"Poor Man's" aero brake

[Tom_Anhalt]

Greg gave me this idea a few months ago, and I finally got around to cobbling it together and trying it out. It's a front brake made from the REAR Oval (or Tektro) "aero" brake. Instead of the noodle coming in from the side like a MTB V-brake, I modified it to work with a center-pull type straddle cable. The "straddle" is a cut down DiaCompe unit and the cable stop on the one end of the straddle cable is a removable one I got from Rivendell. The cable stop at the headset is a CX unit. Got it together and there's plenty of clearance to get the wheel in and out without releasing the straddle, and the power seems pretty adequate on a bench test. I'll try it on the road tomorrow.

[acoggan]

Very nice! Maybe you should start assembling conversion parts kits and offering them as a package along with detailed instructions on how to do this yourself?

Me, I simply opted for a nicely rounded DiaCompe BRS200 brake, which I retrofitted with some old Shimano 105 brake blocks that are molded as one piece, i.e., no pad holder or separate wheel guides. I don't know if it is more or less aero than any alternatives, but it was cheap, and I don't know if I could squeeze a centerpull style brake under my bars/stem anyway. I do know this, though: there's nothing more aero than my (non-existent) rear brake!!

[gregclimbs]

very nice...

the two things I would mention is that fsa makes a nice integrated cablestop headset that would lower stack a LOT... they are for cx brakes.

and I still think you could reduce the size of the "pill" and get the it cleaner a bit...

g

[Tom_Anhalt]

Very nice! Maybe you should start assembling conversion parts kits and offering them as a package along with detailed instructions on how to do this yourself?

Me, I simply opted for a nicely rounded DiaCompe BRS200 brake, which I retrofitted with some old Shimano 105 brake blocks that are molded as one piece, i.e., no pad holder or separate wheel guides. I don't know if it is more or less aero than any alternatives, but it was cheap, and I don't know if I could squeeze a centerpull style brake under my bars/stem anyway. I do know this, though: there's nothing more aero than my (non-existent) rear brake!!

Do you mean something like this?



That's what was on there before I did this...well, the Cane Creek version anyway

[Tom_Anhalt]

very nice...

the two things I would mention is that fsa makes a nice integrated cablestop headset that would lower stack a LOT... they are for cx brakes.

and I still think you could reduce the size of the "pill" and get the it cleaner a bit...

g

I'm not done yet

Actually, now that I've got the threaded pieces for the cable housing stop, I'm thinking that a nice tapped hole through the stem would be pretty slick (like on your DA) and the cable routing would be much nicer above the stem rather than trying to "sneak" it under the stem.

Also, I agree on the "pill" for the straddle cable end...of course, knowing that the 2 holes in the ends of the arms (the ones facing fore/aft) are threaded AND in the same plane...I've had some ideas of a simple "actuator" that gets rid of the straddle cable and just uses 2 small linkage arms that attach to a center "pull" piece. I'm sure I could make it a bit more "sheltered" as well

[alvaro]

first of all, hi to everyone... I was directed here by tom fron ST, and I'm sure I'll find much more useful info here and much less noise.

I'm a Spanish triathlete so you can share your speed secrets with me, It's very unlikely that we race against each other

Tom, have you 'chunged' the PMAB already, did you find any noticeable gains?

cheers, alvaro

[Tom_Anhalt]

first of all, hi to everyone... I was directed here by tom fron ST, and I'm sure I'll find much more useful info here and much less noise.

I'm a Spanish triathlete so you can share your speed secrets with me, It's very unlikely that we race against each other

Tom, have you 'chunged' the PMAB already, did you find any noticeable gains?

cheers, alvaro

Hi Alvaro!

No, I actually haven't "Chung'd" it yet...but compared to the relatively low-profile single pivot brake that was on there previously, I'm not thinking it would be a huge difference, especially at low yaw angles. Based on the data that Damon Rinard took with the "John Cobb mod" style brake, my speculation is that I'd see greater gains at higher yaw angles (and depending on which way the yaw was coming from) as compared to a normal caliper.

I mostly did it as a sort of "what if?" type project. As I allude to above, I'd like to make the actuation a bit more solid...and at the same time perhaps "smooth out" the surfaces presented to the airflow. It's basically a work in progress still

[gregclimbs]

well???

inquiring minds wanna know...



g

[Tom_Anhalt]

well???

inquiring minds wanna know...



g

Are you referring to me? I still haven't done any Chung testing on that...don't know when (or if) I'll get around to it. How's the testing on the "twins" coming

[alvaro]

hi tom,

why a rear brake? can it be done with a front one?

how did you fit a rear into the fork?

any chunging done so far?

cheers, alvaro