Hydraulic brake splitter - I lever two calipers

[methods]

I need to drive two calipers with one lever.
Brakes are Avid Juicy 7

Best I have found is a company that does off-road wheel chairs.
I have a question in to them but judging by the price of one of their chairs. . . I am not holding my breath.

Here is the only real hit I got on Google:
http://74.125.155.132/search?q=cach...juicy+brake+splitter&cd=4&hl=en&ct=clnk&gl=us

Here is the company that is referenced:
http://www.r-onefourcross.com/products.html

I suppose I am over-complicating the issue. . . I guess I can just cut the line and split it.
Oddly - I have an irrational fear of my "Ghetto mod" failing at 50mph and spraying brake juice all over my face while I get smashed by a bus. . . .

I have bled brakes in the past but I have never modified a hydraulic brake system.
Currently I am using 1 lever to drive two mechanical brakes.
Requires too much force - does not have much resolution - and I just dont trust them.

-methods

 

[pmarkiew]

I Think this is what you are looking for:

http://www.pedicabshop.com/shop/spare-parts/brakes/big-magura-twin-hydraulic-disc-brakes.html
http://www.greenspeed.com.au/magura.html

- Peter

 

[biohazardman]

Just hit the nearest hydraulic supply shop they will probly have the hose and fittings you need.

 

[gogo]

This is an interesting question to consider. Most interesting of all is what happens to an interconnected braking system when one wheel loses traction. This could happen from ice under one wheel or lifting a wheel (double the normal force).

 

[methods]

Thanks for the replies.

The Magura looks to be a nice plug and play solution.
I will look into getting the splitter they use.... Unfortunately I have 4 "almost new" sets of Avid Juicy 7's sitting around. A while back I was bidding $50 on any set I saw. Got nothing for a month then in one day I won 4 sets. They are great brakes - I like how I can tune the contact point and the position of the lever. Allows me to put the lever very close to the bar (so I dont have to reach) and it only needs a cm or two of stroke to apply appreciable brake pressure (when bled well).

I will definitely stop by the local "tubes-n-hoses" shop to see if I can find an adapter.

As for the question of how the bike will behave with an interconnected brake system -
What I can say is that this bike has really bad brake steer - if one caliper is adjusted just slightly different it pulls hard left or right.
If it were a better designed bike I would just run separate left and right brakes and be done with it.

So far in my experience if one or the other tire locks up I just back off the brake a little, let it grab traction, then squeeze again.

I will report what I find.

thanks,
-methods

 

[pmarkiew]

The guy on this page made his own splitter: http://www.hellbentcycles.com/winter_trike_construction.htm

- Peter

 

[AussieJester]

Methods...Just so happens i am in the market for a set of Avid Juicy 7s i nearly hit the buy button on last night on Chainreaction Cycles but thought i would check in at LBS and see what they want for them a set, hahaa what a joke they are 180 bucks EACH...SO...if you would like to sell a set i would happily buy them from you, i dont require disks just the callipers and levers...Let me know shall wait till I hear back from you before purchasing...

KiM

 

[enoob]

doh . ya beat me to it Aussie.

this giant i have has the drop outs and is all ready for a disk but did not come with one and as i am getting very close to getting that bike all E'd out front brakes would be tremendous.

So how many of those juicy's you willing to part with ? assuming you are willing

oh and im gonna take a run at your "getto crown" methods . check my latest thread in the "other" section . lol . you'lll see

 

[methods]

Hmmm... I guess if I sell all of the brakes I have I can afford to buy a new set specifically for my Trike.

Avid Juicy 7 Rear - never used $70
Avid Juicy 7 Front - used $50
Pair: $110

Avid Juicy 7 Rear - used $50
Avid Juicy 7 Front - used $50
Pair: $90

Avid Juicy 3 Front - used $30
Hayes Comp Rear - used $30
Pair: $50

-methods

 

[enoob]

Avid Juicy 3 Front - used $30
Hayes Comp Rear - used $30
Pair: $50

-methods

sold . how do i send you $50 . never mind ill send you $50 in a box with return shipping paid.

 

[methods]

The guy on this page made his own splitter: http://www.hellbentcycles.com/winter_trike_construction.htm

- Peter

Thanks for the link - that gives me confidence that there is nothing magical going on.
I suppose now it would just be a matter of finding the proper fittings.

This not being the first one-off I have built. . . I have a sneaking feeling that I will end up spending more on odd bits than if I just bought something
Hoses, barbs, cutters, crimps, fluid, a new bleed kit. . .

-methods

 

[AussieJester]

Ill grab the new Juicy 7 rear and used front Methy pm your paypal details and ill arrange payment

Cheers

KiM

 

[gwhy!]

you could just run a hose from the first caliper bleed point streight to the second caliper..
edit: or you could just get a barbed Y splitter thats what I use on my trial bike for the rim brakes.

 

[liveforphysics]

The guy on this page made his own splitter: http://www.hellbentcycles.com/winter_trike_construction.htm

- Peter

Thanks for the link - that gives me confidence that there is nothing magical going on.
I suppose now it would just be a matter of finding the proper fittings.

This not being the first one-off I have built. . . I have a sneaking feeling that I will end up spending more on odd bits than if I just bought something
Hoses, barbs, cutters, crimps, fluid, a new bleed kit. . .

-methods

I bought all the stuff to do my own 3,000psi hydrolic lines in -3AN and -4AN (very tiny lines, just a little bigger than bike brake lines) for making nitrous lines. I still use the shop when I need a line made, because the semi-affordable hydrolic line crimpers totally suck with stainless steel ends, and brass ends are just a failure waiting to happen. They use an end crushing machine that pushes like 10,000lbs of force into this 2 piece die plate that leaves every fitting perfect. It's like $5 in labor and $10-20 in parts to have them make any line you can imagine, and it will be done right so you don't have "surprize!" nitrous bursts frosting up all the windows in seconds while racing...

