Some of you are going to call me crazy!! Dual master cylinder

[charlesincharge09]

In the process of running a brake pedal on the right side of the bike that will operate both the front and rear brakes. I will be using an adjustable proportioning valve to the rear. What do you guys think? Will the master cylinder have enough power?

 

[Patches]

Depends of the size of the bore.......

 

[Phail]

I've had the same thought for my bike. I'm still at the just get it running phase, so keep us posted.

 

[willyguzzi53]

The rear brake pedal on my ST1100 runs the rear brake and one of the front calipers. The front brake lever runs the other one. Should be easy enough to find a rear brake master cylinder for an ST used.

 

[tonyc]

What happens when you need differential braking, like having to lock up the rear to lay your bike down? The time will come. I have been riding 52 years and three times rear brakes has saved me injury. Good luck. Tony C.

 

[twowheelinjim]

I've often thought about implimenting a proportioning valve. I was hoping to eliminate the master cylinder at the handle bars for a cleaner, less cluttered look. One day I hope to get started on a bobber with a minimalist appearance and rerouting everything through the handle bars. I will be keeping up with this thread since I'm also curious if anyone has attemped this before, and what kind of results they have experienced.

 

[charlesincharge09]

This will be a strictly show only bike or once in a while take it out on the country roads by my house

 

[charlesincharge09]

Do you guys think the stock master cylinder will be enough pressure? Or what should I upgrade to? I can weld brackets or whatever onto the frame

 

[TheRepairMan]

What happens when you need differential braking, like having to lock up the rear to lay your bike down? The time will come. I have been riding 52 years and three times rear brakes has saved me injury. Good luck. Tony C.

Exactly!
Even the bikes with linked brakes still leave you the option of applying more front brake when needed. I still find a LOT of cruiser riders that think you are never to use the front brakes, while in fact about 75 to 90% of your braking power IS in the front. Conversely, probably most sport bike riders hardly ever apply any rear brake. When they do they call it trail breaking, and there are times they may use the rear to help control power to the rear wheel under acceleration, or to get the bike to turn in harder, but hardly ever to bring the bike to a complete stop.

It's a dance to stop efficiently and cleanly under all situations, but there's NO way I'd want my bike's brakes linked... unless it's just for show and not really ridden.

That said... maybe someone understanding what they have with linked brakes knows they can't ride it all that hard. It's just not safe. Just my opinion.

-R

 

[twowheelinjim]

If I'm understanding your question correctly, I'll attempt an answer.
Your front brakes require X amount of fluid displacement to actuate the calipers correctly. If you combine both front and rear wheel caliper displacement you will definitely need a bigger master cylinder. As another member has mentioned this already, it may be accomplished by switching to a larger master cylinder such as the one from an ST1100 which may already have a proportioning valve attached.

 

[burns]

Do you guys think the stock master cylinder will be enough pressure? Or what should I upgrade to? I can weld brackets or whatever onto the frame

I'm thinkin' this not a great idea. You will have to experiment to find the proportion point that gives you decent stopping pressure to the front without locking up the rear, and that will change with tire wear and with road conditions. The bottom line is you really don't know how those brakes are going to behave and you will be shooting the dice every time you ride.

It is less important to have great brakes than it is to have predictable brakes.

I suggest a drum.

 

[paulpops55]

I've been riding an 83 Goldwing for the last 27 years. It was the first year of linked brakes on a Goldwing. I find that you still need the option of a separate front brake for safe stopping power in an emergency situation. You might want to consider going to a dual disc in the front like the Goldwing uses. I'd rather sacrifice esthetics for safety.

 

[tonyc]

Linking of auto brakes is great because you have four contact patch areas. On a bike you only have two smaller areas.

 

[twowheelinjim]

One other solution to this, although a bit unrelated to this topic is to mount the master cylinder like that on a BMW R series bike. The master cylinder is mounted underneath the fuel tank on top of the back bone and manipulated by cables like a mechanical system. I never figured out why sometimes German engineers do what they do.

 

[charlesincharge09]

I've ran bikes in the past with rear only brakes and front only brakes, like I said this bike is primarily going to be a show bike although u want everything to operate properly the proportioning valve I am using is fully adjustable and made by ssbc Here is a link of the valve I will use that will control the rear brake only http://www.google.com/search?tbm=is... proportioning valve&sa=N&biw=320&bih=356#i=0 The way I will run it will be a solid line from the master going to a T block with one line going to the front and one going to the valve which then goes to the rear caliper

 

[charlesincharge09]

I will also have internal throttle and clutch so my bars will be clean and make people say... How the hell does this thing operate

 

[Cafe-Dave]

Patches is correct. Master cylinder and brake caliper bores will need to be accounted for.

Why are you worried about a front brake even, for a show bike. The super long brake line + hydraulic components will be tough to hide.

 

[charlesincharge09]

Not concerned about hiding it, I am going to run solid copper brake line up to the neck the a braided stainless hose

 

[Ghetto]

Pics? I'm liking a lot of what I am reading.

 

[charlesincharge09]

What kind of bigger master should I go with? I was thinking one off of an r6