FJR ABS

[Leartech]

I tested them out on the bike I test rode from about 60 in a straight line. I mean, full grab front and back, about as hard as I could pull the lever. (Just a little bit of faith involved.) I tell you what, that is an amazing sensation. Stopping that quickly on a bike is just remarkable. You can feel the brakes modulate, but it is not severe at all. The bike just comes to a stop and some kind of quick. As others have said, trying that nonsense while leaned over a turn and you are asking for trouble. To dig into the ABS, you need to stand it up to survive it.

It is a nice feature, but probably can't make up for good common sense riding skills.

Bryan

 

[rocketdoc]

My experience with the FJR's abs allowed steerage while under full braking as I was about to plough into a panel truck.

The abs front and rear were activated and as I approached the ultimate I looked to a gap to the right, pushed the right bar and found the 'out'. I was shedding speed rapidly but would have impacted about 20 mph, so the steerability is what it is all about. Practice it on a wet surface, don't make your direction change too abrupt, but smoothly. Get the feel of it, and hopefully if/when you need it on dry pavement you will have the confidence to do it.

 

[OrangevaleFJR]

yep...you can brake so hard that you activate the ABS without going over the bars. Brake with abandon...your son must be pretty good to stoppie an FJR without crunching it

 

[thesonicboom]

When you are trying to brake, you need to realize that you DO NOT want to be in ABS. ABS will take you almost twice as long to stop compared to max braking. Even in a "panic" stop. You need to practice like you never practiced before. ABS was designed so that you do not have a front wheel lock up and wash out when you apply max braking and hit a loose surface. The only way to counter the initial panic grab of the front brake is to keep practicing until you can do it when you least expect it. ABS is definately an awesome addition to a motorcycle. (Bought the 05 FJR abs for that reason.) As for in a turn. NEVER, NEVER try to max brake in a turn, you'll wash out like an old pair of denim. Upright the bike then apply max braking. Although if you want to have hell of a rush, slamming on the brakes as hard as you can at 90 will give you one hell of a rush. Good luck and be careful out there!!!

 

[keithaba]

ABS will take you almost twice as long to stop compared to max braking.

I'm no ABS specialist, but I don't think that is an accurrate statement.

As for entering a turn with the brakes pulled tight and washing out, that is an accurrate statement.

 

[SkooterG]

ABS will take you almost twice as long to stop compared to max braking.

I'm no ABS specialist, but I don't think that is an accurrate statement.

I know that's not an accurate statement.

 

[thesonicboom]

The way abs functions is by compressing the brakes pads and then releasing them then compressing them and repeat. Remember the old cars with manual brakes that you had to pump. Well sort of same concept except the computer applies and reapplies the brakes at a much higher rate. I don't know about yamaha, but BMW is something like 20 pulses per second. Which means it applies and releases the brakes 20x a second. If you take that concept and apply it in the real world you will have a longer braking period. I have been riding an ABS bike for 2 years at 40 hrs a week and I train constantly on the brakes. (If you can't stop the motorcycle, you're gonna be in for one hell of a ride.) At 55 mph you should be able to stop in 102 feet. When you apply abs it takes about 150 feet. I am just saying that max braking will beat ABS everytime distance wise if you have a solid surface. Happy motoring!!! Note, these distances are not for the FJR bike..... Just training studies I have done.

 

[TruWrecks]

The actual goal of ABS is to keep the wheel speeds within roughly 2-5% of each other. If the difference exceeds the factory tolerance, under braking, the computer assumes wheel lockup ans pulses the brakes. The pads don't actually release. The pressure decreases, but the brakes are still on.

And yes, it will take longer for a vehicle to stop with ABS than with standard brakes, if you get on the binders so hard that you lock up the front wheels. That assumes you're able to apply the brakes manually to just under the point of the maximum shearing force of the tires grip and hold it there the entire time. ABS kicks in when you exceed the shearing force. So if you master your brakes you may never experience ABS. You'll have shorter stopping distances, and better control. ABS will be there for the 'un-expected' road hazard, and that's what it was designed for.

Cheers.

 

[thesonicboom]

+1

One great disadvantage to ABS is some people, not all but some, over rely on ABS. When riding, you must know your bike, know your own abilities, and know your riding route. Thanks Truwrecks for explaining it a little better than me, I knew what I wanted to say, but as always, I muffed it up. Ah hell, I'm going riding...

 

[ponyfool]

The way abs functions is by compressing the brakes pads and then releasing them then compressing them and repeat. Remember the old cars with manual brakes that you had to pump. Well sort of same concept except the computer applies and reapplies the brakes at a much higher rate. I don't know about yamaha, but BMW is something like 20 pulses per second. Which means it applies and releases the brakes 20x a second. If you take that concept and apply it in the real world you will have a longer braking period. I have been riding an ABS bike for 2 years at 40 hrs a week and I train constantly on the brakes. (If you can't stop the motorcycle, you're gonna be in for one hell of a ride.) At 55 mph you should be able to stop in 102 feet. When you apply abs it takes about 150 feet. I am just saying that max braking will beat ABS everytime distance wise if you have a solid surface. Happy motoring!!! Note, these distances are not for the FJR bike..... Just training studies I have done.

