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Both Honda scooters I have owned including my current SH300i has linked brakes. I really like them for slow speed braking on automatic scooters. Would it simply be a matter of plumbing to convert my Exec to a linked system? Could, say,the left front caliper be plumbed into the rear hydraulics or would you need to use a pair of 3-piston calipers with just the centre piston being linked into the rears? With the ABS which is fitted to the Exec, would it be impossible to 'overbrake' and lock the front? Could some parts from the linked system that was fitted to the 400 be useable? Has anyone tried this on a 650?
 

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Problem is if you link the rear to a front you could still get lockup since the ABS won't know the mod you did.
 

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you will need an intelligent piece of softare that will control and manage the brake system and how the pistons engage on both the front and rear and vice versa...

I wasn't a big fan of LBS when Honda first introduced it on their bikes, but it kind of grew on me... I like bikes that have a disable option for when you don't want it to be active, especially on dual purpose bikes.
 

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I just tend to think it would be overly complicated for a ABS system. If you didn't have ABS and you could find a proportioning valve (ideally load controlled) for the rear and a matched single master cylinder you might be able to make a setup that would work. Anything you do to the rear is going to affect the front and a brake master has to match the calipers for volume and surface area.
 

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I suppose if you had the correct size masters you could plumb them to both front/rear inputs to the HCU with a check valve so one doesn't bleed out the other.
 

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An intriguing and theoretically possible proposition but I am afraid you would spend an inordinate amount of time and money on this for iffy outcomes.
 

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LeDude said:
you will need an intelligent piece of softare that will control and manage the brake system and how the pistons engage on both the front and rear and vice versa...
Brains work pretty well.

Chris
 

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Daboo said:
Brains work pretty well.
As long as you don't get Abby Normal's. :D
 

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On the pre-'07 400 this was accomplished by having the rear master cylinder feed what Suzuki calls a Delay Valve, which I found to be a spring loaded spool valve. The valve permits initial pressure to pass to the rear caliper only, and then as the pressure builds and overcome's the valve's spring the spool shifts, and pressure is applied to both the rear and the front caliper's "linked" piston.

The front caliper has two pistons, isolated hydraulically, with the topmost piston connected to the front master cylinder and the bottom pressurised by the rear master via the delay valve. The front's top and bottom pads are identical, however the bottom ("linked") piston is much smaller diameter than the top "front brake" piston--22.6 mm vs. 34.0 mm, only 44% of the dedicated front piston's area.

At the rear the hydraulically activated piston is 25.3 mm, so once both the front and rear linked pistons are pressurised the front clamping force is 80% of the rear's. However as the front rotor has a 230 mm working diameter versus the back's 150 mm, this works out to about a +22% front bias. Along with the front and rear tire diameter differences (the front is 3% larger) this makes the front/rear braking ratio approximately 55/45. With application of the front delayed by the spring-loaded valve.

I am 100% neutral as to the linked braking system's performance, as I do not see that it has any profound positive or negative characteristics--it just is what it is...
 

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cliffyk said:
I am 100% neutral as to the linked braking system's performance, as I do not see that it has any profound positive or negative characteristics--it just is what it is...
I have read articles/papers from multiple sources that state linked brakes were created to mitigate a lack of temerity when applying the front brakes.

Basically, linked brakes were created for those folks who foolishly use the rear brake exclusively - or near exclusively.

I modulate braking force and it's distribution when braking nearly every time I use the brakes. I wouldn't want a near perfect 80/20 every time.

Bike brakes work independently for a reason.
 

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I have seen that 80/20 ratio put forth previously, however in practice on my K3 400 it never felt even close to that--that's why I did the analysis and found It is more like a 55/45 front/rear split; which much better fits my impression of it's performance.

That said, I agree with you as to the need for linked braking, all one has to do is learn how to drive and brake safely and you don't need linked braking or ABS. Having ridden bikes for over 50 years, braking under all sorts of roadway and driving situations is something I barely have to think about, and it is based on that that I have no strong opinion ya or nay about the 400's implementation of the link.

