The B-52 is an electric mountain bike built for speed and power though inevitably you will need to slow down and stop. You could simply wait up to 150km for the battery to run out and glide to a halt, you could use your re-gen button to ‘engine brake’, chances are though you will need to apply your actual brakes, a lot.
‘On the Penny-farthing the brake was a small spoon shaped device’
Stealth’s electric mountain bikes are designed for the off-road and shredding steep single tracks and unless you are Aaron Gwin you will be applying your brakes a lot to get the best line and avoid crashing out. Not all brakes perform the same and some brakes are not up to Stealth’s high standard, this is why all Stealth’s electric bikes are fitted with Magura MT5 hydraulic disc brakes as standard.
To help explain why high quality brakes are so important – especially on an electric mountain bike – we thought we would briefly discuss the history of brakes and why we chose Magura.
As far back as the Penny-farthing bikes have incorporated some form of mechanical brake, on the Penny-farthing the brake was a small spoon shaped device activated by pedalling in reverse, similar to a modern day ‘fixie’.
‘Quick stopping could be prevent serious injury’
As technology progressed and through trial and error the ‘rim brake’ became the standard for mountain and road bikes alike. Rim brakes generally consist of two pads (usually made of rubber) which are positioned either side of a rim, they are squeezed together when the brake lever is pulled. The squeezing action of the pads on the rim slows the rotation of the wheel. They are still used on bikes where reactive stopping isn’t critical such as city bikes, BMX’s and some road bikes.
Rim brakes are a cost effective and generally reliable way of stopping a bike, however their effectiveness is reduced in wet and muddy conditions, they are also not reactive or powerful enough to stop heavier bikes or bikes going downhill at speed. This is dangerous for a mountain bike, where hundreds of braking actuations are made during a ride and where quick stopping is essential to prevent serious injury. Out of these potentially hazardous draw backs the use of hydraulic disc brakes for mountain bikes was born.
‘Compromising on the quality of our brakes is not something Stealth could consider’
Hydraulic disc brakes use hydraulic oil pumped by the brake lever to activate pistons which press brake pads together against a steel rotor fixed to the hub of a wheel. Hydraulic disc brakes are idea for mountain bikes as they are not hampered in wet conditions and offer huge stopping power with only small pressure at the brake lever, all in an extremely light weight package. Safe in the knowledge they can stop faster and reliably, mountain bikers can push themselves and their bikes to the limits, going faster and for longer.
As Stealth’s B-52 electric mountain bike is capable of speeds of 80 Km/h we had to consider how our riders were going to stop themselves. Compromising on the quality of our brakes is not something Stealth could consider, this is why we chose to use Magura MT5 brakes with 203 mm rotors.
‘Large surface area prevents heat build up’
The 203 mm rotors are critical as they provide stronger stopping power due to their increased leverage over the wheel. At high speeds the the larger rotors will stop the bike in a short distance with minimal effort. The additional benefit of 203 mm rotors is the rapid heat dissipation caused by continuous braking and brake dragging, the large surface area prevents heat build up in and around the calipers, a critical feature preventing seals from braking or hydraulic oil ‘boiling’, which could cause brake failure.
The MT5’s like their older brother the MT7’s, have 4 pistons powering the brake pads – fitted on both front and rear wheels. This is two more than standard mountain bike brakes and the performance can be felt on the down hills and when decelerating from high speeds. The brakes perform flawlessly on every actuation and provide a reassuring pull without being too over powering or sensitive. The German Magura’s have been designed with comfort in mind.
For riders wanting to push their performance to the limit we provide the option to upgrade to Magura MT7’s. The MT7’s have an adjustable bite point to provide the necessary ergonomics for perfect brake control, even in the toughest of terrains. They provide unparalleled stopping performance when it matters.
If you would like to know more about our bikes please contact us