Jeff Skinner

After many years of riding with one brake (the rear one since as a kid I once went over the handlebars using a front brake on a mate's bike), I've decided - at any price - to find a solution that allows me to control two brakes with my one hand.

I use the bike for London commuting (have done for 20 years) and some long distance. Building a new bike from the ground up based on the Pipedream 29er Skookum frame (internal Alfine 11 gear, belt drive)

I've read the forums and there are a number of solutions - the one that most like (and still allows independent operation of the two brakes) is to stack two levers on one side, operating one with two fingers and two with the other. I would like a more elegant solution and am looking at two alternatives and would value opinions (especially from those who understand the mechanics (physics) of brakes/braking and those who've experimented.

The first is to use one of the dual cable levers (e.g https://www.bikecare.co.uk/product_info.php?id=443) and to channel the two cables into the independent ports of a 'cable to hydraulic' converter (best one seems to be:https://www.hopetech.com/page.aspx?itemID=SPG343) which connects to the two brake callipers.

The second is to use a single hydraulic lever one with a splitter that sends fluid (50:50) to both brakes. To pump enough fluid I'd need the largest possible piston size and the calipers with smallest piston size (e.g. the Hope 'tech evo with 2x X2 calipers'). Even then I'm told that I'd need to replace brakes pads frequently in order to minimise piston travel.


Both have drawbacks of course. Not sure how serious and perhaps there are workarounds.

The main problem on both is the danger of transmitting equal power to both front and rear - with the possibility of locking the front and sending me into a front wheel skid or over the handlebars without applying optimal force to the rear (thus not being able to brake hard if I need to). To combat this I'm thinking about ways of building in a differential 'power' to the two brakes. The trouble is I'm not sure whether there is any 'best' ration and whether the three alternatives I've found/invented would work. Here they are:
1. Different pads size front and rear (does this lead to different braking power under different pressure - not an obvious answer).
2. a device that lowers pressure on one of the hoses (you can buy these but they look very bulky, heavy and 'inelegant')
3. If using the cable option (the first option above) then split the sheath and insert a very stiff spring in the gap which compresses under strain (thus modulating the pull on the respective chamber and thus reducing power.

That's as far as I've got.

My first post so sorry to be asking before contributing. Have read all previous posts on the topic though so hope I built on, rather than repeat, the discussion.

tigat

Welcome to the forum. It looks like you have done a bunch of research already and really drilled down on the right questions. As you probably saw, I'm running hydraulic rim brakes on a drop bar bike with a single lever and splitter.



SRAM engineered the split but it feels pretty close to 50/50. It is somewhat adjustable by setting the rear or front a bit tighter so that it engages slightly sooner and applies more power across the band. The smooth, and pretty linear modulation on the hydraulics has never left me feeling that locking up was a risk.

For a flat bar, I personally think the double cable lever-converter box system would be really cool. In addition to the Hope, TRP has the Parabox and Maqura has the RT series. On the Magura, I know that each of the pistons in the converter box is independently adjustable, and presume the same might be true on the other two. You might want to look at that before experimenting too much with pads and the like.

Either way, although balancing something like this is theoretically challenging, in practice every brake system I've used that fires both brakes has worked well.

Since it looks like you're in the UK, you might want to track down a guy named Oli Sparrow and see where he is on his dual axis, dual hydraulic lever, which would be an optimal front, back or both control. https://olisparrow.co.uk/work_xflow.html

Even if the hydraulics on the X flow prove problematic, using his two axis system to run cables into a converter box would get you really close.

Again, thanks for posting and welcome. I look forward to seeing what you come up with.

Jeff Skinner

This is great information - I owe you. I am running flat bars (I should have said that) so the Oli Sparrow' lever looks like the solution and I can't believe that i've not come across it before. I'll give him a call on Monday and see whether it's available and even order one for my existing bike. I'll then post again to say what I found (and again when I've fitted it. Thanks.

gixer

Hi Jeff,

I've tried the split brakes thing and found i just couldn't get on with it, problem i had was balancing the system out.
Found i was very cautious on the brakes as it was extremely difficult to gauge when one wheel would lock up, and no matter how i fettled the system one wheel would always lock up first.

