Stupid accident due to ABS
Discussion
Discovered the perils of ABS on loose surfaces last night.
Travelling along a narrow (single car width) lane i was just cresting a hill when a car coming the other way meant I had to move to the far left of the roadway. It wasn't a problem or even something I gave any thought to, se were both travelling slowly (around 10-15mph I guess) I then had a sharp right hand corner which dropped down a steep hill.
As I was slightly out of position for the corner as I turned I applied a little bit of brake but the fine gravel on the side of the road caused the ABS to kick in – on my bike this sees the lever pull to the bar and the brakes release completely for what feels like forever but is probably half a second. Because the bike was now heading downhill, the brake's release saw the bike accelerate, which pushed me even wider on the bend and the bike went off the shoulder on the edge of the tarmac onto a grass verge. The ABS is still releasing the brakes because the wet grass has little grip, and the bike is still accelerating because of the steep slope. Me and bike continued down the hill for about 20yds before a discarded paving slab in the grass saw us part company. I went over the top of the falling bike and did a forward roll, finishing a few yards further downhill from the stricken machine.
Nasty gash on my shin, bruised shoulder and bashed elbow are my only injuries, the bike suffered a bent handlebar and a snapped-off gear shifter, so could have been a lot worse.
TBH i feel like an idiot for a such a low-speed fall, but the lack of braking because of the ABS was terrifying. Hopefully more modern systems have improved.
Travelling along a narrow (single car width) lane i was just cresting a hill when a car coming the other way meant I had to move to the far left of the roadway. It wasn't a problem or even something I gave any thought to, se were both travelling slowly (around 10-15mph I guess) I then had a sharp right hand corner which dropped down a steep hill.
As I was slightly out of position for the corner as I turned I applied a little bit of brake but the fine gravel on the side of the road caused the ABS to kick in – on my bike this sees the lever pull to the bar and the brakes release completely for what feels like forever but is probably half a second. Because the bike was now heading downhill, the brake's release saw the bike accelerate, which pushed me even wider on the bend and the bike went off the shoulder on the edge of the tarmac onto a grass verge. The ABS is still releasing the brakes because the wet grass has little grip, and the bike is still accelerating because of the steep slope. Me and bike continued down the hill for about 20yds before a discarded paving slab in the grass saw us part company. I went over the top of the falling bike and did a forward roll, finishing a few yards further downhill from the stricken machine.
Nasty gash on my shin, bruised shoulder and bashed elbow are my only injuries, the bike suffered a bent handlebar and a snapped-off gear shifter, so could have been a lot worse.
TBH i feel like an idiot for a such a low-speed fall, but the lack of braking because of the ABS was terrifying. Hopefully more modern systems have improved.
That sounds very odd as correctly working ABS will will cause a pulsing at the lever as it brakes / releases at high speed retaining the ability to steer, I don't think a correctly working ABS system would release the brakes for long enough to allow further acceleration, they are designed to work best in low grip scenarios ...
I have had a similar thing happen on my MT 10 a couple of years back.
Going slowly down a steep narrow tree covered single track road I braked from maybe 20 mph for the junction so would have been 5 meters from the junction when I went over. Patch of gravel that I hadn't seen.
This activated the ABS which made the lever not loose pressure but made it feel firmer than normal.
I ended up half way across a road that by the grace of god there was nothing coming.
ABS can catch you out.
Going slowly down a steep narrow tree covered single track road I braked from maybe 20 mph for the junction so would have been 5 meters from the junction when I went over. Patch of gravel that I hadn't seen.
This activated the ABS which made the lever not loose pressure but made it feel firmer than normal.
I ended up half way across a road that by the grace of god there was nothing coming.
ABS can catch you out.
It's on a 2006 BMW F800S. Lever def comes back to the bar, and there's a long enough pause between it cutting the brakes and putting them on again to feel a rising panic.
I've no idea if it works properly or not. No warning lights (ABS light illuminates on startup and then goes off a second or two after moving). Brakes work fine on the road, and I'm not the sort of rider who regularly activates the ABS to know if it is any different from when the bike was new..
I've no idea if it works properly or not. No warning lights (ABS light illuminates on startup and then goes off a second or two after moving). Brakes work fine on the road, and I'm not the sort of rider who regularly activates the ABS to know if it is any different from when the bike was new..
boyse7en said:
It's on a 2006 BMW F800S. Lever def comes back to the bar, and there's a long enough pause between it cutting the brakes and putting them on again to feel a rising panic.
