Upgrading ABSI to ABSII on 2000 R1150gs

[The Fabricator]

I posted a year ago about 'testing' my ABS performance on gravel.  Specifically, I applied the front brake at about 5 mph until wheel lock up...which it did and I went down.  The comments I got was to the effect that 'that's the way the early ABS was',  meaning not too responsive. I know an  owner of a 1200GS who just holds the brakes on maximum [on gravel] until the bike comes to a complete stop [rubber down].  I don't know, but I assume the  ABSII system on later R1150GS models are more responsive, meaning it will prevent wheel lock up on gravel until a complete stop.  Is it more responsive?  Has anybody used their ABS II [as I have described] with out incident?

 

I have looked at pictures on ABS I & II modules on ebay, and see they are roughly the same size.  The electrical connector is different.  Pipe locations are different.  It looks like the ABS module has its' own electronics [meaning independent of the Motronic engine control unit].  Assuming I could over come the logistics of mounting, plumbing, and wiring, would it work? Would I need to swap wheel sensors also?

[dirtrider]

17 hours ago, The Fabricator said:

I posted a year ago about 'testing' my ABS performance on gravel.  Specifically, I applied the front brake at about 5 mph until wheel lock up...which it did and I went down.  The comments I got was to the effect that 'that's the way the early ABS was',  meaning not too responsive. I know an  owner of a 1200GS who just holds the brakes on maximum [on gravel] until the bike comes to a complete stop [rubber down].  I don't know, but I assume the  ABSII system on later R1150GS models are more responsive, meaning it will prevent wheel lock up on gravel until a complete stop.  Is it more responsive?  Has anybody used their ABS II [as I have described] with out incident?

 

I have looked at pictures on ABS I & II modules on ebay, and see they are roughly the same size.  The electrical connector is different.  Pipe locations are different.  It looks like the ABS module has its' own electronics [meaning independent of the Motronic engine control unit].  Assuming I could over come the logistics of mounting, plumbing, and wiring, would it work? Would I need to swap wheel sensors also?

 

Evening Fabricator

 

Due to the hydro pumps on the 1150 I-ABS  system the recovery rate is very responsive, WAY more responsive than on the 1100 ABS II  (piston) system.

 

Making the conversion would not be impossible but more complicated than one would think as not only would the ABS module & master cylinders need to be replaced (plus all the wiring involved) but also the brake calipers & the wheel speed sensors & wheel tone rings, & even the brake light switch's as as they work reverse function on the1150 I-ABS system.

 

Your 1100 ABS II system is sort of usable but you need to use the correct-friction-material brake pads on both front & rear as well as use the rear brake in conjunction with the front as that has input on the front releasing earlier.

 

Also, you need to be careful at testing the ABS II system at 5 mph as that is mighty close to the low speed ABS cut off speed, especially if only using the front brake. The ABS can not function all the way until fully stopped as if it did you could never bring the motorcycle to a full stop.

 

Another thing to look at is that the front calipers DO release the brake pads smoothly & quickly, if they hang up (even a little) then that can slow the release response enough to prevent wheel re-spool-up after a start of wheel slide. 

 

The 1100ABS II is a bit slow & kind of un-responsive but does work OK on a moderate to high friction surface like pavement & hard pack dirt (ie clay) but is not the best for loose substrate (like loose gravel or especially bad on wet leaves or ice).

 

The 1100 ABS II system is livable as it buys you enough time under panic braking to have a second to think about the brake apply & regain proper braking control. It's not a crutch but a helper.

 

The 1150 I-ABS system has it's own drawbacks as it is really aggressive on wet grass/wet leaves  at low speeds plus that system doesn't have accumulators so if (more like when) it  quits working you do not have a lot of usable residual braking force. (you kind or trade off better/faster ABS  function for a more difficult to modulate conventional braking with almost no residual braking if/when the system fails just as you apply it.  

 

My 1200 1200RT (I-ABS gen 2) with street tires  is pretty good on dirt & decent on gravel (I could force it to lock a front on gravel at low speeds if I tried hard enough). But my 1200GS-A is a lot better on loose gravel as the  tires are knobies so they do a LOT better at stopping on loose substrate surfaces. (but I seldom leave the ABS  functional on dirt & gravel,  (I turn it off) as ABS on loose dirt & gravel REALLY adds to stopping distance as I lose the buildup/pileup of material in front of the tire when stopping hard on gravel as  well as lose my ability to steer using the rear brake.   

 

One of the big gains in the later 1150 BMW I-ABS & 1200 I-ABS gen2 systems is  they both include the rear brake in the front lever (only) apply as well as front/rear automatic  proportioning so even using 'only' the front brake lever you aren't asking the front wheel to do all the work.

 

 

[Paul De]

A curious question.  If I read your post correctly, you forced a lock up on your front brake on gravel and washed out the front end.  Are you saying the locked the brake didn't release fast enough, or you simply held the brake to the point of crashing?  Was this replicating a real world riding event?

 

If this test isn't a real world situation where you might modulate the brake with the biggest computer on the bike then it seems to be a big lot of work to get a performance result that is typically never realized in normal off road riding. 

 

 

[The Fabricator]

6 hours ago, Paul De said:

A curious question.  If I read your post correctly, you forced a lock up on your front brake on gravel and washed out the front end.  Are you saying the locked the brake didn't release fast enough, or you simply held the brake to the point of crashing?  Was this replicating a real world riding event?

 

If this test isn't a real world situation where you might modulate the brake with the biggest computer on the bike then it seems to be a big lot of work to get a performance result that is typically never realized in normal off road riding. 

 

 

I didn't 'force a lock up'; rather I locked up the wheel by applying too much brake for the condition.  Imagine 'panic stop'.  A 'panic stop'  is a 'real world riding event'.  I  suppose it could be said I simulated abnormal off road riding. If the feature exists that will meet those requirements, I want it.