Brake lines are even more important than nitrous lines (if you're into living at least). Have a pro do them, or buy a proper adapter so you don't have to cut/re-crimp anything yourself.

 

[Vanquizor]

I'll disagree on this one, its actually real easy to do a quality Job on a brake line on your own. Just order up whatever hose size you want and whatever Earl's fittings you need.

On our formula car we try to avoid any crimp fittings- when the hose gets damaged or you decide to make a change you end up buying another batch of fittings. With Earl's fittings you thread them off, grab a new chunk of braided hose (or shorten the old one) , and thread em back on.

Edit- here is the instruction sheet for this type of fitting, only basic hand tools- nothing exotic about it. We do it in the pits in a couple minutes when colission dammage is an issue.

http://www.holley.com/data/TechService/Technical/speedflex.pdf

FYI 2 crescent wrenches/flatwrenches/whatever can be used if you don't feel like using their socket in a vice trick.

 

[MitchJi]

Hi,

As for the question of how the bike will behave with an interconnected brake system -
What I can say is that this bike has really bad brake steer - if one caliper is adjusted just slightly different it pulls hard left or right.
If it were a better designed bike I would just run separate left and right brakes and be done with it.

thanks,
-methods

One of the first steps in Hot Rodding old cars is replacing the mechanical brakes with Hydraulic's. The fluid doesn't compress so if the brake pads have an equal distance to the rotors the braking is equal.

Probably works better with an appropriately sized master cylinder.

 

[methods]

Hi,
The fluid doesn't compress so if the brake pads have an equal distance to the rotors the braking is equal.

Yes. Assuming that one line does not have more air in it than the other since air does compress well.

-methods

 

[gogo]

Probably works better with an appropriately sized master cylinder.

I thought liveforphysics would be the first to comment on this. If you add a second caliper to a one caliper system you get half the pressure on each caliper per unit of pressure on the lever. Also, the amount of lever travel before the "slack" between the pads and rotors is taken up doubles.

Here's what I'm sketchy on, do you only need half the caliper pressure because you have split the braking load between two wheels? And if you lift a wheel, will you run out of lever travel if you need to pull twice as hard to achieve the same braking force?

I'd guess that dual system is the safe bet. I don't know how much rubber line stretches, but to be safe It might be good to have the same amount going to each caliper.

 

[MitchJi]

Hi,

Hi,
The fluid doesn't compress so if the brake pads have an equal distance to the rotors the braking is equal.

Yes. Assuming that one line does not have more air in it than the other since air does compress well.

-methods

Will it work at all with air in the line? (Just one or two air bubbles will make car brakes non-functional.)

 

[liveforphysics]

I thought liveforphysics would be the first to comment on this. If you add a second caliper to a one caliper system you get half the pressure on each caliper per unit of pressure on the lever. Nope, you only get that if you change out your master cylinder piston to be double sized. Also, the amount of lever travel before the "slack" between the pads and rotors is taken up doubles. Yep, the lever will have twice the freeplay, so proper brake adjustement/setup becomes important. Fortunately, it sounds like he set his brakes to only use a small portion of the end of the master cylinder travel the way he was running before, so I think it will work out fine.

Here's what I'm sketchy on, do you only need half the caliper pressure because you have split the braking load between two wheels? And if you lift a wheel, will you run out of lever travel if you need to pull twice as hard to achieve the same braking force? A certain pull force on the lever creates a certain fluid pressure, and it doesn't matter how many calipers are hooked up, the force will still be that certain fluid pressure x the surface area of the piston the fluid is pressing on. The only thing that changes is the distance the lever travels. If one wheel is in the air and locked solid, or both are rolling along, or both are in the air, the braking pressure and hand effort doesn't change a bit towards the amount of force the calipers squeeze the disks with.

I'd guess that dual system is the safe bet. I don't know how much rubber line stretches, but to be safe It might be good to have the same amount going to each caliper. In a single master cylinder system, it doesn't matter how many lines or the distances of the lines, or how squishy the rubber hoses are. The fluid pressure on the backs of the pistons in the calipers will be equal even if 1 brake line is 2" of solid steel, and the other brake line is 200ft of rubber hose. Any part of the system that can deform (like air bubbles, rubber hoses, etc) will effect all the brakes connected to that master cylinder equally.

 

[methods]

I'd guess that dual system is the safe bet.

Unfortunately that is not an option with a bike that has brake steer.

The Juicy 7 brakes I have can lock up a 26" tire on a 100lb bike with only an index finger pulling about 1cm.
I am absolutely positive that a single Juicy 7 lever can drive a pair of calipers more effectively and reliably than this low budget mechanical system I have now.
I have to squeeze so hard on these mechanical brakes that I feel like I am going to break a cable or a lever (Which I have done).

-methods

 

[drummerian]

Apologies to revive an old thread but some searching hasn't found any conclusive results!
Did anyone find an easy(ish) off the shelf solution for this? Currently running mechanical discs but want to 'upgrade' to fluid, but can't without a splitter :/

 

[Trilska]

Hygia has a set for use with two calipers and one lever. http://www.hygia.com.tw/liveshop/index.php?route=product/product&path=49_64&product_id=193

Even have e-brake options and lock for use as a parking brake.

 

[drummerian]

pretty pircey, plus im UK based so shipping is more tricky :/

 

[gensem]

Methods, have a look at hygia

http://www.hygia.com.tw/liveshop/index.php?route=product/category&path=49_64