Brake Lever for Arai Drum brake

[docbluedevil]

We're going to have an Arai drum brake installed on our Co-motion Speedster (on order). It will be set up for the stoker to control the brake from a bullhorn bar. From the Co-motion website, it appears that the brake control is a type of small lever which kind of looks like a downtube shifter lever of yesteryear. Can anyone elaborate how this mechanism works? It doesn't look too intuitive from the pic. Does anyone know if a brake lever similar to ones used on time trial/triathalon bikes could be used to operate the Arai drum brake?

Thanks.
Abe

[TandemGeek]

The generic name is a "bar-end" shifter or, "bar-con" (Suntour's trade name).
http://www.bicyclingdirect.com/pics/ACF6B2.jpg

Bar-end shifters are designed to work at the end of a drop-bar and were pretty much the status-quo shifter for most touring bikes and tandems before the advent of STI. I'm not sure I'd want a bar-end shifter mounted on the leading end of a bull-horn as depicted in the Co-Motion photo as it would seem to be an easy mark for the captain's right cheek. Alternatives would include older MTB thumb shifters or -- although not inexpensive -- using a bar-con in combination with one of Paul's "Thumbies": http://www.paulcomp.com/frmthumb.html

The problem with thumbshifters as drag brakes is, as a consumer you're usually left to purchase a pair of levers and a pair of thumbies. However, it's not unreasonable to imagine that you could easily sell off the "extra" lever and thumbie to another team looking to add a drag brake to their tandem.

As for using other types of "levers", yes, aero-bar levers would work. However, friction type shifters are usually used for drag brakes given how they are used, which is to say that drag brakes are usually set and left "on" to scrub off speed for prolonged periods of time on long descents.

[docbluedevil]

Thanks, Mark for the info.

So, is the bar-con lever either in the on or off position (i.e. leave it "on" for as long as it's needed and then turn if "off")? Or is there some in between setting? Would a aerobar brake lever have to be held for as long as the drum brake is needed for it to work?

I'm wondering if I should have the bar-con up in the captain's compartment if it's just a on/off flip of the lever; I had originally planned for my stoker to control the drum brake, thinking that it required a 3rd hand continuously applying pressure.

Thanks!

[Retro Grouch]

Thanks, Mark for the info.

So, is the bar-con lever either in the on or off position (i.e. leave it "on" for as long as it's needed and then turn if "off")? Or is there some in between setting? Would a aerobar brake lever have to be held for as long as the drum brake is needed for it to work?

I'm wondering if I should have the bar-con up in the captain's compartment if it's just a on/off flip of the lever; I had originally planned for my stoker to control the drum brake, thinking that it required a 3rd hand continuously applying pressure.

Thanks!

That's the advantage of using a shift lever to operate the drag brake. You just flick it on and and the friction shifter holds it until you decide that you don't need it anymore. When I had a drag brake, I liked that because I could control everything myself.

[TandemGeek]

So, is the bar-con lever either in the on or off position (i.e. leave it "on" for as long as it's needed and then turn if "off")? Or is there some in between setting?


In friction mode, bar-con's are infinitely adjustable. Call it progressive resistance; the more cable you take up with the friction shifter (using the same lever movement used by the bar-end shifter to downshift a rear derailleur / upshift a front derailleur) the more braking pressure that's applied by the drum. In actual use, on a moderate to steep descent you might apply 30% drag (moving the shifter 2 "clicks") to scrub-off speed / control your downhill speed in between switchbacks, retaining full use of your front & rear rim brakes for use in slowing the tandem to cornering speeds. The steeper the descent, the heavier the load, or the more speed you want scrubbed off the more brake pressure you apply via the shifter.


Would a aerobar brake lever have to be held for as long as the drum brake is needed for it to work?


Yes it would. Which, if you haven't descended 8 miles of continuous switchbacks with 3% - 10% gradiants, explains one of the other reasons that a friction-type shifter is used for controlling the rear brake: hand cramps. More times than not, someone who hasn't continously used a brake lever on fast, long-winding descents will be forced to stop in order to give their hand a break well before they overheat a tire, bearing in mind that some of the really nasty descents in Europe and North America can take well over 30 minutes to descend. Thus, if you want to do it at 30mph instead of 45, you'll need either really strong hands or a drag brake.


