Going the speed limit

[KawiKid860]

Is it common for motorcyclists to go over the speed limit? I know most cars around here do at least 5 over (and the occasional one that does 5 under..) For me, being a new rider, its so easy to go over the speed limit probably because of the extra freedom and the power my bike has that a car doesn't. I'm just wondering if this is a normal thing for motorcyclists to do? It seems like most go quite a bit over the limit, but a bike won't stop any quicker than a car. However we do have agility on our side + an alert rider will react faster than a less than alert driver. Does the added alertness and agility justify speeding, or would you rather just stay the limit?

[kaiserz]

speeding is "speeding".

[Mountain Dew]

M13 said that according to some study, the safest speed for a bike to be traveling is slightly faster than the flow of traffic. Seems reasonable to me (although I can't find anything about it). If you're 'moving' in someone's view, you're more visible.

If that means going 10 over for me, I'll do it. I've never been bothered and I generally ride 10-15 over (speed limit here is 55 on the highway in most places, so 70 in a 55 isn't that unreasonable), even in front of cops with radar guns. To me it seems like if you're being safe, going a bit over is perfectly acceptable. But if course this is in clear traffic. If it starts getting close to rush hour, you better believe I'm slowing down.

[MotoED]

With the way cops are here in SoCal, I try to stay within the speed limit. But I do tend to go over it sometimes

[Vegedurden]

Originally Posted by Mountain Dew

I've never been bothered and I generally ride 10-15 over

I tend to do the same, but when you have cars going really fast in twisties, you're better off backing a bit.

Remember a car brakes better and can take corners faster than a bike...

[ally99]

I rarely drive the limit whether on my bike or in a cage. I like to get places quickly, and speed limits are always set granny low in most places. I tend to ride 15ish over.

[rockNroll]

Slightly faster than "traffic" on the highway/freeway.
Within 5mph or so in the city.
Whatever speed feels good in the mountains/boonies.

[caps]

Originally Posted by rockNroll

Slightly faster than "traffic" on the highway/freeway.
Within 5mph or so in the city.
Whatever speed feels good in the mountains/boonies.

^
This

[almost40]

Originally Posted by rockNroll

Slightly faster than "traffic" on the highway/freeway.
Within 5mph or so in the city.

+1

[bdavison]

Originally Posted by Vegedurden

Remember a car brakes better and can take corners faster than a bike...

Um...no they cant.

[Alex]

Originally Posted by bdavison

Um...no they cant.

They absolutely can. The performance advantages of a typical bike compared to a typical car are down to an insane power-to-weight ratio that allows for tremendous acceleration. But in braking, most performance cars will stop faster than most performance bikes. In corners 4 contact patches + the aero help at speed will always provide additional cornering capability to a car.

Doesn't mean a nimble bike can't walk away from a car in most any situation on the street.

[CC Cowboy]

As a responsible member of the motorcycle community I feel that setting an example to motorists, that all bikers (motorcyclists) aren't wild and crazy squids, so I ride the speed limit or a little under the limit. If everyone would do the same there would be less accidents, less petrol wasted, less road rage, and people would be generally more happy.

[Kevin2109]

Originally Posted by MotoED

With the way cops are here in SoCal, I try to stay within the speed limit. But I do tend to go over it sometimes

lol I guess the cops around me a chill. Or I just dont get caught

I'm normally 5-20 above the speed limit, depending on conditions of course. Freeway I'm 80-90ish, again depending on conditions

[KawiKid860]

Riding a bit faster for visibility makes sense, and I definitely pay more attention when I'm going over because I'm looking for cops, cars pulling out, etc. Wouldn't it take a relatively sporty car to keep up with a bike in the twisties? I mean your average sedan isn't going to handle that well, something like a 350/370z or even one of the new mustangs. I read that cars may be better handling than bikes but bikes are a way better bang for the buck because a $15k bike can hang with a $60k+ car

[theredsox]

Off topic, but for KawiKid, to compare my Subaru Wrx ('04) and the ninja ('11)

- $24,495 vs $3999
- 0-60 is 5.2-6s for both
- 60-0 in ~107 ft vs ~121.5 ft
- Cornering is hard to provide numbers, but in real world conditions with roads that aren't always clean, pretty sure the subby would be faster 9 of 10 times. All wheel drive is a force to recon with.

On topic, I've always felt safer going just slightly faster than the traffic average, bike or car doesn't matter. In reality though I don't think that is true. Going faster than traffic does mean a harder time keeping safe distances from cars in front of you that you are catching up to. It does reduce time in blind spots though and reduces the chance of being tailgated. Personally, I'd say go with speed of traffic, but increase speeds to move through drivers blind spots. To me, the speed limit has nothing to do with it. It's all about traffic flow...even with cops around because usually they'll slow down traffic flow anyway.

