"I've NEVER seen anything stop that fast!" (R1200RT)

[jay1622]

A tale of the RT's sick ability to stop...

Riding in South Florida can be a tad bit on the interesting side. In the last two or three years, my usual highway, I-595, has been under construction. I was in the #1 lane enjoying an open lane in front of me and a steady flow of cars in lanes 2 & 3. Now, a year or so back, I spent an afternoon practicing hard braking seeing that I was replacing the tires the following day. I practiced swerving and 45-0 stops. On this particular day, I'd venture to say I was somewhere between 60-70 mph. Now, my lane was open in front of me by about 100 yds (rare) and the SUV behind me was about 50-75 yds back. Again, rare. Off to my left, the driver of an empty dump truck must have mistook this patch of openness as the total 175 yds worth of lane to merge into traffic. I'm happy to say the second I saw him, I let off the gas and prepped to brake; however, actively thought... "No way he would ever..." And then he did - pull right out in front of me. I remember yelling at the top of my lungs while squeezing and pressing the life out of my lever and pedal. There was no swerving; only an upright forward traveling emergency stop on dry asphalt with 2,000 mile old Michilin PR2's. Anyway, I believe the only thing that gave me the strength that day to stay on the bike, as opposed to flying over the bars, was my adrenaline kick. Wow.

I never actually came to a full stop... Down to 5-10 mph maybe. I cleared my head and talked myself out of pulling along side this A-hole and telling him off. I rode on. A mile or two up the road, traffic came to a stop. A guy in a newer Corvette lowered his window and asked me if I was okay. We inched a few feet. He told me he's raced amatuer circuits all his life and never saw anything slow down as fast as I did. His last words were classic... "Man, I thought you were a gonner!"

Looking back, I believe it would have been quite different had I not let off the gas and prepped the brakes. While this is intended to share a story of our bikes sick ability to brake, please let this also be a reminder that we should always assume the potential hazard we see ahead will proceed in a manner against us.

 

[Ken F]

Several years ago after about a 15 year hyiatias from bikes, I took my test for a M/C endorsement on the "new to me" 95 R1100RS.

In the portion of the test where you have to stop from 30 mph I was amazed also at how fast the bike came to a stop! So was the inspector, who made me do it again.
She then said SHE had never seen a bike stop that fast either.....

Glad you survived your incident. Something about the best tools doing the best job?

Ken

 

[bikerfish1100]

nice work gentlemen.
however, to be honest, i have coached a variety of bikes/riders in MSF classes where we work on maximum braking. BMWs are not nearly the best bikes at this (tho they are a ton better than cruisers)- the sickest stops i've seen have been on Triumphs and Ducatis. From 30 mph, a BMW will need an additional 10+ feet distance over a well handled Monster or Speed3. Just sayin'.

 

[roborider]

Great story.

Bikerfish, do you think mass has something to do with that? I can't imagine my 05 RT brakes being any better, but I do have a LOT more RT mass than a speed or street triple.

 

[alanrd]

Several years ago after about a 15 year hyiatias from bikes, I took my test for a M/C endorsement on the "new to me" 95 R1100RS.

In the portion of the test where you have to stop from 30 mph I was amazed also at how fast the bike came to a stop! So was the inspector, who made me do it again.
She then said SHE had never seen a bike stop that fast either.....

Glad you survived your incident. Something about the best tools doing the best job?

Ken

on my MC endorsement test I was supposed to ride at 20 MPH and make a panic stop after I crossed line 1 and safely stop at Line 2. I stopped 5 feet short of line 2. They said try again. I stopped 5 feet short of line 2 again.
The flunked me on that portion of the test. When I asked why they answered "You must not have been doing 20 mph like we told you"

 

[dude987]

Glad you had the wherewithal to maintain situational awareness of your surroundings and take proper precautionary measures to anticipate a potential idiot. That driver probably had "IDIOT" stamped on this forehead. What can you do. He/she was born that way. It doesn't make any sense to chase them down just to make a scene. I suppose it's a chance we're all willing to take for the joys of riding a motorcycle. Anyways just a rant. Glad you made it out unscathed. Also appreciate you sharing the story. It's a good reminder for everyone to always be on the lookout and be safety conscience.

