I have had some down time, so I figured I'd overhaul my bike (re-cabling, cleaning, fine tune adjustment, etc.). This made for a perfect opportunity to work on my rear brake.
The DA's rear brake is notorious for being an issue. Regardless, I hope this helps. I'll try to do my best explaining the process, but if I miss something or give bad knowledge/advice please let me know.
Here's a picture of how dirty the ring is.
Soaking in distilled white vinegar.
Cleaned
Disassembled
Partially assembled
Drive side brake arm. Assembly is the same as the non-drive arm.
7. Reinstall the drive/non-drive arms back onto the bike. Put a small amount of grease on the main bolt. On the underside of the frame you have the two brake arm posts. If you look closely there are 3 holes next to each post. This is for your main (major) spring tension adjustment. Be sure to clean both sides thoroughly. Start off by putting each spring arm into the middle/center hole.
8. Check that both arms move freely. If you are hearing a squeaking/rubbing sound, remove the arm and flip the spring.
9. If you haven't already, install an inline barrel adjuster on your rear brake cable running into your aerobars. This is absolutely essential for being able to get nice, tight brakes and still be able to remove your wheel.
10. Clean the brake noodle. Ideally, you would just replace this part. On the inside of the brake noodle there is a clear housing. Chances are it'll be grimy. I've read that some people have cleaned and filled this with grease to prevent dirt from entering. I prefer not to add grease. As long as your brake cable can travel through the noodle with minimal friction, I think you should be ok.
11. Install the noodle back onto the housing.
12. Run your brake cable back through the housing. You want to make sure the housing is the right length and runs directly into the noodle to reduce friction.
13. Pull together the arms with one hand and use the other hand to insert the noodle end into the drive side arm. While holding the arms together pull the cable through the non-drive side and tighten the cable bolt.
14. Make sure your inline barrel adjuster is screwed all the way clockwise. This will allow the brake pads to be farthest/widest apart.
15. Squeeze your brake lever and look at the brake arm movement. You want symmetric arm movement. To make adjustments tighten/loosen the fine adjustment bolt on each arm. Don't worry about getting it perfect right now.
16. Put your rear wheel back on.
17. Align your brake pads and tighten the bolts. Again, don't worry about it being perfect.
18. Tighten up the brake arms. Hold the arms with one hand, loosen the cable bolt, pull the cable tighter, re-tighten the cable bolt. You want to get the arms as close as you can to the wheel so long as you can still pull the wheel off without it rubbing the pads.
19. Screw your inline barrel adjuster counter-clockwise. This will bring the brake arms closer to the wheel. Now it's time to fine adjust everything to where you want it. Remember that you want both arms to contact the same time. This will take some time to get the hang of it. Fortunately, after you do it enough it'll be a faster process. Align the brake pads so that they are completely parallel to the rim when they make contact. Also remember that you can adjust the angle of the brake pads as you tighten them down.
20. Double/triple check everything. Make sure you get it exactly how you want it, so you don't have to remove the crank again.
That's it. It really isn't complex. Just a massive pain in the ass that takes time to get the hang of.
If you have any questions or knowledge to add, feel free to post it.
Edit to add in:
I went ahead and ordered some new brake pads. I didn't take any pictures, but there was a significant difference between the new pads and the old. Best to check your pads as well.
The DA's rear brake is notorious for being an issue. Regardless, I hope this helps. I'll try to do my best explaining the process, but if I miss something or give bad knowledge/advice please let me know.
- Remove the rear wheel and crank. It's nearly impossible to work on the brake with the crank installed. You can do fine adjustments, but that is all.
- Release the brake cable by unscrewing the cable bolt.
- Remove the crimp from the brake cable and pull off the brake noodle. (This is a perfect time to replace your housing/cables)
- Remove the drive/non-drive arm of the brake by unscrewing the main bolt.
- For ease of mind, keep the brake arms separate.
- Completely disassemble the brake arms and clean. This is a very important step. A requirement for this brake to function is the necessity for it to be clean. I soaked several of the parts in a cup of distilled white vinegar overnight. This will help remove any rust formation. If needed take a toothbrush/cloth to remove additional dirt. Be sure to rinse with water and completely dry. Reassemble the brake arms. It is important to note, that you should not use any form of lubrication.
Here's a picture of how dirty the ring is.
Soaking in distilled white vinegar.
Cleaned
Disassembled
Partially assembled
Drive side brake arm. Assembly is the same as the non-drive arm.
7. Reinstall the drive/non-drive arms back onto the bike. Put a small amount of grease on the main bolt. On the underside of the frame you have the two brake arm posts. If you look closely there are 3 holes next to each post. This is for your main (major) spring tension adjustment. Be sure to clean both sides thoroughly. Start off by putting each spring arm into the middle/center hole.
8. Check that both arms move freely. If you are hearing a squeaking/rubbing sound, remove the arm and flip the spring.
9. If you haven't already, install an inline barrel adjuster on your rear brake cable running into your aerobars. This is absolutely essential for being able to get nice, tight brakes and still be able to remove your wheel.
10. Clean the brake noodle. Ideally, you would just replace this part. On the inside of the brake noodle there is a clear housing. Chances are it'll be grimy. I've read that some people have cleaned and filled this with grease to prevent dirt from entering. I prefer not to add grease. As long as your brake cable can travel through the noodle with minimal friction, I think you should be ok.
11. Install the noodle back onto the housing.
12. Run your brake cable back through the housing. You want to make sure the housing is the right length and runs directly into the noodle to reduce friction.
13. Pull together the arms with one hand and use the other hand to insert the noodle end into the drive side arm. While holding the arms together pull the cable through the non-drive side and tighten the cable bolt.
14. Make sure your inline barrel adjuster is screwed all the way clockwise. This will allow the brake pads to be farthest/widest apart.
15. Squeeze your brake lever and look at the brake arm movement. You want symmetric arm movement. To make adjustments tighten/loosen the fine adjustment bolt on each arm. Don't worry about getting it perfect right now.
16. Put your rear wheel back on.
17. Align your brake pads and tighten the bolts. Again, don't worry about it being perfect.
18. Tighten up the brake arms. Hold the arms with one hand, loosen the cable bolt, pull the cable tighter, re-tighten the cable bolt. You want to get the arms as close as you can to the wheel so long as you can still pull the wheel off without it rubbing the pads.
19. Screw your inline barrel adjuster counter-clockwise. This will bring the brake arms closer to the wheel. Now it's time to fine adjust everything to where you want it. Remember that you want both arms to contact the same time. This will take some time to get the hang of it. Fortunately, after you do it enough it'll be a faster process. Align the brake pads so that they are completely parallel to the rim when they make contact. Also remember that you can adjust the angle of the brake pads as you tighten them down.
20. Double/triple check everything. Make sure you get it exactly how you want it, so you don't have to remove the crank again.
That's it. It really isn't complex. Just a massive pain in the ass that takes time to get the hang of.
If you have any questions or knowledge to add, feel free to post it.
Edit to add in:
I went ahead and ordered some new brake pads. I didn't take any pictures, but there was a significant difference between the new pads and the old. Best to check your pads as well.