[Mountain Dew]

http://www.youtube.com/watch?feature...&v=Man0X0bf8vk

This video demonstrates the difference between a bike and a car. Keep in mind the car is a GTR and not some DD sedan.

[alex.s]

what is this "speed limit" you speak of?

[ally99]

^^You live on the Autobahn?

[gfloyd2002]

Originally Posted by Alex

They absolutely can. The performance advantages of a typical bike compared to a typical car are down to an insane power-to-weight ratio that allows for tremendous acceleration. But in braking, most performance cars will stop faster than most performance bikes. In corners 4 contact patches + the aero help at speed will always provide additional cornering capability to a car.

Doesn't mean a nimble bike can't walk away from a car in most any situation on the street.

Agree with Alex here. Cars stop faster. Most bikes and cars have brakes that are capable of lock up on the wheels, so the real limiter is the tires and the tire surfaces. Cars have more of them. It seems like a heavier thing would be harder to stop or corner, but it generally isn't the case.

While counter-intuitive that a heavy thing will brake quicker, cars still have (for the most part) sufficient braking power to lock up their wheels. Heavier weight just means you need more powerful brakes to achieve the same stopping power, and most cars have this in spades. This is because heavier weight offers increased friction that balances out the increased momentum that comes from the weight. (F = mu*N where F = frictional force (braking force between the tires and the road), mu = friction co-efficient (changes based on road/tire condition), N = normal force (force acting directly downwards with gravity i.e., the mass of the bike and rider).

So, more weight means more momentum, but it is cancelled out by the extra friction from the weight. You add even MORE friction with the two extra extra contact patches, and that is enough for a four wheeler to outperform a two wheeler in the cornering/braking department. We can still get them on speed and acceleration, though.

[gfloyd2002]

On topic of post, there is a line of reasoning, supported by accident studies, that riding slightly faster than the speed of traffic is most safe.

The reasoning is twofold. First, it may increase the visibility of the motorcycle to the traffic by distinguishing it and providing a comparison movement/differential in speed that makes the motorcycle easy to perceive rather than blend into the background. The second reason is that riding slightly faster than traffic reduces motorcyclist's radius of attention to 180* from 360* and he no longer has to pay as much attention to what is going on behind or beside him. Compare that to the motorcyclist going slower than (or the same speed as) the traffic around him - now he has to pay attention to the overtaking (or adjacent) drivers who now present the risks of their running over the motorcyclist or making unsafe and unpredictable lane changes to pass the motorcyclist.

That said, doing so in the wrong conditions increases other risks, most notably of overdriving one's stopping distance. You should only ride at a speed at which you can safely stop before a potential hazard. If going slightly faster than traffic means you can't stop in time for that pothole around a blind corner, or someone pulling out from a side road, etc. it is NOT the safer option, and you should instead ride at the speed allowing for a safe stop.

[greatwhiteninja]

i do 80 on the hwy, and thats usually flowing with traffic.. other roads it all depends but usually im about 10 over.

[KawiKid860]

gloyd2002 those were 2 VERY informative posts lol but I got a little lost on the first one :P but I understand the reasoning. So from now on I shall ride slightly faster than traffic to increase others awareness of me (I won't rely on this of course) when someone is making a left turn and there's a chance they might pull out in front of me I usually get ready to swerve if I have to and I increase my speed through the intersection to get out of possible harms way faster, is this a good idea? Or would it be smarter to keep the same speed and be ready to brake rather than speed up? To me it seems like speeding up and getting out of harms way faster is better and if someone turns in front of me I'm most likely going to have to swerve to avoid them, which I'll have less time to do if I'm going faster.

[Numbersix]

I ride to where the cars aren't. That may be faster or slower than they are -- whatever provides separation.

[Boom King]

Around here, unless it's a residential neighbourhood street, if you're not doing at least 10 -15 km/h over, you're holding up traffic. At a light, I'll rev that Ninja hard all the way up to the limit and then more to separate myself from the group of traffic and give myself plenty of room 360 degrees. Then I will cruise at whichever speed feels comfortable to me and appropriate for the street. Of course, sometimes this also invites an idiot cager to think that you want to play cat and mouse.

[KawiKid860]

Around here, unless it's a residential neighbourhood street, if you're not doing at least 10 -15 km/h over, you're holding up traffic. At a light, I'll rev that Ninja hard all the way up to the limit and then more to separate myself from the group of traffic and give myself plenty of room 360 degrees. Then I will cruise at whichever speed feels comfortable to me and appropriate for the street. Of course, sometimes this also invites an idiot cager to think that you want to play cat and mouse.

I do this too, yesterday some guy in a brand new lifted dodge ram took off to at least 70 mph in a 40 around a curve taking up both lanes trying to get me to race him but I decided it wasn't worth losing my license, a limb or my life to prove to some jerk his truck wasn't faster than my bike haha....