You are comparing apples to oranges though. You are comparing an ABS stop to a threshold brake stop. I agree, no one should rely on ABS for normal everyday riding. Nor should they rely on ABS for performance riding. However, for panic braking, the real "oh shit" moments that are unpredictable or unforeseeable, ABS will stop a bike one hell of a lot faster than a bike in a skid or that is sliding on its sliders or tupperware.

Finally, I don't know how old your studies are or on what type of vehicle, but my '06 consistently stops at 115' from 60mph with no ABS and only 130' with full ABS. Both of these are on dry pavement with my fat ass riding. I don't know, nor do I ever want to know what the stopping distance would be if I had a locked up rear brake or sliding on the sliders.

 

[TruWrecks]

I knew what I wanted to say, but as always, I muffed it up. Ah hell, I'm going riding...

Glad I could help.

I would like to be out riding today too. The sun's out now, and the roads are dry (so far). I'm stuck at home because I muffed up my back a few days ago. My new bike will be here Friday, I'm on vacation, and I don't know if I'll be able to ride it. :angry2:

or sliding on the sliders.

Apply the rear brake about 5-10% while coasting. That should be fairly close. :blink:

 

[thesonicboom]

You are comparing apples to oranges though. You are comparing an ABS stop to a threshold brake stop. I agree, no one should rely on ABS for normal everyday riding. Nor should they rely on ABS for performance riding. However, for panic braking, the real "oh shit" moments that are unpredictable or unforeseeable, ABS will stop a bike one hell of a lot faster than a bike in a skid or that is sliding on its sliders or tupperware.
Finally, I don't know how old your studies are or on what type of vehicle, but my '06 consistently stops at 115' from 60mph with no ABS and only 130' with full ABS. Both of these are on dry pavement with my fat ass riding. I don't know, nor do I ever want to know what the stopping distance would be if I had a locked up rear brake or sliding on the sliders.

The bike tested is a 06 bmw r1150rtp which weighs in about 800lbs. I fully agree with you on the unpredictable surface. that was my whole point and the reason for buying the FJR. (previous bike was HD softail. Like stopping an aircraft carrier.) I am so light (145 lbs.) that under max braking, my rear tire still locks up because my ass doesnt weigh the rear end down enough to keep good traction on the rear tire. I am not comparing the two types of stops, just making the point that max breaking will not eat up as much distance as an abs stop.

 

[RsvlFeej]

I am trying to find out what to expect in a panic brake and swerve maneuver on the FJR from a speed of around 80 mph?

Brakes good. Brake and turn bad. I passed a car whose driver decided he really didn't want to get passed, even though there was a passing lane, and I'd been a good boy and hung back on the double yellows for about 10 miles. Unfortunately, at the end of the passing lane was a wicked sharp left turn. Long story short, in trying to get around an asshat on an unfamiliar road, I ended up with my entry speed way too fast for a corner, with a poor starting line so I couldn't look through the corner and a handful of front brake and a foot-full of rear brake. The bike slowed down pretty good until I had to start leaning to make the corner, which triggered a nasty slide with the front and rear both chirping/skipping. Made it, but ABS ONLY WORKS IN THE DIRECTION THE WHEELS ARE ROTATING and sideways ain't that direction.

 

[sprint_st]

The actual goal of ABS is to keep the wheel speeds within roughly 2-5% of each other. If the difference exceeds the factory tolerance, under braking, the computer assumes wheel lockup ans pulses the brakes. The pads don't actually release. The pressure decreases, but the brakes are still on.

I have heard this statement before, but I would like to see some engineering or scientific proof to back it up. I have always believed that the purpose of ABS was keep the wheel from locking up, so as to, in theory, keep it as close to the point where the tires are sliding as possible but not exceed it. Keeping the wheel speeds in that range mentioned may be be a natural outcome of that but I can't see it as the "goal". For example if both front and rear are locked then they are at the exact same speed - zero. Although the FJR has a linked ABS system not all ABS systems are linked some have front and rear being totally independent. Also, there is test data available (too lazy to re-search for it, but I HAVE seen it on various sites) that shows on dry pavement ABS and non-ABS can be very similar but on wet pavement it was no contest with ABS having a clear advantage. There were variations on a bike to bike basis.

 

[Wingman]

<snip>I don't know, nor do I ever want to know what the stopping distance would be if I had a locked up rear brake or sliding on the sliders.

I can comment on the locked rear wheel stopping distance. About two months after I got my first street bike ("91 Nighthawk 750) I was riding along and suddenly the rear wheel locked up. I was doing 55-60 mph on a two lane hwy. The skid mark on the asphalt was in the neighborhood of 180-200 ft with another 40-50 ft in the gravel and grass in the ditch. That bike would usually stop in roughly half of that distance!

