Cycling and bicycle discussion forums. 
   Click here to join our community Log in to access your Control Panel  


Go Back   > >

Adaptive Cycling: Handcycles, Amputee Adaptation, Visual Impairment, and Other Needs Have a need for adaptive equipment to ride to compensate for a disability or loss of limb or function? This area is for discussion among those of us in the cycling world that are coming back from traumatic circumstances and tell the world, "No, you are not going to beat me down!"

User Tag List

Reply
 
Thread Tools Search this Thread
Old 04-06-13, 09:38 AM   #1
mconlonx 
Nobody
Thread Starter
 
mconlonx's Avatar
 
Join Date: Jun 2007
Bikes:
Posts: 7,141
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 473 Post(s)
Mtn bike w/ hydraulic brakes -- one lever to two brakes?

Looking for a solution for someone with multiple left hand finger amputations.

He can work a shifter on the left side OK--still has thumb--but definitely not a brake.

I know we could swap over to cable actuated disc brakes and go with either a cable splitter or one of those two-cable brake levers.

Anyone know of solutions for hydraulic brakes?
__________________
I know next to nothing. I am frequently wrong.
mconlonx is offline   Reply With Quote
Old 04-06-13, 09:13 PM   #2
centralks
Junior Member
 
Join Date: Apr 2013
Bikes:
Posts: 12
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
If you went to a good auto parts store with the fittings they could make you a y fitting to split one line to the front and back but then you would be locking the rear brake as it would be getting the same line pressure as the front. You could try to switch to a very poor pad in the back to counter this. Maybe...

Or, buy another right side lever and cut most of it off to use one finger on it for the rear. I broke my left wrist once and ran my motorcycle with the front brake, clutch, and throttle all on the right for a while.

Last edited by centralks; 04-07-13 at 12:10 AM. Reason: had a better idea
centralks is offline   Reply With Quote
Old 04-07-13, 07:17 AM   #3
mconlonx 
Nobody
Thread Starter
 
mconlonx's Avatar
 
Join Date: Jun 2007
Bikes:
Posts: 7,141
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 473 Post(s)
Quote:
Originally Posted by centralks View Post
If you went to a good auto parts store with the fittings they could make you a y fitting to split one line to the front and back but then you would be locking the rear brake as it would be getting the same line pressure as the front. You could try to switch to a very poor pad in the back to counter this. Maybe...

Or, buy another right side lever and cut most of it off to use one finger on it for the rear. I broke my left wrist once and ran my motorcycle with the front brake, clutch, and throttle all on the right for a while.
Research tells me that a simple Y or T fitting won't work -- effectively halves the travel and pressure being applied at each caliper. Probably would need an aftermarket, maybe motorcycle?, lever and master cylinder, where the piston is x diameter with y stroke = same force a bike brake lever applies x 2.

I was just brainstorming a double-lever solution like you mention this AM. He's running Shimano brakes, which should have easy reach adjustment... so maybe just moving one further inboard and futzing with the reach adjust on both would be a first option...
__________________
I know next to nothing. I am frequently wrong.
mconlonx is offline   Reply With Quote
Old 04-10-13, 06:48 PM   #4
tigat
Senior Member
 
tigat's Avatar
 
Join Date: Apr 2013
Location: Colorado
Bikes: 2013 Trek Domane 6.9+, 2009 Bianchi 928, 1972 Atala Record Pro
Posts: 320
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Magura makes a hydraulic caliper brake system that converts a traditional cable into hydraulic by feeding it into a compressor box mounted on the stem. Front and rear cables from the levers attach on the sides and each has a dedicated cylinder. Pricy and not specced for disks, but the principle looks like it might work for two cables off a single lever or through a splitter.
tigat is offline   Reply With Quote
Old 04-17-13, 02:56 PM   #5
Bezalel
Senior Member
 
Join Date: Mar 2010
Location: City of Brotherly Love
Bikes: Raleigh Companion, Nashbar Touring, Novara DiVano, Trek FX 7.1, Giant Upland
Posts: 1,519
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Quote:
Originally Posted by centralks View Post
...but then you would be locking the rear brake as it would be getting the same line pressure as the front. You could try to switch to a very poor pad in the back to counter this. Maybe...
Maybe using different disc sizes can be used to get the right balance of braking power.
Bezalel is offline   Reply With Quote
Old 04-22-13, 11:27 AM   #6
hotbike
Senior Member
 
hotbike's Avatar
 
Join Date: Dec 2006
Location: Long Island, New York
Bikes: a lowrider BMX, a mountain bike, a faired recumbent, and a loaded touring bike
Posts: 2,860
Mentioned: 1 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
Put the front brake handle on the right, and install a Coaster Brake on the rear wheel.
hotbike is offline   Reply With Quote
Old 05-11-13, 06:44 AM   #7
tigat
Senior Member
 
tigat's Avatar
 
Join Date: Apr 2013
Location: Colorado
Bikes: 2013 Trek Domane 6.9+, 2009 Bianchi 928, 1972 Atala Record Pro
Posts: 320
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Update to earlier post

Quote:
Originally Posted by mconlonx View Post
... I know we could swap over to cable actuated disc brakes and go with either a cable splitter or one of those two-cable brake levers.

Anyone know of solutions for hydraulic brakes?
After earlier posting on the Magura cable to hydraulic converter for rim brakes, I stumbled upon the TPR Parabox. Appears to be a similar concept to the Magura (front and rear cables into the box mounted under the stem, hydraulic lines out), but specifically mated to their disc brakes and less expensive than the Magura. As a one handed rider who spent 30 years wrestling a big steel frame to a halt with first a single front brake, and later pulling two cables with a bar mounted lever and splitter, often with a trail a bike in tow, the notion of stopping more efficiently with boosted effort is somewhat attractive. If it can be accomplished without changing the nature of the bike (coaster brake on back), or trying to understand how to balance a fairly complex fluid pressure equation, all the better. Would love to see, hear what you can come up with.
tigat is offline   Reply With Quote
Old 05-27-13, 04:19 PM   #8
esther-L
Senior Member
 
Join Date: Jul 2007
Location: North Carolina, USA
Bikes: tandem, road bike, hybrid
Posts: 192
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 4 Post(s)
There are some solutions listed at http://www.mtb-amputee.com/bikemodifications.htm for modifying brake and gear controls on bicycles. There are some examples for putting both brake controls on 1 side of the handlebars.
esther-L is offline   Reply With Quote
Old 06-22-13, 04:46 AM   #9
Honza
Newbie
 
Join Date: Jun 2013
Bikes:
Posts: 1
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
What about Hygia Multi http://www.hygia.com.tw/prod-brake01-4.htm?
Honza is offline   Reply With Quote
Old 06-25-13, 04:48 PM   #10
zaroba
Junior Member
 
Join Date: Jun 2013
Bikes:
Posts: 8
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Quote:
Originally Posted by centralks View Post
If you went to a good auto parts store with the fittings they could make you a y fitting to split one line to the front and back but then you would be locking the rear brake as it would be getting the same line pressure as the front. You could try to switch to a very poor pad in the back to counter this. Maybe...
Would just need to restrict the flow of hydraulic fluid to the rear brake so it has less force.

Similar to how cars work. The single brake pedal in a car brakes all 4 wheels, but it's something like a 70/30 split in power between the front and rear brakes. Not enough to lock the rear wheels, but enough to aid in stopping and aid in braking while cornering. Only really notice it if it's not working and it gets fixed, car will suddenly stop a lot faster with the same pressure on the brake pedal and will feel smoother when corning while braking.
zaroba is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -6. The time now is 11:52 PM.