Magura Louise Carbon BAT Review

by Brian Mullin on August 30, 2010

I have been using the very sweet Louise Carbon BAT brakes for just over three months, and they have turned out to be my current favorite stoppers. They are powerful, with good modulation, are quiet, fade resistant, highly tunable and have the bling carbon levers.

Louise Carbon BAT
The Louise Carbon is designed and manufactured in the fatherland Germany (actually in Laichingen), and for 2010 the Carbon’s come in a nifty race white finish. The Magura line of hydraulic disc brakes, includes the weight weenie Marta series, the budget Julie, the Louise and the gravity oriented Gustav. It is interesting, that except for the ultra powerful Gustav, they all have girl names? So considering the Marta’s pedigree, the Louise reminds me of the East German woman swimmers, Anabolic steroid enhanced power machines!

They use an open hydraulic system, with an integrated reservoir and an expansion chamber for fluid temperature control. The aluminum caliper has PM mounts, an adjustable hose fitting, and uses two injection molded composite pistons for less heat transfer to the brake fluid, and the pistons are magnetized for brake pad attachment. The pads come in two models, the default Performance version for maximum power, or the optional Endurance version for longevity. The rotors are sold separately in 160, 180 and 203mm sizes (6 bolt IS or Centerlock) in either the default Drilled SL or Venti rotors. Magura has a wide assortment of adapters so their PM caliper can fit any bike or fork. The hydraulic fluid is Magura’s Royal Blood mineral oil, and the brakes are bled using their Easy Bleed Technology. The aluminum master cylinder, has a carbon lever with reach adjust and Bite Adjust Technology (BAT), and attaches to the handlebars using their Quickfit split clamp system.

Installation
The brakes come with full length lines, so they need to be cut to size, dependent on user preference and bike geometry. I prefer my brakes set up in moto style, with the front brake on the right side. Many years of motorcycle riding has my brain pretty attuned to using the right hand, and in addition, my right has finer motor skills for precision braking.

The lever/reservoir assembly was easy to install, since the Quickfit split clamp doesn’t require the grips to come off. Undo the bolt on the Quickfit, which causes the clamp to swing open, and place it in the desired location (inside or outside shifter pods) on the handlebars, and close it shut and thread the bolt back in. The caliper setup was easy due to the pivoting banjo, which made the hose angle adjusting a snap.

I measured the desired length multiple times (not a place to screw up), and cut them with a sharp set of cutters. Holding the cut section up high to prevent any errant air bubbles, I slid on the sleeve nut followed by the olive, and tapped in the hose insert with a plastic mallet, and finally threaded the sleeve nut into the brake lever, tightening with the proper torque.

Neither brake leaked after the hose shortening, nor did they require any bleeding. The new EBT (Easy Bleed Technology) system which uses a port on top of the reservoir is easy to use, and I have bled my Marta SL Mags a number of times, so I can vouch for the simplicity and ease of the system. Although, bleeding brakes are still like getting poked in the eye, and my preference is non compliance. Basic bleed instructions: level reservoir, unscrew port bolt, insert syringe, unscrew caliper bolt, screw on a filled syringe, push fluid from bottom to top, cycling until bubbles are gone.

Impressions
For the entire testing period, I used the Louise in a 180/160 combination, on my new loyal steed, the All Mountain Yeti ASR 7. The Colorado terrain is predominantly rocky conditions, with many sections of long steep downhills, rock gardens, and ugly loose gravel.

To bed-in the rotors and pads, I drove up and down the street, accelerating, followed by medium braking, repeating this process about 20 times, and then the same scenario for 10 times with a firmer pressure.  This helps burn in rotors, which  integrates pad compound onto their surface, and burnish or polish the pads, both of which give rise to better performance and longevity. The BAT (Bite Adjust Technology), which is the red knob on the lever, allows an adjustment of how far the lever strokes (independent of lever reach) before the pad’s contact the rotor, so you can fine tune where the lever stroke applies the power. The lever reach is adjusted by using a 2.5mm Allen key in the port next to the BAT, which is sort of a pain, and I wish they had on the fly adjuster instead? I preferred a set up with a long reach and a firm bite. The combination of BAT and lever reach allows an entire slew of tunability, dependent on user preference, terrain, bike geometry, etc.

