Brakes and ABS

[Brian ROSEN]

Ok Brian, so just how old are you? You speak with authority & wisdom, but come on... "the Kings bikes"?? Are you a time traveller??? Are you -pause- GOD????

Well, I thought I (almost) was until I fell off my brand new 800GS two weeks ago. My cuts and bruises are now healed - I ring up about the bike tomorrow.
Yes, they were the King's bikes. I was a Lieutenant in His Majesty's Royal Artillery (MTO if you know what that is.) I sadly was one of the route lining troops at his funeral - but compensated by marching in the Coronation of our present Queen.
Now I am way off topic so I had better shut upand go to bed!!!

 

[Der Lustenauer]

You forget that in theory these GS's are off road bikes and when you ride off road there are times when you might want to provoke a skid to slide the back around - with ABS that might be difficult. Also when you are off-road it is much more important tht you retain a greater feel for the tyres and the ground and you don't want any artificial locking/unlocking of the wheels - you do that yourself. Now does that sound convincing? I would not dream of going off road with one of the unwiledly monsters (unless it belonged to someone else) and in fact all my off road experience was on other people's (the King's mainly) bikes! Dates me a bit so you may not believe any of this!

I think in theory these bikes are streetbikes which should be able to go a bit offroad as well (just like Ted Simons Triumph did, despite these new ones having a bit more weight than his).

To provoke a skid to slide the back around, a locking brake is for sure helpful for doing that, but, could one do it with the throttle as well? There might be even other ways, some people say they can steer with weighting the pegs, I am probably not that good on that.

Feeling the tyres and the ground, artificial locking/unlocking, all that I heard already when people have been thinking about and against ABS for road use. Made my mind up on that one.

Since having a bike again, and reading some of the bike magazins, and posts in forums like this, I have kind of accepted that ABS is a no no as soon as one is going off tarmac. That would include probably the gravel drive up to some country mansions.

There was never a good reason given for that. Not that I expect that from the bike magazins, they are happy to tell us that everything is ok as long as the ABS can be switched off.

Tried to do some research today about ABS on gravel and the like. Could not find anything really so far. A report from Australia from, I think 2003, where they mention that there is almost no data about bikes yet, and something on Wikipedia, where the articels were slightly different between the German edition and the English one. And a nice little graph about different surfaces, where the ABS should kick in, and spin and wheelgrip, which I will attach to this post.

So far I learned that ABS can make for longer braking distances on the loose stuff, that on really loose ground, going steeply downhill a normal brake can lock and produce a little bump of matter in front of the wheel which might (or might not!) help to slow the vehicle down, whilst the ABS rolls over those little bumps so the vehicle still accelerates.

In the German Wiki then they say that these shortcomings have been spotted (by the Producers of the big 4x4's I believe, or the Rally car whizz kids) and that new generations of ABS behave differently. To do with the sensors and programs and what they can make out of the data and so on.

I am a bit worried in regard that BMW praises there GS offerings as unstoppable, but as they are normally near the cutting edge of things I hope the ABS systems they offer are of the newer, cleverer type.

So I am asking myself, should one, maybe, leave the ABS on, if one has got one, on the loose stuff, unless one is racing (not very likely in my case) or is going really steeply downhill?

Is there anybody around who can shed light on this, has links to some other information than personal experience only? Not that I do not value personal experience, please do not understand me wrong.

Below the graph mentioned earlier
vertical is level of grip, horizontal wheelspin
the lines from top to bottom are:
dry tarmac, wet gravel, wet tarmac, wet gravel, snow, ice
the little round things on each curve on the lefthand side indicate where the ABS should operate for that road surface.

I hope I hear more about this stuff here.

Sorry, seems I can not upload any pics now. Working on it.

 

[Backmarker]

I might be just stupid, but I do not understand why for braking purposes, offroad or just on gravel, ABS should be worse than normal brakes. Would be interested to learn more about that.

Theoretically, in certain circumstances, a locked wheel provides a little more braking than a rotating one. The clearest example is in thick packed snow (say 3 inches) sitting on top of ice. With no friction between tyre and ice, the ABS would allow the wheel to rotate exactly as it would if you were not applying the brakes. Hence the 'no brakes' sensation. If the wheel were allowed to lock (and this is much more noticable in cars, much wider, squarer tyres etc) then what happens is the tyre slides on the ice but, instead of rotating over the snow, pushes through it. The snow builds up in front of the tyre (like a damn) and hey presto, you have some resistance.

Its not a lot, but it is something, and a hell of a load better than the nowt you get with ABS.

Off road the same effect can be experienced on soft mud on top of a hard compacted surface. Plus, on a bike, I remain convinced that locking the rear and sitting it out slightly (in my case to the right) makes for a good brake as the tyre is now semi sideways to the direction of travel. ABS makes it harder to slide the back wheel out.

However, on gravel roads, were there is still decent grip on the surface (even if that surface is covered in gravel) and there is no depth to the soft covering (to pile up in front of the tyres) and were I am still going fast enough to know that any drag so induced aint going to be noticed by me as braking, then the ABS stays on.

