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Posted

I am a little concerned that some of the posts righting that the stoping distance are based on the tyres.

My thought is that your stopping distance is based on not on your tyres, but the weight the tyres are carrying and the condition of the road at the time you knead to stop.

I am one not to skid my tyres to stop the flat spot it crates is not one I want.

 

The tyres I bye are for handling and distance

 

do you agree. :12101:

Posted

Braking ability has many factors, the tires ability to grip the road is one of them, specifically the tires ability to grip and not lose traction with the surface, the less traction a tire has the quicker it is going to start skiding. Once traction is lost and a skid begins you may actually speed up and you are out of control sliding.

 

The Idea behind ABS, is to apply to maximum braking force to the brakes, without causing the tires to loose grip with the road surface. Thus reducing stopping distance.

Read your owners manual carefully, you will find that most tell you that and overinflated tire will lose traction under hard braking, thus reducing the ABS performance and increasing stopping distance.

 

Which is my point with the radials on the RSV, I can apply more pressure to the brakes without sliding the tires therefore the bike stops faster. esp with the Cobra on frount, the frount actually provides most of your stopping ability.

 

This is why nascar changes compounds on the race car tires at different tracks, for grip, traction works all ways, starting, stopping and in curves.

If you will read on their site michellin guarantees that any vehicle will stop faster and less likely to skid with their hydroedge tires.

 

Gregg

Posted (edited)

The Idea behind ABS, is to apply to maximum braking force to the brakes, without causing the tires to loose grip with the road surface. Thus reducing stopping distance.

Read your owners manual carefully, you will find that most tell you that and overinflated tire will lose traction under hard braking, thus reducing the ABS performance and increasing stopping distance.

 

Gregg

On the contrary ABS actually increases stopping distance. The purpose of ABS is so that the driver can maintain steering control during hard braking. Once the tires break traction with the road surface regardless of the vehicle, the driver no longer has steering control of his vehicle. A good driver knows this and controls his brakes accordingly. However we have a high population of drivers who are inept at emergancy driving skills, so we implement technology to compansate for them. Unfortunatly to gain this electronic steering control, Stopping distance's have been a trade off and increased, hence an increase in rear end collisions have resulted.

Personally I prefer a vehicle without ABS over one with.

 

Where the tires come into play here, usually the harder the tire compound the easier it is for the tire to brake traction. the softer the compound the better it grips. There is a trade off here as well better traction faster tire wear. better tire wear less traction. Then there are tread patterns different design's have different grip characteristic's, each designed for different road surfaces.

Edited by saddlebum
Posted

November 17, 2008

David Kelly

Acting Administrator

National Highway Traffic Safety Administration

1200 New Jersey Avenue, SE, West Building

Washington, DC 20590

Notice of Proposed Rulemaking; 49 CFR Part 571 Federal Motor Vehicle Safety Standards,

Motorcycle Brake Systems; Docket No. NHTSA-2008-0150

Dear Mr. Kelly:

On September 17, 2008, the National Highway Traffic Safety Administration (NHTSA) announced a

proposal to amend Federal Motor Vehicle Safety Standard (FMVSS) No. 122, Motorcycle Brake Systems.

The amendments would strengthen the requirements and test procedures that cover many aspects of

motorcycle brake systems, including antilock braking systems (ABS) voluntarily installed by

manufacturers. The Insurance Institute for Highway Safety (IIHS) supports these changes and submits

with this comment our recent research showing that ABS is improving motorcycle safety.

The proposed changes to FMVSS 122 will create minimum performance standards that have been tested

successfully elsewhere in the world and will help keep motorcycles with unsafe brakes from being sold in

the United States. The proposed ABS tests in particular will help ensure that if ABS is installed on

motorcycles, the system will provide operators with adequate stopping distances and stability.

IIHS and its affiliated Highway Loss Data Institute (HLDI) are studying the safety effects of motorcycle

ABS as its availability increases. Results from our initial analysis of a variety of models show that ABS is

having a positive effect (IIHS, 2008). Both the rate of fatal motorcycle crashes and the frequency of

crashes for which insurance collision claims are filed are lower among motorcycles with ABS compared

with the same motorcycles without ABS. The attached IIHS study (Teoh, 2008) shows 6.7 fatal crashes

per 10,000 registered vehicle years among motorcycles not equipped with ABS during 2005-06. The

corresponding rate for the same models equipped with optional ABS was 4.1 fatal crashes per 10,000

registered vehicle years — 38 percent lower. The attached HLDI (2008) study shows that the estimated

effect of ABS was a 21 percent decrease in overall collision losses, primarily because collision claim

frequencies for motorcycles with ABS were 19 percent lower than for motorcycles without ABS.

