Motorycle Braking Distance

Do motorcycles generally stop at much shorter distance than most cars? I figure it depends on which motorcycle and which car... although in motorycycles, the rider can cut off the momentum quicker than a driver hitting the brake in a car or downshift (manual). But let say cruising on 60 mph, and suddenly had to stop where the rider didn't have much time but to disengage the clutch and apply the brakes, compared to a car, with same velocity stomping its brakes, which would require more distance to come to a full stop? Just wondering what is the general consensus for sportbikes vs car braking power ratio? Thanks.

Bikes would stop faster, they are lighter and the contact patches are more concentrated. If the biker were to use full power and squeeze the handle as hard as he can, The rider would probably fly over the handlebars.

Yeah, causing brake-locks. The front brake power is immense, that's why endos are possible. But a friend and I got into argument about it, he's a a year or year and half old rider in a '03 F4i, and he claimed the stopping distance is more, given if you don't downshift to neutral first.

Hehe, locking which brakes is potentially less dangerous? lol. Front will either catapult you or send the rider to a spilled power slide. And locking the rear can cause also cause spill or highside during lean.

Locking the rear is more dangerous.... if you lock the rear and you let back off before you stop, you're damn near guaranteed a high side. You should just keep the rear locked if you ever do it... it is hard to keep your balance (I've done it) but it's doable. Locking the front, you just let off and reapply brake (carefully, of course). Since your steering comes from the front, you can control where it goes when it's locked.

A bike can stop more quickly on a straight, but a car could stop faster in a turn. Bikes don't stop well in turns, thus the reason you have to stand the bike back up to vertical before applying brakes.

thanks for the tip Saturn, how do you umm practice these timings and reactions? intentionally lock the bike in a closed circuit? lol, i hope never wilingly in the streets. a friend of mine told me after locking the brake, release it asap (within 1-2 sec) and apply it again, but most people panic since never done it before. i hear it's even more difficult to recover if the rear brake is locked during a turn.

Basically, the only way you'd ever get "used" to it is to practice it like you said... They used to teach you how to lock/recover in the MSF, but it became a liability issue. I personally hope to not have it happen again. It scares the crap out of you... especially in traffic.

actually in tests there bugger all in it. between a wrx and an R1 there could be around 1/2 a meter

probably because the WRX sti is one mean stock rally ricer? and R1 is heavier compared to below 1 liter bikes? i suppose it really depends.

In the test i was thinking of, they pitted a WRX in the hands of a local pommy rally champ and an R1 ridden by a SBK rider. The test was about normal 'city' hooning. The WRX beat the bike at some things and vice versa. Ultimately the WRX could stop as quick due to ABS and other electronic help. The final result was even over all tests but the WRX had gone through a set of tyres where as the bike had not.

In another test had a GSXR 1000 against a 4WD twin turbo 4 cyl pommy wierd thing and it came back that the bike stopped in a faster time but in a slightly longer distance. My basic physics and relationships of velocity, time and distance says this can't be done but hey, I'm no scientist.

i forgot to add. The brakes on my 954 are to good for general use. if i need to use the front brakes i must be flying. generally I only need to down shift and rear brake with slight front if required but if i did use the fronts to their full potential chances are the guy behind would hit me.
as for locking the rear as Tangie said its dangerous but can be fun if you pull it off

In another test had a GSXR 1000 against a 4WD twin turbo 4 cyl pommy wierd thing and it came back that the bike stopped in a faster time but in a slightly longer distance. My basic physics and relationships of velocity, time and distance says this can't be done but hey, I'm no scientist.

I could be completely off, but could it be because the Gixxer was travelling at faster velocity than the twin turbo? Perhaps in that sense, Gixxer stopped quicker relative to whatever velocity twin turbo was in, but required more distance due to higher speed. That's the only I can figure it would make sense given the info. Plus there could be many other affecting variables - weight of the vehicles, differences in the speed (even if slight), torque, shifting, etc.

In terms of the gsx stopping faster yet with a longer distance is probably because they were going at the same speed when they went to stop but the gsx's brakes would be to powerfull to put at full force so the brakes were applied slowly causing them to be in the higher speed range for a longer period of time and gradually applying more brake causing them to slow down extreamely fast once the brake could be used to a higher potential... on the otherhand the 4wd had to have been some sort of car so they could apply full brakes without worrying about flying over the front of the vehicle thus allowing them to get into the lower speed range sooner yet slowing down at a constant rate that took more time while the bike slowed at an increasing rate that slowed down faster but kept them in a higher speed range longer. I tried to say that as clearly as possible... if you don't quite understand and want me to explain better I will... :sunglasse.