[ally99]

Originally Posted by KawiKid860

when someone is making a left turn and there's a chance they might pull out in front of me I usually get ready to swerve if I have to and I increase my speed through the intersection to get out of possible harms way faster, is this a good idea? Or would it be smarter to keep the same speed and be ready to brake rather than speed up? To me it seems like speeding up and getting out of harms way faster is better and if someone turns in front of me I'm most likely going to have to swerve to avoid them, which I'll have less time to do if I'm going faster.

Braking is nearly always preferred over swerving to avoid a collision. As I approach an intersection like you mentioned, I'm already scrubbing off a bit of speed and heating my brakes up in case they are needed. You can always brake and then swerve if you need to do them both, just don't do them both at the same time. It hurts nothing to be on the brakes and slow down when approaching an intersection with other vehicles ahead.

[KawiKid860]

Braking is nearly always preferred over swerving to avoid a collision. As I approach an intersection like you mentioned, I'm already scrubbing off a bit of speed and heating my brakes up in case they are needed. You can always brake and then swerve if you need to do them both, just don't do them both at the same time. It hurts nothing to be on the brakes and slow down when approaching an intersection with other vehicles ahead.

The thing is if I slow down I feel like I'm giving the car more chance to not see me, or miscalculate distance and turn right in front of me

[algerath]

Originally Posted by gfloyd2002

Agree with Alex here. Cars stop faster. Most bikes and cars have brakes that are capable of lock up on the wheels, so the real limiter is the tires and the tire surfaces. Cars have more of them. It seems like a heavier thing would be harder to stop or corner, but it generally isn't the case.

While counter-intuitive that a heavy thing will brake quicker, cars still have (for the most part) sufficient braking power to lock up their wheels. Heavier weight just means you need more powerful brakes to achieve the same stopping power, and most cars have this in spades. This is because heavier weight offers increased friction that balances out the increased momentum that comes from the weight. (F = mu*N where F = frictional force (braking force between the tires and the road), mu = friction co-efficient (changes based on road/tire condition), N = normal force (force acting directly downwards with gravity i.e., the mass of the bike and rider).



So, more weight means more momentum, but it is cancelled out by the extra friction from the weight. You add even MORE friction with the two extra extra contact patches, and that is enough for a four wheeler to outperform a two wheeler in the cornering/braking department. We can still get them on speed and acceleration, though.

This doesn't seem to account for the fact that most performance bikes tend to have softer, grippy tires compared to a car. Wouldn't that factor in too? Most average people would never consider tires for the grocery getter that would be worn out in 5000 miles, some of the supersport tires don't last even that. Most common car tires advertise like 40 or 60k miles tread life.

A skilled rider, at least in theory, has the ability to control the front/rear braking ratio to suit the braking conditions, ex. Braking downhill using even more front brake than normal, allowing one to use both the tires to the limit possibly better than the standard ratio in a car.

I mean a race bike using super sticky race tires can brake later and carry more corner speed than if they raced on cruiser tires, or else they would all be racing on cruiser tires right?

[rockNroll]

Originally Posted by algerath

This doesn't seem to account for the fact that most performance bikes tend to have softer, grippy tires compared to a car. Wouldn't that factor in too? Most average people would never consider tires for the grocery getter that would be worn out in 5000 miles, some of the supersport tires don't last even that. Most common car tires advertise like 40 or 60k miles tread life.

A skilled rider, at least in theory, has the ability to control the front/rear braking ratio to suit the braking conditions, ex. Braking downhill using even more front brake than normal, allowing one to use both the tires to the limit possibly better than the standard ratio in a car.

I mean a race bike using super sticky race tires can brake later and carry more corner speed than if they raced on cruiser tires, or else they would all be racing on cruiser tires right?

One thing to note on the car vs bike thing is that most people's cars could only out brake your bike for just a few corners before they get have brake fade and the driver has an oh sh!t moment.

[Alex]

Any advantage in stickiness on the motorcycle tires is greatly outweighed by the much larger contact patch on the car tires, along with the fact that for years now, any driver can stomp on the pedal to bring all 4 wheels right up to lockup, without worrying about upsetting the car's attitude on the road. A rider doesn't have it that easy, even with ABS on board.

Originally Posted by rockNroll

One thing to note on the car vs bike thing is that most people's cars could only out brake your bike for just a few corners before they get have brake fade and the driver has an oh sh!t moment.

True - the ability to shed heat after multiple stops is likely better on the average performance bike vs. the average performance car.

[algerath]

Alex is probably right on the contact patch and abs. It is counterintuitive though, it FEELS like I can brake much faster on the ninja than in my car. I would love to see some mythbusters style tests on cornering and braking car vs bike!!!

