I could not see this anywhere so I thought I would post this up for anyone wanting some direction on how to service these brakes. This process was super easy, uses basic bike maintenance tools, and should not intimidate anyone. Moderator, you are welcome to move this if this is not the right section.Needed tools and supplies:
1) 4mm allen tool
2) Flathead screw drivera
3) Bike grease (I used Phil Wood waterproof grease)
4) Rags & Q-tips
5) Spare tooth brush with soap and a wife-approved sink with running hot water
6) Super glue
This is how these brakes collect dust. This is what you see after a good solid season of crit racing. I could hear the sand/grime crunching away as I would modulate the brakes so I wanted to service them before the anodizing was ground off, causing quicker wear. They use a red grease from the factory so I thought it was suitable to use the bike grease I had even though we know it will collect dust as the factory grease did. These areas are not easy to see when the brakes are mounted, so just get your ear down by the brakes and modulate the brake levers...if it sounds like sandy ball bearings crunching against each other, then it is time to service your brakes.
1) Use the 4mm allen to crack the two pivot bolts loose before removing the brakes from the bike. Be careful not to scratch anything in the process when they break loose. These can be easily loosened when the brakes are off the bike, but that process is a little more awkward since the leverage is just your hand strength. Please note: If you try to break these bolts loose from the back side of the pivot bolts (the side normally facing the bike), the motions are backwards...left tighty, righty loosy.
2) Pull the brakes off the bike and using a flathead screw driver, gently pry the tension spring out of its supports on both sides, easy enough. Push on the spring towards the center of the brake, and once you've cleared the support, gently push up and slowly let the spring push the screwdriver out so the spring is no longer under tension. BE CAREFUL to not jab the screwdriver into your hand. Before you pry the tension spring out, modulate these by hand and you can see how the various pieces move. You should also be able to hear how bad they sound and feel not-so-smooth modulation with all of the various contaminants in the grease.
3) Fully disassemble the three main pieces and take note as to how they go back together.
4) Use the tooth brush, soap, and hot water (as hot as you can tolerate) to get the factory grease, grime, and sand cleaned out.
5) Thoroughly wipe clean and dry all components. A few Q-tips works perfect for getting in the deeper sections and corners. Compressed air is super nice for spraying the excess water out of the tight parts, but a rag and Q-tip worked just fine. Thoroughly inspect for abnormal wear (missing anodizing, scratches, etc.). Check thread condition too, even with silver anodizing, the wear points should be easy enough to see and you don't want to try to tighten the pivot bolts if the threads look like crap.
6) Liberally apply grease to all areas where you saw the factory grease, areas of friction and where you can see the three pieces touching each other, and cover all outer portions of the two pivot bolts. I did not highlight the areas of friction because they are pretty obvious to me. I also pulled the fuzzy stuff off of one end of the Q-tip and used that to help me get the grease into the tighter places.
7) Assemble the smaller pivoting piece onto the center section so the pivot bolt holes align up and insert the first pivot bolt with a few finger turns to hold things in place.
Eight) Assemble the larger pivoting piece onto the center section so the pivot bolt holes align up and insert the second pivot bolt with a few finger turns to hold things in place. Be sure to integrate the left and right pivoting pieces so they mate properly. You will have the excess grease squeezing out, this is fine for now.
9) Use the 4mm allen tool to tighten the two pivot bolts down to just beyond snug (1/16 to 1/8 turn), not too tight. I would rather it be too loose than too tight, stripping things. You can always double check how tight these two pivot bolts are after a short test ride, snug things up if necessary then. Again, too loose is better than too tight on aluminum threads IMO.
10) Use your rag to wipe excess grease from the exterior faces. After the brakes are wiped off, relocate the tension spring in its supports. I could easily get the first one in by hand, then it was easier to use the flathead screw driver to tension and set the other side. Again, BE CAREFUL to not jab the screwdriver into your hand.
Done! Modulate these by hand and you should feel that they are smooth as silk without any sandy crunchyness. Mount these back on the bike and take them for a short test ride. Double check the two pivot bolts and call the jorb done.
In true WW fashion, I found the lightest cable ends possible
. I've used this for a while, it works just fine and holds well IMO.My Comparison KCNC CB1 vs KCNC C7 Brakes:
I also wanted to use this thread to post my comparisons/reviews between the KCNC CB1 brakes and the new C7 brakes. My only experience with KCNC brakes was with the CB1 brakes until now. The CB1s do not bite and the factory pads are to be desired IMO. With that said, their weight to performance ratio is still good IMO. I replaced the front pads with Zipp carbon/aluminum pads and that greatly helped with stopping performance and confidence. I will say that I actually liked how the CB1s (with a front Zipp pad) brake during crit racing...brake that are too good can be a bit scary to deal with upon surprise braking situations. If I had to slam the brakes on the CB1s, I still felt like I had full bike control while hauling ass. The bike was slowing down, but I was not going over the handlebars at the same time.
With that said, I actually appreciate how the CB1 brakes are a little slow to grab. You can see them flex on the bike while you pull the brake levers (this is less the case with the C7s), but I felt I had a better-than-average ability to modulate braking force during braking with these brakes. With the C7 brakes on the bike (using the factory pads), I feel I can flip myself over the bars now. I have not tried, but I don't think I could get the CB1 brakes to fully lock up. With the C7 brakes, I am pretty sure I can lock up the rear wheel and possibly the front...but I don't really want to test that theory.
Again, this is how brakes are supposed to work, but the new C7 brakes are definitely an improvement in breaking performance over the CB1s. I've not had a chance to crit race with these brakes, but I will try to remember to update this post with my impressions after a few races next season. I am sure that I simply need to retrain myself on how to modulate the C7 brakes properly, but I will need to be conscious of this if I jump from bike to bike.
The C7 brakes came with the CB1 instructions, but getting them installed was easy enough with a few minutes of messing around. These brakes still get to a point where the levers flex, but how they perform on the road is much improved over the CB1 brakes. The C7 brakes and factory pads simply grab fast, stop quicker, and require a learning curve with how to properly modulate for varying braking force. Aesthetically, they are very similar to the CB1 in their machined minimalism...something I appreciate.
For this review, please know that I am not the most experienced rider and that I only have Tektro long-reach, Shimano Dura Ace 7800, and late 90s Campagnolo Record (non-Skeleton) brakes for which to compare with.
In summary, on a scale of 1-5 (1 = sucks, 3 = average, 5 = stellar):
CB1 initial grab: 2
CB1 modulation while under braking: 4-5
CB1 stopping power: 3
CB1 ease of maintenance: 5
CB1 long-term durability (with proper maintenance): 4
CB1 overall performance: 3.7 (Average of the above 5 variables)
(The above would be rated lower by at least a factor of 1 with the factory-supplied pads)
C7 initial grab: 4
C7 modulation while under braking: TBD
C7 stopping power: 5
C7 ease of maintenance: TBD
C7 long-term durability (with proper maintenance): TBD
C7 overall performance: TBD (Average of the above 5 variables)
I kept the aesthetics out the ranking because that is more personal opinion. I am appreciative of data, but I've not set up a proper test cell/procedures to get scientific values for the above stuff...so take it for what it is worth to you. I thought of variables in a braking system that are important to me and I did this as an enthusiast rather than a paid professional rider working with an unbiased R&D team. Let me know if you think this post was helpful and I will try to capture the servicing process of other WW (and general bike) parts? I don't have tons of WW stuff, but enough for a few How Tos over the winter.
I hope this helps,