Tandem Cycling - Running V-Brakes with STI Road levers, a Different way

And Hopefully a better & long lasting system too.

First point.

I confess have always being scare of the "Travel agent" adapters, I guess working on bikes for a long time you get to see what works, what fails and over the years I have replace way to many Fried brake cables do to the design shortcomings of this system.

Anyway I decide to experience and experiment what will happen if we run drop bars on the beloved IBIS, the only issue was how to run the STI levers and V-brakes at the same time.

Yes many years ago, IBIS came with a excellent design call the "Love Unit" but good luck finding one of them (I have search for one for at least 15 years, silly me I did not get one when I was a Ibis dealer way before that) that works really well with out any of the cable destructive tendencies of the Travel agents.

The Basic Idea is very simple, find a way to multiplied the Travel of the STI road levers that was also bullet proof and simple to use and adjust and I can fabricate or at least made a working prototype with out the need of complex machining operation.

The elements.
2... Cannondale "force 40" brake "multipliers" from the early 90'
2... adjustable Cable stops.
2... Small but very strong "Ferrules"
1... Cheapo stem that I don't care cutting and hacking as much as i need too.
2... 55mm "Axle" to run the two Force 40 cam units. (in this case two old fork brake mounts and a 6mm bolt)
2... flat pieces of aluminum to act as cable stops.
2... "hole" cable adjuster so you can change cable tension on the fly.
2... short road bike brake cables.
2... somehow normal (no need for the tandem length) brake cables (mtb or road bike)
?... a few ferrules and cable ends

First of all I'm sorry since I'm still far better at making things that explain how they work specially in Ingles.

Here you can see the Force 40 cams and the cable in detail, the incoming cable (the shape of the cams) from the STI levers need to be on a almost vertical position so the mechanical advantage of the Cam can be achieve.


The frontal view of the setup with the cable adjusters on the top plate so the cables going to the V-brakes can be adjusted with ease.


The results so far are really promising but the levers still has some of this "Mushiness" that made the force 40 so famous in the old days.


Oh they Stop really well, but the lever most move almost half way to the bars to achieve the goal.

yes I'm still looking for the other roll of Purple/teal tape to finish the bars

The next step is to machine two "Dual diameter" pulleys in the same fashion of the Travel agent but in this case machining the cable routes independent of each other (one with a build in brake stop) so the cable does not get damage in anyway.


Here you can see the front brake being pull and how the shape of the cam varies.


Another side advantage is that you can disconnect the cables really easy if you need to take the drop bars of the bike for transport or change of bars.

Enjoy.

Looks like quite a complex piece of workmanship.Good thing you have a long steerer tube on that fork!
Remember the 'love unit'. Agree the Travel Agents could be tough on cables.
Our solution: V287 levers, barcons, Tektro MiniMax brake in rear, Dura Ace caliper up front.
Let us know how your unit holds up!
The photos/explanation were appreciated!

Sounds like it would be whole lot easier to change your cables once a year.

Looks like quite a complex piece of workmanship.Good thing you have a long steerer tube on that fork!
Yes Zona is for sure more complex than the travel agent's at the end of the V-brakes, but at least this way I can view the cable all the time and see if something is wrong..

The fork is one of my Mountain bike tandem forks a "answer accutrack" if everything goes well I think i will make the IBIS into a 69er or whatever you call when you run a 700c wheel at the front



Remember the 'love unit'. Agree the Travel Agents could be tough on cables.

the Love unit was massive (needs to be so the cables don't get to kink) but you can trust them.



Our solution: V287 levers, barcons, Tektro MiniMax brake in rear, Dura Ace caliper up front.

Well the problem is that i really like how the STI system works so I want to stick with them as much as possible, at least is a bunch of great old school cantilever & cyclocross brakes that work really well starting with the Scott self energize stoppers using STI lever's


Let us know how your unit holds up!
The photos/explanation were appreciated!

So far we have about 40miles of riding (she is about 145 I'm about 220pounds) and they are working really well with out even a losse cable, but only time will tell of the cable durability.

Sounds like it would be whole lot easier to change your cables once a year.


Mike I'm pretty sure you are Right for the most part, but I have seeing cables run with travel agent damage way before a year (maybe poor installation, I don't know) then again is not a big deal to carry a extra cable just in case (I do it on all my motorcycles).

In any case I enjoy making new things and trying silly ideas, plus this way I don't have "Cable splitters" banging on my downtube.

No way i'd run that long a steerer tube with that many different pressure points on it.

No way i'd run that long a steerer tube with that many different pressure points on it.

You are totally Right Joe, t looks really scary.

But the steer tube is being gusset and reinforced inside and I have Zero problems like bulging, bending, cracks, etc using them.

I have four of them that I made for a taller IBIS I use to have and I never got around cutting them down (so glad) two of them with 20mm axles and two with QR's even riding pretty hard on the dirt and rocks since I made them I never notice any shortcomings.

Actually their is only one "Pressure" point, the rest of them are all axial into the steering column (compressing into the headset) is the leverage and torsional loads generated by the bars into the stem and on his own turn the stem into the steer tube, well that is when I'm not carrying a bag or lights on the secondary stem (thanks to Chris tim for the excellent idea), in any case the steer's are totally rigid and solid as they come.

