ABS Really Works

[Global Rider]

I'm talking grabbing a little brake while cornering which results in a skid. You don't have to hit the brakes all out for ABS to have an effect.

True, all we need is a skid.

Now is anyone willing to try a skid fully leaned over?

I'm not.

[Bjorn Toulouse]

To clarify: I don't think anyone IN THIS THREAD has suggested that ABS be required on all motorcycles.

Obliviously, you didn't read the entire thread.
1st page, 9th post.

It has been a couple weeks since I have been able to say it:  all bikes should have ABS.

Rex

[Dan K]

No, dude, but you clearly missed my point.  Shocking.

I will say that if ABS was effective at less than 1 lb, you would start seeing it on race bikes.

- Dan


From this:

Quote
My skills can always use a little help from technology.  As can every Moto-GP racer on the planet.

 -Dan



From this:
Yeah, right. 


Look, let's get something straight, everyone. I have no problem whether or not you choose ABS for your bike or not; as I've previously stated, I even have a rudimentary version of ABS on my '06 FJR that has resulted in the second or third longest stopping distances of any bike *ever* tested by MCN, at 144 feet from 60 mph. Wonderful. A figure unseen since drum brakes in the 1960s.

I'd still buy the bike (even if I wish the brakes worked better in the dry) because of the riding role for which I bought the bike.

What I object to is people making unsubstantiated claims like the original poster of this thread. He comes on with an anecdote claiming that ABS-- and only ABS-- is responsible for the outcome of an accident. He and his riding partner could have helped themselves more than ABS ever could by taking steps I clearly delineated in an early post. Then, in an admission of guilt, he went off in a huff. 

Others have made similar claims and I call b.s. I'll name one example if anyone wants. And, when I feel like doing so, I'll continue to call b.s.

Why? Because I believe that individuals deserve choice in the market and because All-ABS-All-The-Time gets as sickening as ATGATT.

AAATT.   

Choice. Affordability. Proficiency. User servicability.

Neither of my bikes has ABS, and you're still missing my point.  Technology helps.  POinting out that racers utilize technological improvements (slipper clutch, traction control, etc.) and often pioneer them was simply a way to emphasize that technology has its benefits even for the most skilled riders, ABS included.  So piss off with your  

- Dan

[paddy_crow]

Obliviously, you didn't read the entire thread.
1st page, 9th post.




Rex

Seven pages of pissing contest? Nope, didn't scrutinize each and every post. Sorry for missing that offhand remark from more than a month ago.

[paddy_crow]

True, all we need is a skid.

Now is anyone willing to try a skid fully leaned over?

I'm not.

That's the point of ABS, avoiding.

There are a lot of things I am not willing to try on a motorcycle. It only means that I'm not willing to do it, it doesn't mean that the machine doesn't work.

[Global Rider]

There are a lot of things I am not willing to try on a motorcycle.

Well don't try what I previously suggested not to try, because it won't work. You'll be on you butt, ABS or not.

You mentioned AVOID...I use my judgement to "avoid" situations...it has worked all these years so far.

There are old pilots and there are bold pilots, but there are no old bold pilots.

I prefer my motorcycles without ABS, even if manufacturers chose to give it to me for free. And that is my personal choice!

And for those stories where ABS saved the day, I'm just wondering what excuse I can use for the times I didn't go down...luck or skill?

[bogfro]

To clarify: I don't think anyone IN THIS THREAD has suggested that ABS be required on all motorcycles.

OK then I'll do it!  It wouldn't be a bad idea to require ABS on all cars (because still not all cars have it) and motorcycles.  I see it as like having seat belts and air bags be mandatory in cars.  It's a safety feature that WILL prevent injuries across the board, no matter which way you look at it.  The extra cost will just get absorbed into the retail price, just like it was for seatbelts and airbags.  ABS weighs what, like 5 or 10 pounds?  Big whoopdedoo.  And you don't even notice it's there until you lock your wheels.  Have a disable feature for dirt use, just like you can disable the passenger airbag for child use.

[Global Rider]

It's a safety feature that WILL prevent injuries across the board, no matter which way you look at it.

If it is such a great safety feature, I'm wondering why the number of accidents hasn't decreased drastically.  

[bogfro]

If it is such a great safety feature, I'm wondering why the number of accidents hasn't decreased drastically.  

Car accidents HAVE decreased due to more safety features....I believe this past year had the least crashes per capita on record.

And as to motorcycles, well ABS isn't a standard feature yet!  Only a few models have it.

