Spec help please: ABS - Servo assisted?

[Oil_cooled]

Hi
I am tentatively looking at r1100s's and have seen one close-ish to me for sale. I have been put off other BMW models by the servo assisted brakes after a certain year, which seem somewhat less than reliable and very costly when they do go wrong. The bike is a 2001 model on a Y plate. Could this be servoed and how could I tell when viewing?

Many thanks

[bikesnbones]

The servo's at a standstill with the ignition on will make a whining noise when you apply the brakes.
I'd personally steer well clear of servo assist.
BMW say if it goes wrong, the bike will revert to "residual" braking.
They claim that it is still safe, but it happened to me on an R1200CL and it was truly terrifying.
To get an idea, run your car down a steep hill, then turn off the ignition and attempt to stop quickly.
Oh yes, and a lot of people disconnect and bypass the system when it goes wrong, to avoid a big bill.
Problem is that insurance company's then class your brakes as defective.
It's the same as abs.
If it's fitted by the manufacturer, it has to be working.
Chances are they'd never know, but it is still a risk.

[conkerman]

On a 12 year old bike. Avoid unless you can fix or get cheap.

[ned1]

I had a 2003 with servo assist for about four years which I fitted new hoses and bled
the system without any problems, but on saying that if I got another R1100S I would
also steer clear of ones fitted with ABS. Just in case

Ned

[Oil_cooled]

Many thanks for the prompt replies, and especially the offer of help with viewing. I may try to get up there today for a first look and will try to assess the brake situation. We'll see where we go from there - I'll post back.

Thanks again

[metropolis2k]

According to the information here it could be either.
"ABS2 was used until: Feb '01 on R1100S... Later bikes have iABS"

As far as I'm aware the brake calipers and ABS rings are different - realoem.com might help you spot the different cosmetically but as others have said, listen for that whining of the brakes when you apply them. If in doubt the owners manual (if present) should state and otherwise putting the VIN through here may also tell you.

[Phil Thomas]

Servos....best avoided. I could not hold my 1150RS on my drive without the ignition switched. Residual braking! absolutely terrifying. I,m about to sell my 1999 1100S...non ABS.

Regards to all,

[DaveH]

No offence meant to anyone,but there's so much crap spouted about the servo assisted brakes.

Fact - the servo brakes were an overly complicated solution to a problem that didn't exist.

Fact. - they go wrong with remarkable frequency.

Fact - BMW have never acknowledged that there was ever a problem with the system despite hundreds of failures.

Fact - they are bl**dy excellent when they are working correctly.

Fiction - the residual braking is dangerous. Absolute cobblers. If the system fails during a ride it can catch you out because you won't be expecting the EXTRA effort required to haul the bike up. The amount of braking retardation remains EXACTLY The same,you just need a lot more effort.
Consider this - mot testers have to test the brakes for efficiency during a brake roller test. This has to be done with the ignition OFF so the antilock does not activate. A servo bike will EASILY pass the mot without the servo operating.

My abs failed on day 2 of a 10 day France tour. Despite initial trepidation because of all the hype on the subject, I carried on and by the end of the holiday,didn't even think about the lack of a servo once I had recalibrated my brain. The major inconvenience was lack of a rear brake light.

Bottom line- I was pi**ed at spending over £800 for an optional extra on a new bike that failed after a few years. Ten years on, would it stop me from buying a bike with servo brakes - probably not, but I wouldn't pay any extra for em despite the fact that the system can be easily and cheaply removed WHEN they do go wrong.

Full write up on my website.

[bikesnbones]

Fiction - the residual braking is dangerous. Absolute cobblers.

Sorry but I beg to differ.
When mine went on my R1200CL in Germany, fully loaded with luggage with Wife on the back.
I was only doing 40mph, and with the lever pulled right into the handlebar till it stopped, the bike just didn't stop.
I thought I was going to have to lay it down before the junction,
You can argue till you're blue in the face that I'm wrong, but it was me on the bike that day and it was so scary it took at least 2 years off me.
Truely terrifying.

[Phil Thomas]

It's a "fail unsafe" system...simple as that. Even when working properly there is absolutely no feel to the brakes, so feathering the brakes on with any subtly is virtually impossible.

Regards to all,

[cros]

Fiction - the residual braking is dangerous. Absolute cobblers.