Most of the time it is barely, if at all, noticeable; you have to grab a pretty good handful of rear brake to feel any front wheel braking at all--in fact quite a bit more than I would normally use...
 

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Rather than modify the 650, I would buy a bike with the linked brakes as part of the design.

I would think that it would be "risky" to modify items such as brakes, unless you have good mechanical skills and a willing experimental pilot. :)

As for me, I would rather not have combined brakes. I do have them on my current bike. It would be easier to make low speed manuvers without something applying pressure to the front brake. Otherwise, combined brakes have not changed how I brake.
 

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Mind you I had ye olde svelte with linked brakes and was very happy with their performance.
 

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rustynail said:
cliffyk said:
Basically, linked brakes were created for those folks who foolishly use the rear brake exclusively - or near exclusively.
Yes, these folks are known as "car drivers". They buy a motorcycle just for the "pose value", not to enjoy it for what it is, and refuse to acknowledge that there is a better way to stop.

If only all motorcycles had a rear brake on the left handle bar the world would be a much safer place.
 

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farqhuarforever said:
cliffyk said:
Basically, linked brakes were created for those folks who foolishly use the rear brake exclusively - or near exclusively.
Yes, these folks are known as "car drivers". They buy a motorcycle just for the "pose value", not to enjoy it for what it is, and refuse to acknowledge that there is a better way to stop.

If only all motorcycles had a rear brake on the left handle bar the world would be a much safer place.
How did this happen?

cliffyk said:
Basically, linked brakes were created for those folks who foolishly use the rear brake exclusively - or near exclusively.
I never "said" that--that was rustynails comment--not that I disagree with it...

In any event, and as pertaining exclusively to the 2003 Burgman 400 linked braking system on MY K3 400 as I have described above, I believe that anyone who has actually experienced it would agree that is is relatively and for all practical purposes quite unobtrusive. I suspect that many of its detractors have never actially ridden a pre-07 400 and have just swallowed the 80/20 Kool-Aid...

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BTW, I just did some quick math and if you assume the front caliper's "linked" piston to be the same 34 mm diameter as the front's direct action piston the front/rear ratio does work out to be approximately 80/20. However since it is only 44% of the dedicated front piston's area the real ratio all said and done, and as presented above, is 55/45...
 

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Steve D UK,

I response to you original query. Yes it is quite possible, and I would be pleased to engineer a solution for your at my usual rate. As a ballpark quote I would estimate 75 to 100 hours at $95 US/hour. This would be for design and BOM only, fabrication, implementation, and oversight of same if required would be in addition to design costs...
 

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Discussion Starter #19
InfernoST said:
2011 with ABS, Why bother?
As stated in my original post - because I like 'em and they work for ME.

My current other scooter has linked brakes as well as ABS and they work perfectly. Honda bothered and I wondered why Suzuki hasn't and whether it was possible. I don't think Honda fitted them in order to make their scooters more difficult or dangerous to ride.
 

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Here in the States there is a palpable machismo attached to motorcycle riding, reflected potently in most of the m/c publications, forums, and other venues. This attitude often labels things like linked brakes as undesirable for no reason other than that "real men" don't need no stinkin' linked brakes--despite that their pick-up trucks and cars all have "linked" brakes, and I doubt anyone would endorse changing that.

Relating specifically to the pre-'07 400, I have found the 80/20 ratio claim (I have seen it in online reviews and a number of other sources) to have been spread widely enough to make experienced riders think "OMG, that cannot be desirable or safe!". I had that concern before I had ridden one. However as I said above my immediate reaction was that it could not possibly be so; an 80/20 front/rear bias would be quite noticeable and quite likely unsafe under even the best road conditions.

With the actual 55/45 split I view it personally as something that I do not need, but it is unobtrusive and I am not bothered by it. That is also my opinion of ABS--something I personally do not need, yet if it were there I would not be bothered by it.
 
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