In the end i had the rear wheel locking up earlier, that meant i could feather the brake to use most the stopping power on the front, extremely inefficient way of stopping though and very dangerous on the when you have to brake in the turns.

So i went back to using two brake levers, 2 years on and it works well.
Ideally i would like the levers closer together and i do find my hand gets fatigued on the longer descents, but it's the best compromise i've found so far.

Only other difficulty is finding decent brakes that operate upside down and have a narrow profile so can be mounted close together.

tigat

Unfortunately, it looks like there are only three of us talking about this, with our investment in the subject determined by where we have found ourselves in life. My only experience with discs is on a bike I rode on on a wonderful Irish tour a few years back. Long story, but the tour operator was kind and hospitable enough to modify one of his bikes with a cable splitter to run both cable discs off a single lever. Many hills, many fast descents, much rain, but all in all the trip of a lifetime. Since I usually ride a road bike, often in the mountains, I'm probably more particular on that set up, so I don't question gixer's desire for better balance. Long and short, all three of us are riding and loving an activity that may not have been designed for us, but still is so much better than not doing it.

gixer

It's a tough balance.

I'll be out shopping with the Mrs or sat at work and keep coming up with ideas, at the time they seem like THE solution, but in practice either they lack control or they prove to be a more complicated version of getting the same sort of control i already have.
I've tried everything from downtube mounted brake lever activated by my knee, to mounting a brake lever behind the seat so i effectively brake with my bum.

It's a tough compromise though, that's made even tougher if you use drops as there is no where to fit a second brake lever so a splitter is the only real option.
I've ridden motorbikes and scooters that use brake splitters and to be honest for street use they're pretty good, throw in ABS and they braked hard enough to make holding on tough.

Problem i've had on pushbikes though is the phase between braking and lock up tends to occur very quickly and with a split brake i found it tough to feel just where one wheel or the other was locking up so i can then modulate the brakes to stay in the sweet spot just before locking up.
On a MTB off-road i don't mind locking the rear on occasion, on the road though i found if the rear locked when i wasn't expecting it, it would snap the bike around kinda like a high side on a motorbike.

With modern electronics and batteries "in theory" it should be possible to make a fairly light weight hydraulic ABS system.
You could notch the brake discs (or maybe use the spokes on a cantilever lever bike) as the wheel speed sensors.
A small battery would power the controller a small controller.
Biggest problem would be powering the pump

You could then brake as hard as you wanted without fear of locking up, would it be THAT much better than your system though tigat?
My guess is is not THAT much better that'd it'd be worth the time, effort and expense.


Cheers
Mark

Jeff Skinner

The oli Sparrow solution suggested by tigat looks as if it's vapourware - I think it was a design competition gone big and never made more than a few. A shame but I reckon it isn't exactly commercial even though I would have been happy to pay quite a bit for it.

Wasn't surprised to hear that the 'fixed split ratio' solutions have serious drawbacks (however you do it) but still great to hear from those who've tried some of the solutions i've considered (including knee-operated & wackier. I'd hoped that with the Paralympics there may have been some really innovative engineering.

As a kid I had a back pedal brake but that doesn't go with gears so for years I've effectively had the one brake.

Seems to me that the best way (using readily-available parts) is probably the 'two lever' solution. I would like to see there is some way I could modify them so that they sit next to each other naturally. I'm going to experiment.

Anti-lock brakes? I guess it must be possible and maybe the next big thing in bike brakes. But a way off I think. And rather longer than that to be accepted by the regulators.

Thanks everyone

Jeff

gixer

Had a play with some tie wraps and a few bits i had around the house in making a non working mock up.
Obviously it wasn't connected to anything, but i wanted to get a rough idea on how plausible a system like that is.
For the few mins i played with it i recon having a brake lever move on 2 axis is tougher than it sounds.
You'd have to balance the brakes between pulling in towards you (normal way) plus pushing down at the same time.
Problem most of us 1-armies have is bracing ourselves while braking, for the simple tests i did i found it very difficult to brace myself while at the same time applying pressure in towards the handlebars plus pushing the lever (butter knife in my case) down.