The importance of equipping motorcycles with ABS increases as motorcycling continues to grow in

popularity. Motorcycle sales more than tripled between 1997 and 2005, and motorcyclist deaths have

more than doubled since 1997. Due largely to safety features that are increasingly available as standard

equipment on passenger vehicles, there were fewer passenger vehicle occupant deaths in 2007 than in

any year since NHTSA began collecting these data in 1975. On the other hand, more motorcyclists died

 

 

Posted

All other things being equal stopping distance will be 100% dependent on the tire.

 

Normally sliding friction is less than static friction so skidding = bad for both stopping and steering. Tires are a special case in that they provide the most friction at roughly 10% slip (depends on tire compound).

 

On a 4 wheel vehicle if you start to skid you can let off the brakes and re-apply (that's what ABS is supposed to do automatically). On a motorcycle if you're in a lateral skid and let off the brakes you're almost certain to high side. It seems to me that ABS is an outstanding idea for motorcycles.

 

Some regulation of motorcycle ABS is probably in order. Every Chinese street scooter I've seen has a gadget on the front brake caliper labeled ABS. It's not ABS, it's an expansion chamber to make the brakes less responsive - more correctly it'd be called Mushy Brake System.

Posted

After I wrecked my RSV on a rain slick hwy 3 weeks ago, my next bike will have ABS.

IMO Yamaha has been negligent in not updating the RSV. Every other large touring bike has available ABS. It can be added without a major redesign as HD has done.

Posted

The ABS voyager will stop so quick it scary, I don't know what its 60 to 0 time is, but it's short. The Voyager has the best braking system of any bike I have ever rode.

 

 

Gregg

Posted

There are a lot of people who THINK they can stop a vehicle faster in an emergency than ABS, but probably less than 1% of the driving population has that ability on dry roads, and no one I know or have read about has that ability on wet roads.

 

Sport Rider did a comparison recently of the new CBRs with ABS and the CBRs without ABS. Of all of their riders, only 1 was able to stop the CBR without ABS in a shorter distance than the CBR with ABS, and that took him multiple tries until he finally beat it. That was on DRY clean pavement. NONE of their riders were able to stop the CBR as fast as ABS on wet pavement. These are guys that ride and race the fastest, best handling bikes on the planet for a living, and quite a few have impressive race records.

 

In an emergency, you simply react. Your reflexes do what they have been trained to do. Very few riders have spent enough time practicing emergency maneuvers on every bike they own to the point where their reflexes will provide maximum breaking under full control of the bike on wet or dry pavement. Most riders get their experience just riding, and maybe practicing slow speed turns in parking lots. In an emergency, they absolutely do not stop as fast as ABS would allow, and many times that results in low sides, high sides, or hitting the object in front of them.

 

That's not to say that ABS will stop all accidents, since stopping distances are a small part of accident prevention. But ABS will absolutely stop your bike, especially a 900 pound cruiser in an emergency situation, faster.

Posted

haha as a broke 16 year old i go by price!

I got a pair of tires for my bike for 75 dollars each.

The back one only lasted about 6000 miles, but it was pretty cheap:mytruck1:

Posted
But ABS will absolutely stop your bike, especially a 900 pound cruiser in an emergency situation, faster.

 

 

With all due respect.....so what.

 

At what point, with all of this "life saving technology" do we stop controling our vehicles and become simply PASSENGERS.

 

As we remove the responsibility from the rider to learn how to operate his machine well enough to stay alive, we remove the joy and satisfaction of obtaining a valuble skill, gained over many years and miles.

 

Too much more, and we'll all be riding merry-go-round motorcycles.

We've made it hard to get lost (GPS).

We've made it hard to miss a gear (automatic tranny).

We've made it hard to crash (ABS).

We've made it hard to get hurt (air bags and safety gear ad nauseum).

 

Just keep going round and round, safe as in your mother's arms.

 

As risky as they are to ride, I'll take my old fashioned, still dangerous, need some skill to ride, fun mobile without all of the safety amenities.

 

Of course it's dangerous. That's part of what makes it fun.

:soapbox:

Posted
With all due respect.....so what.
I believe his reply was more to help overcome some of the false notions presented here that an ABS equipped vehicle won't stop as quickly. Seems he was just stating a fact. :)

 

As we remove the responsibility from the rider to learn how to operate his machine ...
Who is doing the removing of responsibility? Features, safety or not, do not remove the responsibility.
Posted
With all due respect.....so what.

 

At what point, with all of this "life saving technology" do we stop controling our vehicles and become simply PASSENGERS.

