Tandem Cycling - STI shifter for actuating drum brake

Hi everyone,

I currently have an old bar top shifter actuating a drum brake. I don't really like this setup because I need to get out of the hoods to actuate/modulate the brake and for some reason the shifter I'm using can't take the tension and slips. I use barends for my shifting which I like.

I'm thinking of getting a right STI shifter and routing the drum brake to the shifting mechanism. That way I can module all brakes without moving my arms. Has anyone tried this before? Any comments?

Thanks,

Seng

Nope...

No, but if you try it, let us know how it goes. Some have tried splitting the cable to actuate both rear brakes with one lever.

No, but if you try it, let us know how it goes. Some have tried splitting the cable to actuate both rear brakes with one lever.

I would think they all failed, it seems it would be very difficult to adjust and you loose independent control of the brakes.

Tohso Let us know how you make out, though I can see some Shimano technician speak like the rocket manufacturer in Apollo 13 "it was never designed for that... it is a contingency we have never even simulated...."

I would think they all failed, it seems it would be very difficult to adjust and you loose independent control of the brakes.


"Tandem" brake levers (http://www.lickbike.com/productpage.asp?PART_NUM_SUB='1347-00') have a dual pull right lever...I believe the original idea was to pull both your drum and rear rim brake with a single lever; my first tandem was set up this way--I noticed no difference in the stopping power after I decided to lighten things up by removing the drum.

I've since met many people who routed both rim brakes to one lever, and the drum to the other. I could not tell you if this works any better or worse.

I tried using some standard drop bar brake levers in the stoker position to actuate and Arai drum. They didn't pull enough cable to do the job. I then drilled another hole in the brake arm - closer to the pivot to make the cable attachment. This reduced the stroke by 30% or so. This still did not pull enough cable. I gave up and went back to the cheap racheting bar top shifter.

However, we rarely use the drum & haven't had it installed for a long time. Rim brakes work OK unless you are doing descents with a lot of switchbacks or have a heavy load.

I would think that the STI duel lever control of indexing would be less than ideal for any brake. First, you have basically 9 or 10 indexed jumps to move the cable( actually that may work very well). Second, in critical situations there is the danger of selecting the wrong lever releasing the brake when you intended on using it or the reverse.

It would be interesting to have indexed control over the amount of braking at the drum. I'd just worry that one click would be too little pressure, and then the next would be too much. I don't think an STI shifter would pull enough cable to effectively brake with just one indexed click, unless you had it tuned just right... and at that point, it might be dragging. Good luck, though, sounds interesting. Wer'e still getting by with a friction thumb shifter mounted on the *stem*.

and then the next would be too much

My experience with the Arai is that there is no such thing as too much. Usually, I wonder "is it really on?"

Wer'e still getting by with a friction thumb shifter mounted on the *stem*.
On the stoker bar of their tandem, Koga Miyata mounts an SRAM X.9 shifter that actuates the drum brake. Neat solution, in my opinion.

STI levers pull cable up to 3 or 4 clicks at a time, which should allow the drum to be fully applied in two throws.

Second, in critical situations there is the danger of selecting the wrong lever releasing the brake when you intended on using it or the reverse.
As far as this goes, even if you were to make this mistake, STI shifters will only release one "gear" at a time. It wouldn't be too catastrophic if this happened. There's always the "regular" brakes, and your hands would already be there since you were working with the STI shifter.

I don't have too much experience with these drum brakes, or tandems in general, really, but if other shifters work for the drums, I can't see any reason STI's wouldn't. They are expensive and fragile, though!

Why not put the front derailler on the STI and put the Arai on the bar end shifter. I control my Arai with a bar end shifter and it works great. There is enough friction in the barend shifter to hold the arai right where I want it.

Using an STI lever sounds like a very creative solution. I have had a similar idea, which may be a bit more versatile (and a lot cheaper, if you are lucky):

I don't have a drum on my tandem, as I still haven't done any loaded touring on it. But that day will come (I hope), and for this purpose I bought a NOS Suntour Command Shifter years ago. As I said, I haven't tried it, but I think it may be the ideal solution for tandem drum brake control.

If you don't know what this thing is, here is a photo http://img2.travelblog.org/Photos/39/50753/t/305463-Take-Command-of-your-Shifts-0.jpg

and a link (in case the photo doesn't make it)
http://img2.travelblog.org/Photos/39/50753/t/305463-Take-Command-of-your-Shifts-0.jpg

It's an early 1990s 7 speed indexed, friction capable shifter that mounts just behind a brake lever on a drop bar. Mechanically it is virtually identical to a bar-end shifter, but the handle and mount have a different shape. Early 1990s Bianchi cyclocrosses came with these.

Here is another nice close-up (click on the third thumbnail), showing the D-ring folded out with which you can switch from indexed to friction mode (like on a bar-end shifter).
http://www.mombat.org/Shifter_Museum.htm

It can be operated while braking with the regular brake levers. From the hoods you can up- and down-shift (release or engage brake; pull or push with thumb) while from the drops I think it is only feasible to release the brake. This seems like an advantage over the STI, with which I think it is rather hard (or impossible?) to down-shift (engage drum brake) while using the regular brake lever. Another advantage is that you have a visual indication of whether your brake is engaged (people sometimes do seem to forget to release their drum brakes at the bottom of the hill, I hear) :). Also, if indexed drum braking doesn't work out too well, you can use friction mode.

Anyway, this is all (still) hypothetical, but seems like a good option. I got mine from an LBS "obsolete" parts bin for $5. Hard to beat, though just now looking on eBay I only saw a complete set (left and right, as well as a front derailer for $80! If any of you have actually tried this setup, I'd be very interested to hear what you think.

Cheers,

Gernot

1993 Ibis Uncle Fester

Gernot wrote of the Command Shifter:

It can be operated while braking with the regular brake levers. From the hoods you can up- and down-shift (release or engage brake; pull or push with thumb) while from the drops I think it is only feasible to release the brake. This seems like an advantage over the STI, with which I think it is rather hard (or impossible?) to down-shift (engage drum brake) while using the regular brake lever.

Chris adds:
How you operate the command shifter is a function of how and where it is mounted. I have mine mounted with the cable running forward and the mount far enough below the brake lever that it rests under my thumb when I am in the drops. This allows me to operate the drum brake in both directions with my thumb without removing my hand from the braking position. See attached.

In reference to the inititial question, the forces involved might be pretty hard on an STI lever. I really like the Command Shifter, but if, as you suggest, you are braking from the hoods, as another option you might look for a Kelly Take-Off and mount a power ratchet downtube shifter on it; power ratchet mechs seem better able to cope with the cable force than modern indexed shifters.

Cheers,

Chris

Umm... How about doing the way it was designed to work?

Better to use the STI to shift gears and the bar end shifter to control the drum.

IMHO keeping your hand on the STI lever to steer, brake and change gear all at the same time is a neat feature that is much better than bar end shifting. I regularly brake into a corner and change down 2 gears or brake to a stop and select the right gear for setting off... Your mileage may vary.

That said I think either way would work fine in theory - it's just indexed brakes are a bit unusual and not really desirable. A second crazy thought would be to use a left hand sti shifter - these normally last longer than the right one, so are often cheap on ebay. Also only 2 index positions - on or off. Only issue would be whether there is enough cable pull.