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Discussion Starter #22
First off good on you for keeping on a bike. A average person would give it up. As you go down this path, don't forget the is a leverage ratio at work and master cylinder piston travel at work. It has to do with the diameter of the master cylinder piston and the diameter of the slave (caliper) piston. Honda uses different piston diameters to bias the brake, adjust the lever-pedal pressure and adjust the feel. For example if the diameter of the master cylinder is 16mm the surface area of the master cylinder piston is 2.01 Sq. centimeters. If the diameter if the slave is 37 mm the surface area of the piston is 10.75 Sq. centimeter. This makes an effective ratio of 10.75/2.01 or about 5 to 1. If you add a second slave to the same master the total surface of the slave will be 10.75 x 2 = 21.5. The effective ratio will be about 10 to 1. This will make the brake feel a lot more spongy. The other issue is to move the double slave cylinder, the master piston will need to move twice as far for the slave to move an equal amount. On modern bikes with huge rotors and four to six pot calipers, the ratio is turned way down to give the brake a hard, powerful brake. I would measure the piston diameters, total up the surface area of the slaves and try to keep the ratios close to stock. Just my 2¢

OUTSTANDING. Thank you ... this gives me a way to calculate what will work rather than 'just trying stuff' and hoping it will work out ! Thank you James !


As it stands now:

The stock master cylinder was sized to activate the front single caliper only. It has had the Sidecar caliper plumbed in as well, and sure enough it feels spongy. I should be able to research the piston sizes of the calipers, and find an appropriate sized master cylinder to do the job ...



Maybe even find a master cylinder that can drive all three calipers (Both front calipers and sidecar caliper) so that I can

A. Stop in a timely fashion, a very desirable behavior.

B. Not experience the left hand veer on hard braking. I could live with this as a trade off for safety, but would rather have my cake and eat it too ...

Again , thank you for the info !
 

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Discussion Starter #23
IMO,


the first investment should be SS lines... getting rid of the rubber lines will make a HUGE improvement in stopping power.

I agree completely. I have changed to SS lines on other MCs and felt the difference. First though I need to know what the line routing will be. SS lines being pricey, I would prefer to do this only once :-D


Thank you for the tip !
 

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Maybe even find a master cylinder that can drive all three calipers (Both front calipers and sidecar caliper)
Why not just a single front caliper, but all three wheels instead?
 

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I think i read that bmw used a servo on one of there bikes
All of them with ABS use servos but that has nothing to do with the brake hydraulics in normal braking.
 

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Discussion Starter #27
Thanks for the help

I want to thank you for all the great input. I appreciate you taking the time to help me to solve this problem.

:bowing:
In short, I am going to un-link the brakes. Hand brake master will drive both front calipers. To do this I will upgrade (use a larger bore) master cylinder. I need to do a little more investigating, but it is likely either an (early)GL1100 or GL1000 master cylinder should do the job. Further, I will make all the lines Braided SS lines. The foot control will not be used by me, but while I am in there I will plumb the Sidecar and rear brake from the foot brake. If a rider with a sound right foot borrows the machine, it will perform as expected ... safety safety safety.



Cheers,
John
 

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I want to thank you for all the great input. I appreciate you taking the time to help me to solve this problem.

:bowing:
In short, I am going to un-link the brakes. Hand brake master will drive both front calipers. To do this I will upgrade (use a larger bore) master cylinder. I need to do a little more investigating, but it is likely either an (early)GL1100 or GL1000 master cylinder should do the job. Further, I will make all the lines Braided SS lines. The foot control will not be used by me, but while I am in there I will plumb the Sidecar and rear brake from the foot brake.



If a rider with a sound right foot borrows the machine, it will perform as expected ... safety safety safety.



Cheers,
John

glad you are making progress, hope it is done before Riding Season is on you.
 
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