Personally, I think a few people have read about this, and then translated it to ABS = 'BAD' (and I include Bike magazine) without ever actually having experienced the conditions which make ABS less than desirable.

I stand by my position that on road I will always ride with the ABS on. Even in snow/blizzards.

 

[Der Lustenauer]

Its not a lot, but it is something, and a hell of a load better than the nowt you get with ABS.

Despite being a fifty year old Austrian with some experience of snow and ice in winter on mountain roads (the snow nowadays is not what it used to be anyway) I and the bike probably go down in those conditions. If not it's sheer luck, nothing with using ABS or not using ABS in those circumstances.
But, as posted above, I accept the principle.

Are there any other advantages of non ABS brakes than that build up of stuff in front of the locked wheel?

 

[Backmarker]

Despite being a fifty year old Austrian with some experience of snow and ice in winter on mountain roads (the snow nowadays is not what it used to be anyway) I and the bike probably go down in those conditions. If not it's sheer luck, nothing with using ABS or not using ABS in those circumstances.
But, as posted above, I accept the principle.

Are there any other advantages of non ABS brakes than that build up of stuff in front of the locked wheel?

No.
Nothing.
Nowt.

On a car ABS makes more sense because you cannot control all four tyres with one pedal. On the bike you are controlling each wheel with a separate lever so you can control the braking to each wheel individually without ABS.
In car terms, everyone talks about the critical advantage of ABS is being to steer whilst hard on the brakes, 'stamp and steer' so to speak. On bikes, no one talks of steering whilst braking (possibly because we have all been taught not to brake in anything but a straight line and upright), so the issue of being able to stand on the brakes and still steer is never raised.

Personally, for me, the main advantage of ABS is that after 20 years of riding I bought a BMW with ABS. And I started braking harder than I would have ever thought possible, because I was not (so) scared of the front locking. And then I learnt I could brake even harder. And harder. In all weathers, conditions, I am now happy to brake far, far harder than I would have ever dared on a (say) Yamaha R1. Although I accept absolutely that given any time/place a good rider could outbrake me on an R1, I believe that given a random road, random weather, random circumstances, 9.9 times out of 10 I can stop faster on a GS than on any non ABS equiped bike, if only because I have the courage to brake and trust the ABS to save me if the road surface is not what I thought it was.

Maybe this just says a lot about me. Without ABS I assume I have no grip, when I probably always do have it. With ABS I can assume I have it, and know that someone else (the ABS) will tell me when I dont. And it will tell me by cutting the braking so I know I have to find another way out of my predicament, and not by telling me I have no grip by locking the wheels and throwing me down the road.

Finally, for every rider in the bike press I have read complaining that the ABS increases stopping distance by the critical metre that led to the crash, I have read 100 stories where they crashed because a wheel locked on diesel (under moderate braking), marbles, dirt, cow pat, etc etc.

 

[BLUEJAY]

Pity the 650/800 brakes are not semi linked.

No offense, but even though the arguments on having ABS for paved roads are well leaning towards the Pro-ABS, in no way I will be convinced it would be good to have ABS turned ON for off-road riding (either professional or novice-like) and having semi-linked brakes either.

OK, I admit I am a bit skeptical (read...old timer ) when it comes to modern devices on motorcycles/cars, but I believe that on trails the Rider needs to have as much control as He can on the bike (front brake-rear brake-throttle) and not having some computer "stuff" kicking in unexpectedly, because of all the variables and terrain conditions and thus experience can make up for many situations, in my personal opinion

I do not consider myself as a good rider by no means. Just average

Maybe because I am coming from a 100% off-road riding background (Trial bikes), but I will never (never say never... ) consider these two options for the dirt

Just my 2 cents

Cheers

 

[Tim Cullis]

To clarify what I wrote earlier... If you're going downhill offroad on a horribly loose surface the rear brake isn't a lot of good and if the engine braking isn't sufficient (first gear is way too high on the 1200GSA) you need to be able to use the front brake to control your speed. But by using the front brake there's the chance of locking the front wheel.

In situations where there's a corner with a sheer drop ahead it's better to risk locking the wheel and dropping the bike on the trail, rather than having the ABS release the brake and send you plumetting over the edge.

So whether or not you use ABS offroad is down to your riding style and the conditions. The GS is NOT a dirt bike, it's a road bike that's capable of riding gravel roads, and that's how I use it.

For quick and neat cornering you need to be able to lock the back wheel to bring you almost to a halt, before shifting bodyweight and accelerating out of the turn. If you have ABS on you can't do that and will probably end up shooting way past the turn.

Tim

 

[Backmarker]

No offense, ........in no way I will be convinced it would be good to have ABS turned ON for off-road riding (either professional or novice-like) and having semi-linked brakes either.


Just my 2 cents

Cheers

Fine. Plenty of peope are happy with their opinions, and have no desire (or willingness) to be swayed by others. I offered my opinion not to 'persuade' you, but because someone requested others opinions.

 

[Ducksbane]

A Thought from the antipodes

I can assure you that turning off your ABS is a VERY good idea if you are going to ride on gravel, firetrails etc.