Obviously my playing about is in no way conclusive and even if it didn't work for me it doesn't mean it wouldn't work for someone else.

With regards to the paraolympic thing, it's off but there seem to be very few sports tailored towards those of us with 1 arm (or 1 working arm in my case).
Obviously those with leg problems need to take priority as it's their mobility at stake, but i still thought things would filter down to use 1-arm lot, just doesn't seem to be the case.


The other thing to consider with my opinions Jeff is that i cycled for years with both arms, so my criticism of a particular solution is based on my experiences riding with both arms.
I admit my expectations are high in wanting a braking system that offers the same sort of control and power as i had with both hands, but that's what i'm striving for.

You also need to remember that i only ride MTB's now and mainly off-road so that also needs taking into consideration.

tigat

Alas--that is what I feared with Mr. Sparrow, given the passage of time since he first threw it out there. Sorry for the false hope. As for the dual axis method of applying brakes, my Bianchi has an Ultegra brake shifter lever, and I am often using both planes simultanously, for example downshifting and braking coming into a tight turn. My thumb is hooked around the hood and I haven't noticed any loss of stability. I may have an opportunity to resurrect the dual axis approach with help from a more experienced design/manufacturing viewpoint, and if so will let you know. The other, obvious design path is electronic, but that's going to take some serious r&d effort, and a normal commercial application to become feasible.


My final suggestion, offered partly in jest. Get yourselves a drop bar bike and copy the Bandit. It works very well, and you'll never have to remember which lever to pull how hard when you're launcing off a cliff into a stand of pine trees. That happens on a roadie only by terrible accident rather than intent.

As for different set ups of what you're looking at Jeff, there are several examples at https://www.mtb-amputee.com/bikemodifications.htm

Wanderer

I know this sounds crazy, but is it plausible to just put a balancing block, in line, that would split the hydraulic system to send 60% to the rear, and 40% to the front? I good machinist ought to be able to make one, just using a block of aluminum/or steel, large and small drill bits, and tapping holes for hydraulic line connections. Just calculate the area of the feed line, and then split it 60/40 on the outlets. One additional hole would be required transversely to connect the two outlets (this hole could be tapped and plugged after drilling)

I assume that those with one hand have enough hand strength to send a lot of pressure from the master cylinder of the braking system.

Also, it might take a few prototypes to finally get the balance right.

I also think it wise to send most power to the rear, to prevent front wheel lock up, while still activating the front brake, if only partially.

This way, the system is all simple hydraulic/manual/mechanical, and less to go wrong.

gixer

Good point on road bike shift/brake levers, never thought of that.

Actually that's a pretty good idea.
Likely need some bracket and lever to apply a little extra leverage and increase the throw, but maybe a STI level could be modified to work as the brake (in the sideways direction)
Shifting is easier to sort as it could be done using Di2 electronic shifters.

Problem i had for MTBing was because i shift my weight a lot depending on how steep a drop is i find i need different ratios of front and back brake depending on the terrain, grip and steepness.

As an example, if im going down a muddy steep slope i want very little if any front brake.
If on the other hand i'm riding down a steep a wet road the rear brake is pretty much useless.

You could conceivably fit a adjustable biased lever/knob on the handlebars to allow adjustment, problem there though is i often don't know what the grip levels will be like until i'm committed.

On the road a splitter system might work better as the grip levels are generally consistent, off-road though i feel that i really need to be able to feather each brake as needed on the fly.

Bezalel

I can think of two solutions. Either use brakes with different sized slave cylinders or get two different sized master cylinders. Additionally you can use different sized rotors and different pads.

