Bike vs Car

[Erunanethiel]

If the corner is not a fast one, because the weight then will play his role

Why would that be the case?

[mzivtins]

With everyone expressing the differences between the cornering abilities of a motorbike VS a car, if you are passing bikes in a corner, and they are not dragging their knees, then the comparison cannot be made. It is the same as arguing you are faster than a car in a straight line when the opposing car is at 50% throttle.

Lean angle is critical to a motorbikes cornering abilities. When you see bikes on the ring, the only thing stopping them from being faster than most normal road cars, is the rider and his (quite correct) sense of mortality.

Remember, anytime you feel the front push a little wide, or the rear snap out, on a bike that is a one way ticket to broken bones and ego.

cars corner faster than motorbikes? the only answer it, it depends on the corner
https://www.youtube.com/watch?v=0ncgT008MxI

To add to the thread: Bikes all have sequential gearboxes, i wish cars did! clutch-less gearshifts on a bike are faster than most accessible flappy-paddle gearboxes out there.

[autogyro]

With everyone expressing the differences between the cornering abilities of a motorbike VS a car, if you are passing bikes in a corner, and they are not dragging their knees, then the comparison cannot be made. It is the same as arguing you are faster than a car in a straight line when the opposing car is at 50% throttle.

Lean angle is critical to a motorbikes cornering abilities. When you see bikes on the ring, the only thing stopping them from being faster than most normal road cars, is the rider and his (quite correct) sense of mortality.

Remember, anytime you feel the front push a little wide, or the rear snap out, on a bike that is a one way ticket to broken bones and ego.

cars corner faster than motorbikes? the only answer it, it depends on the corner
https://www.youtube.com/watch?v=0ncgT008MxI

To add to the thread: Bikes all have sequential gearboxes, i wish cars did! clutch-less gearshifts on a bike are faster than most accessible flappy-paddle gearboxes out there.

Basic physics dictate that a car corners faster than a car.
A good driver with a conventional dog engagement gearbox can easily out perform a sequential gearbox with flap levers.
Shifting across the gate is a huge benefit on circuits with multi type corners or on loose surfaces.
Dual shaft /clutch gearboxes have more oil drag than conventional lay shaft boxes and transfer less torque.
Racing cars today use sequential boxes because in F1 and hybrid operation it is essential in controlling the rear torque delivery.
IMO this has taken away at least half of the drivers required skill.

[Andres125sx]

If the corner is not a fast one, because the weight then will play his role

Why would that be the case?

Can´t provide a technical explanation, probably someone around here can explain it, but I´d venture to say probably aero has a part of responsability, as it affect cars without downforce decreasing grip as speed is increased due to their´s aero properties

[Tommy Cookers]

all road cars are certified as being stable eg in cornering
in cornering their front:rear distribution of contact load is sub-optimal for cornering eg maybe 65/35 on the outer wheels (rwd)
(made that way so that in cornering throttle-off or even with braking, only the front end will ever go, never the rear)
ie the stable behaviour that is legally mandated

traditionally this appears as understeer, but performance cars now cancel understeer by design (so the journos are happy)
however they still have sub-optimal load distribution, that's how they get the mandated stability
(and this load distribution also helps traction as such, so the journos are again happy)

ARBs can be modified to give cornering-optimal contact load distribution eg maybe 50/50 - or stiffer rear springs will do
when I did this (rwd car) it was worth 10 -12 sec/lap on trackdays (after learning how to drive it, and how not to)

then one trackday I was shocked by closeup serious lean of a serious bike, and shocked that I was genuinely catching it mid-corner

[Phil]

Lean angle is critical to a motorbikes cornering abilities. When you see bikes on the ring, the only thing stopping them from being faster than most normal road cars, is the rider and his (quite correct) sense of mortality.

True enough. But I wouldn't lean on this argument too hard, mind you, as the ability of a car to extract a higher percentage of its potential in most circumstances is precisely its advantage. In other words; that a car can pretty much deal with load shifts in a safe manner, be on the brakes at maximum stopping power within the split of a second, regain grip in corners that you misjudged or deal better with bumpy roads altogether is its advantage. Also that potential accidents aren't necessarily mortal. We shouldn't be interested in comparing these very different vehicles in a vacuum because life and typical road surfaces aren't that.

And the rather most simple and non-refuted argument in the whole argument between bikes and cars in a corner speed comparison is that the car can pretty easily and simply increase its grip by using wider tires to enlarge its contact patch where as on the bike you can not and are limited by the grip coefficient and the lean angle (that has a theoretical max). It's not to say that you can take any car and just slap wider tires on it mind you, but on a 4 wheeled vehicle, you have options (extending contact patch, lowering weight, lower CoG, adding downforce).