Later

nope, got it! thanks.

well Blayne said it sort of violated the laws of physics... as I understand now, it didn't; it was a consequence of the rider and mechanical application; i.e. deterrant variables from going quasi-full kinetic to maintain consistency. and I had no idea whether they were exact same speed or off by a little.

Another words, my guess is a bike in lower speed stop quicker than cars, where as higher speeds take a bit longer. but only if the brake is applied closer to full potential.

i forgot to add. The brakes on my 954 are to good for general use. if i need to use the front brakes i must be flying. generally I only need to down shift and rear brake with slight front if required but if i did use the fronts to their full potential chances are the guy behind would hit me.
as for locking the rear as Tangie said its dangerous but can be fun if you pull it off
Aussie, you do realize that 75-80% of your stopping power is in the FRONT brakes, right? I almost NEVER use my rear, unless I am "emergency braking" and need a little extra stopping power.

two parts to this
1. To tangie.
I do realise that the majority of stopping power is in the front but what I tried to say was that I don't tend to ride at speeds requiring the full use of the fronts. When in built up areas I don't feel the need to go more than 20k's over limit just in case (45 mph in a 30) and the fronts are so powerful that only slight pressure is all thats required. Even on the track I never used the full potential because it felt as if I'd lose control.
That said I know that I can use it when needed with confidence because I still practice emergency stops every now and then. usually with full hard fronts emergency stop the back is in the air slightly.oops : )

2. To Beast and Z

ok I'm not the best at physics (passed higher school cert and 1st year uni) but if both parties are travelling at the same speed (velocity is only speed in a direction). both apply brakes at the same time but at a variable due to braking abilities. Wouldn't it be that the shorter the distance equal a shorter time. Braking variables aside due to abs and driver ability and all that, in my mind the shorter the distance the shorter the time. I do get what you are saying about the speed range. We have road safety adverts saying half your speed is taken off in the last 5m (16 feet) therfore a car can decelerate evenly to a stop whereas a bike takes most of its speed of later but at a much higher deceleration to be "quicker"

ve·loc·i·ty ( P ) Pronunciation Key (v-ls-t)
n. pl. ve·loc·i·ties

1. Rapidity or speed of motion; swiftness.
2. Physics. A vector quantity whose magnitude is a body's speed and whose direction is the body's direction of motion.
3.
1. The rate of speed of action or occurrence.
2. The rate at which money changes hands in an economy.

ve·loc·i·ty (v-ls-t)
n.

Rapidity or speed of motion; specifically, the distance traveled per unit time.

I used the term loosely you see, not as a component to relate to physics.

Anyway, I am not sure about the car, but I think that's what beast tried to say - as you get down lower range of speed in bikes, you can apply more pressure, which is obviously stopping quicker than a car.

ok I'm not the best at physics (passed higher school cert and 1st year uni) but if both parties are travelling at the same speed (velocity is only speed in a direction). both apply brakes at the same time but at a variable due to braking abilities. Wouldn't it be that the shorter the distance equal a shorter time. Braking variables aside due to abs and driver ability and all that, in my mind the shorter the distance the shorter the time. I do get what you are saying about the speed range. We have road safety adverts saying half your speed is taken off in the last 5m (16 feet) therfore a car can decelerate evenly to a stop whereas a bike takes most of its speed of later but at a much higher deceleration to be "quicker"

OK... I will explain to you with an example... probably not how it happend but a possibility::


You have your car and you bike both going at 60m/h when the brakes are applied. Hypothetically it will take the car 6 seconds to come to a stop and the bike 5 seconds to come to a stop... this may be longer or shorter than it took them to stop but it will allow me to explain it easier for me.

So you have the car stop at a rate of -10m/h/s alright... so in the first second it will slow down to 50mph and causing it to have traveled an average distance of .0153miles. The next second it slows to 40 and travels an average distance and so forth. In the end the car has taken 6 seconds to stop but has traveled an average distance of .05miles.

The bike on the other hand... as Z_fanatic pointed out::
as you get down lower range of speed in bikes, you can apply more pressure, which is obviously stopping quicker than a car
So with that said... your bike in its first second hypothetically slow from 60m/h to 55m/h and travels and average distance of .016miles, then it slows to 50m/h and travels .0146miles, then slows to 35m/h and travels .0118miles, then slows to 20m/h and travels .0076miles, and finally comes to a stop to finish with an additional .0028miles... thus totalling up to be a distance of .0528 miles in 5 seconds.


Again in no way am I saying that this is exactly what happened it was just a hypothetical scenario that I created and solved to show you and help you understand that it is in fact possible to the upmost degree(not trying to sound rude in that statement if you do take it that way).