Darth Lefty 

Just making a splitter fitting with a larger and smaller hole won't achieve what you want since it's the pressure, not the flow rate that makes the braking force. The proportioning valve on an old car is more complicated, it has a second piston that changes the pressure in the back circuit. There are adjustable ones. I have no idea if an automotive one would work on a bike but it might be worth a look.

onehandman

Has anyone found anything else on this topic. I only have a right hand and would love to hear more! I have some ability to use the front lever on the road and mountain bike. I am looking into buying a new cyclocross bike and think it would be sweet to have one lever run the rears and front. I would much rather have back tire lock up before my front( that is what I'm use to!).

Jeff Skinner

Three months after posting the original question I'm on the verge of taking delivery of the new bike. In the end I decided to go for two independent hydraulic brakes (hope V4 on rear operated by good left hand) and hope X2 on the right, (operated by right 'wrist') with a newly-learned rotational movement and adapted handlebar.

I'll a couple of pictures. But in pure words:
- flat bars (Ritchley as it happens)
- large Ergon GP5 bar ends (which are lovely in own right)
- bought 15cm x 15cm square of thick Formica and cut to sit snugly under the 'enclosure' formed by the RH bar end and fixed with plastic ties under the RH Ergon. In this way I have a plate on which I can rest my stump which is anyway much safer that regular handlebar grips.
- I straightened the RH brake lever (as bought it slopes up at the end) by taking a vice to it.
- I then fiddled around with the position of the braked lever (up/down, left/right) until my right stump (wrist) could operate the brake by rotation. This used the Elliptical nature of my wrist, although at one point I had toyed with creating a little prothesis for the stump to make it more elliptical.
- then adjust resting position of brake lever end so that it sits at just the position where it engages with the wrist and can be operated by twisting (rotating) the wrist.

I experimented (fiddled) extensively with my current bike (with shimano hydraulics) before spec'ing the new one. The biggest things I learned was that millimetres matter and that it takes practice. To begin with I had to make a conscious effort to move my hand into position and then twist. Not much good in an emergency. But over time (a couple of months) the action became second nature and I now use both brakes without thinking.

That is how hydraulics have revolutionised things for me. My RH wrist would never have the torsional power to operate cable brakes of any kind. But hydraulics work brilliantly.

Maybe I'm lucky because of the elliptical nature of my wrist (stump) enabled this kind of rotational operation. But even without this I think I could have rigged up something to utilise this degree of freedom.

Two other things:
- I've been in contact with Oli Sparrow.. He tried to get brake firms (including Hope) interested in his dual axis lever but none took any interest. So after a year he gave up. He has the only one in existence! But would still like to see it happen.
- I came to the conclusion that any one lever, two brake 'solution' could be dangerous since it would potentially lead to locking up one brake before the other was at top braking force/pressure.

Will post a few pictures.

jeff

riadahmed3624

I look forward to seeing what you come up with.

Wanderer

Is there such a thing as an internally geared hub, with a coaster brake? Maybe an 11 or 7 spd with a coaster brake? Then just a regular hyd disc brake on the front?

I thought SRAM made something like that, but I can't find it!

A triple on the front, and you are good to go.

Maybe NOS somewhere?

fietsbob

I think S-A https://www.sturmey-archer.com/products/hubs/cid/4/id/35.html in 5 speed is as many gears as their line has with a coaster brake..

3 shell versions ,Al,.. hi,& lo flange, and steel .


BTW these https://problemsolversbike.com/products/cable_doubler
[TABLE="class: part-nums"]
[TR]
[TD]BR3341[/TD]
[TD]Cable Doubler 1:2[/TD]
[TD]Pulls two brakes with one lever

