NOTE: Along with my review I've included a tuning guide for new owners of Avid Disc brakes. I included this tuning guide in my review since almost ALL of the Avid brakes I have seen were not tuned as well as they could be, and some actually braked worse than standard V-Brakes. If you're not interested in the tuning guide just jump past the section cleverly named... Tuning Guide!
Thanks for reading,
Openroad


Brakes are a crucial part of any bicycle, whether ridden by an amateur or a professional. Avid has been in the bike component business for over 10 years, and over that time the company has risen to the top level in quality and innovation. Along with companies such as Hayes, Magura, Shimano, and Hope, Avid is building the best disc brakes you can buy for your bicycle. While the aforementioned companies are focusing mostly on hydraulic disc systems, Avid has developed the cutting edge in cable-actuated disc brakes. The Avid Ball Bearing Disc system is simple to use and tune, durable, and effective. Combining the already reliable and proven cable actuated system with an ingenious adjustable floating caliper design allows the user to fine tune the braking feel and force to their preference.

----- Which system is right for me? -----

As of March 2004 Avid is selling 4 different Ball Bearing Disc systems. First we have the 6” rotor road bike version, then the 6”, 7” and 8” MTB versions. The MTB versions are identical except for the rotor size. This allows you to upgrade to a larger rotor at any time to increase your braking power. One problem with going with the largest available size is the increased stress on your spokes and rim. If you have a super-light wheelset the higher braking forces exerted on your hub by a larger rotor size will cause the spokes to possibly pull through your rim with time. The larger rotors also cost more and are heavier, so only buy as much braking power as you’ll need. I personally use the 6” system and find it has plenty of power to stop my 26lb bike and myself (170lb). You can purchase the brakes as a pair or individually. This allows you to mix and match sizes to create your perfect combination. A 7” front paired with a 6” rear is a combo used successfully by some riders I have talked with. Each brake comes with the caliper, pads, rotor, and all mounting hardware needed to install. Remember, cables, housing, and brake levers are not included.

----- Let’s get dirty… can I install and tune these myself? -----

Since very few bikes come with Avid discs, the most common purchaser will be someone looking to upgrade. Since these are a very simple part to install, I know most semi-mechanical mountain bike riders could install these brakes. The only things that might prove difficult are the specialty tools required. As I’ve told other bikers, the labor cost a shop will charge you to install the brake set will pay for the tools required to install it yourself. Once your done, you’ll still have the tools for other jobs in the future! If you already own these brakes, move on down to the tuning section to get your discs working like the bees knees!

Tools needed, info required, and responsibility avoided…

Tools needed:
5mm Allen wrench
Park Tool bike cable cutters/crimpers ($15 - $35)
Ideally you will have a complete set of metric Allen wrenches since some V-brakes have different sized mounting bolts.
About 5’ of brake cable housing ($5)
Two new individual brake cables, I recommend the Teflon coated cables for better corrosion resistance and long term performance. (about $12)

NOTE: Attempting to install these brakes and damaging something else is not my fault! If you don’t have enough mechanical knowledge to change your own tires, install a new chain, or adjust your derailleurs, you should probably leave this job to a reputable bike shop. There is a possibility you could damage your bike’s paint and/or components, in that case you did something wrong and you didn’t hear any of this from me.

Another word of caution, before purchasing a set of these brakes you need to make sure your bike has several important things:

1: Disc brake caliper mounts on your suspension fork and rear triangle.
2: Disc compatible hub assemblies.
3: Avid or Shimano V-brake levers.

The first two things are easy to spot if you know what to look for, or you can take it to your local bike shop and ask them the above questions. Caliper mounts will be two small holes about 2.5” apart on your left fork leg and left rear triangle. Most recent bikes have caliper mounts on both fork and frame… if you don’t have these, a new bike should be your next purchase anyway.

Disc compatible hubs are also easy to spot: Look at your front and rear hubs (the part in the middle of the wheel where spokes meet) and focus on the left side. You should see six holes mounted on a spider shaped section of the hub. These are where your rotor will fasten to the hub, and if you don’t have disc hubs this project will get more expensive. Talk to your LBS about hubs, and then decide if you still want to continue.

Any of the Shimano brake levers will work fine, but XT and XTR models have the best feeling and are a better match for Avid Discs. Avid Speed Dial lever are also a great choice, and if your bike already has them you’re set to go! Simply follow the instruction included with your new brakes and you'll be riding (and stopping) in no time at all.

--------{TUNING GUIDE BEGINS}--------

Since you’re still reading the tuning section, I’ll assume you already have Avid Discs installed and want to make them perform better.

