Topic: idea,suggestions wanted

[dusterdude]

is it feasible/advisable to actuate the front and rear disc brakes with the front brake handle.if feasible how would one go about doing this.all replies are welcome

[mgbgt89]

Some newer bikes have linked brakes. I think they also have ABS though. I would think building your own system that would work safely would be pretty difficult. You would probably need a larger master cylinder, proportioning valve, as well as lines, and some sort of backup in case the system failed.

I personally feel safer controlling each individually on my own.

[MCRider]

Actually most newer Hondas and Jp bikes have some sort of linked braking, with or without ABS. My wifes Burgman 400 (Suzuki) is like 66f/33r  when you pull the front brake and the other way activating the rr. No ABS. It was controversial at first MANY years ago, but is accepted practice now. Exceptions are some of the sportbike models.

But no need on our stuff. That's what make them different.

[GammaFlat]

My FIL's '85 GoldWing has linked front and rear.  The hand brake operates both front and rear and the foot brake operates only the rear.  I think the piston size dictates how hard the brake will be actuated.  With the front brake, I've never been able to lock up the rear and I'm sure that's by design. 

[MCRider]

My FIL's '85 GoldWing has linked front and rear.  The hand brake operates both front and rear and the foot brake operates only the rear.  I think the piston size dictates how hard the brake will be actuated.  With the front brake, I've never been able to lock up the rear and I'm sure that's by design. 

If the caliper has multiple pistons, sometimes they divvy up the chores that way. ie Front brake activates only one piston of a two piston rear caliper.

[mgbgt89]

My FIL's '85 GoldWing has linked front and rear.  The hand brake operates both front and rear and the foot brake operates only the rear.  I think the piston size dictates how hard the brake will be actuated.  With the front brake, I've never been able to lock up the rear and I'm sure that's by design. 

If the caliper has multiple pistons, sometimes they divvy up the chores that way. ie Front brake activates only one piston of a two piston rear caliper.

Wouldn't that cause uneven pad wear?

[Gordon]

My FIL's '85 GoldWing has linked front and rear.  The hand brake operates both front and rear and the foot brake operates only the rear.  I think the piston size dictates how hard the brake will be actuated.  With the front brake, I've never been able to lock up the rear and I'm sure that's by design. 

If the caliper has multiple pistons, sometimes they divvy up the chores that way. ie Front brake activates only one piston of a two piston rear caliper.

Wouldn't that cause uneven pad wear?

It probably does, but since disc brake pistons/pads are self-adjusting it shouldn't matter.  You probably just have to change one more often. 

[MCRider]

I lifted this quote from a pamphlet on the 2006 ST1300:
"Linked Braking System (LBS) uses a second master cylinder and a proportional control valve (PCV) to couple the three-piston calipers of the dual-disc front and single-disc rear brakes for even better braking feel, while providing the peace of mind of an LBS system. Using the front brake lever activates the outer two pistons of the front calipers and the two outer pistons of the rear caliper. Rear pedal engagement activates the center piston of the rear brake caliper and the center pistons of the front calipers, and a delay valve slows initial front brake response to minimize front-end dive."

Modern motorcycle technology is so far past what we deal with on our CBs, it makes my head spin. I bot my 03 FJR new and its an antique now by today's standards. THough it will stomp on the best CB750 ever modified, and thats with saddlebags and a full fairing (with an electric windshield), without breaking a sweat, and with very low maintenance.

It tells me two things: modern motorcycles are amazing and old CBs are amazing.

But back to the OP question. If your bike has discs front and rear, I'm sure you could rig up a linked system. There would be a lot of trial and error and I'm not sure you could accomplish much benefit.  You'd need a partial pressure on the rear from the front lever, but full pressure on the rear from the rear pedal. Adopting a 2 piston caliper from a modern linked system sounds like the best bet. But I'd have better things to do twere me.

[GammaFlat]

But I'd have better things to do twere me.

twere me too

[bucky katt]

BMW has linked brakes too

[swellguy]

Linked brakes are nothing new. Did a bike once with them but ran the braking from the rear pedal instead of the front lever. Used a larger than normal master cylinder with the proportioning valve to adjust the ratios.

I just don't see it working for most sohc bikes since you've got hydraulic and drum brakes.

[ChortlingSandcaster]

rear brake scares me.  It dont help you stop much and it does a MUCH better job making the back end start sliding out from under you.

I would think of it this way.  When I'm in a corner and the road surface is less than 100% I'm much more likely to leave off the back brake than the front due to the rear end 'whipping around' risk.  In a corner the rear end is tending to whip around by nature, because you're using the front wheel to change the direction, and the back wheel is being forced to follow, so if the rear brake is wrong that back wheel doesn't follow the new angle, it slides out from under you.
If they were linked I'd get real nervous in that situation.

Seems like without some *really* comprehensive testing of the linked setup at
- different speeds
- different road conditions
- different types of corners (off camber, flat, banked, long sweeper,  short radius 180 degree corner, and so on)

you are kinda putting your life on the line out there on the road.

I don't think the risk is worth it.  I bet the new bikes have LOTS of engineering, testing and empirical evidence to get the setup right.  Risky stuff there, brake mods, if you get something a bit wrong.  You can better control the braking of each wheel with a different control.

Interesting engineering and technical challenge though!

[dave500]

you could use parts and systems from a late model machine,ide rather have the rear end lock and skid a little in a turn than the front,just my riding style though.when i was due for a new rear tyre last year ,i purposely locked and turned my 500 to see how an emergency stop would go without ruining a good tyre,for about half an hour,straight ahead,then a bit left,then a lot left,then a bit right etc,over and over,max was 80 klm per hour,mostly at 50,like quite a few here ive spent years on two stroke dirt bikes and in my youth was quite good at having fast fun,these skills are a bit lost on the highways and i just thought ide brush up and see what it would be like.

[lrutt]

My 1977 Guzzi Lemans has linked brakes. Front master activates the left front disk, rear master activates rear disk and right front. I find myself rarely using the foot brake, but when you do it will haul you down quickly.

[sparty]

You mean our bikes have brakes?  Hmmm.  I would only call them slowing mechanisms.  I am still trying to find a way to bring my bike to a quicker stop.

[Johnie]

My 2000 Goldwing 1500 (last year of the 1500) works like this. The front brake handle works only the front right caliper. The rear brake pedal works the rear brake and the front left caliper.

[dusterdude]

im sure there is a way,i dont think im enough of an engineer to figure it out.like i said,its purely exploratory at this point.

[swellguy]

rear brake scares me.

Rear brakes have saved my ass a number of times.