down as quickly as possible rather than show off! The fact that the back lifts suggests (a) they are getting no braking from the rear wheel whatsoever and (b) that the front could brake harder (as the wheel isn't locked at that point) if it wasn't for the whole thing trying to do a forward roll

A car lifting a single back wheel in a turn is a bit different - you can bet it'd be out-braking a bike in the same bend! And unlike a bike they don't do it in a straight line - you can get maximum braking effort from the front tyres (right up to the point where they break traction) plus some braking from the rears too.

 

[BTB 500]

In an effort to avoid hitting the back of the car in front of me, he braked so hard, the rear of the bike flipped up and he went over the handlebars and landed on the road in front of his bike.

http://www.mbclub.co.uk/forums/497863-post30.html

Had a feeling this had been discussed here before!

 

[st4]

http://www.mbclub.co.uk/forums/497863-post30.html

Had a feeling this had been discussed here before!

and whatever happened to rf065????????

 

[BTB 500]

and whatever happened to rf065????????

Yeah, another name from the past!

Last Activity: 14-03-2010 04:10 PM

 

[st13phil]

It would be interesting to see where the braking points are and what the straight and corner entry speeds are for different vehicles on the same circuit.

I think it was Bike magazine (but it may have been Performing Berks) a few years ago who took a Lotus Elise and a Yam R6 around a circuit then plotted braking points, corner entry speeds, acceleration and max speeds for both. It made an interesting read. Basically the car and the bike had similar lap times (within a tenth or so) but how they did it was completely different.

The car had significantly higher corner entry and mid-corner speeds than the bike, while the bike's superior acceleration meant that it scurried off out of a corner quicker than the car, and also hit a higher top speed on the relatively short straights. The bike had to brake earlier than the car as it had to scrub off more speed - higher speed pre-braking and lower corner entry speed - so the car would then close up and effectively overtake again through the corner.

The really fascinating thing was that the car was driven by a Lotus test driver and the bike by a national-level racer. When an ordinary road rider (one of the journo's) attempted laps in both the car and on the bike there was a huge disparity in lap times, with him being within a few tenths of the expert car driver but a matter of seconds slower than the racer had been on the bike. The conclusion was that it took a much higher skill level to get the best performance out of the bike than it did the car.

 

[Dryce]

In a straight line on dry road they will be pretty much the same (cars have more tyre contact area, but weigh more). In less than perfect conditions much more skill will be required to bring a bike to a safe stop, whereas in a modern car (with ABS, ESP, etc.) you just need to stand on the brakes. So with an average rider and an average driver, my money would be on the car.

I concur with this.

Bike has lot less weight, probably has stickier rubber, and also more drag.

But control is the problem. Any road surface imperfections or contaminants and things become very difficult for the bike very quickly.

 

[Mactech]

I agree! Having to study the data output of both cars and bikes on circuit there is a massive difference in the 'shape' of the speed traces. Bikes can often accelerate at much the same rate as they brake (hence mono wheeling), but rarely manage more than 1.2g under brakes. That's just physics. This means they use up to 40% of some straights slowing down!
Cars normally have a much lower power to weight ratio, and race cars much more drag, but......using the additional grip and downforce can often brake in just the final 10% of the straight and pull up to 4 or 5g!
On the road and in the dry the skilled biker will brake at much the same rate as the car (best of about 1g) but if you throw in tricky (slippery) or extreme conditions (ie circuit!) you'll find me in my car
It does take a lot more skill (and therefore risk?) to get the best from a bike but with all the 'nanny' aids of a mordern Mercedes most will stop much faster in a car.
One of the reasons I will never 'filter' in traffic when on the bike at more than about 10mph quicker than the stationary or slow moving traffic.

 

[Spinal]

Just a quick one as I'm on my way to work (officially) - when learning to ride a bike, I was told to be weary when braking as bikes can stop in a much smaller space than a car and as such, when braking quickly I was likely to get rear-ended.

In fact, I do believe it was a question on the theory test....

Will do some research later...
M.

 

[Spinal]

Correction - I was wrong. Or at least, not totally right. DVLA published figures only for cars, and expects bikers to learn those too.

Apparently 5th gear did a test between a Gallardo and a 1098; and the lamo beat the Ducati... but I can't find the clip anywhere....

M.

 

[del320]

Going off on a bit of a tangent, here...

I recently visited a 73 year old retired architect acquaintance of mine and he showed me his selection of toys. He still races cars and bikes and has, amongst other things, a racing special with 4.7l v8 Ford block and Allard head, a 1988 Carrera and an Alfa.

But I was intrigued with his 1000cc Buell racer: why has its unusual brake disc arrangement not been employed more widely? He explained the benefits of lower unsprung weight, cooler operation and greater braking surface and it all seemed to make sense to me.

Along with its other novel features is it, in fact, an engineering cul-de-sac?

 

[Mactech]

But I was intrigued with his 1000cc Buell racer: why has its unusual brake disc arrangement not been employed more widely? He explained the benefits of lower unsprung weight, cooler operation and greater braking surface and it all seemed to make sense to me.

Along with its other novel features is it, in fact, an engineering cul-de-sac?

Yes! Given the same pad size, the weight of the disc or discs will be proportional to the diameter. About 12" is the normal and adequate size. With the disc on the rim it's about 17"! Then it's also more difficult to get a sensible rigid caliper mount. The Buell is unique for a good reason

 

[martin_a]

This was a good one on 5th Gear... note that the bike isn't a MotoGP bike which I would say is more like the equivalent of F1....

YouTube - Honda F1 Bike Boat Race

m.

 

[Spinal]

Oh, one more thing to add to the thread...

While I still feel that the stopping distance of a bike is less than a car (reasoning below), take an inexperienced driver and an inexperienced rider... one who hasn't had to do many emergency braking stops...

Put them side by side in a car and a bike, and get then to stop from 120mph in as short a space as possible...

Why do I have a feeling the car driver will probably survive unscathed, while the rider will be quite bruised?

M.

Reasoning: I've heard of many motorbikes with bent frames due to a very sudden emergency braking manouver... I've never heard of a car braking so hard that any part bent...
M.

 

[iscaboy]

Reasoning: I've heard of many motorbikes with bent frames due to a very sudden emergency braking manouver... I've never heard of a car braking so hard that any part bent...
M.

I have, it's called an "accident".

 

[Spinal]

I have, it's called an "accident".

I meant, bike frames get bent under extreme braking without actually impacting anything...

I've never seen/heard of a car getting distorted purely through braking... without any physical impact...
M.