For those of with less time and/or fewer mechanical gifts, how about using a couple of these?

(I bet I could duct tape them to the stem for the same effect.)

I great experiment that if refined could be a great alternative to a travel agent.

For those of with less time and/or fewer mechanical gifts
well senor If you spend more time around you tools you will gain more Mechanical skills, in my case something i like to ply with them more than ride them.

how about using a couple of these?Oh I'm in Love..:love::love::love:

Wow those thing are beautiful, do you have any more information about them, I have seeing them in the past, I think they are made by "Winwood" or something but I can not find them anywhere, I want some for sure...




(I bet I could duct tape them to the stem for the same effect.)

A sure something more elegant than tape can be arrange.

I great experiment that if refined could be a great alternative to a travel agent.

That is the spirit that keeps the world evolving:thumb:

http://www.sidetrak.com/Catalog/components.html

I think they are sold under a few different names. I think mine was called a "Sidetrack Power Booster", or something like that. It's a recommended option for Santana's Winzip disk brake, so Santana dealers should have them.

http://www.sidetrak.com/Catalog/components.html

I think they are sold under a few different names. I think mine was called a "Sidetrack Power Booster", or something like that. It's a recommended option for Santana's Winzip disk brake, so Santana dealers should have them.


Thanks senor i'm on my way to order some right now.

Scott SE brakes?
Specced way back when on our Co-Mo tandem and put 57,000 miles on them. Simple and very effective!

Scott SE brakes?

Oh those "self Energize" brakes are wonderful, so reliable, dependable and powerful, in the old days I use them on my tandem's, loaded touring and also on the Moutainbikes but I think they work far better on the tandem since they are a little to gravy for technical riding.

Oh Boy the U-brake version of the scott's on My GT Avalanche skid the rear tire for miles on end, not that great if you want to save tires and for sure not so good if you actually want to stop.


Specced way back when on our Co-Mo tandem and put 57,000 miles on them. Simple and very effective!

57.000Miles.. Rudi I know many people that call them self "motorcyclist" that don't put the many miles on MotorBike in their life time, Good for you as usual.

Okay I already have two loops to the Marin headlands from San Francisco, not really far but for sure some pretty steep hills to test the brakes, plus a few city trips including one critical mass.

So far the brakes work really well even if I'm not exactly used to the drop bar/STI ergos (no way Lauren can ride as the captain with Drop bars but she can ride in the front with the flat bars no problem), enough to give us full confidence to do anything.

But a even more important and interesting, I think I'm starting to understand why you gals and guys like road specific tandems so much (even if my kaddywompas modified IBIS just give us a glimpse of that a road tandem can really do in terms of speed.)

My soon to be Wife has a Wilier road bike and a Kona cross bike and this clumsy Clyde rides on a Trek madone and also a Empella cross bike, but even with the 26" wheels and not super light components the tandem is already much faster (well even with the knobby tires and flat bars the tandem is really fast) and then she has four more 26" bikes (she does not want to ride because they are to slow) and I have nineteen 26" bikes my self.

Well time to start looking for a nice 700C type tandem frame (I have millions of parts already), since it makes more sense to keep the IBIS as a 26" dirt demon and then get a proper road tandem.

Hi Ricky.

I am also not a fan of the caliper mounted travel agents for the rear brake at least. IMO, they give up the biggest advantage of running V brakes on a Tandem: lower sensitivity to cable stretch. So I run an inline travel agent mounted just ahead of the front cable stop.



With any variable leverage brake system, you need to make sure the mechanical advantage doesn't get too high as the pads wear thin...it looks like this can be adjusted out with your system, but it is the problem that killed the Campagnolo delta brake.

Hi Ricky.

I am also not a fan of the caliper mounted travel agents
I think (I use to think, before reading your argument below) that the location of the Travel agent at the brake was stellar, since you kind of kill two birds with one stone.

*diminish friction from the standard "Spagetti" type routing.
*Multiplication of cable travel.
* you don't need to find a place to attach it, mount it, becomes almost invisible, etc

What I don't like about it, for the same reason i did not like the old Tioga "Vapor" stem (stem with a "Powercam") and many of the early MTB stem with Rollers is that the tight radius of the pulley tends to fry the cables much to fast, specially on designs like the travel agent that require to make a "kink" at the wire that almost assure a short life expectancy and integrity of the wire.


for the rear brake at least. IMO, they give up the biggest advantage of running V brakes on a Tandem: lower sensitivity to cable stretch. So I run an inline travel agent mounted just ahead of the front cable stop.

Senor don Kevbo Your clarity of thinking always impress me:thumb:

I did not even think about that fact but as usual you make perfect sense, maybe that is another reason why this system is working so well.




With any variable leverage brake system, you need to make sure the mechanical advantage doesn't get too high as the pads wear thin...it looks like this can be adjusted out with your system, but it is the problem that killed the Campagnolo delta brake.

Oh you know well enough, I'm all about adjustability and the facility to modified a parts and/or a system with out generating any damage (I test this system with permutations every 5deggres or so before finding the optimal location).

for example The cable at the travel agent will not cooperate if you need to move it to change the progression of the "Cam" (moved fore and/or aft) in reference to the pulley because is being King already in a certain location.

Ps: what a pretty silver thing you have there..



Thanks as usual for your insightful comments.