[Boom King]

Even your average car nowadays comes with so much tech. ABS, traction control, stability control, brake assist, electronic brake force distribution, etc. Even with the bike's ability to shed heat of the brakes faster, I'd still take a high performance car's cornering ability on a road course. In some cases though, the end results are probably so close and might boil down more to the skill of the respective operators.

http://www.flixxy.com/car-vs-motorcycle.htm

[Vegedurden]

Originally Posted by algerath

Alex is probably right on the contact patch and abs. It is counterintuitive though, it FEELS like I can brake much faster on the ninja than in my car. I would love to see some mythbusters style tests on cornering and braking car vs bike!!!

It is definitely counterintuitive, especially to us. On the Mythbusters thing: I have seen a few videos pitching superbikes against sport cars, bikes systematically destroy the cars in straights, thanks to power to weight ratio, but inevitably cars retake the advantage in the corners. Search youtube or some other video site, you're bound to find a few examples.

The important part, though is that I'd never trade the feeling of taking corners on a bike for a few additional mph.

[algerath]

Ok so I was still a little skeptical about the whole braking thing, so I looked up some numbers. I thought I would maybe expect a high performance car to out brake me on the ninja but what about a common commuter, like my car a 03 cavalier, surely I could out brake my car. Well short story, nope.

2011 ninja 250 143 ft from Motorcyle usa
2003 cavalier 132 ft From motor trend

So I thought what about high performance bike and car

2011 mustang gt with brembo pkg 105 ft also motor trend
2010 Yamaha R1 132 ft motorcycle USA

So long story short, in any apples to apples comparison the car wins, it takes a high performance bike to get into the ballpark of my commuter car!

So I am convinced, Alex and Floyd you are correct, but if all 4 can brake hard enough to lock the wheels where does the variation in distance come from? Is it ALL in the tires and the friction they can generate? Is the variation just because high performance bikes and cars come with sticky tires. If I could put the mustang tires on my cavalier could I stop in 105 ft? Same question r1 tires on my ninja would I stop in 132 ft?

[Alex]

While all of the systems have enough capability to lock the tires, those with more excess capability, better components allowing better feel and modulation, and those with stickier tires will all be able to perform a bit better.

Putting uber-sticky tires on the ninjette would likely shave a few feet off the emergency stop distance in dry conditions. Probably not more than a handful at most, but perhaps a little. With better braking components (steel lines, larger disk, a second disk up front), a rider is more likely to be able to keep the tire right at the edge of lockup, which minimizes the stopping distance.

[KawiKid860]

2010 Yamaha R1 132 ft motorcycle USA

That much distance for an R1??? and 143 feet for a ninjette still sounds way off, thats like Harley status! My 500 has a braking distance of 115 feet and it only weighs 14 lbs less than an R1 but it only has a dual piston brakes and a single disc up front not to mention smaller, less grippy tires...

[Xoulrath]

Originally Posted by algerath

If I could put the mustang tires on my cavalier could I stop in 105 ft? Same question r1 tires on my ninja would I stop in 132 ft?

I don't know about the 105 ft, as Alex pointed out, it is a combination of better parts that include stickier tires to get those lower numbers. And again, as Alex already pointed out, the same goes for the Ninjette.

Braking is the single largest performance advantage cars have over bikes. It's like when I take a right hand 90 degree I have to take to go to my house on the way home from work and school from a 60 mph speed. In my GTI, I don't even start braking until I'm about 80 or so feet from the turn, maybe closer, and I brake all the way into the start of the turn and don't release the pedal until after I have gone half way through the motion, though I have eased up on the pressure.

That same turn on my bike sees me stopping about 40 feet further back, and not braking as deep into the turn.

And the other advantage cars (mostly performance cars) have over bikes is corners where high grip is advantageous.

[LazinCajun]

Originally Posted by KawiKid860

The thing is if I slow down I feel like I'm giving the car more chance to not see me, or miscalculate distance and turn right in front of me

Slowing down slightly before an intersection is the safest thing to do for three big reasons:

1) If you slow down a little as you're coming into an intersection, you actually can reduce your stopping distance dramatically. If you do the physics the distance it takes to stop is like a parabola: it's some number times speed squared. Since that curve gets steeper as the speed is bigger, slowing from 50-0 takes a significantly longer distance than 40-0. Even though the speed is only 25% greater, the stopping distance is 56% greater, all other things being equal (!!!).

2) If you do actually get in an accident, you're less likely to be hurt at the slower speed. Duh.

3) If you're going a little slower, you have more time to react AND more traction available if you decide that swerving is the right answer (for many bad situations, emergency braking is the better answer, as mentioned earlier).

[blink]

I only go speed limit in

1.playground zones
2.school zones
3. if theres a cop

=]

[blink]

also completely irrelevant I hate when people do 30 in school zones outside of the posted time!