T.R | Title | User | Personal Name | Date | Lines |
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1675.1 | HEAT IN THE RIM | WFOV12::SISE | | Tue Jul 31 1990 10:22 | 23 |
| david,
The main problem with braking a tandem is the heat build up in the
rim itself. The Santana's use a drum brake as a "drag" brake for
long loaded desents.
The Opus having the smaller dia. wheels 26" and the front BMX rim,
will have different heat dispursion (sp) than the 700cm rims. They
have more mass, but they spin at a higher RPM. I am not sure on the
effect this will have on the heat retention.
As for a hydraulic brake, I think that it will not be that big of
an improvement. You can apply plenty of force with the cantilevers,
the hyd. brake will have the same heat problem.
If you can get a disk or a drum brake that would be a real bonus.
But will you realy need it? Try the stock brakes first then think
of the upgrade.
P.S. thanks for the call
John
|
1675.2 | Trust the Builder | CSG001::MILLER | Ubi dubium, ibi libertas | Tue Jul 31 1990 10:51 | 17 |
| We bought an Opus III in 1987. We have the disc brake system in
addition to the cantelevers that came with the bike. I have no idea
what kind of pads are on the brake system, but I have the Matheusers
on my Trek, and like them very much.
I moved the lever for the disk brake. Since it wasn't something
I'd use often, and wasn't something we needed in an emergency, I
moved it to the tube support for the recumbant seat. That got rid
of a lot of clutter up on the handlebars.
I offered to install the lever up front where my wife could use
them if needs be, but she preferrednot to have it . The option is
there however.
Congrats on making the decision to go with the Counterpoint. I love
ours, and I believe you'll truly enjoy yours as well.
=-=-=-=-=-=-=gary=-=-=-=-=-=-=
|
1675.3 | Have you seen a Maxi-Car hub?? | KBOMFG::KLINGENBERG | | Tue Jul 31 1990 12:14 | 57 |
|
My wife and I got a tandem that was custom built by a local hobby shop.
The frame is custom made by Achim Noell, who owns a small company for
quality frames.
We have a system of three brakes on it: two Weinmann side pull brakes
and a Maxi-Car rear hub drum brake. The idea behind this is to have one
brake that is not affected as much by rain as normal brakes are, and to
have still two brakes available if one should be failing (you know,
these cables don't break as long as you break gently, they break in
emergencies). We never had a problem yet, under all circumstances we
were able to stop with only one brake. Achim Noell objected against
cantilevers because of the additional stress they put on the frame.
And we are very happy with our good quality standard brakes (on
aluminum rims, of course!).
There are some setups available on tandems that I don't trust. For
example, two brakes pulled with one lever. I cannot imagine to adjust
them to pull at the same time, and even if they would, you would still
reduce the force you can apply with your hand by dividing it into two
brakes. I - as the captain - have the levers for the front wheel brake
and the rear wheel drum brake, the stoker has the lever for the
standard rear wheel brake and usually very rarely uses it.
I can highly recommend the Maxi-car hub. It is french made, especially
for tandems (big diameter) and has some nice features:
1. industry bearings (smooth running, maintenance free)
2. drum is mounted outside of spokes opposite to the
freewheel. This means the spokes are at nearly
symmetrical angles and not as prone to breaking
on the freewheel side as they usually are.
3. if they still break, the flange diameter is so big
that you can swap spokes without removing the freewheel,
even if it's got 32 teeth.
I don't have personal experience with the Magura Hydro brake. Magura,
although it sounds Japanese, is a west german company with long years
of experience for motorcycle brake systems. They weren't available when
we bought the tandem, but when I bought my (touring) bike, I thought
about them. But they were fairly new at that time, and to be honest, I
didn't trust them. They are very strong (friction losses greatly
reduced), but hard to dose. People reported that on the first ride,
they were nearly forced to go over the handlebar. What I was wondering
about: the hoses are just pressed on the nipple of the brake. Will that
hold for years? Will it stand high pressures after some winters with
temperatures below freezing? Then again, it won't break under normal
conditions...
I just wasn't convinced that it's worth to try. And I'm perfectly happy
with what I've got.
Just my two cents worth...