 

As we remove the responsibility from the rider to learn how to operate his machine well enough to stay alive, we remove the joy and satisfaction of obtaining a valuble skill, gained over many years and miles.

 

Too much more, and we'll all be riding merry-go-round motorcycles.

We've made it hard to get lost (GPS).

We've made it hard to miss a gear (automatic tranny).

We've made it hard to crash (ABS).

We've made it hard to get hurt (air bags and safety gear ad nauseum).

 

Just keep going round and round, safe as in your mother's arms.

 

As risky as they are to ride, I'll take my old fashioned, still dangerous, need some skill to ride, fun mobile without all of the safety amenities.

 

Of course it's dangerous. That's part of what makes it fun.

:soapbox:

 

 

Ever had the cars in front of you wreck on a wet interstate? I have. My bike was totaled but I walked away. Maybe your skills are better than mine. Good luck to you if it ever happens.

Posted
Once traction is lost and a skid begins you may actually speed up and you are out of control sliding.

 

The laws of physics makes this impossible.

 

ABS actually increases stopping distance.

 

Also not true.

 

The Idea behind ABS, is to apply to maximum braking force to the brakes, without causing the tires to loose grip with the road surface. Thus reducing stopping distance.

 

Footsiebiker is correct.

 

It's all simple physics. The more contact between the road surface and the tire, the more traction. Softer compound tires have more contact with the road surface because they can squish themselves into the tiny cracks and pits in the road surface where a harder compound can't. Adding more weight forces a tire to do the same. But adding more weight will affect inertial forces that may add other problems.

Posted
On the contrary ABS actually increases stopping distance.

Also not true.

 

 

 

I'm sorry to say, but a1bummer is right.

 

In a perfect World, the ABS Regulation would relief the exact Amount of hydraulic Brake Pressure from the Line to keep the Wheel rotating, just before skidding. Even the latest Systems are not that perfect, they will allways take of more Pressure off than needed, thus you will have a increased Stopping Distance.

 

But, if you only look at the sheer Braking Manoveur, a little Skidding is better for the Stopping Distance than not braking with full Force. A top Class Racer will still outbrake any standard ABS System. If a ABS is designed for Racing Purpose, the Software will allow some Amount of skidding and sliding and it will be hard for a human to outbrake that System over a lenghty Period of Time.

 

The real Advantage of the newer ABS Systems on Bikes are on the different Side, this should also been in the Arcticle about the CBR mentioned above. Who actually can apply full Braking Force, in other Words GRAB a HANDFULL of front Brake while going 70 or 100 mph. There's the pure Advantage. If you know you can do this and you got yourself trained to do so, you will have gained a much better Stopping Distance. If not, you won't have the best stopping Distance for one Reason or the other.

Posted
I am one not to skid my tyres to stop the flat spot it crates is not one I want.

 

I too try not to flat spot tires, because you can stop in a shorter distance if you dont slide your tires......

Posted

Nothing like a good ole' ABS debate to heat things up.

 

As I see it, the first ABS systems were so slow that it wasn't hard for a half-way decent driver with some skill to out brake them. Since I have raced, been an instructor and also tow trailers, I knew threshold braking techniques before ABS was introduced. And that is what ABS does well, is threshold brake.

 

The new ABS systems are so fast that it takes a VERY good driver to out brake the system.

 

Tire compound has a fairly large effect on braking distances, but tread design and the weather and how those tread compounds and designs interact with the weather and road surface all make differences.

 

Example. Summer compound or "race" compound tires will stop better than any other tire (size and contact patch, weight etc being equal) in warm weather. Lower the temperature or add in some ice/snow and they are the worst tires.

 

Winter tires will do best in ...winter ...(duh on myself!) and will be OK the rest of the time. All season tires are a good compromise for all types of roads/weather. Not the best in any extreme, but really good.

 

The Tire Rack web site has a lot of info, and I hear a recent test of winter tires VS summer and all season. Results pretty much what you would expect.

 

Yes, most of this is about cars, but most does apply to bikes.

Posted
There are a lot of people who THINK they can stop a vehicle faster in an emergency than ABS, but probably less than 1% of the driving population has that ability on dry roads, and no one I know or have read about has that ability on wet roads.

 

Sport Rider did a comparison recently of the new CBRs with ABS and the CBRs without ABS. Of all of their riders, only 1 was able to stop the CBR without ABS in a shorter distance than the CBR with ABS, and that took him multiple tries until he finally beat it. That was on DRY clean pavement. NONE of their riders were able to stop the CBR as fast as ABS on wet pavement. These are guys that ride and race the fastest, best handling bikes on the planet for a living, and quite a few have impressive race records.

