ANY ALTERATIONS TO ORIGINAL EQUIPMENT SYSTEMS MAY VOID WARRANTY AND POSE SERIOUS SAFETY RISKS OR DEATH. YOU ARE RESPONSIBLE FOR ANY AND ALL MODIFICATIONS PERFORMED ON YOUR VEHICLE.
Removing the BMW Integral ABS 1 system (iABS1-"ectomy") is fairly simple and can be inexpensively implemented. I've ridden many thousands of miles following iABS1 removal, without problem or complaint. Having owned and ridden a factory non-ABS R1150R Roadster for several years, I was already familiar with the performance of the non-anti-lock brakes, and very satisfied with BMW's Evo braking system (calipers, brake discs, and master cylinders). Converting 2004 iABS1 Rockster to non-ABS has simplified maintenance and potentially enhanced long-term reliability.
Owners of R1150R, R1150RT, R1150GS, and R1100S bikes have completed the iABS1 removal process and report good results. The iABS1 bikes include R1150** variants, along with some early K1200 bikes and even a few R1200 hexheads. Sometime in 2006 the BMW Integral ABS 2 system (iABS2) was introduced, with a simpler non-servo system (no "power brakes" effect), lower unit replacement cost, lighter weight, and improved performance per BMW literature:
It's easy to appreciate the utility and wisdom of ABS on streetbikes. There are many anecdotes here on the Roadster board and elsewhere describing how the BMW iABS system saved equipment and lives. But after riding my iABS1-equipped Rockster, I quickly grew to dislike and distrust the iABS1 power brakes implementation. Even more so, the possibility of iABS unit failure and US$2500 cost of replacement (2008 cost) prompted the idea of "ABS-ectomy" for my Rockster, and I took the plunge in 2008 after the bike's warranty had expired.
My local BMW Motorrad dealer had this OE parts assortment displayed near the service desk for many years. There was good reason they chose to include the iABS1 servo modulator... a mission critical module for sale as replacement part, only $2600+. The sad fact of too frequent iABS1 system failure - plus power brakes lacking any "feel" - prompted my proactive ABS-ectomy project. Note also the F800 fuel pump assembly... another infamous BMW quality failure.
Purchased for Rockster conversion:
1. non-ABS front brake circuit "Y-connector"
2. new banjo bolts
3. new crush washers
4. bleed screws & caps
5. non-ABS rear brake line
*Linked photobucket album instead of posting all the pics here on Roadster board in order to keep downloads manageable.
Please note that for Rockster conversion, only the y-piece, one banjo bolt, a few crush washers, and a bleeder+cap were actually required to complete the non-ABS plumbing. The original ABS-spec rear brake line works just fine on the Rockster, and I could have saved US$60+ for a new brake line. Banjo bolt was required because I stripped out original during removal. Bleeder was required because I decided to change out the OE pressure bleeder fitting.
1. Remove seat and fuel tank, disconnect the battery
FYI - YouTube vid that shows tank removal in case you've never done so before:
Please be careful with fuel line quick-connects (QCs) if your bike is so equipped. On day of my ABS-ectomy, one of my plastic male QCs failed to release, broke in half, causing fuel spill:
With tank off you can look at iABS1 system and reconsider the value of ABS... is it worth $2500 to you for failed unit replacement? Answer might be yes or no.
2. Drain all the brake fluid
While you cannot easily drain the fluid inside the iABS1 module nor the steel lines running to front/rear brakes, you should definitely drain as much fluid as possible from master cylinders and connection hoses. Remember that brake fluid is nasty stuff.
3. Remove iABS1 module (did you disconnect the battery?)
Start by disconnecting steel brake lines. Pull cap off connector:
Pull out retainer clip in connector:
The steel lines will now pull up & out of the connectors. Be ready to catch brake fluid drips.