Anyway I hope this helps...
Later

lol, damn it's funny, but with your hypothetical equation, I am getting totally different/off numbers. how'd you get your average distance per sec?

lol, damn it's funny, but with your hypothetical equation, I am getting totally different/off numbers. how'd you get your average distance per sec?
OK... first off everything is a huge average between 2 vehicles. The different velocities at each second were compleately made up by me merely to demenstrate that it is false to say that whichever vehicle stops the quickest will require the least distance to stop. Now to get to your question... to get an average distance when given initial and finishing velocities and time you must first get the average velocity(and this is for each interval just to make try to cover every possible question)... so you take (Vf + Vi)/2. Once you acertain that you must then figure how far you travel with that average speed in the time given(which in my scenario is 1 second intervals). In order to perform this correctly you must first convert m/h into m/s by taking that average speed and dividing it by 3600(I assume you want to know why you use that number... well it is because to convert from hours to minutes you must multiply by 60 and then to get to seconds you must multiply by an additional 60... to shorten it up 60*60=3600 so you can shorten the process and just multiply hours by 3600 instead... sorry I know some of this is probably repetative but I am just trying to ensure I don't leave anything out)... so now you have taken m/h and made it (m/3600h) = (m/s). Now because it is in m/s and we are in 1 second intervals there is no more math to do and however many average miles per second you are going is now the average distance as well. Now all you do is take the average distance for each interval, add them together and you have your total distance traveled... again as an average.

If I recall correctly there is a much simpler way to do all that by incorperating Calculus into the Physics into one simple equation but I have been out of both Calculus and Physics since summer started the last week of May and I have placed all my Calculus into the back of my mind... most of the physics too... I am just applying basic principles in this scenario to make it easy on me. But anyway that is how you do it...

"Class dismissed" :)

Later

Ohh and if you have any other questions feel free to ask... that is pretty damn jumbled up right there so I understand if something is unclea... you won't be irritating me any... I am fucking bored right now so it will keep me entertained.


EDIT::After reading your question again I think I might have over- answered.

yeah thanks, got it, I always forget to convert in the end, in this case, m/h to m/s. :grinno:

personal question, since you took cal and physics, are you in college or high school?

So with that said... your bike in its first second hypothetically slow from 60m/h to 55m/h and travels and average distance of .016miles, then it slows to 50m/h and travels .0146miles, then slows to 35m/h and travels .0118miles, then slows to 20m/h and travels .0076miles, and finally comes to a stop to finish with an additional .0028miles... thus totalling up to be a distance of .0528 miles in 5 seconds.

ok so your first sec. interval is going from 60 to 55, implyng slow deceleration at high speed range. 2nd sec, 55 to 50, same rate. but then you jumped from 50 to 35, implying rapid deceleration for lower range of speeds. and the pattern follows until 20 mphs, keeping that 15 mph rate of declination, and once again, it shifts from 20-0, whoa... some figures you got there. I doubt that's how bikes function though, I can understand the top range, but I think perhaps the rate of deceleration is higher at 55-40 than explained. I know you tried to get a point cross. :) But there has to be a constant increasing rate of deceleration in bikes in terms of capabilities, not so much the consistency in how fast it loses momentum like in a car, but rather the inclination in deceleration. Which is evident in the lower range, but not so much in the higher. This of course is theoretical, not accounting the rider's input.

personal question, since you took cal and physics, are you in college or high school?I am 16 going into my Senior year of high school but the classes I took... well the Calculus one... was an AP class for college creditt as long as I passed the final test.

As for the hypothetical example... I am most possitive that the numbers given are off... I just set something up to as you said "get a point cross" and show aussieidiot an example of how one vehicle could slow faster overall yet travel a longer distance to do so than another vehicle. All in all however I hoped this has helped out...

Later

i haven't done physics for over 10 yrs so i had to try and remember all the formulae and theories. you have explained it just fine although being from a METRIC country and given away the old ways years ago i still understand. he he any chance for a dig

took high school Cal once, it's nothing like college Cal of course, hell, College Algebra is more difficult than high school Cal/AP Cal. Probably taking physics this semester or next. Hopefully, I dont get probation in college. :rofl: that would be first.

Shit, I'm a math education major, and I've NEVER had physics in 4 years of HS and 4+ years of college!!! I guess that's why I was unsure of what's up. It seems like you could have taken the derivitive at some point on something in that big equation, but not knowing how it works or why, I don't think I could say anything more. :redface:

graduated early or something? you'd have to closer to 21-22 at least.

who cares

just try and stop before you hit something

that wasn't the point.