I've no idea if it works properly or not. No warning lights (ABS light illuminates on startup and then goes off a second or two after moving). Brakes work fine on the road, and I'm not the sort of rider who regularly activates the ABS to know if it is any different from when the bike was new..
Does indeed seem odd, and not trying in any way to blame you, might be worth checking the manual as on my Hyper and my Multi when I activate the ABS the light on the dashboard goes mad, might be worth seeing if yours should.I've no idea if it works properly or not. No warning lights (ABS light illuminates on startup and then goes off a second or two after moving). Brakes work fine on the road, and I'm not the sort of rider who regularly activates the ABS to know if it is any different from when the bike was new..
May also be worth finding a decent quiet straight road and emergency stopping to see if you can trigger it, and if it feels the same as what happened.
boyse7en said:
It's on a 2006 BMW F800S. Lever def comes back to the bar, and there's a long enough pause between it cutting the brakes and putting them on again to feel a rising panic.
I've no idea if it works properly or not. No warning lights (ABS light illuminates on startup and then goes off a second or two after moving). Brakes work fine on the road, and I'm not the sort of rider who regularly activates the ABS to know if it is any different from when the bike was new..
It definitely shouldn't do that.I've no idea if it works properly or not. No warning lights (ABS light illuminates on startup and then goes off a second or two after moving). Brakes work fine on the road, and I'm not the sort of rider who regularly activates the ABS to know if it is any different from when the bike was new..
I suspect you will have had air in the ABS modulator so it will have lost pressure when a particular valve has opened.
If you have had a brake service by a dealer I would be going back to them and kicking up a stink.
I'll do some testing and trying it out once i've got it fixed and back on the road.
It's prompted me to do some quick research, and I found this an an old riders forum...
"If you jump on the F800 forum you'll notice that,- when braking (and it doesn't have to be hard)- on a dry road- in a straight line- and you hit a small bump the size of a catseye or dip in the road of a similar depth- the bike will do what appears to be a release of all brakes for up to two car lengths while you still have the brake lever firmly held. Then it reapplies them again. There has been a crash as a result of this and I consider it’s only a matter of time before a rider is seriously injured or killed.In Germany's latest response they have now acknowledged that this event does occur and that its a result of the bike trying to maintain directional stability and detecting the rear wheel slowing more than the front."
So if I was applying rear brake (and I may well have done in the heat of the moment) and it locked up it looks like the ECU thinks I am sliding and releases the front brake too.
and in another forum, a rider had a similar situation to mine approaching a junction, which saw him sailing across the road with no brakes. A reply to his query was:
"I think the popular view is that it is not the ABS per se, but the fact that BMW uses the wheel rotation sensors to detect wheelies or stoppies and cuts off the braking to avoid these. It's using the ABS as a crude traction control system. When it does this you don't get the conventional pulsing - it seems to release all braking for about 0.5 seconds, which can mean quite some travel before the braking comes back on.
That would be fine, but apparently on S and ST models simply going over a bump can fool the system into thinking that you are in a wheelie or stoppie situation."
and...
"The F800 ABS should behave similar to car ABS one difference is the pulsing to the lever and peddle is reduced they just stay firm. The cycle time on the F800 ABS is much slower than you may have experienced.
For the vast majority of riders , most of the time the ABS will engage and pulse and then return normal braking all while the brakes are held on. Manually pumping ABS brakes defeats the whole purpose of the ABS operation.
However for a few rare riders under rare conditions the ABS seems to decide to release both front and rear brake for an extended time. A long enough time for the rider to release and re-apply the brakes to defeat the ABS blocking of the brakes.
BMW are aware of this and have been for a number of years now. They claim it's by design and ensures your safety as a rider as you maintain directional stability."
To be honest, i sounds like a s
t design decision by BMW.
It's prompted me to do some quick research, and I found this an an old riders forum...
"If you jump on the F800 forum you'll notice that,- when braking (and it doesn't have to be hard)- on a dry road- in a straight line- and you hit a small bump the size of a catseye or dip in the road of a similar depth- the bike will do what appears to be a release of all brakes for up to two car lengths while you still have the brake lever firmly held. Then it reapplies them again. There has been a crash as a result of this and I consider it’s only a matter of time before a rider is seriously injured or killed.In Germany's latest response they have now acknowledged that this event does occur and that its a result of the bike trying to maintain directional stability and detecting the rear wheel slowing more than the front."
