In today’s send I’m going to talk about brake pads, and how to choose the right one for your riding. I’m also going to talk about how to do a lever bleed in a pinch.

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Brake pads: what are your options, and why you should choose one over the other.

I have been riding mountain bikes with disc brakes for about 20 years, and I know the different types of brakes and pads can be confusing. You will have three basic types of pads to choose from, and each has advantages and disadvantages. The three types are organic, metallic, and semi metallic.

Organic (Resin):

• Made from a mix of organic fibers like rubber and graphite bonded with resin. 

• Provides good initial bite and modulation, making it easier to control braking. 

• Wears out faster, particularly in wet conditions. 

• Quieter than metallic pads.

Metallic (Sintered):

• Composed of a mixture of metal particles like copper, nickel, and iron, bonded together through high heat and pressure. 

• Offers strong braking power and better heat resistance, ideal for demanding descents. 

• Can be noisier and wear rotors faster than organic pads.

• Semi Metallic

  Made from a resin-based compound with added metal particles, providing better heat resistance than organic pads while still being quieter than fully metallic pads. 

  • Good all-around performance in both wet and dry conditions 

  • Better longevity than organic pads 

  • Less noisy than fully metallic pads 

  • May not have the ultimate stopping power of fully metallic pads in extreme situations 

  • Can still glaze under heavy use, similar to organic pads

As you can see a lot of factors involved with choosing the right pad has a lot to do with where and what you ride. A good rule of thumb is to pick pads based on how you ride more often than not. For example if you mostly ride areas that have short punchy ups and downs and you ride downhill a few times a year, a semi metallic pad will be fine even though most downhill riders choose metallic pads. For more casual riding and dry conditions organic pads will have better modulation and quieter. For more aggressive riding with steep and/or wet conditions a metallic pad is best. Semi metallic are a good all around choice since they have properties of both organic and metallic. They are not a magic bullet because they can still glaze under high heat. When you glaze a pad you essentially melt the pad surface with heat caused by prolonged braking, and it becomes smooth and hard. Once they are glazed pads are useless. Glazing can also happen when you are using undersized rotors. For the most part now, manufacturers spec the proper size rotors. Changing rotor size is pretty easy with a new rotor and adaptors.

Bike I’m Eyeing: Kona Process 153

Maintenance files: how to do a lever bleed.

Occasionally you may find yourself with a brake lever that pulls a little too far to the bar. Here you can do a full bleed, but that can take a some commitment and time you might not have. A lever bleed can be helpful in these situations.

First I want to explain a little bit about hydraulic brakes and how they work. A hydraulic brake is a closed system that uses either mineral oil or DOT fluid. They consist of a lever, a hose, a caliper and a rotor. When you squeeze the lever you a plunger pushes fluid down towards the caliper. The caliper has pistons that move out pushing the pads into the rotor slowing you down.

Air is the enemy here. If air gets into you brake lines, levers or calipers you can lose braking power. You might be thinking how can air get in if it’s a closed system? Air can get in if the last bleed wasn’t done properly, or one of the many parts or seals are a little loose. When you have air in the system the lever will go to the bar, and you have very little or no braking power. A quick and easy fix here is a lever bleed. If you need to do a lever bleed there is a good chance you will need to do a full bleed in the near future. If you need to do a full bleed, it’s a good time to change pads if you need to.

In order to do this you will need a bleed cup, brake fluid, and the tools to loosen your lever clamps and the bleed port screw. Most manufacturers will either use torx bits or hex bits here. Usually T25 torx or 4mm hex for the lever and 2.5mm for the bleed port. A word of caution about brake fluid. Some brakes use mineral oil while others use DOT fluid. You need to use the correct fluid. Mineral oil is fairly benign, so if you spill it on yourself, the garage floor etc. it’s not a big deal. You can clean it up with a rag and isopropyl alcohol. DOT fluid on the other hand is pretty caustic nasty stuff. You need to be very careful, and using rubber gloves and eye protection isn’t a bad idea.

First, you want to loosen the lever, so you can make it level with the ground. Once it’s lever snug the bolt enough to keep it from moving. Next, you remove the bleed port screw. This is small flat screw that will sit flush with the lever. There will be a small O ring with it. Be sure it comes out with the bolt. If it doesn’t use a small pick to pull it out. Then you thread your bleed cup into the opening after you remove the screw. Leave the plunger in the cup, and put in a little brake fluid. Next remove the plunger/stopper to allow the fluid to get into the lever. Look directly into the bleed cup and squeeze the brake lever. This should cause a small air bubble to come up. Keep squeezing the lever over and over until this stops. It should only take a minute or so. Once the air bubbles stop, put the plunger back into the cup. If you miss this step you will spill oil once you remove the cup. Remove the cup, and replace the bleed port screw. Clean everything up with isopropyl alcohol. Finally return your brake back to it’s original position. Give the lever a squeeze, and it should feel much better. If not it’s probably time for a full bleed which I will get into in a future issue.

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