7

How are the levers for 3rd brakes on tandems usually set up?

These tend to be additional rear brakes used to keep the speed down when descending, rather than the main stopping devices, and can dissipate quite a bit of heat.

For background, my daughter and I are looking at getting a tandem, having hired one recently. We're pretty flexible about what we get so long as it suits a captain of about 1.95m (6'4") and a stoker who's 1.5m (5') and growing fast. It will be second hand. We're not planning on doing long distances or touring, but might carry a lot of heavy shopping or even tow a trailer. It's not impossible that I'll ride it with friends as well, or lend it to pairs of adults, and then maybe carry more.

We live in quite a hilly area, and many of the available bikes have rim brakes possibly with a drum brake as a drag brake. If there's no drum brake I would consider adding a rear cable disc using an adaptor like the A2Z DM-UNI (I could rebuild the rear wheel myself so it's not a huge expense).

In our particular case, as she's young and prone to grabbing at the brake unexpectedly if she gets scared of the speed, I'd want the drag brake lever to be in the captain's position. But I'd want it to be operable from a normal hand position - and still be able to stop from that position.

I'm open to either drop or flat bars (or indeed something else) for the captain, though we'll probably have flat bars for the stoker.

So as well as the usual setup, I'm interested in other reasonably standard options.

6
  • 1
    I doubt it's relevant to the question, but going by our rental experience she's likely to have to climb up rather than being able to reach the ground. That worked well, but she was used to that on a child seat.
    – Chris H
    Commented Aug 8, 2022 at 13:08
  • 1
    I'm wondering if this is close enough to How to use the 3rd brake on a tandem? as found by Andy P to count as a dupe. I'm on the side of saying it's just different enough but won't push it
    – Chris H
    Commented Aug 8, 2022 at 15:03
  • 2
    I think they are different enough. Yours is about the technical options for having 3 brakes to control. Mine is about how/when to actually use the 3 brakes when setup in the typical fashion. The bar end lever seems incredibly clumsy to me
    – Andy P
    Commented Aug 8, 2022 at 15:22
  • On our tandem, the left brake lever operate both rim brakes and the right lever operate the rear drum brake. This an old (~1980) Velo Gitane tandem and I don't know if this is really up to today's standard. But I would not recommend such a setup, it is quite hard to stop on step downhill roads.
    – Puck
    Commented Aug 9, 2022 at 7:51
  • 1
    @Puck I wouldn't fancy the front brake sharing a lever with anything - both because I don't want it giving up some hand force, and because I want the independence between front and back. A nice hypothetical system might use one lever for the front, and another lever that engages the drum brake first then the rim brakes on a harder pull - if drum brakes don't take too much force. The nice Gitane I was looking at on ebay only has canti brakes (and is too small for me). I'll be looking seriously in a few weeks when I'll have time to collect one, hence the homework now.
    – Chris H
    Commented Aug 9, 2022 at 8:35

4 Answers 4

4

I set up a 1980s tandem with flat bars, front V-brake and rear Magura hydraulic HS33 rim brake. The rear hydraulic brake gives alot of power for relatively little force. Our gear shifters are classic Deore thumbshifters (above the levers) so I used a 3rd lever (usually used in the middle of drop bars as a "crosstop" lever) to allow use of the drum brake with my left index finger. This gives enough control to slow down the tandem (dissipate some heat) with one finger, stop the tandem on the rear brake with remaining fingers with the powerful magura and have full control on the front with the V brake. I wanted hydraulic on the front too but will have to have a new fork made to accomplish this, though the braking is fine with the current setup. Using a LH thumbshifter instead of a bar end is another option for rear drum braking that allows to you set the brake to "on" without changing the control to the rest of the handlebar setup, and this is something I had also considered for this bike.

enter image description here

enter image description here

enter image description here

3
  • That sounds like an interesting setup - stacking rear brake levers somehow felt like it should be an option, and quite intuitive to use. I don't suppose you have a picture, do you?
    – Chris H
    Commented Aug 9, 2022 at 10:47
  • Great, thanks. You've mounted the extra lever a little lower than I would have guessed, which might work well for me (I have very long finger bones, such that I've never been able to set up full-size levers for single finger operation because the lever hits my middle knuckle)
    – Chris H
    Commented Aug 9, 2022 at 12:40
  • This looks like the flat-bar solution to me, now I'm wondering about what I could slightly repurpose on drop bars
    – Chris H
    Commented Aug 9, 2022 at 12:41
6

The typical setup for a drum brake is that it is operated by a bar-end shift lever (friction lever, not indexed) controlled by the stoker to act as a check on an over-exuberant captain. The barcon does not have a return spring, so it's a "set and forget" affair.

