Re: Tandem brakes

[Peter Clinch]

Colin Blackburn wrote:

> wheel. I know tandems need very efficient brakes but is it normal to
> have two rear brakes in addition to a front brake?

I believe my pals' G-twin has something along these lines, though I
can't remember what sort of brake the second one is, but nothing so
serious as a hydraulic disc. Neil said he was thinking of Magura rims
to replace the basic cantis at some point for a bit more ooomph.

> brake used in conjunction with the first or as an emergency brake? Are
> the two rear levers both on the pilot's bars?

Can't answer that for the above, I'm afraid.

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net http://www.dundee.ac.uk/~pjclinch/

[Just zis Guy, you know?]

Colin Blackburn wrote:

> When I went in for the next round I had a look at the then parked up
> tandem, an Orbit, and noticed it had both disc and V brakes on the
> rear wheel.

Are you sure it was a disc? Many tandemists use a drum brake on the rear
wheel to give controlled braking on long descents - this is known as a drag
brake (we have one on our Megabike). It allows you to mitigate the tandem's
tendency to go downhill like a homesick brick without cooking the brakes and
wearing out the rim.

Drag brakes are often worked from an indexed gear lever on the pilot bars.

--
Guy
===
May contain traces of irony. Contents liable to settle after posting.
http://www.chapmancentral.co.uk

Victory is ours! Down with Eric the Half A Brain!

[Michael MacClancy]

On Thu, 03 Jun 2004 09:21:57 +0100, Colin Blackburn wrote:

> I was walking in and around the Howgills over the bank holiday. One walk,
> away from the Howgills proper, took me to Dent. Sitting in a pub at the
> end of the walk, sampling some fine beers from the Dent Brewery, a tandem
> with a baby seat pulled into the outside seating area-cum-car park.
>
> [Aside: The stoker got off and took the toddler from the seat. As she
> walked towards me I noticed she had a Che Guevara (sp?) t-shirt on. Right
> next to me was a Skoda with a Che Guevara stencil on the boot lid. She
> noticed the car's stencil and said to the toddler, "Look Che, it's Che!"
> It turned out the toddle was named Che, after Che G.]
>
> When I went in for the next round I had a look at the then parked up
> tandem, an Orbit, and noticed it had both disc and V brakes on the rear
> wheel. I know tandems need very efficient brakes but is it normal to have
> two rear brakes in addition to a front brake? Is the second rear brake
> used in conjunction with the first or as an emergency brake? Are the two
> rear levers both on the pilot's bars? (I forgot to look, I had had a few
> pints of Kamikaze by then.)
>
> Colin

More than you probably want to know about tandem brakes:

http://www.sheldonbrown.com/tandem-brakes.html
--
Michael MacClancy
Random putdown - "I have never killed a man, but I have read many
obituaries with great pleasure." - Clarence Darrow
www.macclancy.demon.co.uk
www.macclancy.co.uk

[Colin Blackburn]

On Tue, 8 Jun 2004 12:06:32 +0100, Just zis Guy, you know?
> wrote:

> Colin Blackburn wrote:
>
>> When I went in for the next round I had a look at the then parked up
>> tandem, an Orbit, and noticed it had both disc and V brakes on the
>> rear wheel.
>
> Are you sure it was a disc?

Yes, discs front and back with a v-brake on the back. I studied it in
detail but forgot to look at the levers, the second pint of kamikaze had
kicked in.

Colin

[Colin Blackburn]

On Tue, 8 Jun 2004 12:11:50 +0100, Michael MacClancy
> wrote:

>
> More than you probably want to know about tandem brakes:
>
> http://www.sheldonbrown.com/tandem-brakes.html

Which is of course where I should have looked in the first place. Thanks.

Colin

[Clive George]

"Peter Clinch" > wrote in message
...
> Colin Blackburn wrote:
>
> > wheel. I know tandems need very efficient brakes but is it normal to
> > have two rear brakes in addition to a front brake?
>
> I believe my pals' G-twin has something along these lines, though I
> can't remember what sort of brake the second one is, but nothing so
> serious as a hydraulic disc. Neil said he was thinking of Magura rims
> to replace the basic cantis at some point for a bit more ooomph.

Well worth it - the cantis that a galaxy twin came with were rather poor. 7
years on our HS66s are still great.

cheers,
clive

[Just zis Guy, you know?]

Colin Blackburn wrote:

>> Are you sure it was a disc?

> Yes, discs front and back with a v-brake on the back. I studied it in
> detail but forgot to look at the levers, the second pint of kamikaze
> had kicked in.

In which case the V-brake is almost certainly a drag brake.

--
Guy
===
May contain traces of irony. Contents liable to settle after posting.
http://www.chapmancentral.co.uk

Victory is ours! Down with Eric the Half A Brain!

[Peter Clinch]

Clive George wrote:

> Well worth it - the cantis that a galaxy twin came with were rather poor. 7
> years on our HS66s are still great.

Though there wasn't anything especially /wrong/ with the Vs on the
Streetmachine I'm glad I fixed them with HS33s anyway. Everything is
just so consistent and smooth now :-)

Pete.
--
Peter Clinch Medical Physics IT Officer
Tel 44 1382 660111 ext. 33637 Univ. of Dundee, Ninewells Hospital
Fax 44 1382 640177 Dundee DD1 9SY Scotland UK
net http://www.dundee.ac.uk/~pjclinch/

[Zog The Undeniable]

Colin Blackburn wrote:

>
> I was walking in and around the Howgills over the bank holiday. One
> walk, away from the Howgills proper, took me to Dent. Sitting in a pub
> at the end of the walk, sampling some fine beers from the Dent Brewery,
> a tandem with a baby seat pulled into the outside seating area-cum-car
> park.
>
> [Aside: The stoker got off and took the toddler from the seat. As she
> walked towards me I noticed she had a Che Guevara (sp?) t-shirt on.
> Right next to me was a Skoda with a Che Guevara stencil on the boot
> lid. She noticed the car's stencil and said to the toddler, "Look Che,
> it's Che!" It turned out the toddle was named Che, after Che G.]
>
> When I went in for the next round I had a look at the then parked up
> tandem, an Orbit, and noticed it had both disc and V brakes on the rear
> wheel. I know tandems need very efficient brakes but is it normal to
> have two rear brakes in addition to a front brake? Is the second rear
> brake used in conjunction with the first or as an emergency brake?

Tandems should all have a rear hub brake. The rim brake is there for
stopping; the hub brake is as a drag brake and heatsink on long
descents, because otherwise tyres will blow off the hot rims [1]. Often
the rear brake is operated via a thumbshifter because it's designed to
be left on for long periods.

I've seen a newer tandem with front and rear Hope disc brakes and no rim
brakes. This also works well although the discs will get extremely hot
(the riders were a substantial Geordie couple - if you see a blue tandem
with "Howay the lads" at the front of the top tube and "Wor lass" at the
rear, that's them!).

[1] tyres rarely blow off solo bikes, but tandems have to dissipate
twice the energy with the same number of wheels, so it's a real problem

[Tony Raven]

Colin Blackburn wrote:
>
> [Aside: The stoker got off and took the toddler from the seat. As she
> walked towards me I noticed she had a Che Guevara (sp?) t-shirt on. Right
> next to me was a Skoda with a Che Guevara stencil on the boot lid. She
> noticed the car's stencil and said to the toddler, "Look Che, it's Che!"
> It turned out the toddle was named Che, after Che G.]
>

Boy, that takes me back. I thought he was long gone and forgotten amongst the
young today.

> When I went in for the next round I had a look at the then parked up
> tandem, an Orbit, and noticed it had both disc and V brakes on the rear
> wheel. I know tandems need very efficient brakes but is it normal to have
> two rear brakes in addition to a front brake? Is the second rear brake
> used in conjunction with the first or as an emergency brake? Are the two
> rear levers both on the pilot's bars? (I forgot to look, I had had a few
> pints of Kamikaze by then.)
>

Many tandems have double rear brakes. One is used as the normal brake and one
actuated with a thumbshifter as a drag brake to keep the speed under control
on hills. Unlike a single, the back brake is equally effective as the front
on a tandem. The drag brake stays constantly on during the descent, hence the
use of a thumbshifter to set it, but that means it gets very hot. Usually
disc brakes are not recommended as they are not designed to cope with that
amount of heat. The standard is an Arai drum brake which has a big finned
outer to disippate the heat. So the sequence is to set the thumbshifter to
give background braking to keep your speed under control and then use the
normal rear brake lever if you need to slow more at any point.

Tony

[Clive George]

"Zog The Undeniable" > wrote in message
news:40c5f2b8.0@entanet...

> Tandems should all have a rear hub brake. The rim brake is there for
> stopping; the hub brake is as a drag brake and heatsink on long
> descents, because otherwise tyres will blow off the hot rims [1]. Often
> the rear brake is operated via a thumbshifter because it's designed to
> be left on for long periods.

I wouldn't go that far - I'd say tandems used in hilly country where you
have to brake could benefit from a drag brake. We were touring in Devon with
friends, both on fully laden tandems, and they only had the two rim brakes.
No tyre problems because the hills weren't long enough. We didn't use our
drag brake that much - mostly it gave my hands an easy time.
Times I've appreciated having the drag brake:
Descent into Dent from Barbon
Hills in the Jura. (not the bigger alps - the descents were fast enough that
I didn't need the heat capacity).
I wanted one for the descent of rhynose - we melted a patch on that one, and
my hands hurt. I refitted ours shortly after that. But prior to that we'd
done a fair bit of riding round here (dales - not exactly flat!) and it was
fine.

cheers,
clive

[Mark South]

"Tony Raven" > wrote in message
...
> Colin Blackburn wrote:
> >
> > [Aside: The stoker got off and took the toddler from the seat. As she
> > walked towards me I noticed she had a Che Guevara (sp?) t-shirt on. Right
> > next to me was a Skoda with a Che Guevara stencil on the boot lid. She
> > noticed the car's stencil and said to the toddler, "Look Che, it's Che!"
> > It turned out the toddle was named Che, after Che G.]
> >
> Boy, that takes me back. I thought he was long gone and forgotten amongst the
> young today.

