brake seatstay mount on the backside instead of top?
 

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Spotted this on a bike recently, and I think I've seen it done that way once or twice before.

http://bikeforums.net/attachment.php...hmentid=404461

Anyone reason why this isn't more common? There's a couple of ideas I have, but they are just speculation, I imagine some of you frame-builders know why, if there's any technical reason.

Tradition, mostly. In the case of the bike in the picture you provided, it allows the straddle cable to pass around the seat tube without interference.

It's a U brake Too . the other place they put them was under the chainstays..

BMX bikes that use U brakes on the rear top of the seatstays also have the cable pulling from ahead of the seat tube..

Yeah, I've had and seen MTB's that have U-brakes under the chainstays. Supposedly, when set up right, they are quite powerful. I didn't know that and cut off the mounts and a friend welded in canti bosses in the usual place, so I've never actually used a U-brake there. Seems common in the years right around '89.

No reason the odd position I originally asked about couldn't be a cantilever though.

I was just wondering if there were any technical disadvantages to that placement other than perhaps harder to service. I figured it was a combination of tradition and meeting peoples expectation of where the brakes should be mounted. If there's no disadvantages to it, I'm surprised someone hasn't reprised it recently to stand out or in an attempt to make the bike appear "cleaner" or less cluttered looking.

under the chain stays was apparently a horrible place due to crud buildup. I have seen people say that under the seat stays doesn't work that well, but I don't recall the reason.

Just found a picture, not your bike?
Wouldn't speculate on the service convenience of your bike. if it were.. Burn them off and put cantilever bosses on..

world touring Ian Hibell's bike did something along those lines
http://www.bikebrothers.co.uk/ianhib...2_files/10.jpg
http://www.bikebrothers.co.uk/ianhib...2_files/04.jpg

of course there have been others, just not mass production manufacturers..

I have the rear cantilevers ahead of the seat stays on a frame I built in 1977.
Had to use the short arm Mafacs to get heel clearance.


planning to have something built like that?


Noted under the chainstay U brakes Pad wear tended to be ignored, then the brake pads wore a hole in the tire sidewall .

So actually being up where you could do a safety check easily, could be better

Under the chain stays location was bad for a few reasons. Two not yet mentioned are that the pads are close to a lubed chain (and how many chains get over lubed then splat lube out) and also look at a pro wrench's hands if he's had to service an under CS mounted brake. Like mine there will be small scars from the ring teeth...

As for mounting a SS mounted brake under the stays- this has been done for years. Brake reach is different on either side of the stays. cable routing is different too. Andy.

I hated working on those dang things. They were always corroded and gunked up and in a tight space which made adjustment more difficult and painful. So,not only was the likelihood of doing the safety checks diminished but the fear of finding that work was needed was another reason to ignore them!

And then they started adding Anti Chainsuck Devices which took up more of that real estate.

I think one of the benefits was that they were on bigger tubes so, there was less flex than on thinner seatstays .

My touring bike has a chainstay brake... it works exceptionally well on a bike that sees cleaner riding conditions and less mud than an mtb.

You do have to be attentive to the pad wear and oil contamination has not been an issue, these brakes are fine for people who pay attention to such things and maintain them which excludes a good percentage of the riding population.

Routens did it too in the 50's

http://bikeforums.net/attachment.php...hmentid=404706

from Bikeville thoughts: Yellow Jo Routens Touring/Camping bicycle

I like the idea routing the cable like that, it goes in straight line which should improve the braking feel. However, it's likely more difficult the adjust/install the brakes in this position.

I did something similar but with the brake in the normal position. Cable goes trough the seat tube and post.

http://bikeforums.net/attachment.php...hmentid=404705

my thesis is that just about everything in this regard has been tried many times. If something isn't done, then it probably wasn't a good idea.

The tri-geeks are bringing back chainstay mounted brakes because of aero.

I'd love to see the finished version of the last photo. Really interesting routing. I'm assuming that you had to drill through the seatpost?

Thanks. Yes I'll have to drill though the post... not a big range for saddle heights :) It hasn't been painted yet. It's been done before, I got the idea from J. Heine's Herse which uses a roller behind the lug.

Very nicely done. I've seen other examples on CX frames but I liked your method.

if you look at the 2 pictures linked in 6 (Someone can imbed them if they wish).. running the cables around the seat tube wotks too ..

I just put the Arch for the brake housing stop above the brakes on the same side .. It works fine..



I got the seatpost drilled. my father, retired Machinist made a little ball-roller that slipped inside the seat post to smooth the cable motion

eliminating the regular hanger off the seat tube clamp bolt.. On the AlAn Cross super .. 25.0 Campag super record if anyone needs one .

With a brake in that position you would be limited to a long transverse cable. If you wanted to increase mechanical advantage by shortening the Transverse cable with that setup you'd be SOL.

Pic is from a Craigslist seller.

Idle curiosity on my part.

Ah! This might be the biggest disadvantage I've seen so far. One of the ways I get the most out of cantilevers is by going to an adjustable straddle carrier and running it as low/wide as I can.