Tandem drum brakes are scarce—the company that made them hasn't done so in decades. I'd be cautious about committing to an obsolete technology. I'd also be cautious about putting a disc-brake adapter on any bike, since the forces a disc brake applies to the frame are not forces it was designed for, but I'd be especially cautious on a frame that is as loaded as a tandem.

1
  • I know what you mean about the disc adaptors, but tandem frames are pretty beefy, at least the ones I'd be looking at. And if used as a drag brake the forces aren't so high. If I can get a tandem with cable discs all round as stock, that's good. And plenty of the ones I'm looking at are old enough to have had drag brakes from new. They do tend to be lightly used and stored indoors after all
    – Chris H
    Commented Aug 8, 2022 at 15:01
3

Disclaimer: I've never ridden a tandem so the following answer is all theoretical based on reading.

I did a bit of research into this area around the time I asked this question.

As you can see, in this common setup the captain operates this drag brake by the use of a friction shifter at the bar end. To my mind this is quite a clumsy solution and requires taking the hands off the main brakes. I found that drum brakes were widely regarded as the best type of brake for this application as they are the least prone to overheating.

Since you wanted to operate from a normal hand position, there are various options, each with it's own drawbacks to carefully consider. You could consider the use of a twin pull lever or cable doubler used in two different methods.

  1. You can configure one lever to operate both front and back brakes whilst leaving the other hand free to operate the rear drag brake. This carries a risk of locking up the rear under hard braking - especially when combining with the drag brake.
  2. You can configure one lever for the front and the other to pull 2 different rear brakes which will spread the heat. Skilled use of the brake would be required here since overzealous pulling on the lever would give very powerful braking and risk locking the rear.

A couple of random examples of twin pull/splitting devices:

  1. https://www.tredz.co.uk/.Dia-Compe-Tech77W-Double-Cable-Lever_225443.htm?sku=734951
  2. https://www.tartybikes.co.uk/hydraulic_disc_brakes/magura_mt2_twin_caliper_hydraulic_disc_brake/c558p13126.html
  3. https://problemsolversbike.com/products/brakes/12_-_8816o
2
  • I must admit I like the independence of the bar-end lever, and if used as set-and-forget at the top it frees up the hands to ride like normal. I'd be more keen on that than on various doublers. Another ting I wondered about was a flat bar lever for the drag brake on the bar top, though again you're in a different braking position. A cable disc with sintered pads is essentially heat-proof (unlike the resin-bonded ceramic that contributed to my worst crash by far by melting)
    – Chris H
    Commented Aug 8, 2022 at 14:57
  • (above comment implicitly assumes drop bars)
    – Chris H
    Commented Aug 8, 2022 at 15:48
2

One option that has not yet been mentioned is to install an electric assist motor with regenerative braking option. This would mean a hub motor that either has regenerative braking capability built-in, or the internal freewheel has been disabled. The electronic controller also has to have regenerative braking capability.

The typical hub motors can handle continuous braking up to about 10% grade. The energy will go back into the battery. If you start at the top of a hill with a full battery, it is possible that battery maximum voltage is reached and regenerative braking gets disabled by the controller. Thus it couldn't be relied on as the primary means of stopping, but should be ok as a drag brake.

Front wheel hub motors are quite simple to retro-fit. Steel forks are best for this, and a torque/braking arm connected to the wheel axis gives extra strength also. Hardest part is usually finding a good place to mount the battery.

Typical way to control regenerative braking is to replace one of the existing brake levers with one that has a switch. The electronic brake is applied as soon as the lever moves, even if the brake pads don't actually touch the wheel. Some controllers allow the braking power to be automatically controlled based on wheel velocity, others apply a constant amount. It is also possible to just install an on/off switch instead of using the brake lever.

1
  • Not the solution for me, but have a +1 anyway for an interesting idea. It should be possible to dump generated power into a load resistor when the battery is full, but that might take a custom motor controller
    – Chris H
    Commented Aug 9, 2022 at 19:08

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.