[/TD]
[/TR]
[/TABLE]

lets you use most any lever

Cyberpaw7

So this is not just my first post on THIS forum, but I'm pretty sure this is my first post on ANY forum. I was very to excited to see a thread like this still relatively recent and hopefully still alive. I saw one of the posts stating that there are only a few people in this thread actually dealing with a missing hand so I figured it could use one more. was born without a left hand and spent my entire life adapting. I'm happy to say there is pretty much nothing that I cannot do. I rode bikes like every kid growing up and took a long leave of absence since I got my license (which I'm sure others can relate to as well lol). What I used to do was flip my left brake lever up and kind of tuck my nubb into the crook of the lever itself. I have the ability to make a very slight "hook" by flexing my wrist which for the most part worked for basic street riding. I naturally favored the rear break and hardly ever used the front brakes. Now here I am wanting to get back into the hobby and I know that I should definitely figure out a safer way to be able to use the front brake while keeping both hand and nubb still attached to the handlebars. I pick up my new Trek Xcal 7 either tomorrow or this weekend so I will soon begin to tinker. I just wanted to let everyone know that you have another mind trying to help out - with an engineering degree as well. I wish I had a machine shop at my disposal but I will do my best to help contribute. This is a weird but comforting feeling knowing that there are others that can relate with me lol.

VegasTriker

I don’t normally read this sub-forum but my eye caught the listing as I opened the forum this afternoon. I ride a tadpole recumbent trike and am familiar with an older version of the Hope hydraulic disc brakes (C2 type on a 2001 Greenspeed GTO). You can steer a tadpole trike by pulling harder on one brake so this is a big problem with anyone who only has the use of one hand. It is difficult to steer straight and also stop if the brake system doesn’t stop each front wheel exactly the same. There is a website dealing with recumbents and I know the question of how to adapt to a single brake handle for mechanical and hydraulic disc brakes has been discussed at least a few times. The site is 'BentRider Online and the sub-forum there would probably be Technical Discussion.

A couple of the trike manufacturers like Greenspeed (AU) and Trident (US) have been using adaptive technology for decades for one-handed braking. You might also find some information at either site.

Don’t worry about replacing brake pads on Hope brakes. You don’t have to buy the Hope OEM pads. Here’s a site that sells replacement pads at a fraction of the price of genuine Hope pads: DiscoBrakes.Com :: Shop :: Disc Pads. I’ve used them for years and am quite happy with the stopping power. Good enough to lift the rear wheel on a trike if you pull hard on the handles.

Rootman

Sorry to jump in, I have no details to offer but I have seen what I think you are looking for.

I met a gent on a trail while stopping for a break, he had a weak left arm and hand due to a congenital defect and setup the right brakes for both brakes. What he had was a mechanical disc brake setup, the levers were stacked on the right handlebar, the front one was a smaller trigger shaped lever that stuck out at more of an angle, was shorter and had a loop in the end for his index finger. The back brakes were the normal braked lever that sat beneath front lever and sat closer to the bar. He said it worked wonderfully for him. He gripped and pulled the front brakes with his index finger and pressed the back brakes with his remaining three fingers. I frankly can't recall what he had for shifters.

Sorry I have no details on where he got the setup, I've never seen him again since that one time either.

Zedoo

Coaster brake on a 3 speed.

When I had a broken hand, I didn't have a coaster brake, but the bike was slow enough for one brake.

twolegs

Great posts, thanks for this as my brother has one hand and I will show him these comments

cdRomio

I got flat bars on my hybrid bike with shimano lx dual control levers, those lever allows you to control hydraulic brakes and shift gears with one finger simultaneously or independent whatever you want. Here's some video showing its operation (note: there is mechanical brakes variant on video but it works the same way).
I am sure with some modification (just grind the hook that holds the shifter cog) this lever can be adapted to control mechanical disc brakes with shifter cable. In result it will be somthing similar to already mentioned Oli Sparrow X flow but at least it can be bought without problems. Although dual control levers wasn’t so popular and they are no longer produced, but there are many of them on ebay, just search for “SHIMANO M585” or “SHIMANO M765”, or gogle for “shimano dual control mtb”.
I apologize for the quality of photos, I had to take them in a haste.

1handrider

I use a Duel brake lever on all my bike, which enable you to control braking bias independently

Dual Brake Lever - Brake Levers

Using this brake lever in combination with V-Twin Brake | Hope Tech | Made in Barnoldswick, England should give you the ability to control braking bias on hydraulics independently.

Little late, but hope it helps