After coming to a stop and cleaning out my pants, I checked the bike over. It took me about 30 minutes to remove the backpack I had been carrying on the back seat from BETWEEN the swingarm and tire. The stitching holding the strap to the fabric had let loose. Perfectly good jacket and gloves in there that would have done me absolutely no good had I gone down. It was very warm that day, but I know now that should be no excuse. The tire (Metzeler ME880, replaced the day before) had a lovely flat spot with cord showing in an area about the size of a quarter. I rode it home with a disheartening THUMP THUMP THUMP feeling. It was only about 10 miles to the house but it seemed like an eternity at 15 mph. I dropped the bike off at the dealer for a new tire the next day, and picked up a new jacket and gloves while I was there. The guys in the shop had that tire hanging on the wall for several years to show people what can happen when people are careless about securing stuff. (We always got a good laugh when the sales guys would offer that tire at half price citing that it still had about 90 percent tread remaining)

If I hadn't been riding dirtbikes and used to sliding it around in the dirt, I don't think I would have been able to ride that fishtailing beast out. Still scares me to think about 10 years later! I did learn my lessons though:

Always secure all cargo and double check the integrity of mounting points frequently.

All the protective gear in the world does absolutely nothing if you ar not wearing it.

I can only assume that the bike would slide further on the sliders than a locked tire, but I don't know for sure. . .And hope to never find out! On a side note, I am SLOWLY experimenting with the ABS on this bike and have to say it seems to work very effectively.

Keep the shiny side up,

David

 

[TruWrecks]

I have always believed that the purpose of ABS was keep the wheel from locking up, so as to, in theory, keep it as close to the point where the tires are sliding as possible but not exceed it. Keeping the wheel speeds in that range mentioned may be be a natural outcome of that but I can't see it as the "goal". For example if both front and rear are locked then they are at the exact same speed - zero.

The "goal" is a result as well as what many car computers use to ensure proper operation of the ABS system.

Many modern vehicles use an accelerometer, and wheel speed, to tell if the vehicle is still decelerating. If you lock up all wheels but your still moving the accelerometer will detect hard braking forces. Hence, "pulse the brakes" says the computer. Non-accelerometer based systems only check to see if the wheels are still rolling when the brakes are released (pulsed). This requires the brake pressure to by reduced more (harder pulse) than that of the accelerometer based systems, requiring more distance to stop. The newer systems 'feather' the brakes much smoother and lighter than the non-accelerometer systems. An accelerometer is what enables some sports cars the ability to perform "Stability Control", and triggers brakes for individual wheels to help get the car going straight when it slides sideways.

My experience comes from working on cages. I'm sure some motorcycle systems are advancing along a similar path. I'm just not sure (yet) how advanced the FJR's ABS is. I do know it uses wheel sensors but I'm not sure if it has an accelerometer. I know more when I have a chance to tear the 07 down and find out.

Cross-Linked Brakes are a whole different concept. It has has a different purpose than ABS. It makes it much harder to lockup both wheels at the same time. ABS compliments CLB very well, and makes it extremely effective under almost every condition.

Is that long winded enough? Is my Geeky-ness showing?

Tru.

 

[SLK50]

The Factory Service Manual gives a very detailed explanation as to how ABS works on the FJR.

It's easy to see in this thread who has read it and has an understanding of how it works as opposed to those who are speculating or repeating here-say. The FJR's ABS DOES NOT wait until the wheel(s) stop rotating to kick in: it's actually much more sophisticated than that. ABS is activated when wheel lock-up is eminent based on rate of deceleration, wheel speed differential, etc.

On a non-ABS bike, if the wheels have not locked up then maximum braking has not been achieved: you can brake harder still until a wheel actually does lock up at which point you should release and re-apply the brake(s) to avoid a potential spill. Keep in mind that during the "release" the bike is no longer decelerating.

On an ABS equipped bike, if ABS has activated you've EXCEEDED maximum braking ability. The wheel(s) keep spinning thus avoiding a potential spill. However, during activation the bike is continuing to decelerate which may result in SHORTER stopping distances.

Up to the point of activation both bikes would be stopped in the same way. ABS will allow a rider to "explore" braking limits without dire consequences.

I attended an ABS demonstration a few years ago where a BMW RT went from 60 to 0 on a lightly sand covered road using maximum braking and did so without ANY drama. Quite impressive!

I'm sold on ABS and wouldn't leave home without it.

 

[thesonicboom]

On a non-ABS bike, if the wheels have not locked up then maximum braking has not been achieved: you can brake harder still until a wheel actually does lock up at which point you should release and re-apply the brake(s) to avoid a potential spill. Keep in mind that during the "release" the bike is no longer decelerating.

I really don't know where this came from. MAX breaking is not at the point where you achieve wheel lock up. Locking the front wheel up is a VERY bad thing, trust me. Max breaking is the point just shy of a skid, hench the impending skid soud some, or all of you may have heard under max breaking. Also, if you really think that you can stop quicker by locking up the wheels, releasing it and re-applying, then come to PHX and I'll give you $100 if you can. :blink:

 

[keithaba]

This is getting good! Where's my popcorn.

 

[thesonicboom]

Now Now, we are all playing nice :drinks: