disc or drum on tandem?

[David Adams]

We bought a cheap tandem 6 months ago and in that time we have destroyed two rear tyres due (I
think) to the rim overheating on descent.

The bike only has V brakes front and back although there seems to be a spacer on the rear axle where
another brake could be fitted. This would be what I understand is called a drag brake.

The question is - What do I fit?? disc or drum seem to be the obvious choices -- can anyone shed
some light on the pros and cans??

Thanks

Dave and Anne

 

[Anonymous]

"David Adams" <[email protected]> wrote in message
news:[email protected]...
> We bought a cheap tandem 6 months ago and in that time we have destroyed
two
> rear tyres due (I think) to the rim overheating on descent.
>
> The bike only has V brakes front and back although there seems to be a spacer on the rear axle
> where another brake could be fitted. This would be what I understand is called a drag brake.
>
> The question is - What do I fit?? disc or drum seem to be the obvious choices -- can anyone shed
> some light on the pros and cans??

1) Read the archives of tandem@hobbes, accessible via http://search.bikelist.org/. It's a frequently
discussed question.

2) Look at the tandem club discussion board for the same question. www.tandem-club.org.uk.

Summary : Tandems are really hard on drag brakes. Coming down a hill with the brake continuously on
to keep your speed down will generate a _lot_ of heat. Pretty much the only brake that can hack this
is the Arai drum brake.

Avid mechanical discs are not warranted for this use, as they've got plastic bits which could melt.
People have melted the pipes on hydraulic systems.

If you've got a suitable hub (left hand side is threaded), then the arai is pretty easy to fit. If
the frame doesn't have suitable brazeons for the reaction arm, you'll need some form of clamp
arrangement, but this is fairly common.

Your next question is who controls the drag brake. Some say captain, some say stoker. Front
advocates point out that having somebody in charge of a brake who can't see where they are going is
a bad idea, as you could accidentally lock up at an inopportune moment. The traditional cabling for
this is two rims off one hand, and drum off the other. Some rear advocates say the drag brake isn't
strong enough to lock the wheel up anyway, so there's no worry about control. (This is me - I've got
rim brakes for stopping, the drag is just to make hills easier on my hands/tyres).

(If your frame has suitable braze ons, you could try a disc. You can get threaded adaptors to mount
a disc rotor onto a tandem hub where the drum goes. But in this case you would probably want captain
control, as it would be quite easy to lock the wheel with a disk. But I guess since it was a cheap
tandem there won't be any mounts, so this option is really out).

If you don't have a suitable hub (threaded) then don't forget to budget for a new back wheel.

cheers, clive

 

[W K]

"David Adams" <[email protected]> wrote in message
news:[email protected]...
> We bought a cheap tandem 6 months ago and in that time we have destroyed
two
> rear tyres due (I think) to the rim overheating on descent.
>
> The bike only has V brakes front and back although there seems to be a spacer on the rear axle
> where another brake could be fitted. This would be what I understand is called a drag brake.
>
> The question is - What do I fit?? disc or drum seem to be the obvious choices -- can anyone shed
> some light on the pros and cans??

I'd go for the aria drum myself. BUT if its a cheap tandem I imagine it might not have the right
spacings. Even well known tandem specialists might be selling you 130mm. Which is a bit poor.

To get the aria Drum brake to work you will need a rear hub with the right screw thread on. A
standard feature of LX hubs, but perhaps you have standard (non tandem) kit. Having said that
sorting things out for disks might be even more hassle.

Now you can fart about with such things, but I do (have been!) wondering whether its good money
after bad trying to improve a cheapish tandem.

You could also look at the way you go down hills. I either go down at walking pace, or with no
brakes, full yeeehaaah style - anything in between causes far more heating. This might be
inconvenient (40mph, sitting bolt upright pyreneean hairpins, stopping for a couple of mins at each
hairpin) , but it can also be fun (Arran!).

I may end up fitting a drum brake, but I may end up upgrading the tandem its self, the inconvenience
of the above is fairly rare, and I do live very close to some of the hilliest parts of england.

 

[Tony Raven]

David Adams <[email protected]> wrote:
> We bought a cheap tandem 6 months ago and in that time we have destroyed two rear tyres due (I
> think) to the rim overheating on descent.
>
> The bike only has V brakes front and back although there seems to be a spacer on the rear axle
> where another brake could be fitted. This would be what I understand is called a drag brake.
>
> The question is - What do I fit?? disc or drum seem to be the obvious choices -- can anyone shed
> some light on the pros and cans??
>

Arai drum hub with a thumbie gear shifter to apply it - you'll want to leave it on to control the
speed on long descents. Fraction of the cost of a disc brake and handles the heat load much better.

Tony

--
http://www.raven-family.com

"All truth goes through three steps: First, it is ridiculed. Second, it is violently opposed.
Finally, it is accepted as self-evident." Arthur Schopenhauer

 

[Robert Saunders]

"Tony Raven" <[email protected]> wrote in message
news:<[email protected]>...
> David Adams <[email protected]> wrote:
> > We bought a cheap tandem 6 months ago and in that time we have destroyed two rear tyres due (I
> > think) to the rim overheating on descent.
> >
> > The bike only has V brakes front and back although there seems to be a spacer on the rear axle
> > where another brake could be fitted. This would be what I understand is called a drag brake.
> >
> > The question is - What do I fit?? disc or drum seem to be the obvious choices -- can anyone shed
> > some light on the pros and cans??
> >
>
>
> Arai drum hub with a thumbie gear shifter to apply it - you'll want to leave it on to control
> the speed on long descents. Fraction of the cost of a disc brake and handles the heat load
> much better.
>
> Tony

Or for drop bars, you can use a bar end shifter (you can get tandem length brake cables with a gear
nipple at one end and a brake nipple at the other).

I used to have a two-cable brake lever, but didn't like it.

Robert

 

[Marten Hoffmann]

[email protected] schreef ...

> Arai drum hub with a thumbie gear shifter to apply it - you'll want to leave it on to control
> the speed on long descents. Fraction of the cost of a disc brake and handles the heat load
> much better.

Not only does the Arai handle the heat load "much better", it is the *only* brake that handles the
load. There is no disc brake that can safely be used as a drag brake. Period.

--
Regards, Marten www.tandemclub.nl

 

[David Adams]

Thanks for all the advice folks

There seems to be a rather large spacer on the left hand side of the rear hub - possibly where a
drag brake goes on a more expensive model??? I will investigate - but I have to do something - if
the tyre ever went whilst we were still actually on the hill it would not be fun and would upset my
lovely stoker!!

Looks like it's going to be the drum with a lever for the stoker

Dave

 

[Marten Hoffmann]

[email protected] schreef ...
> Thanks for all the advice folks
>
> There seems to be a rather large spacer on the left hand side of the rear hub - possibly where a
> drag brake goes on a more expensive model??? I will investigate - but I have to do something - if
> the tyre ever went whilst we were still actually on the hill it would not be fun and would upset
> my lovely stoker!!
>
> Looks like it's going to be the drum with a lever for the stoker

In the meanwhile you might try fitting the biggest tyre that fits into your frame. The bigger the
tyre, the slower the heating. And remember: bikes are for riding, not for braking ;-)

--
Regards, Marten