Avid BB7 - brake disk and pad options, tandem specific?
#27
Junior Member
Thread Starter
Some questions: what exactly does "hilly" mean, i.e. vertical drop, duration of runout, elapsed time to next descent, etc. 200mm rotors are about as big as they get. Teams that used to need a drag brake find that they no longer do with 200mm rotors. Just asking, is it possible that you can experiment with different brake applications the way teams with rim brakes need to to avoid blow-outs. Is it possible to mount a rim brake (hydraulic?) and alternate between the rear disc and rear rim brakes?
Thanks everyone for your input. Appreciate the help! This forum is great.
#28
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I have the Avid BB7's 203mm rotors on my 2009 Cannondale RT2. Just bought the bike a few months ago, PO had flat bars and MTB levers. It would stop on a dime, but screech like crazy. I've just went back with road bars and 105 brake/shifters.
I used my orbital sander and scuffed the rotors good, put new avid pads on, and bedded them in. Screech is gone, but I sure don't have the braking power that the MTB levers applied. I think the bike came out OEM with Problem Solvers Travel Agents to increase the amount of cable travel when using road levers, but I'm hoping I can get by without them by tuning the brake pads as close to the rotors as possible. I live west of Houston and it's flat as a pancake; brakes don't get a lot of use.
So I'm not answering any of your question, but wanted to ask you if your Co-motion came with travel agents?
I used my orbital sander and scuffed the rotors good, put new avid pads on, and bedded them in. Screech is gone, but I sure don't have the braking power that the MTB levers applied. I think the bike came out OEM with Problem Solvers Travel Agents to increase the amount of cable travel when using road levers, but I'm hoping I can get by without them by tuning the brake pads as close to the rotors as possible. I live west of Houston and it's flat as a pancake; brakes don't get a lot of use.
So I'm not answering any of your question, but wanted to ask you if your Co-motion came with travel agents?
#29
Rod & Judy
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I'll answer from my point of view, I prefer OEM pads, but have found none that are quiet enough to suit us. Currently using swiss organic, stop well enough (keeping adjusted, etc), but will be honest to say Avid OEM metallic do stop better.
R
R
#31
Senior Member
I have the Avid BB7's 203mm rotors on my 2009 Cannondale RT2. Just bought the bike a few months ago, PO had flat bars and MTB levers. It would stop on a dime, but screech like crazy. I've just went back with road bars and 105 brake/shifters.
I used my orbital sander and scuffed the rotors good, put new avid pads on, and bedded them in. Screech is gone, but I sure don't have the braking power that the MTB levers applied. I think the bike came out OEM with Problem Solvers Travel Agents to increase the amount of cable travel when using road levers, but I'm hoping I can get by without them by tuning the brake pads as close to the rotors as possible. I live west of Houston and it's flat as a pancake; brakes don't get a lot of use.
So I'm not answering any of your question, but wanted to ask you if your Co-motion came with travel agents?
I used my orbital sander and scuffed the rotors good, put new avid pads on, and bedded them in. Screech is gone, but I sure don't have the braking power that the MTB levers applied. I think the bike came out OEM with Problem Solvers Travel Agents to increase the amount of cable travel when using road levers, but I'm hoping I can get by without them by tuning the brake pads as close to the rotors as possible. I live west of Houston and it's flat as a pancake; brakes don't get a lot of use.
So I'm not answering any of your question, but wanted to ask you if your Co-motion came with travel agents?
My experiment with Short Pull levers, MTB calipers and Travel Agents can be seen here, note the DIY brake booster because the inline Travel Agents create a ton of drag that BB7 calipers cannot overcome. Standard Travel Agents will not work with disk brakes, you must use the inline version shown in the picture. As far as I know they are no longer made. I got mine for a very good price and only used them for a couple of seasons, and I am willing to let them go for postage as I no longer need them. You will need them if you want to use road levers with those calipers. And you will probably need to fashion brake boosters for your calipers which as it happens was recently discussed in the thread on TRP Spyres nearby in this forum.
#32
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They are Avid BB7 Road calipers; PO had just went to mountain levers. I'm now back to drop bars and road levers Shimano 105. However I don't have compressionless brake cable housing on it, maybe that's where my problem lies. I just restrung it recently with new Jagwire https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1.
