Front brake circuit ABS

[rbt1548]

Hello all,
I am new to the forum but have had a number of BMW's over the years my first a new R80/7 back in 1978, I have also had a R100RS, R1150R, R1150RS, and a R1200ST as well as a number of other bikes. I have just bought a Edition 80 Rockster which will sit nicely alongside my Norton Commando and my BSA A65 Lightning Clubman.
The previous owner had done a few mods to the bike to make it to her liking and comfort, one was, she had fitted a pair of bar risers and a set of higher bars to give a more upright riding position, in doing this the control and brake cables were lengthened, luckily the original cables, bars, and hose are coming with the bike, it is my intention to revert to the standard bars, therefore replacing the bar reservoir to abs reservoir hose with the shorter one, this is where my question comes in.
Although I have made up brakelines before and bled brakes it is my first time bleeding an ABS system, I have read the articles on bleeding the front system but would like to know, will I have to bleed the whole system, "front wheel calipers and control circuit" or just the "front bar to reservoir circuit" using the 3 bleed screws on the ABS unit ? Also if I have to do the whole lot, is the sequence, calipers first then bar reservoir?
Thanks
Robert

[sweatmark]

You might not need to replace that section of brakeline, if reverting to OE handlebar setup doesn't introduce excessive slack in the brakeline or cause interference problems as bars are moved side to side. I added a 1" riser to my Edn.80 and lost a bit of brakeline slack, but have had no problems following the change.

Should it be necessary to go back to the original brakeline piece, you should not need to bleed anything besides the circuit from iABS servo module up to the front brake master cylinder.

The balance of the front brake circuit, from iABS module to front calipers, will not be affected.

The rear brake circuit is physically separate and will not be impacted by any front circuit changes. Interaction between the front and rear brakes' operation is controlled by the iABS circuit board rather than physical/hydraulic interconnection.

Lastly, should the iABS cause you difficulties down the road, please note that it's a simple process to remove the iABS system and convert bike to conventional braking. That's what I've done, with good results.