Linked Brakes Open Discussion-Thoughts

[RonBB]

I totaled my 05ABS in October. I am now sufficiently recovered and have started looking for a replacement. I got to thinking about the differences in the Gen 1 & Gen 2 FJR's. The linked brakes caught my thoughts and got me to wondering; Why do different Manufacturers set them(the linking) up differently? Generally the physics should be the same, i.e. two wheels. I guess I am a bit concerned about getting into a slick curve a bit too fast and trail braking and having the front wheel slide out due to the brake linking which I would think could result in a low-side. Perhaps this is an unfounded fear. Are the superbikes and supersport bikes brakes linked? Not really trying to start a linked Vs. non-linked argument but just looking for everyone's thoughts. Ron

 

[otrfjr]

I did a search but failed to turn up what I was looking for. IIRC, someone somewhere mentioned at what psi the linking begins on the FJR. You have some play on the rear brake before the front calipers come into play, so it doesn't happen immediately. I haven't had any problems with low-speed maneuvering using the rear brake. At speed I'm guessing that you would have to really get on the back brake before something "bad" happened up front since only part of the calipers are applying pressure. And if you're braking that hard in a turn, I hope you're on the track.

 

[Warchild]

I guess I am a bit concerned about getting into a slick curve a bit too fast and trail braking and having the front wheel slide out due to the brake linking which I would think could result in a low-side. Perhaps this is an unfounded fear. Are the superbikes and supersport bikes brakes linked?

One of the the aspects of the FJR linked brakes that is a touch misleading is that they are not really "linked" in the way most modern LBS systems are linked. Only when you use the rear brake does the other wheel also engage its brake (though it's only two of the eight front brake pistons that activate). In most Linked Brake Systems, activating one brake will also engage a little braking action on the other. Not the case if using the FJR's front brake only.... nothing is activated on the rear brake when that is done.

Re: your concern of a low-side. I don't think I would (personally) be as concerned about the scenario you describe as much as I would be concerned about other scenarios where you want absolutely no front brake action: when you find yourself needing to turn on a fairly steep incline and there is: i) potential icy conditions, ii) small pea-gravel, or iii) riding over damp, slippery leaves, etc. Any front braking under those conditions could mean an instant lay-down as your front wheel washes out beneath you. If you need to control your speed under these conditions, you want to use your rear brake only..... which might be an issue on the Gen II bike.

Re: superbikes and supersports: none of these bikes have Linked Brakes, and likely never will.

I don't want to give the impression I am against LBS; I don't mind it if it is as refined as that found on the Honda CBR1100XX. At least, LBS hasn't been a problem for me the last 100,000 miles on the Blackbird. But then, it is in it's 3rd generation of development, and really seems to work quite well and in an unobtrusive manner.....

 

[RonBB]

i) potential icy conditions, ii) small pea-gravel, or iii) riding over damp, slippery leaves, etc. Any front braking under those conditions could mean an instant lay-down as your front wheel washes out beneath you

This was exactly my concern. Thanks much for your thoughts.

 

[charismaticmegafauna]

<snip>...other scenarios where you want absolutely no front brake action: when you find yourself needing to turn on a fairly steep incline and there is: i) potential icy conditions, ii) small pea-gravel, or iii) riding over damp, slippery leaves, etc. Any front braking under those conditions could mean an instant lay-down as your front wheel washes out beneath you.

Isn't that what the ABS is there for? Tire wants to skid -- but, ABS computer won't let it....? :huh:

Everybody's happy...... :blink:

 

[Mike-H]

The only downside I can see with linked brakes & or abs systems, is the rider tends to dull & lose his or her skill sets because the machine now does it for you....the problem with that is if the person steps up or changes (whatever) to a true performance machine, they could be in for a rude (& possibly life changing) awakening....(the same can be found with cages)....(I have personally worked a very long time to reach the level I have attended & don't want to sacrifice that)....though it would be nice if you could turn the systems on & off.... :huh: .....

 

[teerex51]

The only downside I can see with linked brakes & or abs systems, is the rider tends to dull & lose his or her skill sets because the machine now does it for you....the problem with that is if the person steps up or changes (whatever) to a true performance machine, they could be in for a rude (& possibly life changing) awakening....(the same can be found with cages)....(I have personally worked a very long time to reach the level I have attended & don't want to sacrifice that)....though it would be nice if you could turn the systems on & off.... :huh: .....

Mike, I just test-rode two different 2007s (one was the ES) and tried their brakes. As far as I'm concerned the jury's still out on the linked brakes.

They're way more gradual than the Beemer ones but, creature of habit that I am, I prefer my own Jurassic Euro-2003 FJR.

With progressive fork springs and a bit of preload, my front-end dive is very acceptable while my "Zcoo" (zee-coo) pads allow me to stop on a dime... B)

At least that's what I think. YMMV. I'm certain that someone can prove that stopping distance with the new system actually decreases.

As for the "skill set" you mention, that's absolutely my opinion, too.