Best regards,
Hartmut
|
1675.4 | Phil Wood | ANOVAX::JGUYDISH | JOE | Tue Jul 31 1990 23:10 | 4 |
| Phil Wood makes a disc brake that is better then anything on the
market. A disc brake is an absolute must if you will be riding in any
hilly areas. It might cost a couple extra bucks to purchase the brake
but its well worth it.
|
1675.5 | resource: John Allen | KOOZEE::PAULHUS | Chris @ MLO6B-2/T13 dtn 223-6871 | Mon Aug 06 1990 12:19 | 7 |
| I recently was talking to John Allen about his Expert Witness
testimony on brakes on tandems (you can abuse them to the point of
really hurting yourself on mountain descents). John knows enough about
the subject to fog your brain. And he likes to talk/give advise. I'd
call him before making a decision.
I don't have his phone # here, but you can call me evenings at
(508) 772-0784 for the number. - Chris
|
1675.6 | Our decision | ULTRA::WITTENBERG | Uphill, Into the Wind | Tue Aug 07 1990 11:48 | 22 |
| Thanks for all the advice.
We decided to go with cantilevers with Matthauser large pads with
cooling fins, and a Arai drum brake. The cantilevers will have
levers with the pivot at the end because that's how the shop likes
to set them up, and I can change it easily if I don't like it.
They claim you get extra leverage that way. The drum brake will
have a ratcheting shift lever to control it.
The theory is that two brakes aren't enough for a tandem going
down hills, and we wanted some type of a hub brake so that one
brake wouldn't heat the rims. There are a lot of reports of tandem
rim brakes failing from overheating, and we wanted to have a hub
brake to prevent that. We wanted each brake controlled seperately
because each of them serves a different purpose.
We didn't choose the Phil Wood disk for two reasons, the first is
that it's very expensive ($275 vs. $100 for the Arai drum), and
the second is that it's not clear that it can dissipate heat as
well as a drum can.
--David
|
1675.7 | Graftons | DECWET::BINGHAM | John | Wed Aug 08 1990 18:25 | 3 |
| A custom brake, cantilever, that has come available recently are made by
Grafton. They aren't cheap at close to $300 for a set. They can use the
Matthauser pads. You might see if they are available locally.
|
1675.8 | Drum vs. Disc | ANOVAX::JGUYDISH | JOE | Thu Aug 09 1990 10:01 | 6 |
| I just wanted to make one last comment on brakes. Phil wood is
expensive but just remember you get what you pay for. Phil wood also
carries a lifetime warranty.
As far as heat dissapation on disc verses drum brakes, just look at
what kind of brakes NASCAR and Formula one race cars use not to
mention your BMW's and Mercedes
|
1675.9 | More info on disk & hub brakes please | DOOZER::PENNEY | Richard Penney 830 4114 @RKA 1/19 | Tue Jan 08 1991 15:24 | 21 |
| Re last few,
- Where is Phil Wood based?
- Is the Arai drum brake a separate fitment, or is it combined as a
complete brake & hub unit (as I think the Maxicar is)? Anyone know if it's
available in Britain?
I'm asking because I want to fit a better brake to the rear of my Higgins
trike. Currently it's got its as-supplied Cyclo (British, 1950s/1960s) hub
brake, which always was pretty useless.
Do people know of any other separate hub or disk brakes? I don't mind
having to do some adaptation, we have access to machine tools.
Wasn't there a Japanese disk brake marketed some time ago?
Thanks,
Richard
ps Anyone got a Phil Wood they want to sell cheap? ;-)
|
1675.10 | | ULTRA::WITTENBERG | Uphill, Into the Wind | Tue Jan 08 1991 16:49 | 18 |
| Phil Wood is somewhere in the US, but I'm not sure where.
The Arai can be combined with a different manufacturer's hub (my
tandem has a Phil Woods hub with an Arai drum brake.) I don't know
how they're added, but it looks like a seperate piece. Note that
we don't use the drum for stopping the bike. It's used as a drogue
going down steep hills to control speed without overheating the
rims. I'm not sure if it would be very effective at stopping the
bike when fitted with a standard brake lever. (Ours is controlled
with a thumb operated shift lever.)
Since the Phil Wood is a disk brake, I would assume that it can be
added to most hubs.
The Trice comes with Sturmey Archer drum brakes (I think as part
of the hub), and I'm told that they are quite good.
--David
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1675.11 | | TALLIS::JBELL | Zeno was almost here | Tue Jan 08 1991 19:13 | 3 |
| > Phil Wood is somewhere in the US, but I'm not sure where.