True though; how well a bike fairs in a corner depends also on the corner and the 4-wheeled vehicle in question. Optimal case; Car with downforce, large grip levels and high performance (like a F1 car representing the most extreme you can get) and there too, 4 wheels beats two.

[emaren]

[
And the rather most simple and non-refuted argument in the whole argument between bikes and cars in a corner speed comparison is that the car can pretty easily and simply increase its grip by using wider tires to enlarge its contact patch where as on the bike you can not and are limited by the grip coefficient and the lean angle (that has a theoretical max). It's not to say that you can take any car and just slap wider tires on it mind you, but on a 4 wheeled vehicle, you have options (extending contact patch, lowering weight, lower CoG, adding downforce).

I always used to think that bolting a set of really wide tyres on would give me a much bigger contact patch and hence more grip.

Except that it doesn't. In reality it changes the shape of the contact area.

http://www.performancesimulations.com/w ... -pressure/

It gets confusing, but the contact area is mostly to do with the weight and (correct) tyre pressure. The shape of the contact patch and the pressure on the patch are a huge factor when it comes to grip and rolling resistance too. Not only that but wider tyres need wider wheels and that all adds to the unsprung weight and the braking efficiency too.....

Many of the videos shown in the previous thread also debunked the car is faster, the McLaren vs Ducati showed that in all but the tightest of bends, the bike out-ran the car significantly.

https://www.youtube.com/watch?v=IteniLcLImU

I think that the issue is that any comparison is flawed.

In the rain, a car will win, traction in the rain is tough on a bike
On a super-tight track (like a go-kart track), a go-kart will win.
On a really tight track an Elise or a 7 is probably the thing to have
As soon as the track becomes a little more open and the weather is good, then the right bike, with the right rider can leave pretty much any car.

[mzivtins]

Lean angle is critical to a motorbikes cornering abilities. When you see bikes on the ring, the only thing stopping them from being faster than most normal road cars, is the rider and his (quite correct) sense of mortality.

True enough. But I wouldn't lean on this argument too hard, mind you, as the ability of a car to extract a higher percentage of its potential in most circumstances is precisely its advantage. In other words; that a car can pretty much deal with load shifts in a safe manner, be on the brakes at maximum stopping power within the split of a second, regain grip in corners that you misjudged or deal better with bumpy roads altogether is its advantage. Also that potential accidents aren't necessarily mortal. We shouldn't be interested in comparing these very different vehicles in a vacuum because life and typical road surfaces aren't that.

And the rather most simple and non-refuted argument in the whole argument between bikes and cars in a corner speed comparison is that the car can pretty easily and simply increase its grip by using wider tires to enlarge its contact patch where as on the bike you can not and are limited by the grip coefficient and the lean angle (that has a theoretical max). It's not to say that you can take any car and just slap wider tires on it mind you, but on a 4 wheeled vehicle, you have options (extending contact patch, lowering weight, lower CoG, adding downforce).

True though; how well a bike fairs in a corner depends also on the corner and the 4-wheeled vehicle in question. Optimal case; Car with downforce, large grip levels and high performance (like a F1 car representing the most extreme you can get) and there too, 4 wheels beats two.

I think that solves it for me Phil! You're correct... my previous statement around "well it depends what corner", is kind of like me saying "Hey, i beat you 1 time out of 100! Therefore we are equal footed"
It is a bit of a childish way to look at things!

In my own personal circumstances, i can feel that my own car is much better in the corners compared to the motorbike. However, the bike feels so much more natural, tipping in aggressively seems to be as natural as breathing, no noises, chassis doesn't make any complaints, suspension seems to barely make a fuss and physically i have so much spare concentration to help with the actual act of cornering.

In the car i find i need bucket seats and it always sounds expensive! Two days on a brand new set of 9.5 inch wide Falkens resulted in completely shredded fronts i'm far to aggressive!

[Phil]

Except that it doesn't. In reality it changes the shape of the contact area.

I wasn't assuming equal tire pressures, but pressures optimally suited to the tire and weight of the vehicle. It's a good point though, none-the-less. I was also assuming adequate rims suited to the task, not slapping (too) wide tires onto narrow rims. That's a given. Theoretical, there's also a limit on cars on how much cornering load you can achieve because the engine might run dry without taking measures (talking about more affordable cars here). I didn't want to drag the discussion into comparing a specific vehicle with a given set of boundaries, but wanted to keep it neutral, which is why I just wanted to make the point that on a car, generally, you can do things to improve grip & cornering (or design your car to fair better in those specific areas) whereas a bike will always be rather limited by the physical boundaries and more importantly the ability of the rider willing to get close to that limit on suboptimal track conditions.