I have had some very scary moments on Australian gravel roads when I have forgotten to turn it off ... for example turning left on a sandy T junction and having been very lucky I could continue on up the "escape" road as my R1100GS hardly slowed at all after the ABS came on. On another occasion it just would not turn into this fast gravel corner but luckily I found another line that worked ... scary though. I have also seen a video (again from Australia) about what happens when an R1200GSA with the ABS on is ridden down a track with loose gravel and big rocks ... again very scary.

Obviously conditions are different in Australia but you might be surprised by how off road some of the big GS's get here, and I can guarantee that no experienced rider I know would ever not turn off his (or her) ABS off road.

Just trust me on this!

The good thing about BMW's ABS is that it CAN be turned off, so really why wouldn't you want it (apart from the cost). After all if you are on gravel, rocks, snow, etc you can always turn it off.

 

[beemerboy9]

I have heard that when journos and racers get together on a nice, smooth flat airfield and try to stop as quickly as possible, the non-ABS bikes can be stopped fractionally quicker than ABS bikes BUT...........
I have read that when journos and racers get together on a tyre company test track and try to brake over simulated pedestrian crossings, wet or rutted (e.g. concrete motorways) or badly repaired surfaces, etc. the ABS bikes always stop quicker than the non-ABS bikes.
Take your choice. It's like insurance - you pay and hope never to use it.

 

[Brian ROSEN]

You MAY never use it

"...Take your choice. It's like insurance - you pay and hope never to use it...." This of course is the crux of the whole matter. We all know that motorcycling can be dangerous - that is why we wear crash helmets, armoured clothing, special boots and gloves. All these 'restrictions' have been phased in over the years and have become acceptable. ABS is now a 'normal' option on most bikes so it seems foolhardy to reject it.

 

[BLUEJAY]

Fine. Plenty of peope are happy with their opinions, and have no desire (or willingness) to be swayed by others. I offered my opinion not to 'persuade' you, but because someone requested others opinions.

Got the point.

No intentions to be offensive.

Cheers

 

[samuelsnow]

"...Take your choice. It's like insurance - you pay and hope never to use it...." This of course is the crux of the whole matter. We all know that motorcycling can be dangerous - that is why we wear crash helmets, armoured clothing, special boots and gloves. All these 'restrictions' have been phased in over the years and have become acceptable. ABS is now a 'normal' option on most bikes so it seems foolhardy to reject it.

I think this is the most sensible way to look at it. Its a £500 life insurance policy. For what its worth I share the opinion that the F800 ABS is way to sensitive (to the point of being annoying) I had ABS on my 1150GSA and it was the perfect balance I never knew I had it until I needed it. The 800 version goes off at least once a day but its that one day where you are not quite with it and someone pulls out/stops etc that it might just save your life so I can live with it.

 

[Brian ROSEN]

Getting accustomed to it

The 1150 and the 1200 GS brakes are linked, back and front. That in itself makes the brake operation more balanced (and less likely to trigger the ABS.) I also had servo assitance on my 1200 which I liked very much and made braking easy to regulate with one or two fingers; When I switched to the 800 I found I had to relearn my technique (and start using the brake pedal again!) I am sure that you will get used to the change in operation.

 

[forestry]

Linked brakes

The 800 brakes are also linked.

 

[Argonaught]

I agree that the ABS on the 800GS is too sensitive, I very nearly ran into the back of a car yesterday in wet conditions & at very low speed, scared the bejesus out of me, if i'd been able to get my brain to release then reapply the brakes then i'm sure all would have been fine, but what happened was i was braking & watching myself crash in slow motion. Terrifying & tortuous! As it was i stopped centimeters from the car. & then turned the ABS off for the rest of the journey...

Is the ABS sensitivity adjustable does anyone know?

 

[Brian ROSEN]

That is news to me!

The 800 brakes are also linked.

I am surprised because here in France they are not!

 

[Tim Cullis]

The 800 brakes are also linked.

The system on the 1200GS ABS models is semi-linked--the front lever operates front and rear brakes, the rear lever operates only the rear brake.

The brakes on the F650/800GS are not linked which is a great pity. The front lever operates only the front brake, the rear lever operates only the rear brake. I suspect this is a deliberate marketing differentiator between cheapo GS models and more expensive ones.

What I'd prefer to see is a semi-linked system on both bikes which, when ABS is turned off for offroad, becomes unlinked.

I've been told the non-ABS 1200GS bikes are not linked but I'm not sure if this is true.

Tim

 

[everywherevirtually]

ABS

A guy pulled out in front of me from a junction yesterday and the ABS Kicked in. It was a two lane road and I'm assuming the car to my left flashed him to go right at the same time that I was riding over a bad road surface. I could see my headlight reflecting off a road sign in the usual juddering way and I think he might have mistaken my shaking headlight with a flash to go.

I was on top of him when he pulled across me. Without a doubt the ABS saved me and the bike!

 

[forestry]

Linked brakes

I collect my new f800gs from mottorad east next Friday and was told by the salesman that the brakes were linked when i did my test ride. If this is not the case i am a tadd peeed off, not because i particularly wanted them linked just that to have a salesman who doesnt know his stuff or is prepared to lie doesnt sit well with me.