[paddy_crow]

Well don't try what I previously suggested not to try, because it won't work.

I don't ride in such a manner that I have to "fully lean over," so the likelihood that I'd have to brake while doing it is pretty slim.

It seems to me that it would be unwise to hit the brakes at all in your hypothetical situation. I guess I don't see how that's relevant to a discussion on the merits of ABS.

I drove automobiles for quite awhile before ABS was available. I managed to survive. But having experienced the benefit firsthand, there's no way I'll buy another daily commuter without it.

[Global Rider]

I don't ride in such a manner that I have to "fully lean over," so the likelihood that I'd have to brake while doing it is pretty slim.

But we're not discussing what you or anybody else would do.

Someone brought it up, so we're discussing whether ABS would or would not work while in a turn...and if you're in a turn...you are leaned over...at least you should be.

Now in a grandpa or grandma turn where a rider is almost upright, the chances are better the more upright you are...as in a straight line and upright which is where ABS is designed to work best.

[paddy_crow]

But we're not discussing what you or anybody else would do.

Someone brought it up, so we're discussing whether ABS would or would not work while in a turn...and if you're in a turn...you are leaned over...at least you should be.

Now in a grandpa or grandma turn where a rider is almost upright, the chances are better the more upright you are...as in a straight line and upright which is where ABS is designed to work best.

You said, "Well don't try ..." Was it unreasonable to say that I wouldn't?

You also said, "fully leaned over." When did we go from being fully leaned over to partially leaned over? Your hypothetical situation keeps changing.

Again, ABS is designed to prevent the wheels from locking up. It works the same regardless of the angle of the tire to the pavement or the direction of travel. It isn't that ABS works better in a straight line, it's that a motorcycle stops better in a straight line regardless of whether or not it's equipped with ABS. In fact, I would say most vehicles stop better in a straight line. That doesn't mean that ABS doesn't work in a turn.

[ajf]

ABS is designed to prevent the wheels from locking up. It works the same regardless of the angle of the tire to the pavement or the direction of travel

You're getting plenty of dogmatic disagreement, but little explanation.  This topic was discussed at length last year in this thread:

http://www.sport-touring.net/forums/index.php/topic,30855.0.html

A variety of good explanations for why your belief is incorrect can be found there.  One of them eventually got through to me.

[paddy_crow]

My belief? We're not talking about religion, we're talking about mechanics and semantics.

When you say it doesn't work in a corner, it says to me that the system doesn't perform its function of preventing wheel lockup. That is what I disagreed with.

The forces acting on a tire in the plane of contact can be divided into two components, one tangential (braking) to the path and one radial (cornering). When the sum of those two components exceed the adhesion limit of the tire, a skid ensues.

The presence of a radial force vector does not preclude ABS from preventing wheel lockup. As that vector approaches the adhesion limit on its own, the more dangerous the situation is. The introduction of a braking component will cause the wheel to lock up and traction to be lost. Recovery depends on reducing the braking force, which an ABS system will do almost immediately. If, however, the required radial force can not be matched by friction with its lower sliding coefficient, recovery will not be possible. But that's the case whether the vehicle is equipped with ABS or not.

So if someone were to say that ABS will not prevent a rider from losing control when cornering close to the tire's limit, I would agree. But I don't agree that the system didn't work.

[delta one]

OK since this is getting out of hand I wrote out some force vectors to think about it a bit. and no ABS will not ALWAYS help in a corner, not only because of what Paddy_crow said (he was also right by the way) but also because when the total frictional load is pushed beyond the capacity of the tire it may begin to slip to the side BEFORE the tire locks up. if the difference in rotation is not great enough for the ABS system to intervene it will continue on its merry way thinking all is well. during this event your front tire will "push", this is easy to experience in a FWD car where you continue on a straight path despite the wheel being turned. this will be a front end slide out. while your front end slides out your front tire may still be turning  (rotating). to witness this put a toy tire on a pencil and push it straight across a table, next push it along the same line with the tire facing 30 degrees to one side. it will still rotate without stopping but it is clearly not applying a desired amount of lateral forces.

Sorry for the lack of punctuation I was in a bit of a hurry.

And yes as it turned out I answered my own question.

Note also that this assumes that you are exceeding the static friction coefficient of your tires, I don't think I would do this in most day to day scenarios, so for my uses I should not encounter this on a commuting bike. I am willing to bet that even in moderate touring many would not experience this unless they came across a friction modifier on the roads surface. (sand gravel rain oil etc.)