So if I was applying rear brake (and I may well have done in the heat of the moment) and it locked up it looks like the ECU thinks I am sliding and releases the front brake too.
and in another forum, a rider had a similar situation to mine approaching a junction, which saw him sailing across the road with no brakes. A reply to his query was:
"I think the popular view is that it is not the ABS per se, but the fact that BMW uses the wheel rotation sensors to detect wheelies or stoppies and cuts off the braking to avoid these. It's using the ABS as a crude traction control system. When it does this you don't get the conventional pulsing - it seems to release all braking for about 0.5 seconds, which can mean quite some travel before the braking comes back on.
That would be fine, but apparently on S and ST models simply going over a bump can fool the system into thinking that you are in a wheelie or stoppie situation."
and...
"The F800 ABS should behave similar to car ABS one difference is the pulsing to the lever and peddle is reduced they just stay firm. The cycle time on the F800 ABS is much slower than you may have experienced.
For the vast majority of riders , most of the time the ABS will engage and pulse and then return normal braking all while the brakes are held on. Manually pumping ABS brakes defeats the whole purpose of the ABS operation.
However for a few rare riders under rare conditions the ABS seems to decide to release both front and rear brake for an extended time. A long enough time for the rider to release and re-apply the brakes to defeat the ABS blocking of the brakes.
BMW are aware of this and have been for a number of years now. They claim it's by design and ensures your safety as a rider as you maintain directional stability."
To be honest, i sounds like a s
t design decision by BMW.You got lucky.
There are so many electronic systems around now, ABS/cornering ABS/TC/WC/etc but nobody teaches you how to "use" them or what to expect from them.
There should be courses for this, maybe on a bike with support wheels, where you experience how these systems operate in reality.
There are so many electronic systems around now, ABS/cornering ABS/TC/WC/etc but nobody teaches you how to "use" them or what to expect from them.
There should be courses for this, maybe on a bike with support wheels, where you experience how these systems operate in reality.
ABS operation definitely sounds dodgy. I've had a couple of F800 loan bikes and have fired the ABS off on these and that was not what i experienced. My complaint on the F800 ABS is actually that it is a little "too smooth" in that you don't necessarily know it's fired other than the rate of deceleration being less than it was.
What is "comical" is the fact that you locked the front wheel on a bend, but blame the ABS for your accident. A locked front wheel on a bend without ABS is almost 100% guaranteed to result in an accident. The thread title would be better as, ABS nearly saved me!
What is "comical" is the fact that you locked the front wheel on a bend, but blame the ABS for your accident. A locked front wheel on a bend without ABS is almost 100% guaranteed to result in an accident. The thread title would be better as, ABS nearly saved me!
Ho Lee Kau said:
You got lucky.
There are so many electronic systems around now, ABS/cornering ABS/TC/WC/etc but nobody teaches you how to "use" them or what to expect from them.
There should be courses for this, maybe on a bike with support wheels, where you experience how these systems operate in reality.
Your bike! Empty road! Teach yourself!There are so many electronic systems around now, ABS/cornering ABS/TC/WC/etc but nobody teaches you how to "use" them or what to expect from them.
There should be courses for this, maybe on a bike with support wheels, where you experience how these systems operate in reality.
black-k1 said:
Ho Lee Kau said:
You got lucky.
There are so many electronic systems around now, ABS/cornering ABS/TC/WC/etc but nobody teaches you how to "use" them or what to expect from them.
There should be courses for this, maybe on a bike with support wheels, where you experience how these systems operate in reality.
Your bike! Empty road! Teach yourself!There are so many electronic systems around now, ABS/cornering ABS/TC/WC/etc but nobody teaches you how to "use" them or what to expect from them.
There should be courses for this, maybe on a bike with support wheels, where you experience how these systems operate in reality.
Ho Lee Kau said:
black-k1 said:
Ho Lee Kau said:
You got lucky.
There are so many electronic systems around now, ABS/cornering ABS/TC/WC/etc but nobody teaches you how to "use" them or what to expect from them.
There should be courses for this, maybe on a bike with support wheels, where you experience how these systems operate in reality.