When I first started to use the brakes, I kept locking up the rear, since I wasn’t used to that much power, since these babies are powerful suckers, and I had to use the rear more gingerly. No matter where I was riding or the terrain I was on, I could stop on a dime, and bring my momentum to a quick standstill. The modulation was good, but not on par with the Marta’s, but their Uber power more than made up for it. By varying the amount of force on the levers, you had amazing control and precision, which was always predictable, and could easily scrub off speed anywhere, although their bite (sharpness) might not be for everyone’s tastes, although I liked it just fine. The strength and bite of the brakes, allowed great versatility in technical terrain, and helped with trial moves at slow speeds. The levers had a comfortable, solid feel without any mushiness nor flex, felt good in my hands, and they looked sweet in carbon.

I slammed the brakes as hard as I could, taking them onto the ugliest long steep descents that Colorado has to offer, and they performed admirably, never fading, and allowing a good deal less hand fatigue, even when pulling for prodigious periods of time. I like to ride the brakes on steep terrain to maintain my speed, and the Louise took a lot less effort to scrub speed, just a light feathering was all that was required. I used my Marta’s on the same terrain, and my hands ached, were tired, and scrubbing speed required additional pulling pressure overall. When the brakes got wet in the typical Colorado rain deluge, they would maintain their stout power and control even when soaked. They have stayed pretty silent overall, and only required an occasional sanding of the brake pads to silence them.

The Drilled SL rotors worked just fine, and I never had any warping issues, and they were pretty silent even when pushing the brakes fade limits. They are not the lightest rotors, but they have been reliable and very durable. Even with all the mileages and hard braking I have done, the brake pads have been long lived, and their wear has been minimal. The Performance version of the pads, which I used most often, suit the braking style of the Louise better than the Endurance series.

Measured Specs
Front brake uncut (64″ hose) – 277.2 grams
Rear brake uncut (64″ hose) – 277 grams
180mm rotor – 153.3 grams
160mm rotor -132.6 grams
Front total (uncut) => 430.5 grams
Rear Total (uncut) => 409.6 grams

QM6 adapter (front) – 23.5 grams
QM12 adapter (rear) – 19.2 grams
Bolts – 5.8 grams

Bottom Line
I am not sure how many superlatives can be piled on top of each other to describe the Louise, but they are pretty close to being a perfect brake, albeit they are slightly heavy. The Louise has proven themselves to be tough, robust and a reliable all around brake. They are powerful, fade resistant, quiet, predictable, with a crisp and snappy feel, and offer excellent control and precision. The On Demand power, allows speed scrubbing or an all out stop, anywhere and at any time, with an easy dab from the lever, giving rise to less effort being required and decreased hand fatigue. The carbon levers look good, are light, comfortable, and have a nice feel without any mushiness. The BAT and the reach adjustment, allow lots of tunability, for rider versatility.

They do have a sharp bite, which may or may not suit everyone’s tastes, but I enjoyed the control and feeling that characteristic brought forth. They are not the lightest brakes, but their power and reliability, and inherent features more than make up for this slight deficient. The Louise is the Uber stopping Queen, and are my current favorite brake.

Strengths
- BAT (on the fly): in concert with lever reach adjustment
- Fade resistant
- Uber powerful
- Quiet
- Reliable
- Quickfit slit clamp
- EBT system

Weaknesses
- Lever reach adjustment not on the fly
- Heavy rotors
- Heavy brakes

MSRP: brakes $233 each, rotors $19 each

Overall Rating: 5 Flamin’ Chili Peppers

Magura Louise Carbon BAT Specs
Technical features: Open hydraulic disc brake system with integrated reservoir. Dual piston fixed caliper with automatic pad wear adjustment. Heat Eater: Toolless adjustable hose fitting (45°) with integrated cooler. Pad wear thickness can be checked without removal of the pads. Quickfit brake lever (master) for superfast installation and removal, featherlight 2-finger carbon lever blade with reach adjust and integrated Bite Adjust Technology (BAT) for pressure point modulation. Ventidisc rotor with 15% improved ventilation in three diameters.
Weight: From 439g/0.96 lbs. (Ventidisc) resp. 400g/0.90 lbs. (drilled SL rotor).
Colours: Brake lever and caliper race-white.
Gear Shifter compatibility: Compatible with all Shimano STI, Sram trigger and Sram and Rohloff twist grip shifters. Not compatible with Shimano Dual Control. Dual Docking. Trigger shifters can be mounted both inside and outside the brake lever.
Note: Also available with lighter drilled SL rotor for weightweenies. Ventidisc also available in Centerlock version.
Guarantee: 5-year leakproof warranty after online registration on magura.com

Magura Louise url: http://www.magura.com/en/products/disc-brakes-2010/prod/louise-carbon.html

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