Last year I swapped bikes with a friend who rides an MT-01.

I nearly wrecked it that time. When I got a little carried away straddling that fun thing I plain forgot there's no ABS on that puppy and I was suddenly sideways to the direction of travel...

Relying on good old ABS for years had dulled my senses. A rude awakening indeed... :blink:

Stef

 

[FJRottie]

Isn't that what the ABS is there for? Tire wants to skid -- but, ABS computer won't let it....?

Not on very slippery surfaces. The slight grabbing of brake will make the wheel slide on ice for example before the ABS kicks in. The slowing down of the wheel at a faster rate than momentum slowing on very slippery surfaces is a slip, and a possible sliding of the the wheel. Would not be good on the front wheel of a motorcycle during a turn.

The Gen II FJRs....????...as said above, only two of the front pistons activate with the rear brake.

 

[charismaticmegafauna]

Isn't that what the ABS is there for? Tire wants to skid -- but, ABS computer won't let it....?

Not on very slippery surfaces. The slight grabbing of brake will make the wheel slide on ice for example before the ABS kicks in. The slowing down of the wheel at a faster rate than momentum slowing on very slippery surfaces is a slip, and a possible sliding of the the wheel. Would not be good on the front wheel of a motorcycle during a turn.

The Gen II FJRs....????...as said above, only two of the front pistons activate with the rear brake.

Say what? The ABS doesn't operate on slippery surfaces? Flesh this out for me....okay? Does the ABS computer have some sort of (built-in) model that determines how much slip is too much -- or not enough?

 

[FJRottie]

[SIZE=8pt][/SIZE]

Say what? The ABS doesn't operate on slippery surfaces? Flesh this out for me....okay?

No problem.

As I said,

The slight grabbing of brake will make the wheel slide on ice for example before the ABS kicks in.

Note the word "before".

ABS (Anti-Lock) is not instantaneous. You need a lot of braking force/pressure before it kicks in.

Slight braking does not engage ABS. When the wheel is about to lock, it activates.

Here is a snippet of info about ABS in general,

Anti-lock Brake System (ABS) operates as follows: [SIZE=8pt]When the brakes are applied, fluid is forced from the brake master cylinder outlet ports to the HCU inlet ports. This pressure is transmitted through four normally open solenoid valves contained inside the HCU, then through the outlet ports of the HCU to each wheel. [/SIZE]
[SIZE=8pt][/SIZE]

[SIZE=8pt]The primary (rear) circuit of the brake master cylinder feeds the front brakes. [/SIZE]
[SIZE=8pt][/SIZE]

[SIZE=8pt]The secondary (front) circuit of the brake master cylinder feeds the rear brakes. [/SIZE]
[SIZE=8pt][/SIZE]

[SIZE=8pt]If the anti-lock brake control module senses a wheel is about to lock, based on anti-lock brake sensor data, it closes the normally open solenoid valve for that circuit. This prevents any more fluid from entering that circuit. [/SIZE]
[SIZE=8pt][/SIZE]

[SIZE=8pt]The anti-lock brake control module then looks at the anti-lock brake sensor signal from the affected wheel again. [/SIZE]
[SIZE=8pt][/SIZE]

[SIZE=8pt]If that wheel is still decelerating, it opens the solenoid valve for that circuit. [/SIZE]
[SIZE=8pt][/SIZE]

[SIZE=8pt]Once the affected wheel comes back up to speed, the anti-lock brake control module returns the solenoid valves to their normal condition allowing fluid flow to the affected brake. [/SIZE][SIZE=8pt][/SIZE][SIZE=8pt]The anti-lock brake control module monitors the electromechanical components of the system. [/SIZE]
[SIZE=8pt][/SIZE]

[SIZE=8pt]Malfunction of the anti-lock brake system will cause the anti-lock brake control module to shut off or inhibit the system. However, normal power-assisted braking remains. [/SIZE]
[SIZE=8pt][/SIZE]

Loss of hydraulic fluid in the brake master cylinder will disable the anti-lock system. [SIZE=8pt][/SIZE]

And again, as I said,

The slowing down of the wheel at a faster rate than momentum slowing on very slippery surfaces is a slip, and a possible sliding of the the wheel. Would not be good on the front wheel of a motorcycle during a turn.

[SIZE=8pt]A general statement..that it is possible to wash out on very slippery surfaces with slight front braking.[/SIZE]

It does not take away the make up or function of ABS or the Gen II FJRs.[SIZE=8pt][/SIZE]

 

[charismaticmegafauna]

Thanks FJRottie -- educational. Sounds like while there may be some lunches better than other lunches -- there ain't no free lunch. :blink: B)

Braking your modern motorcycle is still in your hands -- literally.

 

[Mike-H]

Thanks FJRottie -- educational. Sounds like while there may be some lunches better than other lunches -- there ain't no free lunch. :blink: B) Braking your modern motorcycle is still in your hands -- literally.

Only literally "IF" you don't have abs or linked braking, otherwise it is in the computers hands (so to speak).... ....