Your bike! Empty road! Teach yourself!There are so many electronic systems around now, ABS/cornering ABS/TC/WC/etc but nobody teaches you how to "use" them or what to expect from them.
There should be courses for this, maybe on a bike with support wheels, where you experience how these systems operate in reality.
Training with stabilisers. Amazing.
Ho Lee Kau said:
black-k1 said:
Ho Lee Kau said:
You got lucky.
There are so many electronic systems around now, ABS/cornering ABS/TC/WC/etc but nobody teaches you how to "use" them or what to expect from them.
There should be courses for this, maybe on a bike with support wheels, where you experience how these systems operate in reality.
Your bike! Empty road! Teach yourself!There are so many electronic systems around now, ABS/cornering ABS/TC/WC/etc but nobody teaches you how to "use" them or what to expect from them.
There should be courses for this, maybe on a bike with support wheels, where you experience how these systems operate in reality.
The only experiences I've had of front ABS on my bike have never been great. Very similar to the OP - when the ABS kicks in, it's pretty much zero braking then it hammers back on when it decides - so may have avoided a skid but outs you uncontrollably on another part of the road before determining when to reapply the brakes and knocking the bike even further out of balance from where it was.
The same offroad - I loath it offroad - it's so unpredictable - whilst generally I avoid the front brake, there are times when you use it (steep downhill it can be helpful) but when it (predictably) slips, rather than me working out letting go or releasing, it applies ABS - zero braking for a period then it applies and compresses the front forks knocking you out of balance a bit, so you let them go, bike lurches forward where actually you'd be safe and wanting some front braking on... and so on.
Def not a fan of ABS - that said, I'm not knocking it - I'm pretty sure on tarmac and wet tarmac it may hold it's own and be needed so not itching to pull the fuse or anything.
The same offroad - I loath it offroad - it's so unpredictable - whilst generally I avoid the front brake, there are times when you use it (steep downhill it can be helpful) but when it (predictably) slips, rather than me working out letting go or releasing, it applies ABS - zero braking for a period then it applies and compresses the front forks knocking you out of balance a bit, so you let them go, bike lurches forward where actually you'd be safe and wanting some front braking on... and so on.
Def not a fan of ABS - that said, I'm not knocking it - I'm pretty sure on tarmac and wet tarmac it may hold it's own and be needed so not itching to pull the fuse or anything.
boyse7en said:
It's on a 2006 BMW F800S. Lever def comes back to the bar, and there's a long enough pause between it cutting the brakes and putting them on again to feel a rising panic.
I've no idea if it works properly or not. No warning lights (ABS light illuminates on startup and then goes off a second or two after moving). Brakes work fine on the road, and I'm not the sort of rider who regularly activates the ABS to know if it is any different from when the bike was new..
ah. The F800's ABS.I've no idea if it works properly or not. No warning lights (ABS light illuminates on startup and then goes off a second or two after moving). Brakes work fine on the road, and I'm not the sort of rider who regularly activates the ABS to know if it is any different from when the bike was new..
Of all the various BMWs and an ABS shod Honda VFR, only the F800 tried to maim me; when the ABS would cut in then unexpectedly release. Twice when coming to stop, the ABS released, whilst I'm still holding the brake lever and I carried further than expected towards traffic. I too had one of the first F800 bikes, I don't know whether the ABS has improved since.
However, I wasn't the only one who experienced this.
Part of it is down to the light weight of the bike, also if the rear wheel gains air the ABS will disenange. Then it turns out the ABS used in the F800 is a much cheaper version than used in the R1200s for instance and doesn't work as well.
I was very happy when the gearbox ( which is part of the engine ) broke at 25000 and I binned it off for a R1200GS.
black-k1 said:
What is "comical" is the fact that you locked the front wheel on a bend, but blame the ABS for your accident. A locked front wheel on a bend without ABS is almost 100% guaranteed to result in an accident. The thread title would be better as, ABS nearly saved me!
Well yes, maybe locking the front wheel would have caused the bike to wash out, but it would have been at 10mph, rather than 20yds further down the hill and at a faster speed. But having looked at the experiences of the F800 forum users, it looks like i didn't lock the front wheel anyway, it was probably the use of the rear brake that caused the ACS to disengage the brakes completely for around half a second. I can tell you that half a second of unrestrained freewheeling while gripping the brake lever feels like a long time!
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