I'm wondering if I should have the bar-con up in the captain's compartment if it's just a on/off flip of the lever; I had originally planned for my stoker to control the drum brake, thinking that it required a 3rd hand continuously applying pressure.


Here's something I wrote for someone back in July of '02 who asked this same question:

"As for who gets it? Wow, that depends on your relationship with your
stoker, your stoker's cycling skills, and their druthers.

If you were likely to have different stokers on rides where the drag brake
was going to be used, you should have it.

If you will have the same stoker and any one of the following is true,
consider putting on the back:

1. Your stoker has expressed an interest controlling the brake.
2. Your stoker sometimes feels uneasy on descents.
3. You'd rather not have to deal with the extra lever and your team
communication skills are excellent.
4. You'd like to get your stoker more involved and think it would be neat to
extend your "team skills".

Otherwise, just put it up front."

Early on, there was no question in my mind that I would have and control the drag brake on our tandem. Several (7) years later, I'm not sure if that would still be my choice as Debbie is now an accomplished stoker who has even taken up riding her own bike -- something she didn't do before we started riding tandems. In some respects it would really be nice to just call out or signal for "brake on / more / less / brake off" and not be left fumbling around with three brake levers and two hands since the place most teams want a drag brake is between the turns or on long, straight fast descents, not in the apex and certainly not when exiting the turns. But, as I wrote in '02, it's really a personal decision for each team.

[zonatandem]

Howdy from Duluth!
If you've been riding TWOgether 7 years we are sure stoker knows your riding style/capabilities.
Brake control on rear of tandem, operated by stoker would be more ideal. If you'd go for full drop bars for the stoker, barcon would be mounted in drop position where it would not interfere with pilot's leg. Would elminate pilot fumbling with extra lever on his front bar and would also be a shorter cabe run.
A set of dummy stoker levers would give stoker more hand positions, including the drops, as opposed to cowhorns; and drops would be a bit more aero.
Co-Mo folks would be glad to make the change; however, your tandem/your decision!

Pedal on TWOgether!
Rudy & Kay/Zona tandem

[docbluedevil]

Thanks for all the info! Makes more sense now. Sounds like the bar-con is the way to go and probably stick with my stoker controlling it. We're also gonna stick with the cowhorn bar for now to give a little more room for my stoker. I can see how the shifter on the cowhorn's bar end could be a problem for the captain's leg, but I don't recall noticing any problems on a similarly set up bike on a test ride. I'm thinking that a stoker with cowhorns would probably have his/her hands on the barends at speed (or at near the ends of the tops). Could a thumb lever/shifter be placed and used there so my stoker wouldn't have to move her hands at speed? I should probably stick with convention, but it's a thought?

Regards,
Abe

[TandemGeek]

We're... gonna stick with the cowhorn bar for now to give a little more room for my stoker.

Just remember where your stoker's nose ends up when she puts her hands on the ends of the cowhorns to get that "extra room". You'll find my comments on Cowhorns elsewhere in the archives; just search on keyword "cowhorn" and userID "livngood".


I'm thinking that a stoker with cowhorns would probably have his/her hands on the barends at speed (or at near the ends of the tops). Could a thumb lever/shifter be placed and used there so my stoker wouldn't have to move her hands at speed? I should probably stick with convention, but it's a thought?

While I'm not exactly clear on where you think the stoker's hands might be (e.g., at the end of the horn where Co-Mo already mounts the bar-end shifter or on the tops near the bend), I'll just note that you can mount a lever in either position. The bar-end shifter obviously sticks right into the open end of the horn of the cowhorn for the more aggressive descending position. As for the tops, an older Shimano or SunTour thumb shifter or a bar-con used in conjuction with one of Paul's "Thumbies" (see link in previous post) can be mounted anywhere else along the bar, although they're usually mounted close-in to the stem clamp (same location of where you would install a computer) so as not to be "in the way" of other useable hand positions on the bars.