Tandem Cycling - Chop, Chop V-brakes, possible STI compatible for use in Tandems

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ricardo kuhn
12-24-07, 11:11 AM
I modified this brakes for my cross bike and so far the results are very Impresive, to the point I beleive they will work for tandem use so I'm posting it here.

Keep in mind I asume no responsibility on this modification (I'm becoming so american scare of ambulance chasers) since the brake arms are not design to be tread it at that point like you need to do to make them work, then again is more than sufficient wall thickness so for all practical porpuse I think they will for a long time..

Ps: If you are not worry about mud clearance or things like fenders, you can run this brakes using the typical V-brake horizontal set up, just move lower, in the case of the cyclocross bike you need as much mud and tire clearance as possible.


Now for the proper posting
Okay I got tired of adjusting Standard Canti brakes trying to make them stop a little better, so I end up hacking up a set of the newer XT brakes that I never really like, yes to see what will happen.
http://patineto.smugmug.com/photos/235025883-XL.jpg
Yes I know my Hybrid front tire is lamme, I'm waiting for a Little Bro-deal coming soon

As you can see they have tons of mud clearance
http://patineto.smugmug.com/photos/235025912-XL.jpg

I cut them about 3 milimiters above the spring retainer.
http://patineto.smugmug.com/photos/235025966-XL.jpg

For the Quick release side I use a piece from a WTB canti brake, i just tap a 4 mm tread, shape the head of the bolt so the QR WTB piece will not come off no matter what (Shave sides) then I use a spacer about 8MM long (Two spacers from the rollers of a 8speed chain)
http://patineto.smugmug.com/photos/235026001-XL.jpg

The quick release action is super easy.
http://patineto.smugmug.com/photos/235026029-XL.jpg

More than sufficient clearance in between the bolts and the seatstays, at least on the Empella frame
http://patineto.smugmug.com/photos/235026226-XL.jpg

Same thing for the back
http://patineto.smugmug.com/photos/235026306-XL.jpg

Well the best part is that they work a lot better, no mussy feel at the lever, much more braking power,(I can not even run the RED pads in the front since they have to much stoping power)

I don't think they are perfect but for sure they are far better than any cantilever brake I have ever try.
http://patineto.smugmug.com/photos/235026922-XL.jpg

I keep you guys and gals Updated when I find the parts to make prototype number II


Leigh_caines
12-24-07, 11:37 AM
Neat work

JanMM
12-24-07, 01:41 PM
Clever.
But, why not use V-brakes?
STI lever compatibility?


LWaB
12-24-07, 01:56 PM
Close clearances on the pads, just saying...

ricardo kuhn
12-25-07, 03:33 PM
Clever.
But, why not use V-brakes?
STI lever compatibility?

Because you need a "Potentiometer" A device that will change the short pull of the STI lever to the long pull require to operate the ful length V-brakes.

Generation II will use full size V-brakes with a set of "Cams" operated on a linear fashion to decrease cable damage and improve lever feel and performance.

ricardo kuhn
12-25-07, 03:38 PM
Close clearances on the pads, just saying...

Well they are the same as any other V-brake will be, unless I'm not understanding the comment.

so far with about 30% of the STI lever travel I can move the pads from about 1MM away to full stopping power, if I set them loser (more cable travel) I can have about 2mm of brake pads distance for mud clearance but still only need about 55%/60% of the lever pull.


In contrast using cantilever's (even wide type like Mafac's) the brake lever was bottoming out with out reaching full stoping power.