[Andres125sx]

[
And the rather most simple and non-refuted argument in the whole argument between bikes and cars in a corner speed comparison is that the car can pretty easily and simply increase its grip by using wider tires to enlarge its contact patch where as on the bike you can not and are limited by the grip coefficient and the lean angle (that has a theoretical max). It's not to say that you can take any car and just slap wider tires on it mind you, but on a 4 wheeled vehicle, you have options (extending contact patch, lowering weight, lower CoG, adding downforce).

I always used to think that bolting a set of really wide tyres on would give me a much bigger contact patch and hence more grip.

Except that it doesn't. In reality it changes the shape of the contact area.

http://www.performancesimulations.com/w ... -pressure/

It gets confusing, but the contact area is mostly to do with the weight and (correct) tyre pressure.

Exactly, with the correct tyre pressure. If you double tire width and keep same tyre pressure, you´re not using the correct tyre pressure, so that explanation is not very accurate

Anycase I´m not sure about if doubling tyre width means tyre patch will be a half, even with same tyre pressure. That statement is assuming deformation of tyres under load is linear. That´s correct? I don´t think so



About total grip related to tyre width, Tim posted this several times, so I´ll save him from repeating the same again

The tyre produces grip from 2 mechanisms:
1. Coulomb friction - this is independent of contact patch area
2. Adhesive forces - these are proportional to contact patch area

So if you increase the tyre size, you increase the adhesive component of the total grip.

I've seen the same tenancy on the Nordscleife too. The bikes get in everyone's way in the corners, and then disappear on the straights.

[emaren]

I've seen the same tenancy on the Nordscleife too. The bikes get in everyone's way in the corners, and then disappear on the straights.

Yup - most of that is related to the cost of commitment.

In a car you can corner at high speed with acceptable risks to you health. On a bike it is a lot different. I've raced cars and bikes and the bikes, even the 250's have incredible limits, but stepping over them can be life changing.

On track days I rarely reached anything close to 'the limit', because my reactions and my skills are not adequate to deal with the consequences of over-stepping them. A 'high speed tank-slapper on a track day a few years ago ended when the GSXR600 spat me over the high-side taught me an awful lot in terms of the limits of my bravery and my skills. It also taught me just how destructive such a crash can me, pretty much nothing that went into the crash was usable post crash...

To go truly fast on a bike takes a lot more skills than I have, but then cars 'on the limit' are pretty tricky too, but the risks tend to be considerably lower.

[J.A.W.]

A car is faster around a corner....

If the corner is long enough so both lines have similar radius, because a bike is thinner so if it´s an angle type corner the real line will have a wider radius than the line the car will do

If the corner is not a fast one, because the weight then will play his role

If it´s a single corner, because a chicane (again, if corners are short) can be taken on a more straight line with a bike

So you can compare bike vs cars on a specific corner, but generally speaking there are many parameters wich will make a generic discussion endless

What is not debatable:

A bike is much much faster on straights

A car is much faster on brakings


But even so it may be debatable because.... what bike compared with what car?

And that´s without mentioning what´s the reason to ban cars with downforce, because that´s one of the advantages of cars over bikes, so if you want to compare MotoGP bikes vs production cars I don´t think that´s a fair comparison, but comparing production cars vs production bikes I think those are the main differences

Actually those points are quite debatable..
Especially those incorrect assumptions - so baldly repeated..

You could ride a Moto-GP or WSBK machine on the public highway, & apart from the loud exhaust, you could
ride it practicably & not draw too much unwanted attention, this is certainly not possible with a wing-festooned
Formula 1 car..

[J.A.W.]

A look at the lap times recorded at even the natural, flowing circuits such as Donington Park, Phillip Is, & Laguna Seca,
( let alone the I.o.M. TT course) clearly show - that top-spec bikes set quicker times than all but
definitively race-spec aero-downforce set-up equipped cars.. even including dedicated race-car Formula Fords..

[nmoleiro]

Aren't you tired of comparing vehicles with such a different power/weight ratio?... I am a little bit...

Best regards.

[J.A.W.]

Aren't you tired of comparing vehicles with such a different power/weight ratio?... I am a little bit...

Not at all.. there are many different performance parameters at play - that is what makes it interesting..
..'swings & roundabouts'.. ( & the topic is evidently - not too tiresome to attract a comment, I note)..