—- as I get questions I am adding, editing and clarifying this post to keep the information in one place—-
This is my response to another thread.
I am posting here as its own subject for easier forum search purposes as this is the most definitive information on the subject that I have seen to date. Each system has advantages.
I’ll also add here that my opening line, if I re-edited the post would be, “I delinked to simplify the system”
I delinked my VFR to reduce potential problems, and because I had some braided lines laying around that happened to fit.
So when I bought the 2006 ST1300 I considered the idea until another 2006 ST1300 went up for sale as a result of damages caused by a smc failure. Then I thought let’s simplify this. Anyway I rode 9,000 miles linked. (Previously rode 15,000 ST1100ABS II)
I delinked the 06 this winter.
Front master cylinder connects to outer front pistons.
Rear mc operates three pistons in rear caliper, with new oil passage drilled from middle piston to passage between outer pistons.
Edit, Capped the brake line port to the rear caliper middle piston with appropriate size bolt and crush washer.
Capped the front middle pistons and drilled a vent hole through the bleeder to the outside to ensure no pressure build up from heat in middle piston. End edit.
Essentially the known formula for the Blackbird.
What I find riding is that
- the rear wheel takes more effort to lock up which I happen to appreciate.
- I use the rear brake lever more.
- The front brake lever by itself does not slow the bike down as quickly, presumably because the bike brake system is not activating the rear brake and subsequently the front inner pistons.
3a. Using the front and rear levers together stop the bike just as fast as linked.
- The front wheel can be locked up more or less the same as on similar bikes that I’ve owned like ST1100 or Concours 1000
- I kinda miss linked brakes for the last few feet of braking prior to a stop on pavement because I like the landing gear down on both sides while still having the advantage of front and rear brakes applied.
- I feel safer delinked on gravel coming to a stop where I make a point of using more rear brake bias.
I will test adding in one middle front piston hoping to get a lighter effort.
My ST1300 works fine with 4 but I am curious how 5 would feel.
Just my opinion, but I overcame the fear of delinking when I thought about the 70,000 miles I rode on standard ST1100s with no problems and a thorough study of the ST 1300 system and its comparison to the ST1100, ST1100ABSII, Blackbird and VFR.
Post note.
Remember, I did this to simplify things.
I had the 03 abs just about ready to ride last night when guess what?
The proportional control valve leaks out. Geez! Good thing I delinked the 06 and had a spare valve.
This is a thread where everyone is right.
So let’s keep the peace and saves the proxy wars for the oil thread.
Edit 6/8/20
I finally tied in a fifth piston by drilling a hole to intercept the passage between the outer pistons on one caliper and ran into the same problem that in had in a similar project with my VFR800. After a lot of head pounding it occurred to me that there could be air under the block off bolt that I used.
I cracked that bolt and sure enough a small amount of air came out. There was just enough air to make the lever just soft enough to confuse whether it was a master cylinder to slave cylinder ratio thing or air in the system. I should have stuck to the logic that the lever would move more until the pads hit. Beyond that, within reason, the lever has hit an unmoving wall regardless of ratios.
I had linked the three rear pistons by drilling internally. That brake felt OK. I cracked the bolt while a friend pumped the pedal. Now the rear brake feels excellent.
With 5 pistons working up front the lever travels a little further until the pads contact. Beyond that the lever feel is correct.
I can lay down rubber with two fingers. Not too easily, just right for me to be a definite two finger operation like my linked bike got me spoiled to.
