All out breaking ???

[Xfz]

This morning about 6:30 AM, still dark, I had an extremely dangerous encounter on Front Street just north of Greenlawn. A car pulled out from a side street and turned left ( mostly in my lane). I knew that there was not enough distance to stop the bike. The only thing left to do was to scrub off as much speed as possible to minimize impact. All you guys out there with liter bikes, they will pull a stoppie with stock brakes (two fingers on the brake lever). So, what is the most effective breaking technique??? The conventional wisdom of rear brake, front brake caused me to slide forward onto the tank. Additional brake pressure pulled the rare wheel off the road in a hart beat. This was my first stoppie and I puckered to 100%. I could not stop but miraculously slipped between the back of the car and the cars parked on the side of street.:bow:I think there is some dirt from the car on the side of my pants.

By the way the Michelin Road 2's never slid and pretty much saved my bacon.

Edited September 3, 2010 by Xfz
I cant spell, wher the hell is spell check.

[chevysoldier]

Sledge hammer.

[Xfz]

I agree with you. Not much space to carry a sledge hammer.

[BadTrainDriver]

U broke what?

[chevysoldier]

U broke what?

[magley64]

i think you meant braking....

sounds like you did it right, Jam both, and squeeze til your back end starts to come off, and hold til you stop.

[chevysoldier]

Wait until you hear the tires howling and keep em there. Anymore and they will lock up.

[hummingbird]

dont override your headlight... i mean drive slower when its dark

you need better rear brakes

[Bubba]

Mus' be the day for idjits in cages. I was out just doing some easy backroad cruising this afternoon thru Boone County, KY, just west of the airport. I was headed north on Bullitsville out of Burlington doing just over legal following an old guy in a pickup. I wasn't pushing him--we were both doing about 45 in a 35--and I was pretty relaxed since there was zero traffic, so I was sitting up with my left arm just hanging loose, when all of a sudden, he locks up the brakes and brings his truck to a complete stop! No deer...no driveway...no intersection...no turn signal...and luckily no one behind us. It prolly wasn't REALLY close, but I had to grab a fistfull/footfull of all three discs, howlin' the tires, and it sure got my attention, so I look at the driver--he's stopped in front of me grinnig in his mirror. I thought about blowin' around him and flipping him off, but didn't want to give him the opportunity to run me off the left side fo the road, so I waited until he pulled ahead and went on his way. Only explanation I can come up with is that he was tryin' to take me down, God knows why.

Later in the ride on the OH side, a brainless teen child talking on her cell clicked her right turn signal on and started into a subdivision. I was just passing her in the left wheel track when she jerked the wheel and came out into the road like I wasn't there. Again, prolly not death-defying, but starting to give me an 'invisible man' complex.

Remember....Let's be careful out there.

[Xfz]

dont override your headlight... i mean drive slower when its dark

you need better rear brakes

No doubt, its good advice. (20-20 hind site?) Would you explain about the rear brake comment.? In my case the rear tire was not on the ground so its a moot point. I am just curious as to what you mean?

No, I did not use my brakes correctly. I just got LUCKY, VERY LUCKY, and survived the encounter without a scratch. All kinds of things happened in that 1-1/2 seconds but I did not want to dwell on it.

[hummingbird]

well i may not know much about bikes but; its obvious physics that if you only had rear brakes you would probably not be able to do a stoppie.

the front brakes provide about 70% of the stopping power, so if you could get a bigger rear disc or double up and bring that ratio down to about 60/40 then you wont lift the rear as soon.

lifting the rear happens when the weight of the rear overcomes opposing G forces and with the help of the front brake creating its own center of gravity so to speak

the reason they dont let the rear do most of the braking is because weight gets transferred to the front during braking and the rear would lock up

so in the end all my logic may be wrong... would have to talk to some pros

i dont believe in luck but yes you were very fortunate

[max power]

well i may not know much about bikes but; its obvious physics that if you only had rear brakes you would probably not be able to do a stoppie.

the front brakes provide about 70% of the stopping power, so if you could get a bigger rear disc or double up and bring that ratio down to about 60/40 then you wont lift the rear as soon.

lifting the rear happens when the weight of the rear overcomes opposing G forces and with the help of the front brake creating its own center of gravity so to speak

the reason they dont let the rear do most of the braking is because weight gets transferred to the front during braking and the rear would lock up

so in the end all my logic may be wrong... would have to talk to some pros

i dont believe in luck but yes you were very fortunate

Uh, your logic is very flawed. What you are proposing would only create longer stopping distances in which case our OP here would be road pizza.

[magley64]

Uh, your logic is very flawed. What you are proposing would only create longer stopping distances in which case our OP here would be road pizza.

I disagree, the logic is flawed, but this wouldn't lengthen the stopping distance at all...

a bigger rear brake (more stopping power @ rear wheel) would have done precisely dick.

the reason IS weight distrobution, now if the CG of the bike were further back, and lower, then the rear brakes would have done more of the stopping, and the bike designers would have made the rear brakes more robust to compensate. but because the CG is so high, and so far forward, you must rely on your front brakes to do most of your stopping, and the rear only so crub off a little speed before it loses contact with the pavement.