He did a lot for the world. He put Fidel in power in Cuba, and then Cuba
drained the USSR economically to the stage where it collapsed. So Che
ultimately demolished world communism.

Now if only someone would do the same for the US....

The rest of the post is on topic and about bikes, so it's snipped.

OBTW Tony, Che never wore a helmet, even in a combat zone, so he might be a good
role model for you and Guy :-)
--
"To ... just not care that there are naked triathletes running
across your lawn, that's just a waste of exhibitionism."
- Kibo, in alt.religion.kibology

[Marten Hoffmann]

schreef ...

> Many tandems have double rear brakes. One is used as the normal brake and one
> actuated with a thumbshifter as a drag brake to keep the speed under control
> on hills. Unlike a single, the back brake is equally effective as the front
> on a tandem. The drag brake stays constantly on during the descent, hence the
> use of a thumbshifter to set it, but that means it gets very hot. Usually
> disc brakes are not recommended as they are not designed to cope with that
> amount of heat.

Not only are they "not recommended", it is bloody dangerous to do this!
When (not if) everything starts to melt back there you're left with only
your front brake. Oops!

Just recently I heard of a couple who wanted both a Rohloff hub *and* a
drag brake on their tandem. Someone at their LBS had simply said that a
disc brake on the Rohloff would be just fine for this...... Luckily they
came into contact with the people who will actually build the tandem and
who said "no way!". So now they are in doubt: drag brake and derailleur
or no drag brake and Rohloff?! Decisions, decisions, decisions ..... :->

> The standard is an Arai drum brake which has a big finned
> outer to disippate the heat. So the sequence is to set the thumbshifter to
> give background braking to keep your speed under control and then use the
> normal rear brake lever if you need to slow more at any point.

For the design freaks: IMHO the neatest way to control an Arai is
through a front Grip Shift lever.

--
Regards,
Marten

[Tony Raven]

Marten Hoffmann wrote:
>
> Not only are they "not recommended", it is bloody dangerous to do this!
> When (not if) everything starts to melt back there you're left with only
> your front brake. Oops!
>

You'd still have your second back brake and IIRC one of the Magura disc models
is rated for tandems

> Just recently I heard of a couple who wanted both a Rohloff hub *and* a
> drag brake on their tandem. Someone at their LBS had simply said that a
> disc brake on the Rohloff would be just fine for this...... Luckily they
> came into contact with the people who will actually build the tandem and
> who said "no way!". So now they are in doubt: drag brake and derailleur
> or no drag brake and Rohloff?! Decisions, decisions, decisions ..... :->

Disc brakes on tandems have been know to melt the grease in the hubs ;-(

>
> For the design freaks: IMHO the neatest way to control an Arai is
> through a front Grip Shift lever.

Which is what I use, fitted on a Minoura space grip off the stem as there was
no room on the bars.

Tony

[Harri Nieminen]

"Colin Blackburn" > wrote in message >...
> wheel. I know tandems need very efficient brakes but is it normal to have
> two rear brakes in addition to a front brake? Is the second rear brake

Our beautiful Kuwahara tandem has a rim brake and a drum brake in rear
wheel.
Right hand brake lever is made so that both brakes are operated with
the same
lever. There is enough stopping power even with a child carrier behind
the tandem. Though we don't have any hills here in Oulu region.

Harri

PS Do we still have to be aware of paving slabs here in u.r.c

[Marten Hoffmann]

schreef ...
> Marten Hoffmann wrote:
> >
> > Not only are they "not recommended", it is bloody dangerous to do this!
> > When (not if) everything starts to melt back there you're left with only
> > your front brake. Oops!
> >
>
> You'd still have your second back brake ...

.... true, IF your tandem actually has two back brakes and not just one
(disk) in the back.

> ...and IIRC one of the Magura disc models is rated for tandems

Two, even: both Gustav M and Julie Tandem are rated for tandems. But NOT
(and they will put this in bold and underlined letters) for use as a
drag brake, only as a normal brake. I reacted on the suggestion, you
could use the disk brake as a drag brake, something you never should do.

> > Just recently I heard of a couple who wanted both a Rohloff hub *and* a
> > drag brake on their tandem. Someone at their LBS had simply said that a
> > disc brake on the Rohloff would be just fine for this...... Luckily they
> > came into contact with the people who will actually build the tandem and
> > who said "no way!". So now they are in doubt: drag brake and derailleur
> > or no drag brake and Rohloff?! Decisions, decisions, decisions ..... :->
>
> Disc brakes on tandems have been know to melt the grease in the hubs ;-(

I can imagine they would, but personally never heard of this happening.
We'll find out this summer when we go out on our Julie-ed tandem.

> > For the design freaks: IMHO the neatest way to control an Arai is
> > through a front Grip Shift lever.
>
> Which is what I use, fitted on a Minoura space grip off the stem as there was
> no room on the bars.

Smart :-)

--
Regards,
Marten