Somewhere in California.
|
1675.12 | Arai drum can be added | ULTRA::WITTENBERG | Uphill, Into the Wind | Wed Jan 09 1991 10:02 | 6 |
| I took a look at my Arai drum brake last night. It is completely
outside the spokes, but I'm not sure how it is attached to the
hub. Suffice to say it can be added to a different manufacturer's
hub, so it should work as a bolt on to most hubs.
--David
|
1675.13 | various | DOOZER::PENNEY | Richard Penney 830 4114 @RKA 1/19 | Wed Jan 09 1991 14:07 | 51 |
| Thanks for info. so far.
I would assume that both the Phil Wood and the Arai (pleased to hear it's a
separate unit) fit by simply screwing onto the hub.
I believe most tandem hubs have freewheel-sized threading on both sides,
one of course being for the freewheel block itself, the other for a brake
if desired. In other words the (rotating part of) a hub- or disk-brake has
female threading just as a freewheel block does, and of the same size.
For interest, many solo bike rear hubs used to have this feature, i.e. were
threaded for a sprocket on both sides. This was so that you could have a
freewheel sprocket on one side (typically single - who needs gears anyway)
and a fixed wheel sprocket on the other. Changing from fixed <-> free was
simply a matter of turning the wheel around.
Anyone who hasn't tried riding a fixed wheel should do so. Great fun, it's
essential to ultimate stark simplicity & lightness of whole machine (eg in
the UK you only legally need one brake - true elsewhere?). It's also a good
discipline, and once you get used to it - especially the idea of forcibly
keeping up a constant pedalling rhythm up hill and down dale - the need for
gears can genuinely start to seem questionable. Speaking from distant
experience, including a 10 day round-England (well, not quite) tour when I
was *much* younger. Plus, another key advantage, you need a fixed wheel to
ride backwards!
Sorry if that seemed like a digression. It wasn't really - a fixed wheel is
surely the only *pure* form of brake...
Still very interested to know more about all available hub & disc brakes.
One thing I wonder about is making my own disc and adapting to it the
Magura hydraulic mechanism mentioned in earlier replies. I wonder if it has
sufficient oomph, bearing in mind the very much smaller radius of a disk
compared with a rim. Somehow doubt it. How big are the pads on a Phil Wood?
One more point - the idea of using a drum brake - or disc come to that -
for 'drogue' braking down mountains worries me a bit on behalf of anyone
who does it. Ok, the rims are not heating up (but the large radius = high
linear speed of a rim surely means that it gets very well cooled by air
anyway?), but the drum or disc will certainly get hot, and I would think
must transmit some of this heat to the hub bearings, which on a bike are
not designed with this in mind. Molten grease trickles out => dry bearings
and/or dirt gets in?
I also instinctively don't like the idea of any propulsive or retarding
force being applied to a bike other than directly "then and there", through
my hands and feet. Drogue braking via a gear shift lever sounds like the
dreaded cruise control in reverse.
- Richard
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1675.14 | Why I got a hub brake | ULTRA::WITTENBERG | Uphill, Into the Wind | Wed Jan 09 1991 14:25 | 24 |
| I know of a few cases of tandem brake pads melting from long
downhills (I haven't seen one, but I've talked to someone who has
testified in court on this several times and he's seen the melted
pads.) For that reason it seemed important to get some braking off
the rim.
The arai drum has a fair-sized finned heat sink on the spinning
part of the brake which should provide pretty good heat
disipation. The fins probably give better heat dissipation than
the smooth rims, and certainly give two different areas
dissipating heat, so the total energy dissipated is more than rim
brakes alone. In any case, the rear bearings freezing after
cooking out all the grease isn't nearly as bad an accident as
molten brakes will cause.
I've seen some tandems where the stoker controls the hub brake,
and others where the captain has two brake levers, one of which
controls both rim brakes and the other controls the hub brake.
I suspect that the Magura mechanism is too thick to fit between
the disk and the spokes on any reasonable wheel. The Magura is a
hefty device.
--David
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1675.15 | Phil Wood & Co. | EAGLE1::CAMILLI | | Wed Jan 09 1991 15:40 | 9 |
|
At least as of a few years ago:
Phil Wood & Co.
153 West Julian Street
San Jose, CA 95110
(408) 298-1540
"Member of California Bicycle Products Group"
|