 

[dbrick]

on my MC endorsement test I was supposed to ride at 20 MPH and make a panic stop after I crossed line 1 and safely stop at Line 2. I stopped 5 feet short of line 2. They said try again. I stopped 5 feet short of line 2 again.
The flunked me on that portion of the test. When I asked why they answered "You must not have been doing 20 mph like we told you"

That's funny. I had a friend in law school who had to take the bar exam four times before he passed. He persisted in telling the examiners what he thought the law was - and probably correctly, he was quite a scholar - rather than what the examiners wanted to hear.

The flunkys you were dealing with couldn't see beyond the instructions: "...safely stop at Line 2." In their minds, a rider who stops at Line 2 has demonstrated a panic stop; others haven't. What idiocy.

 

[ANDYVH]

If your MC endorsement test for the quick stop is the same as a MSF Quick Stop evaluation, then I know the first stop reference line is at 15 feet and the second one is a t 23 feet, for 20 mph.

I do know for certain that I can stop in less than 23 feet from 20 mph on my 94 RS. So for the examiner to fail you can claim you weren't doing 20 mph shows to their lack of knowledge of bikes, and quick stop evaluations. I have done SO many quick stop evals as a MSF instructor, I can certainly perceive the difference between a bike approaching at 20 mph versus one going slower. But they could easily verify that with a stop watch checking a 20' distance before the stop zone.

 

[exgman]

Great Braking Demonstration

I took the on-road course at the BMW Performance Center in SC a year ago. In just one minor part of a terrific class, we accelerated on our bikes (I was assigned an R1200GS) up to about fifty MPH, then had to stop using rear brake only (ABS off), then front & rear (ABS on). That was a real convincer and confidence-builder as those binders with the ABS on brought the 550# of the GS and 225# of me to a very short stop.

Fortunately, in the last 20,000 miles of riding, I've only had to replicate that once. I was so pleased to still be upright and alive after a cellphone gabbing woman drove out in front of me that I didn't even demonstrate to her that she was "#1" with me. I must be maturing...

 

[f14rio]

aww..stopping isn't all its cracked up to be............

...for norton drivers like me with drums all around. if i need to, i can use my right (sic) foot as an aux brake.

 

[ozonewanderer]

In David Hough's book Proficient Motorcycling, he talks about practicing coming to a complete stop from various speeds without stalling the engine and while shifting down so that you can immediately take off again (as in making an emergency stop for an obstacle then needing to get moving so that the SUV behind you doesn't plow into you). I practice this several times a year and it gives me more confidence in my riding. I also taught this to my son when he started riding. He used this skill to minimize a bad situation (too much speed - his fault) to a relatively minor spill.

 

[redhededgreg]

Front and rear, or front only

Your instincts plus perhaps training and past good practices led you to apply both the front and rear brakes according to your description of your emergency stop. With our linked braking system, i'm wondering if our most effective stopping in a situation like this might be from the application of the front lever only, since it will also apply braking to the rear wheel. I learned and continue to practice the use of both brakes, particularly in heavy braking and also because i ride another bike without linked brakes. (Also, old habits are hard to brake-bad pun intended.) However, with the sophistication of a linked braking system, i'm wondering if optimum braking might not be achieved by not touching the rear brake pedal and allowing the system to interpret and apply our hard squeeze to the lever in a manner that will avoid over braking the rear wheel and possible engaging the ABS as might be the case if we stomp on it with all our might. A somewhat lengthy and well informed discussion of this is here:
http://bmwsporttouring.com/ubbthreads/ubbthreads.php?ubb=showflat&Number=747400&page=2

 

[Rinty]

Nice riding, and glad you're OK.

 

[mpmarty]

I was tooling down Oregon Highway 97 from the junction with 38 towards Klamath Falls when a young lady in a large Mercedes decided to keep me from passing her by flooring it every time I tried to pass and then slowing down in front of me. I was on my 04 RT and two up heading for our vacation in New Mexico. Finally there was a clear oncoming lane and I started a pass when she emitted a blast of smoke and tried to keep me from passing. I dropped down a cog and wound it up and went flying by her and as I moved over in front of her saw an Oregon State Police car at the side of the highway. The officer stuck out his hand and waved me over. I moved to the right shoulder and threw out the anchor. We got off the bike and the officer got out of his car and walked up to us. The officer looked back at his vehicle and then told us "I just finished an accident reconstruction class and know how long it takes to stop at speed" he went on to say that his radar had to be mistaken as no motorcycle could stop as short as we had at the speed his radar reported. So anyway good brakes saved us a performance driving award.

