Hi All,

I'm looking for ideas on how to operate two hydraulic disc brakes with one lever. If I still had my mill, I would just make a manifold and call it a day. Has anyone tried this? Its for a tadpole trike I'm building btw. Thanks

Not fully hydraulic..


Want disc brakes ? I'd use the TRP Hy Rd, and a cable splitter from QBP..
and then its cables all the way to the caliper,
which is both master and 2 slave pistons ..

Greenspeed modifies S-A drum brakes to be single sided
and uses cables all the way , on their tadpole recumbents..

I see 2 cable levers offered, they can work ..
though some pull differences can happen
if 1 cable head is closer to the pivot than the other.

if they're side by side, equidistant from the lever pivot..
that should be better.

of course when splitting the 1 master, oil pressure volume, in 2,
each slave cylinder needs to be smaller ,
or it will move half the amount, it did before..

some previous posts you might read, are here..

I added pictures in 23rd frame



LBS carries Cattrike, they sort out most of that..



....

Magura Big was a 2 caliper 1 lever system, I don't think they make it anymore but you might find one secondhand.

Don't forget to add a biasing valve.

I found a new Magura Big Twin setup on line, but in France. It was $335. Wicked expensive! I'll figure something else out.

The key thing is you need to move twice the volume of brake fluid. You should take a look at Motorcycle components. Several motorcycles have two brake operated by one lever.

Closed system Magura could be daisy chained*,
but they're rim brakes.. on V Brake Posts,

Lever master, to 1 piston, which has a hose *to the opposite side,
where 2nd piston , is.
so they squeeze the rim from both sides. smooth and no squealing ..

those would be double disc on the front wheel , racing,
not general consumer bikes.
rear brake is a foot pedal on a motorbike (had one decades ago).




....

And the smaller cylinder will exert less force so a stronger lever pull would be required. There is no free lunch.

I now have partially converted from BB7 Mountain, to Hy Rd short pull Hydro calipers
With the Avid Speed Dial levers I don't need much lever pull to set the brakes on hard.
even with the cable pull dialed to shortest pull ratio.. considering cantilever pull levers next..

part of why the cable splitter inline , seemed a good approach..
the brakes use the cable pull power efficiently ..





...

What about TRP HY/RD brakes and a duplexing lever?

Since you're operating two front brakes with one lever, I'm thinking you can probably get away without a biasing valve. And possibly the effort won't be much more than a single brake, since each brake would be doing half the work.

Perhaps you can find some standard hydraulic fittings that will work with bike brake hose? Maybe banjo fittings? Otherwise you'd need to have something machined to accept the bike fittings.

looked it up :

Yes, I agree.

Maybe adapting two cable actuated hydraulic calipers to one lever would be easier (I can't think what else they'd be good for).

Hope Tech 3 X2 Uno



Probably near the cost of the Magura setup, really. It is a super niche item. Have you considered trying to mount a pair of the same-sided levers on one side of the bars?

I've decided to build a single-lever-two-caliper-system (cable-drawn), of which I will post the results of here.

Actually, come to think of it, you can just do it with banjo fittings and a suitable bolt.

A friend with significant weakness in the R arm/hand has an ICE trike with all controls on the L side of the steering bar. It has 3 hydraulic disc
brakes all controlled via a manifold by one lever. A twist grip controls the rear derailler, and a bar end shifter on the top the FD. Apparently
ICE sourced the manifold and the dealer set up the shifters. Bike bought in early 2018, I suspect but haven't confirmed from a dealer in Nashville, TN
Actually Murfreesboro TN

BMWs and (I think) Moto Guzzis offered (still do, I think) the option of single lever operation, where the RHS lever operated both front and rear brakes. This was in conjunction with ABS, which I presume obviated the need for a brake biasing system.

Bob, my friend, take a run down to your local motorcycle dealer and look; there are MANY sport and touring models with dual front discs, and there are touring bikes that control one front disc and the rear brake with the foot pedal, and the other front disc with the lever.

my 68 BMW R60 , was my frame of reference, owned in the 70's

Where I live now only shop sells KTM in next town over
, as its woods around here .. (no Paris Dakar enduro types)

all the rest is tourist dentists on Harleys , in the summer, passing thru
and renting motel rooms..



..

Many tadpole trikes have one lever for each front brake. This can create problems if the rider has one hand that is significantly stronger than the other (per SCH above) but unimpaired riders adapt quickly. They also can use the brakes to turn the trike with differential braking.

https://problemsolversbike.com/produ...kes/12_-_8816o



+ https://www.trpcycling.com/product/hyrd/

I resonate with your opinion, but some of us dentists prefer Beemers!
I have a '67 R69S and a '77 R100S. The latter has dual front discs, and stops nicely.

you* pass thru quietly, I have double pane windows in my house, now,
to cut down the summer racket.

*(I had an R60 in the 70's)

try this maybe?
https://www.speedwaymotors.com/Brake...alve,8904.html