Sorry but I beg to differ.
When mine went on my R1200CL in Germany, fully loaded with luggage with Wife on the back.
I was only doing 40mph, and with the lever pulled right into the handlebar till it stopped, the bike just didn't stop.
I thought I was going to have to lay it down before the junction,
You can argue till you're blue in the face that I'm wrong, but it was me on the bike that day and it was so scary it took at least 2 years off me.
Truely terrifying.

On two 1150rt`s I have owned i have never had any problem with the servo assistance on them, also the ABS but only for the reason that it did work it became a danger within itself.

An incident’s of the ABS not working as it’s purpose several times before I realised what was happening.

After several thousands of miles travelling on a trip, I would say a rider would become more complacent to there riding abilities and take risks unknown to themselves. The weather was dry and I was approaching a roundabout on a decline at a reasonable speed but not enough that I could not control the bike, While applying the brakes before the broken lines in front of me the bike continued with no brakes then what seemed instantly the brakes applied.

I was turning into the transport cafe at Retford roundabout at the time (roundabout not there now,A1 goes straight through) so I walked back to the roundabout to have a look, there was no diesel spills only the surface of the tarmac was in a rippled wave form and a few holes before the white broken lines, this I assumed would be by heavy traffic slowing down or coming to a halt and pushing the tarmac in warm weather.

I then realised what had happened! My bike had become airborne on the rippled, wave form road, the ABS did its job but at the wrong time when I need it and because I was to complacent from all the miles I had just covered on the continent (3950 mile trip) I was going too fast for the unknown.

The ABS did its job correctly but was it at the correct time! There is a bulletin sent out by BMW about the problem as I received one about 2008/9, five years later than my experience.

It sounds like bikesnbones had the same experience.

[DaveH]

Fiction - the residual braking is dangerous. Absolute cobblers.

Sorry but I beg to differ.
When mine went on my R1200CL in Germany, fully loaded with luggage with Wife on the back.
I was only doing 40mph, and with the lever pulled right into the handlebar till it stopped, the bike just didn't stop.
I thought I was going to have to lay it down before the junction,
You can argue till you're blue in the face that I'm wrong, but it was me on the bike that day and it was so scary it took at least 2 years off me.
Truely terrifying.

Isn't that what I said?
It WILL. catch you out if you are riding the bike when it fails. It's a bit like power steering going on a car, you can still turn but it's heavy.
I found that the initial 'take up' in the accumulator with the servo not working was the bit that can catch you out as under normal riding conditions you only have to feather the brakes to stop the bike. Suddenly they need full travel and a hefty pull. My bet is you normally ride with the lever set somewhere in the mid range rather than on full span.
I was fortunate as mine failed at the first start up of the morning. No K line signal on the diagnostics either from the engine or abs ecu. Removed the abs as soon as I got home.
I managed 2.5k of 'spirited riding on the residual braking and it was fine once I knew what to expect.
I suppose it may cause problems to anyone with anything less than a strong grip and/or levers set at less than maximum span.
Good news is the bikes are no worse in the braking department once the system is removed. You actually get some feel back into the brakes.

[timbox2]

Hi
I am tentatively looking at r1100s's and have seen one close-ish to me for sale. I have been put off other BMW models by the servo assisted brakes after a certain year, which seem somewhat less than reliable and very costly when they do go wrong. The bike is a 2001 model on a Y plate. Could this be servoed and how could I tell when viewing?

Many thanks

Firstly has it got ABS? You can tell that by an ABS ring on the front wheel, then, if the Calipers have "Brembo" on the outside its early ABSII if they say "BMW" its I ABS with servo assistance, simples.

[bikesnbones]

Fiction - the residual braking is dangerous.

It WILL. catch you out if you are riding the bike when it fails.

I would suggest that something that can "catch you out" is potentially dangerous, and not "fiction" as you suggest.

[Bikerhoss]

Spookily enough, and in time to add a comment to this thread, my mate who bought an old RT to commute on has just de-ABS'd his after the servo failed, He was fed up of dangerous low efficiency on the brakes and is now delighted with the 'normal' system.

He's been riding for over 30 odd years and knows his stuff, and I know he's not someone to ride on his brakes, in fact he hardly ever needs them but still thought the residual system was crap.