Abs?

[paddy]

I've been thinking. Which is always a dangerous thing. I've had some thoughts around ABS and I wanted to put them out there for argument. (Really I wanted to put them out there for sensible discussion in the hope I can learn something - but I'm not that naive - so I will settle for vigorous argument.)

For the sake of argument, lets consider a very simplistic view of ABS, that when a wheel stops rotating, the brake pressure is momentarily released before being re-applied (and repeat ad infinitum).

Lets also consider, that it seems to be a fairly common argument that a competent and practised rider can stop a non-ABS bike more quickly than an ABS equipped bike. For the sake of the argument, lets just assume that the experienced rider won't just panic and grab a handful of brake in the same way that a learner might.

So here is my question: The experienced rider can stop the non-ABS bike more quickly because he can maintain brake pressure right at the threshold of traction. Here's where it gets a bit hazy for me though - he can also do this on the ABS equipped bike. The only difference would seem to be when he misjudges and gets it wrong.

I pose the question because this is often given as the argument against ABS equipped bikes. But it seems to me that the comparison is not actually between ABS and no ABS, but rather between braking styles - can the rider maintain brake pressure at the threshold of adhesion or not.

I'd like to hear what peoples thoughts are. And again, I am naively hoping to avoid this becoming a "pissing match" as I am actually interested in the debate.

(If you're female and easily offended please feel free to substitute "she" for "he" in the above. I'm not inferring anything. I'm male. I used "he".)

[kave]

My only real concern about ABS is how it copes with stopping in a low traction environment such as on gravel roads. Sometimes locking up a wheel can be the preferred course of action, and I dont know if I would be happy with that option being removed.

[Naki Rat]

On a bike, the same as in a car, there are times when locked brakes are preferable to give the desired stopping result.

Example being in the case of a speedway or rally type 'sideways' stop. In such cases the wheels are purposely locked up in order to present the tyre side-on to the direction of travel thereby increasing the tyre footprint's width by a factor of 3 or 4 times. This makes for a big friction advantage in some situations, particularly on metal/gravel.

Although I have been saved from harm by ABS in the odd situation, particularly braking hard when towing an unbraked trailer, I tend to prefer to be able to react to situations without unexpected inputs. For this reason on gravel roads the traction control is turned OFF.

[The Baron]

Can the rider maintain brake pressure at the threshold of adhesion or not?

Yes. But are all riders equal?

I still like ABS on heavier road bikes. I find ABS very good. So one vote for ABS.

[paddy]

Can the rider maintain brake pressure at the threshold of adhesion or not?

Yes. But are all riders equal?

I still like ABS on heavier road bikes. I find ABS very good. So one vote for ABS.

I would personally definitely prefer ABS. In reality, in an emergency, I am probably going to grab the brakes hard...

[paddy]

My only real concern about ABS is how it copes with stopping in a low traction environment such as on gravel roads. Sometimes locking up a wheel can be the preferred course of action, and I dont know if I would be happy with that option being removed.

On a bike, the same as in a car, there are times when locked brakes are preferable to give the desired stopping result.

Example being in the case of a speedway or rally type 'sideways' stop. In such cases the wheels are purposely locked up in order to present the tyre side-on to the direction of travel thereby increasing the tyre footprint's width by a factor of 3 or 4 times. This makes for a big friction advantage in some situations, particularly on metal/gravel.

Although I have been saved from harm by ABS in the odd situation, particularly braking hard when towing an unbraked trailer, I tend to prefer to be able to react to situations without unexpected inputs. For this reason on gravel roads the traction control is turned OFF.

I agree with some of what is above - so lets constrain the argument to motorcycles in a paved public road situation.

[AllanB]

Darn - saw the title, grabbed my camera and ripped off my shirt for you .........



I predict there will be a day when ABS is standard on bikes over 500cc.

[Sidewinder]

you cant do stoppies with abs and that sucks

[st00ji]

the level of intrusion into the riding experience offered by ABS really depends on how the manfacturer has set it up. in cars, nanny mode has it kicking in early, whereas sports cars systems will mostly only make themselves felt when its really needed (for example in your panicked handfuls of brake scenario)

presumably most bikes would be equipped with a brake system to suit the manner in which the manufacturer expects them to be ridden.

i'd be very surprised if a human could consistently outbrake a modern ABS system in real world situations, hence the reason they exist in the first place

[paturoa]

I've just bought an ABS bike for 1 reason, panic stops.

I don't rate my skills ahead of modern electronics that are checking hundreds of time per second.

Sure if I practiced a lot, say regular racing, then I might match, but what about that patch of oil / diesel ?

[jim.cox]

I'd vote against ABS

I like a bike to move around. I dont mind locking wheels, I dont mind spinning wheels. I do a significant amount of riding on gravel.

Also I have old old bikes which are hard to keep on going. ABS is just one more thing to go wrong.

And as a general principal I dislike the idea of brakes (or any bike part) that disable themselves.

So not for me (please)

Just my $0.02

[NDORFN]

If you want ABS, do some sit ups. If you don't want ABS, drink some beer.

[paturoa]

If you want ABS, do some sit ups. If you don't want ABS, drink some beer.

I drink beer and still have abs, they are just coverred up now!

[Devil]

I'd vote against ABS

I like a bike to move around. I dont mind locking wheels, I dont mind spinning wheels. I do a significant amount of riding on gravel.

I leave my ABS switched on on the gravel and i find it fantastic, I can still get the rear sliding should I wish.

One of the UK bike magazines recently had a brake test. The ABS equipped BMW K1300S whipped the arse of their benchmark Daytona 675 in both the wet and the dry.

ABS doesn't stop you from doing stoppies either.

[Ender EnZed]

If you want ABS, do some sit ups. If you don't want ABS, drink some beer.

If you're really after a good time try both at once.


I've never ridden a bike with ABS but I'm not going to pretend I could reliably stop faster in an emergency. So I'm in favour.