Disconnect iABS1 fluid lever sensor wires:
Disconnect iABS1 wiring harness and giant proprietary AMP plug:
Remove three (3) bolts that attach iABS1 module mount bracket to battery tray:
There are two fasteners on right side, and one on left side.
The iABS1 module can now be removed.
4. Install new plumbing hardware - front brake circuit
Disconnect brake lines at original ABS distribution piece located at right side of front subframe. I don't have a pic of this, but you're probably staring at it now if your fuel tank has been removed.
Rebuild front brake circuit using the new y-piece:
Note that bike's wiring bundle rests on top of the bleed screw installed at top of y-piece. I added some protective tape around the wiring to prevent wiring damage. If desired, you could retain the original pressure-bleed fitting (with internal grub screw) and install at the top location of y-piece.
Check all plumbing connections, add brake fluid, and bleed front brakes. The R1150** front brake circuit is a pain to bleed. Use favorite technique/bleeder and you will eventually get solid lever feel.
5. Install new plumbing hardware - rear brake circuit
Actually, there's no new hardware aside from new crush washer, as long as you retain original rear brake line and avoid stripping out the banjo bolt. I can only confirm re-use of the R1150R's original ABS-spec rear brake line for non-ABS conversion; if you have a different R1150**, R1100S, or K-bike, then check the available length of the ABS-spec rear brake line.
See photobucket notes for each of the following rear brake circuit pics:
Check all plumbing connections, add brake fluid, and bleed rear brake.
6. End of plumbing changes. Celebrate responsibly.
The iABS1 controller manages the brake lever + pedal switch circuits, along with the brake lamp and tail lamp. The controller also connects to the two ABS warning lamps (triangle "!", and "ABS"), with the latter operated via a normally-closed (NC) relay in the fusebox. For some bike applications (R1100S, Rockster, maybe some K-bikes), the iABS1 module also converts the rear wheel speed ABS sensor signal into a signal that drives the speedometer/odometer. When you remove the iABS1 module, you need to address the circuit requirements by either retaining the iABS1 controller board, or creating needed circuit support.
Your options for ABS-ectomy electrical work depend on year/model of bike, status of your old iABS1 module, and comfort level with electrics.
Option A - retain the iABS1 controller board.
This is the simplest option if your iABS1 module is hydraulically kaputt but electrically functional. All that's required is a module hack like this guy did:
Aside from dissecting the iABS module and sealing up the ABS controller box, all you need to do is pull the "ABS" lamp relay and defeat the "!" warning lamp (remove bulb).
Option B - build necessary circuits.
If your iABS1 controller circuit is fried, or if you decide to remove a serviceable module and sell it for beer money, then add-on circuitry is needed to replace the iABS1 controller's electrical functions.
Here's how the electrical part of the iABS1 removal varies according to bike:
R1150R Roadster, R1150GS, R1150RT, some others
These bikes use conventional speedometer drive on front wheel, so all you have worry about is the brake switch/lamp connections. Other intrepid iABS1-ectomizers have purchased BMW front/rear non-ABS-spec OE switches for their projects, but being a cheap a$$, I decided to keep the original ABS-spec switches and came up an idea for using a conventional 5-pin automotive relay to connect switches with brake lamp... the circuit is described later in this topic thread. "Works a treat" as the Brits say. The brake switch issue arises because ABS and non-ABS switches work in opposite fashion: non-ABS switches are normally-open (NO) circuits, while the ABS switches are normally-closed (conducting, NC) in order to provide the iABS1 controller a means to check each switch circuit via continuity during startup.
Here's the conventional brake switch setup:
And here's how I was able to reuse the iABS1 brake switches following ABS-ectomy:
For the wire and relay pin assignments, please check out my later posts within this thread.
R1100S, Rockster, some K-bikes
These models require new brake switch/lamp circuits AND some means of generating a speedometer signal. In another thread I'll cover modifications to make your speedo go.
PM me if you have questions.
The balance of this thread contains ramblings collected as project originally unfolded, plus updates as appropriate.