World's first wireless braking system - is this the future of wireless tech?
GMBN's Blake Samson builds his own wireless brakes and tests them out on a downhill mountain bike trail
Alex Hunt
Junior Tech Writer
The concept of wireless brakes has been around for as long as wireless groupsets. It seems like the natural direction for bike tech to go, but in the past seven years since we first saw those groupsets, nothing has progressed. This is why GMBN presenter Blake Samson decided it was time to take matters into his own hands and set about creating a pair of homemade wireless brakes built from RC car parts and consumer-level electronics.
It's not the first time Blake has taken a seemingly crazy idea and turned it into reality. In the past, viewers of our sister channel GMBN have seen him build a bike cave, convert a van and even build his own mountain bike frame! In the most recent instalment of his Blake Builds series, he set out to make something that many thought would never exist. So just how did he create a wireless braking system and was he brave enough to put it to the test? Well before we answer that question let's take a look at why no-one has attempted this before.
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Why aren’t wireless brakes already a thing?
In a world where bikes are covered in wireless electronics, it would seem to make sense to completely remove cables and hoses from our bikes.
We've had electronic groupsets for nearly 15 years now, and wireless groupsets have been around for seven. The technology is clearly in a place where we could have wireless brakes, so why don’t we?
© GCN
Shimano's Di2 platform came in to existence as early as 2009 but we have never seen a Dura-Ace electronic brake
There are a few reasons but perhaps the biggest and most obvious is safety. The main consideration here is the consequence of a system failure. With wireless gears, a system failure can prove problematic, especially if you are 50 miles from home, stuck in one gear. It's inconvenient but not hugely consequential. However if you're hurtling down an alpine descent and there's a system failure with your brakes, the results could be fatal.
This is why wireless brakes have never really been pursued. Brands like Shimano and SRAM certainly have the available budget to design, test, and develop a working wireless brake. It's just not commercially viable for these brands, considering the potential risks it could present. Hydraulic or mechanically actuated brakes are far more robust and dependable. Even in the event of a failure, the other brake will likely still work. With wirelessly controlled brakes, a failure would mean a complete loss of both the front and rear brakes.
How do Blake's wireless brakes actually work?
Unlike Shimano or SRAM Blake didn't have millions of pounds to spend on developing and refining his solution. So he set about using a combination of parts from an RC car and off-the-shelf electronic components that wouldn't need any tailored manufacturing.
To make the build feasible the brake callipers are from TRP and use cable actuation but have hydraulic pistons. This makes the interface that operates the brakes a lot less complex than it would be if using fully hydraulic callipers.
© GMBN
Blake's plan uses off the shelf parts to create a wirelessly controlled servo actuated disc brake
As there is no physical connection between the brake lever and the calliper the actuation unit needed to be housed alongside the calliper on the fork leg and chain stays. To achieve this Blake used some 150kg servo motors. These are small but powerful electronic motors that provide linear motion, which allows the brake cable to be pulled. As the motor moves away from the calliper it pulls the cable in the same way it would if it were being pulled by a brake lever.
A small battery is also required around the calliper to not only provide power for the servo motor but also for the wireless receiver unit that will communicate with the lever.
© GMBN
The servo motor, battery and receiver all needed to be nestled in and around the calliper
Getting the lever to work is an equally ambitious task as it also needs to have a battery and transmitter unit fitted. Without any cable or hydraulic fluid to act as resistance, the brake lever also has very little regard for feel. The lever used was simply the trigger from the RC car remote rather than a specific brake lever, with the only resistance provided coming from the small return spring on the trigger itself.
One of the issues with this build is getting the rigidity for it to work. The servo is mounted on a bracket made from sheet steel that clamps under the calliper. Under extreme braking forces, the tension in the brake cable was enough to bend the bracket the servo was mounted on, resulting in a loss of braking potential. Some vertical reinforcement on the bracket gave it the rigidity needed, however, in an ideal world the servo would be bolted directly to the frame removing this issue altogether.
© GMBN
The brake lever used the trigger from an RC car remote both for the transmitter and actual lever
The transmission unit that communicates between the lever and the calliper has been borrowed from an RC car remote control. To give the brakes a progressive feel when increasing the braking force, Blake has used the throttle control from the remote. This variable switch allows for the sensation of brake modulation.
Putting them to the test
With the brakes seemingly a working reality in the workshop, the next logical step in Blake's mind was to head out to the Forest of Dean in the UK and put them to the test on some mountain bike trails. You can see how he gets on in the video, however, he did run into a few teething issues.
The rear brake lever tended to stick in the fully-on position if the lever was pushed down whilst it was pulled. The result has Blake uncontrollably skidding down the trail to a halt. Fortunately, the same issue did not present itself with the front brake which could have ended in disaster.
© GMBN
Blake did have issues with the rear brake getting stuck on as a result of a sticky trigger
On smooth trails using the levers is fairly straightforward, but when the technical difficulty is stepped up a notch, being delicate with the levers is easier said than done. Hitting a particularly rooty section of trail Blake found that it was hard to be precise with the brakes – something that he notes to remedy in version two!
Drawbacks and considerations
It's fair to say that Blake’s first-generation wireless brakes are a resounding success. While he admits there is plenty of scope for refinement, as a concept, they worked. Is Blake likely to keep them fitted to his bike? We'd say it is unlikely for a few reasons beyond just their rough and ready aesthetic.
One of the biggest struggles with this prototype is that the brake levers had both no feel and very little stroke travel. In practicality, both of these paired together made modulating the brakes incredibly difficult. Blake has suggested that a generation two lever would need to have some sort of adapted leverage ratio or gearing system to provide more lever throw to allow for better fine control.
They were also missing any sense of resistance. Adding some sort of tactile feedback resistance unit would give a more natural feeling to the brake that would once again aid modulation.
Bracket strength was something that afflicted the performance of the rear brake. The shape the bracket needed to be to sit under the calliper clamp bolts and align with the seat stays meant the bracket was susceptible to bending under braking forces. A reinforced bracket could solve this issue but Blake himself found that the rear brake didn’t have the same rigidity as the front brake.
For what was a first attempt Blake proved that wireless brakes could be a reality., with a little refinement.
That being said, we wouldn’t hold our breath on seeing anything like this hitting the production line any time soon. The potential danger associated makes it hard to justify, especially with stealth hose routing making bikes look almost hose-less anyway.
This is certainly one of Blake's wilder builds but we'd love to hear your thoughts on it. Let us know if what you think in the comments section below.
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