After trying a Tektro front brake on my bike, only to discover it didn’t actually fit, I decided to build my own. So far there are about half a dozen prototypes. The latest is the pulley operated aero model. I believe this design is unique - at least I’ve never seen anything like it… It works quite well, with the same feel as Dura Ace 7800, but a little lighter with a little less braking power. Is it more aero? I have no idea, but it does look fast. Isn’t that what really matters? There are two other models. They use a link and pivot design, that I believe is also unique. (Although the function is similar to the cam design on ZG brakes) There is a single pivot and a double shown. The double has very strong braking force, but the feel is mushy - too much leverage causing flex in the arms. The single is better, with a little better stopping power than Dura Ace and only a slightly mushy feel.
Check out the pictures below.
Pulley brake operation - the loop is around a ball bearing pivot and works
like a block and tackle to increase the leverage ratio.
Front view
Side view
Closeup (Showing that I should have cleaned it before taking pic…)
Dura Ace - for reference
Weight of the pulley model
Double pivot and link design - third link is needed to keep pads centered
Tektro - also for reference
Light weigt pulley design - works well, just not quite so aero
Single pivot and link design - built very stout to minimize flex
That would be great, except brakes behind the fork are actually slower. Put your regular brake back in front. You’ll be faster than what you’ve got there. A true aero brake in front is faster than a regular brake. But brakes behind are always worse.
I read that. I believe it was mentioned that the advantage was that the wheel could be closer to the down tube with the brake in front. In any case, I believe the difference is very small - and this arrangement looks cool. I love to tinker with these things and at my age I’m not fast enought to take advantage of the added aero.
Is it more aero? I have no idea, **but it does look fast. Isn’t that what really matters? **
Ummm…no. Well, not to me at least…
Interesting concepts, although one of the BIG problems I have with the rear mounted front brakes with both the way you and tektro have routed the cable to them, is that you end up with a fairly significant length of cable housing “hanging out in the breeze” and screwing up the flow over the top portion of the downtube (at least on one side). Due to the downtube being basically a “swept wing” in relation to the air flow, the flow tends to “fall” down the downtube (at least that’s what Mark Cote told me ;-). If you screw up the flow “up top”, it doesn’t really matter a whole lot WHAT the shape of the downtube is after that…it’s all just going to “tumble” down the tube…and that’s not “fast”.
In the first picture, does the bolt on the right function as a pulley to create mechanical advantage? If so, don’t you get a lot of friction on the cable?
EDIT: Never mind. I just read your explanation below the picture. Nice work.
Tom, I agree. However, within the design parameters of a rear mounted brake, there are very few options for cable routing without serious frame mods. By the way, the problem also appears to exist with standard brake configurations (front mounted), I think maybe I’ll try and build a very areo front mounted brake with a central cable routing coming straight down from the top. But it should use the operating design of my rear mounted designs. ie. A pulley or linkage arrangement.
Tom, I agree. However, within the design parameters of a rear mounted brake, there are very few options for cable routing without serious frame mods. By the way, the problem also appears to exist with standard brake configurations (front mounted), I think maybe I’ll try and build a very areo front mounted brake with a central cable routing coming straight down from the top. But it should use the operating design of my rear mounted designs. ie. A pulley or linkage arrangement.
Have you ever thought about running the cable down the steerer tube? Just a thought…
Tom, Yes about the down tube. However, at the bottom, just above the tire is a very small space to turn the cable. Hydraulic is probably the only realistic option for that. Maybe that’s the answer to the cable problem in any case. Tricky to do though…
Couldn’t agree more. That’s one of the the main reasons for doing the brake systems. (And all the feedback is really a great help) I’ve gotten a lot of info from Slowtwitch on improving my speed. Not so much on how to keep the 1945 vintage parts from wearing out though. I’ll see what I can do for a little better (more aero) front brake. Maybe duct tape the shifter cables to the head tube as well. Get them out of the wind. Right now I’m unwilling to drill a big hole in my top tube behind the steerer to route the cables. (They’re hard enough to string through the frame as it is)
That would be great, except brakes behind the fork are actually slower. Put your regular brake back in front. You’ll be faster than what you’ve got there. A true aero brake in front is faster than a regular brake. But brakes behind are always worse.
I cringe, literally, when I see this word used in discussions of bicycle aerodynamics. Let me help you out: “most currently available brakes seem better on the front”.
Is it more aero? I have no idea, **but it does look fast. Isn’t that what really matters? **
Ummm…no. Well, not to me at least…
Interesting concepts, although one of the BIG problems I have with the rear mounted front brakes with both the way you and tektro have routed the cable to them, is that you end up with a fairly significant length of cable housing “hanging out in the breeze” and screwing up the flow over the top portion of the downtube
agreed. what about this as a solution; drill a hole in the top tube and down tube, and run the cable through that, down to the brake. I'm thinking that would be pretty slick. Of course, it involves drilling holes in the frame.
I think if you were going to do that, you might as well make a fork that integrates the brakes into the fork blades, and have the brake cable run down the steerer. Seem like it would be just as much work. It might even be doable with something like an argos fork which is steel and a custom item anyway.
The other problem with routing the cable through the tubes is the forks must move relative to the top and down tubes. Running the cable through the top and down tubes would make steering somewhat of a problem. That’s what started this excercise originally: the Tektro brakes interferred with the down tube when used during a turn. Almost spit me off the first time it happened.
I think if you were going to do that, you might as well make a fork that integrates the brakes into the fork blades, and have the brake cable run down the steerer. Seem like it would be just as much work. It might even be doable with something like an argos fork which is steel and a custom item anyway.
Stephen J
there was a picture of an ancient steel bike which had done this exact thing–and it looked really slick, except for the cable routing. I’ve got the picture…somewhere…
The other problem with routing the cable through the tubes is the forks must move relative to the top and down tubes. Running the cable through the top and down tubes would make steering somewhat of a problem. That’s what started this excercise originally: the Tektro brakes interferred with the down tube when used during a turn. Almost spit me off the first time it happened.
“Ignorance is curable, stupidity is not…”
yeah, there is that… On something like the Felt DA (and integrated head tube/fork) this would probably be more doable. I do wonder if there could be a work-around though?
Sorry, I’m a little slow to get back to this. The “feel” at the lever on the pulley brake is the same as Dura Ace. The actual weight of the caliper is less (see the pictures of them on the scale) and the braking force is a little less. However, the stopping power is more than enough for any race I’ve been in, including some with very tight 180 turnarounds. While riding, I can still stop both wheels on dry pavemant, it just takes more effort to stop the front now. With the double pivot linkage brake it’s too easy to stop the front wheel while moving.