[AOW]

I disagree, the logic is flawed, but this wouldn't lengthen the stopping distance at all...

a bigger rear brake (more stopping power @ rear wheel) would have done precisely dick.

the reason IS weight distribution, now if the CG of the bike were further back, and lower, then the rear brakes would have done more of the stopping, and the bike designers would have made the rear brakes more robust to compensate. but because the CG is so high, and so far forward, you must rely on your front brakes to do most of your stopping, and the rear only so scrub off a little speed before it loses contact with the pavement.

If you're rear wheel came off the ground it means you didn't brake correctly. Now that you have proven the awesomeness of your front brakes, get ye to a vacant lot and practice your emergency stops with both brakes and keep both tires on the ground.

I don't know what you weigh, but can only assume you're a buck'05 dripping wet. Or you are too inexperienced at hard stops to keep your ass on the seat instead of coming forward and doing a "stoppie"

[fusion]

Just curious, how fast were you going?

[hummingbird]

Its definitely a good idea to practice emergency stopping at least once a month to stay sharp

[grapesmuggler27]

are you sure that was car dirt on your pants?

Edited September 2, 2010 by grapesmuggler27

[RFM]

Make sure the brake lines are full, the reservoirs are within the limits, there is enough travel in the brake levers, and of course the brake lights have enough fluid. That's almost as important as having the right oil for your muffler! Keep it safe out there.

[dustinsn3485]

Completely off topic, but something I was reading the other day...about braking, so maybe sort of on topic....Anyways...

I saw that at a 45 degree lean angle your tires still have 75% of the braking traction I suppose. That surprised me, considering I ride well under my limits and get slowed to what I feel is a comfortable cornering pace, really before ever entering the corner. To know that in the middle of the corner as long as I don't grab a handful of brake, but rather ease into it I still have 75% as much traction as I do in a straight line. All assuming I ever get near a 45 degree angle on the street...Which I doubt I do.

That was all...

[Xfz]

are you sure that was car dirt on your pants?

Yeah, I checked .

No experience in true PANIC stops and I intend to get some muscle memory going. I have been in bad situations before and handled them correctly. Didn't see this one coming and my reactions were purely instinctive. There were two huge errors . Over rode my headlight and I pulled the rear tire off the ground. For our scientists out there, a more powerful rear brake would have put me in a skid. I started the evasive actions correctly. Rear brake, front brake. Closing on the car quickly made me grab for more front brake. NOT RECOMMENDED. It started a chain of counter productive results.

[Xfz]

Completely off topic, but something I was reading the other day...about braking, so maybe sort of on topic....Anyways...

I saw that at a 45 degree lean angle your tires still have 75% of the braking traction I suppose. That surprised me, considering I ride well under my limits and get slowed to what I feel is a comfortable cornering pace, really before ever entering the corner. To know that in the middle of the corner as long as I don't grab a handful of brake, but rather ease into it I still have 75% as much traction as I do in a straight line. All assuming I ever get near a 45 degree angle on the street...Which I doubt I do.

That was all...

No, its not off topic. If I remember correctly the force of friction = the normal force time the coefficient of friction. I think the normal force at 45 degrees is 0.7 of 90 degrees. So you got 70% available. Where did this come from?

[hummingbird]

so really it all comes down to speed, no matter what youre driving or riding, if youre going to fast when something pops out in front of you, theres simply nothing you can do.

but hey wait! motard or supermoto whatever those crazy dirtbikes on pavement are called- those guys can slow down by skidding the rear tire and kicking it out like a drift, the more sideways they are the faster they slow down...

[jbot]

you mean like this, huh?

it sure is admirable

[max power]

^

Uh, your logic is very flawed. What you are proposing would only create longer stopping distances in which case our OP here would be road pizza.

I disagree, the logic is flawed, but this wouldn't lengthen the stopping distance at all...

a bigger rear brake (more stopping power @ rear wheel) would have done precisely dick.

the reason IS weight distrobution, now if the CG of the bike were further back, and lower, then the rear brakes would have done more of the stopping, and the bike designers would have made the rear brakes more robust to compensate. but because the CG is so high, and so far forward, you must rely on your front brakes to do most of your stopping, and the rear only so crub off a little speed before it loses contact with the pavement.

Thats pretty much what I was saying Magz, except without all the spelling errors and boring explanation.

hummingbird reasoned that a bigger rear disc should slow him down faster, but that set up would, possibly, increase his stopping distance (everything else being the same) due to the fact that the weight is being distributed to the front and the rear has far less traction. He would lock up the rear every time he touched it (assuming he was using the rear brake) causing loss of control and increase the stopping distance while regaining control.

Edited September 3, 2010 by max power

[hummingbird]

so no rear brake is better?

another factor that helps the rear come up is the forks compressing under the added weight, so if the forks would lock whenever braking, then there wouldnt be a reverse lifting effect on the rear. the bike would be much more stable