Cable actuated disc brakes can feel much better than V-Brakes and even approach the feel of hydraulic, but they have to be adjusted correctly. First we need to tune the calipers for maximum performance, and then work on the cable tension. This tuning guide isn’t just for new owners, it works just as well for those of you already using Avid brakes. First you need to loosen the brake cable locking screw at the caliper and turn your brake cable adjustment knobs at the brake levers nearly all the way in, which will give you maximum cable slack.

Since both sides of the caliper have independent adjustment knobs, I’ll explain how to get your brakes tight as a drum. The inside (toward the spokes) pad never moves, the outer pad does all the work and pushes the rotor onto the inner pad. Make sure you have the brake cable loose and slack at the caliper. The next step will be easier with the bike either upside down or supported in a bike stand or work bench. Spin the wheel and tighten the inner pad several clicks at a time until it makes contact with the spinning rotor. Back off the knob one click at a time and cycle the brake caliper arm with your fingers each time. Keep doing this until you are 2 clicks away from the pad rubbing the rotor. Check each adjustment with a quick twist of the caliper arm to make sure the pads have taken a set in their new position.

Now turn the outer adjustment knob until the outer pad touches the rotor, cycling the brake caliper with your fingers as you go. Back it off 3-5 clicks from rubbing and test again. Brake engagement should be firm and within the first third of the caliper’s movement. Now is the time to connect the brake cable, and adjust final tension. Insert the cable and pull snugly enough to remove all slack from the brake cable. Tighten down the caliper cable lock screw, and check brake feel at the lever. If there is still too much play before the brakes engage, turn the cable adjustment knob at the brake lever outwards ½ turn at a time until optimal tension is reached.

Repeat these steps for the other wheel and take your bike for a ride. Since you’ve just tuned your brakes yourself, you have a better idea how to adjust them if need be while riding. Congratulations, you just saved yourself a $25 shop charge and more importantly learned more about your bike.

--------{END OF TUNING GUIDE}--------


----- My experiences with Avid disc brakes -----

Since all my old bikes including my 2001 Specialized Stumpjumper had V-brakes I was quite familiar with their downfalls, namely foul weather performance and vague lever feeling. I decided to equip my S-Works Epic with disc brakes right from the beginning and not have to spend the money and upgrade later.

Over 1,000 miles later I couldn’t be happier with my Ball Bearing Disc brakes and have influenced three of my friends to upgrade to Avid BB Discs. During the summer of 2003 I had three races that took place in pouring rainstorms or right after a heavy rain. The advantages disc brakes have over V-brakes was immediately apparent the first time I slowed down after a deep puddle or muddy section. Since the rotor is mounted to your hub the braking surface is far from the rim and any mud or debris from the trail won’t come in contact with your brakes. Several times I had to ride through flooded trail sections with 6-7” of water, and here the brakes did get quite wet. Since the rotors are slotted the water and any residue scrubs off quickly and you still maintain excellent braking power.

If we forget about nasty weather and muddy condition, the Avid discs still give you better control in dry weather. The lever is much firmer and easier to modulate than most V-brakes (except for XTR), and you can apply enough pressure to stop your bike quickly with only two fingers.

----- Bottom Line -----

The two things I consider most important in a mountain bike are its shifting performance and braking power. The Avid Ball Bearing Disc brakes are the very best braking upgrade you can buy for the money. V-brakes get the job done fair enough but fade badly in poor weather conditions and don’t give you top-notch braking power. Hydraulic brakes are the best you can buy for power and lever feel, but require more maintenance and cost quite a bit more. I'm currently running 2004 Shimano XTR Hydraulic brakes on my Epic, and while they do "feel" nicer and stop slightly better they aren't really worth the extra $300.

The Avid Ball Bearing Mechanical Disc brakes have won multiple awards, including Mountain Bike magazine's Best Disc Brake award (Oct '00), Bicycle magazine's Best Mechanical award (Dec '01) and Best Value award (Dec '01), and lastly MTBR.com awarded these brakes their coveted Choice Award for 2003. Many riders have jumped on the disc brake bandwagon thanks to Avid, and are enjoying better stopping power and decreased "pucker factor".

If you only trail ride on smooth trail systems with friends at a recreational pace you don’t really need a brake upgrade. On the other hand, beginner racers, sport racers and hardcore trail enthusiasts will appreciate the benefits and value of Avid discs. You can find these brakes at most local bike shops, or you could look online at e-stores and Ebay.

Thanks for reading, and feel free to comment!
Openroad

Related Reviews:
Shimano BR-M965 Hydraulic Disc Brakes
Shimano XTR RD-M953 Derailleur
Shimano M965 Dual Control Shifters

Recommended: Yes