 

[ka5ysy]

... The officer looked back at his vehicle and then told us "I just finished an accident reconstruction class and know how long it takes to stop at speed" he went on to say that his radar had to be mistaken as no motorcycle could stop as short as we had at the speed his radar reported. So anyway good brakes saved us a performance driving award.

Good brakes and the fact he/she had no idea of braking force versus the mass of the particular vehicle being clocked !

Whatever works

 

[jnerges]

Several years ago after about a 15 year hyiatias from bikes, I took my test for a M/C endorsement on the "new to me" 95 R1100RS.

In the portion of the test where you have to stop from 30 mph I was amazed also at how fast the bike came to a stop! So was the inspector, who made me do it again.
She then said SHE had never seen a bike stop that fast either.....

Glad you survived your incident. Something about the best tools doing the best job?

Ken

When I got back from Iraq, I had to retake the MSF Advanced Rider course again, I think I am up to 5 times. The Army makes all motorcyclists who want to ride on post take a safety course after just about every big event. I am happy to do it.

Anyway, doing the emergency brake portion, bring it up to 30 or so and do an emergency stop when I signal.....

Guy raises his hand and assumes you will stop on about 20 feet or so, and boom, I have to let the clutch out again and ride up to him so he can tell me that BMW ABS dont really count in this exercise. I smugly ride away and wink at his HD.

 

[jnerges]

on my MC endorsement test I was supposed to ride at 20 MPH and make a panic stop after I crossed line 1 and safely stop at Line 2. I stopped 5 feet short of line 2. They said try again. I stopped 5 feet short of line 2 again.
The flunked me on that portion of the test. When I asked why they answered "You must not have been doing 20 mph like we told you"

I understand this exactly. They were just jealous.

 

[bdimon]

Weight is not the limiting factor

do you think mass has something to do with that? I can't imagine my 05 RT brakes being any better, but I do have a LOT more RT mass than a speed or street triple.

Theoretically, weight should not matter since traction (weight times friction) increases linearly with weight. I think the main difference between bike types is the geometry, wheelbase and center of mass.

If you add a 200 pound passenger to your bike, you can theoretically stop as quickly as solo by squeezing the brakes harder to take advantage of the increased traction. In the real world, you can't because you don't practice quick stops with a passenger. My wife refused! Also the shift in center of mass should affect braking performance. The rear brake should be able to contribute more.

 

[bikerfish1100]

Theoretically, weight should not matter since traction (weight times friction) increases linearly with weight. I think the main difference between bike types is the geometry, wheelbase and center of mass.

If you add a 200 pound passenger to your bike, you can theoretically stop as quickly as solo by squeezing the brakes harder to take advantage of the increased traction. except that most/all of that increased weight is hanging out over teh rear tire, rather than the front tire, and thus does not increase the front tire weighting to as great a degree as we would like. more traction to the rear will not benefit as much as more traction up front.In the real world, you can't because you don't practice quick stops with a passenger. and even if you do practice those stops with a passenger (you should, if that is how you typically ride!), you are still not very likely to apply the brakes with as great a force as you would solo. banging helmets is really annoying.My wife refused! Also the shift in center of mass should affect braking performance. The rear brake should be able to contribute more.

other factors that likely impacted the braking performance- 1) better quality binders. yeah, they all have Brembos, but not all Brembos (or similar) are created equal. 2) stickier tires. A GS or a RT will not have the same level of tires, vis a vis traction, as a Monster, Speed 3 or other similar bikes.

fwiw- my son rides a 2005 Speed3. when it came out, that bike had the shortest tested stopping distance (60-0, 88 ft, iirc) of any production bike, ABS or not.

 

[BMW Triumphant]

Mass does matter!

Kinetic Energy = 1/2 x Mass x Velocity squared

You use your brakes to reduce kinetic energy to zero, or you are still moving. This assumes no locking, no sliding, so traction will be present.

Note the velocity squared term in the equation. Think how this affects the energy you must dissipate in the brakes as heat if you double your speed.

Lots of swept area, and use of all brakes, these are good things.

By the way, there is a difference between mass and weight. Weight is the force resulting from mass times g, where g = acceleration due to gravity, 32 ft/sec/sec

See http://en.wikipedia.org/wiki/Mass for more than you wanted to know...



Oh, i am ignoring the energy stored in the rotating wheels, due to their property of moment of inertia, a counterpart of mass.

See http://en.wikipedia.org/wiki/Moment_of_inertia and note the similarity of equations to those in the mass article, especially the ones with squared quantities...

All that energy also has to be dissipated by those same brake pads...