 

In an emergency, you simply react. Your reflexes do what they have been trained to do. Very few riders have spent enough time practicing emergency maneuvers on every bike they own to the point where their reflexes will provide maximum breaking under full control of the bike on wet or dry pavement. Most riders get their experience just riding, and maybe practicing slow speed turns in parking lots. In an emergency, they absolutely do not stop as fast as ABS would allow, and many times that results in low sides, high sides, or hitting the object in front of them.

 

That's not to say that ABS will stop all accidents, since stopping distances are a small part of accident prevention. But ABS will absolutely stop your bike, especially a 900 pound cruiser in an emergency situation, faster.

 

 

Absolutely correct, it take a highly skilled rider to think about braking control in an emergency, most just step down hard on the pedel, and its strange that all the data on ABS bike shows them with shorter stopping distance than their non ABS counter parts.

I think the article you quoted proves that point.

 

Gregg

Posted
Nothing like a good ole' ABS debate to heat things up.

 

As I see it, the first ABS systems were so slow that it wasn't hard for a half-way decent driver with some skill to out brake them. Since I have raced, been an instructor and also tow trailers, I knew threshold braking techniques before ABS was introduced. And that is what ABS does well, is threshold brake.

 

The new ABS systems are so fast that it takes a VERY good driver to out brake the system.

 

 

Actually for the last few years the newer ABS systems are so good that only professional motorcycle road racers on clean dry tracks have been able to out brake ABS systems. And even the racers have not been able to brake as fast as ABS in less than optimum conditions.

 

Along with the stopping distance, it was found that less than half of all riders tested, of varying abilities, could even keep a bike upright when the traction was less than optimum while making an emergency stop. And remember, this was during a testing situation when the rider knew they would have to simulate an emergency stop.

Posted

i just passed the MSF (motorcycle safety foundation) rider course this past friday. while i'm not qualified to debate ABS vs standard braking - i can safely say that without the basic riding skills and understanding of many factors affecting m/c safety and operation - the safest bike in the hands of an unskilled driver isn't all that safe. i learned several very important lessons (micarl pointed out 'high siding') - if i were to make a suggestion about the safest way to stop a bike - i would say find a MSF course near you and take it. i was pleasntly surprised when my instructor informed me that i passed the written test with 100% and scored zero on my riding test (zero being highest score) - he encouraged me to look into becoming an instructor (which greatly inflated my head). all the best gear and latest bike technology is virtually wasted if not instructed and have practiced safe riding. i wish all the best to our family riders !

 

buz

Posted (edited)

There may well be a difference in the way ABS effects motorcycles compared to larger vehicles, but I can tell you the abs on my trucks and cars have scared me so bad sometimes with close calls that I have disabled it on all my vehicles prefering to rely on my own driving skills. I have also repaired front end damage on many trucks were the truck driver swore up and down that if it were not for ABS he would have stopped in time to avoid the collision. Even a skidding tire on dry pavement has sufficiant friction to stop faster than a wheel that is constantly being released and reapplied By an ABS system. When ABS 1st came out I had to go on several training were they emphasized that although braking distances were somewhat increased the improvement in overall handling of the vehical during hard braking on slippery surfaces was well worth the trade off. In the training video they showed a two transport trucks stopping in a straight line , the truck without ABS stopped in a shorter distance than a truck with ABS, even on wet pavement the truck withoutstopped in a shorter distance. However when it came to hard braking while in a turn the rig with ABS was better able to avoid jacknifing. Again when steering (weaving) through a row off pillons while braking hard the truck with ABS was better able to maintain steering control.

 

In the mid seventy's ABS was implamented on big rigs under FVMS 121 it was such a disaster tht it was canned a couple years later. Don,t forget many times things are implamented not because it is a better idea but because someone stands to make money from it, and has the right political connections to make it happen.

 

In the case of a motorcycle I could see an advantage due to the fact when a motorcycle tire breakes traction, it not only skids but it can slide sideways out from under you.

Edited by saddlebum
Posted
do you agree.

 

I disagree. The tire is part of the braking varible, but is only a contributing factor. All braking potential is based on the footprint of the tire to the surface, nothing else. Where the rubber meets the road so to speak. All other variables such as tire compound, pad condition, surface condition, are contributing factors.

Posted

My 1997 BMW K1100 had ABS and it was a constant maintenance item. Hopefully the newer ones are better.

 

Because of my prior experience with ABS, I didn't want a new bike with it. Hopefully I was wrong and newer ABS systems are more maintenance free and live up to their expectations.

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