I'm 21. Will turn 22 in August. ;) I'm an old fogie 'round these here parts.

what does it mean if your 30 then. should i be dead and buried?

what does it mean if your 30 then. should i be dead and buried?
Yes, but only b/c you're from Oz. :p

Being an Aussie is cool, he probably does rally racing too, I mean with all the sand around. :D

Plus, plenty of backroads sorrounded by desert, to roll the throttle all the way up in his bike.

I was just messin w/him. He's just jealous that his accent isn't as beautiful as New Zealand's. ;)

I know you were. Yeah, Kiwis are cool. Best place for scenaries. I mean Lord of the Rings settings, awesome! Plus the college education there is the best. Would you believe that the government actually pays the tuition? And that's without all the scholarships. My cousins there are living it up.

If NZ is so good, then how come they all end up here on the dole. as for rally bashing, i'm 10 min from a great series of dirt roads but all the kangaroos and drop bears get in the way of a fast lap time

they probably go there to pet the koalas. :D

they probably go there to pet the koalas. :D
The go to Oz to remind themselves of how good they have it. :p

little known fact is that koalas aren'y cuddly in the wild and we call them 'drop bears'. the bastards drop from the trees and scratch the shit out of your face.
ever heard of Bondi, sydney. thats where all of NZers live. they came here for a holiday and got to pissed to swim home.

little known fact is that koalas aren'y cuddly in the wild and we call them 'drop bears'. the bastards drop from the trees and scratch the shit out of your face.
ever heard of Bondi, sydney. thats where all of NZers live. they came here for a holiday and got to pissed to swim home.

im guessing you had a personal encounter with one of those yoggi bears? were you two fighting over eucalyptus trees? Is Australia like Texas and NZ like Canada? :evillol:

not personally but 'vegemite' was developed by our army as a 'drop bear' deterant to be worn on clothing but ended up as a sandwich spread.
'yogi' lives in yellowstone doesn't he
Why is there only one Yogi Bear?
Coz when God tried again he made a Boo Boo.
is texas full of canadians?
I'd love to put shit on where you guys are from but i don't know anything about the individual states. not through lack of knowledge, its just that i don't give a shit. he he
ps do you guys know of our Prime minister? how much of an ass licking rodent is he?

yeah, we have world series baseball you know. and of course, which ever states wins the final, is the world champion team. :D All you have is Cricket, and only win against the Kiwis.

well people in Texas are either mighty sweet or kinda outlandish. and Canadians are usually the most polite Americans. :iceslolan I hear the same about the Kiwis in the Pacific/Australian continent.

hey we actually do have a world series. it includes england, south africa, pakistan, india and the west indies.

in which, those guys have you beat most of the times. :)

btw, I thought they had more teams. Im forgetting the rest, didn't New Zealand and/or Bangladesh make it to the world series once?

personally i dont care about any sport that doesn't involve engines. i know 'how very un-australian' but my old man was into motor sport so i followed.

eh, surprisingly I watch Cricket more than any baseball games. Australians team is pretty good, in fact, they all are. as for engines, if I every go to Arizona or Australia, whichever comes first, I wanna drive dune buggies! what sort of motor sport were you guys involved in?

my old man used to race "scamblers" which were long wheel base trail bikes raced on an oval dirt track back in the 60's.
we always followed F1 until Senna died. we have V8 supercars series now which are Ford versus Holden (GMH) basically.
i tried rallying when i was younger then got into track days with my '94 suzuki swift gti. now i'm into bikes. how about you?

wasn't much into conventional sports. lol. you could say, that's very Un-American-like, considering how much we worship Football, Baseball, and Basketball. Few years back went to Melbourne and Sidney, played cricket there, and hooked. But too bad, we don't play cricket in the States. Otherwise, I spent those no sports time on playing electric guitar with friends, hehe. wanted to get into MX or ATV, or anything with wheels and motor on a traill. but couldn't, thanks to super-protective conservative parents. lol. did a little surfing and scuba trips here and there. wasn't much into cars either, until I started taking my 4 banger out into the backroads started hitting over 90. then bought a 90 300ZX for a lot more power. but I liked how speed tasted, hehe, but I figured unlike all the other ricer boys forking over all their money under the hood and decaling R type stickers, it's not something I could afford having to still attend college, nor will it make my car the ultimate speed-demon. in retrospect, I think this is all very un-American like, since most of my friends were also into V8 big blocks. so I started hearing stories from my dad from his motorcycle days, and all those crazy jumps and and mishaps, hehe. I never knew he had it in him. so now I am looking to get a decent bike, learn some neat stuff, take it to track, and not die young. :D