Not only is compressionless brake housing more expensive, on their site they say to use ez bend housing segments - I assume because the compressionless housing may be too stiff to fit up next to the road bars at the bends. And new bar tape again... Good grief!
Not only is compressionless brake housing more expensive, on their site they say to use ez bend housing segments - I assume because the compressionless housing may be too stiff to fit up next to the road bars at the bends. And new bar tape again... Good grief!
#33
Clipless in Coeur d'Alene
They are Avid BB7 Road calipers; PO had just went to mountain levers. I'm now back to drop bars and road levers Shimano 105. However I don't have compressionless brake cable housing on it, maybe that's where my problem lies. I just restrung it recently with new Jagwire https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1.
Not only is compressionless brake housing more expensive, on their site they say to use ez bend housing segments - I assume because the compressionless housing may be too stiff to fit up next to the road bars at the bends. And new bar tape again... Good grief!
Not only is compressionless brake housing more expensive, on their site they say to use ez bend housing segments - I assume because the compressionless housing may be too stiff to fit up next to the road bars at the bends. And new bar tape again... Good grief!
#34
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Verbosity
Welcome to the site!
The BB7 was designed for single bikes, and it has largely fallen out of favor due to far better designs. It's rare to find the BB7 on new single bikes (mid to high-end) due to its single piston design. The BB7 uses one piston to push a pad against the rotor until it flexes against a fixed pad. It's difficult to setup the BB7 to be quiet and provide enough braking power for steep descents. The constant rubbing may explain your warped rotor.
By comparison, the TRP Hy/Rd and Shimano R785 hydraulic brakes use dual pistons to squeeze the rotor from both sides. They're quiet and are powerful enough to long, steep descents (8-12%). The Hy/Rd should be compatible with your Shimano 105 shifters, while the R785 brakes will require new shifters. Check with Co-Motion to see if the Mocha rear triangle can handle a hydraulic brake. If your team weight is around 300 lbs, you can probably use 180mm rotors with the R785.
In our experience, the Hy/Rd and R785 are substantially better than the BB7, regardless of the pad or rotor combination. If the BB7 is not good enough for a 170lb rider on a single bike, why use it for a 300lb tandem team?
The BB7 was designed for single bikes, and it has largely fallen out of favor due to far better designs. It's rare to find the BB7 on new single bikes (mid to high-end) due to its single piston design. The BB7 uses one piston to push a pad against the rotor until it flexes against a fixed pad. It's difficult to setup the BB7 to be quiet and provide enough braking power for steep descents. The constant rubbing may explain your warped rotor.
By comparison, the TRP Hy/Rd and Shimano R785 hydraulic brakes use dual pistons to squeeze the rotor from both sides. They're quiet and are powerful enough to long, steep descents (8-12%). The Hy/Rd should be compatible with your Shimano 105 shifters, while the R785 brakes will require new shifters. Check with Co-Motion to see if the Mocha rear triangle can handle a hydraulic brake. If your team weight is around 300 lbs, you can probably use 180mm rotors with the R785.
In our experience, the Hy/Rd and R785 are substantially better than the BB7, regardless of the pad or rotor combination. If the BB7 is not good enough for a 170lb rider on a single bike, why use it for a 300lb tandem team?
interesting thoughts....maybe from “your experience”.......a little immodest if you don’t mind me saying so.......
#35
Senior Member
Our 2005 Flatbar Road Tandem came stock with BB7 x 160mm rotors. The shop didn't know how to set them up and we didn't know any better. We moved cross country with the tandem and joined a tandem club in Portland, OR. We did screaming descents at 40+ mph a time or two. We did finally get it to a shop that understood how to set them up, not that it made much difference. Even mis-adjusted they were able stoppers. I 'upgraded' to drop-bars and by this time (2016) the BB7's were feeling the heat from the dual piston designs. So we 'upgraded' to TRP Spyres. Not from any lack on the BB7, just because we could.
#36
Senior Member
we just put on shimano deore 4 pistons with 203 rotors on our tandem. ice tech with finned pads and the rotors. the front especially in the cold warps for a few seconds or so after short braking sessions. but the back is always stable just the front,
#37
Senior Member
Before the advent of disc brakes, tandems used to have drag brakes for use on long descents. The drag brake was mounted on the rear wheel on the side opposite the cogs. There is no space for a drag brake there on a bike with disc brakes. Perhaps someone will develop a front wheel with a disc brake on one side and a drag brake on the other.
#38
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There is nothing comparable to the heat dissipation of the Arai drum. Unfortunately, disc brakes have overwhelmed the market. Great for single mountain bikes during short stops, but for tandems, discs are a new age "product" for something that was solved years back with the Arai. We descended Mt. Lemmon (AZ) the other day on our newer tandem (no Arai), the 5% grade was ok for an unloaded tandem, but on the edge for 2 tall people. If we were heavily loaded on tour, the discs would fail on such a descent. Think about that when staring down a mountain pass the next time.
#39
Senior Member
It would not be my thinking that a tandem with two modern hydraulic disc brakes with 203mm rotors of an 'Icetech' kind of technology would have heat dissipation capacity inferior to an old style Arai drum brake! But, if I'm wrong, then the solution of course is to buy another tandem with an Arai drum. It will have to be used and probably be from the mid to late 90's but it will probably be cheaper than just the brakes of a 2020 spec tandem. Surely the supersaver shopping tip for the 2021 touring season.
#40
Senior Member
It would not be my thinking that a tandem with two modern hydraulic disc brakes with 203mm rotors of an 'Icetech' kind of technology would have heat dissipation capacity inferior to an old style Arai drum brake! But, if I'm wrong, then the solution of course is to buy another tandem with an Arai drum. It will have to be used and probably be from the mid to late 90's but it will probably be cheaper than just the brakes of a 2020 spec tandem. Surely the supersaver shopping tip for the 2021 touring season.
#41
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The only issues we have had with disc brakes on our tandem were fade in a panic stop and rotors warping.
The panic stop was from about 50 MPH to 0 on Shetland on a downhill blind corner with a 12% slope with a tail wind better than 40 MPH. The total weight of riders, bike, and luggage was a little over 500 pounds. The brakes returned to normal operation once they cooled a bit. The issue was solved by switching from Hope E4 ("Enduro") calipers to Hope V4 ("downhill") calipers. These calipers are mostly a flat bar solution, but if you can find a now discontinued Hope V-Twin master cylinder they could be used on a drop bar bike. Hope also makes calipers which are compatible with Shimano or SRAM master cylinders which others have used successfully.
The warpage issue seems to have been solved by switching to a Shimano IceTech rotor in front and a vented Hope rotor in the rear. If the front warps, I will get a Hope vented disc to replace the IceTech, since the IceTech fitted to the rear did warp, while the Hope vented rotor has not. As others have pointed out, the Hope vented rotor is thicker than their standard rotors, and will probably not work with other calipers.
The panic stop was from about 50 MPH to 0 on Shetland on a downhill blind corner with a 12% slope with a tail wind better than 40 MPH. The total weight of riders, bike, and luggage was a little over 500 pounds. The brakes returned to normal operation once they cooled a bit. The issue was solved by switching from Hope E4 ("Enduro") calipers to Hope V4 ("downhill") calipers. These calipers are mostly a flat bar solution, but if you can find a now discontinued Hope V-Twin master cylinder they could be used on a drop bar bike. Hope also makes calipers which are compatible with Shimano or SRAM master cylinders which others have used successfully.
The warpage issue seems to have been solved by switching to a Shimano IceTech rotor in front and a vented Hope rotor in the rear. If the front warps, I will get a Hope vented disc to replace the IceTech, since the IceTech fitted to the rear did warp, while the Hope vented rotor has not. As others have pointed out, the Hope vented rotor is thicker than their standard rotors, and will probably not work with other calipers.
Last edited by DangerousDanR; 01-03-21 at 10:20 AM. Reason: correction
#43
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Please enlighten me about my "immodest" thoughts.
#44
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This is old news, LOL. Is there any who still thinks that the BB7 is close to the performance of a cable-actuated hydraulic disc brake (eg. TRP Hy/Rd) or a full hydraulic disk brake (eg. Shimano R786, BR-R8070)? Just read bike magazines or walk into bike shops.
Please enlighten me about my "immodest" thoughts.
Please enlighten me about my "immodest" thoughts.
hey everyone look at me i know a lot about nothing really and I’m going to tell you all about me