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drum brakes on non-drum designed hubs



 
 
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  #1  
Old April 1st 06, 09:42 AM posted to rec.bicycles.tech
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Default drum brakes on non-drum designed hubs


Can I take a drum brake and mount the rotor on a non drum hub to some
plates inside the flanges and spokes and secure plates through the
spokes and flanges via bolts? Seems it might put some stresses on
spokes in directions they were not designed to handle so might bend.
Anyone tried this and had success or failure?
Anyone think it would work/fail?
If so why/why not?


--
meb

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  #2  
Old April 1st 06, 11:39 PM posted to rec.bicycles.tech
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Default drum brakes on non-drum designed hubs

meb wrote in
:


Can I take a drum brake and mount the rotor on a non drum hub to some
plates inside the flanges and spokes and secure plates through the
spokes and flanges via bolts? Seems it might put some stresses on
spokes in directions they were not designed to handle so might bend.
Anyone tried this and had success or failure?
Anyone think it would work/fail?
If so why/why not?



Well, drum brakes work by pushing pads against the inside of the hub shell,
so no, that wouldn't work. But you're description is that of disc brakes.

And no, if you tried to attach the rotor straight to the spokes, you would
be forcing the wheel out of dish, if not out of true, with every
application of the brakes.

And to anticipate the unasked half of this question, no, it's generally not
a good idea to mount disc brakes on a frame or fork not designed for them.
  #3  
Old April 2nd 06, 08:48 AM posted to rec.bicycles.tech
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Default drum brakes on non-drum designed hubs


Hank Wirtz Wrote:
meb wrote in
:


Can I take a drum brake and mount the rotor on a non drum hub to

some
plates inside the flanges and spokes and secure plates through the
spokes and flanges via bolts? Seems it might put some stresses on
spokes in directions they were not designed to handle so might bend.
Anyone tried this and had success or failure?
Anyone think it would work/fail?
If so why/why not?



Well, drum brakes work by pushing pads against the inside of the hub
shell,
so no, that wouldn't work. But you're description is that of disc
brakes.

And no, if you tried to attach the rotor straight to the spokes, you
would
be forcing the wheel out of dish, if not out of true, with every
application of the brakes.

And to anticipate the unasked half of this question, no, it's generally
not
a good idea to mount disc brakes on a frame or fork not designed for
them.


I meant drum-I mispoke when I called it a rotor.

Your answer on the spokes was fortunately directed at the issue I was
concerned about.

Thanks


--
meb

  #4  
Old April 2nd 06, 09:32 AM posted to rec.bicycles.tech
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Default drum brakes on non-drum designed hubs


meb wrote:
Hank Wirtz Wrote:
meb wrote in
:


Can I take a drum brake and mount the rotor on a non drum hub to

some
plates inside the flanges and spokes and secure plates through the
spokes and flanges via bolts? Seems it might put some stresses on
spokes in directions they were not designed to handle so might bend.
Anyone tried this and had success or failure?
Anyone think it would work/fail?
If so why/why not?



Well, drum brakes work by pushing pads against the inside of the hub
shell,
so no, that wouldn't work. But you're description is that of disc
brakes.

And no, if you tried to attach the rotor straight to the spokes, you
would
be forcing the wheel out of dish, if not out of true, with every
application of the brakes.

And to anticipate the unasked half of this question, no, it's generally
not
a good idea to mount disc brakes on a frame or fork not designed for
them.


I meant drum-I mispoke when I called it a rotor.

Your answer on the spokes was fortunately directed at the issue I was
concerned about.

Thanks


--
meb


One thing perhaps worth pointing out - one of the eletric-assist
retrofit kits out there has a rear rack mounted motor that rotates a
big plastic disc attached somehow on the left side of the rear wheel,
and the force is transmitted by the big plastic disc pressing on a
handful of spokes, like 3 or 4. I think the contact point is around
mid-span but I'm not sure - I only saw one of these in person once and
it was a while ago. The design struck me as really sketchy and
ill-conceived, but perhaps I'm missing something and the spokes don't
particularly mind this treatment. It was a bit like what I think you're
describing, with the spokes being pushed on oddly to deliver a
torsional load to the hub.

  #5  
Old April 2nd 06, 02:18 PM posted to rec.bicycles.tech
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Default drum brakes on non-drum designed hubs

Don't forget the mopeds of the 30's and 40's:

http://www.geocities.com/motorcity/garage/2136/

I would assume that one of those would be placing a much higher load on
the spokes than an electric retrofit.

  #6  
Old April 3rd 06, 12:45 AM posted to rec.bicycles.tech
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Default drum brakes on non-drum designed hubs


meb wrote:
Can I take a drum brake and mount the rotor on a non drum hub to

some
plates inside the flanges and spokes and secure plates through the


I meant drum-I mispoke when I called it a rotor.

Your answer on the spokes was fortunately directed at the issue I was
concerned about.


There are very few drum brakes which are separate from the hub. I'm
only aware of one, the Arai:
http://harriscyclery.net/page.cfm?Pa...ils&sku=BR5001
This attaches to a rear hub which has threads on the left side.

My feeling is that you *could* mount it as you suggest, but it would be
extremely difficult to get the clearance between the pads and the drums
adjusted properly. This has to be very small so that there's very
little slack in the cable- otherwise, you run out of lever travel
before you get all your braking power.

You could attach one of these to a rear freewheel (threaded) hub and
use it on the front, but there's a bunch of additional considerations.
I've seen it done, and it ain't straightforward.

Jeff

  #7  
Old April 3rd 06, 01:43 AM posted to rec.bicycles.tech
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Default drum brakes on non-drum designed hubs


JeffWills wrote:
meb wrote:
Can I take a drum brake and mount the rotor on a non drum hub to
some
plates inside the flanges and spokes and secure plates through the


I meant drum-I mispoke when I called it a rotor.

Your answer on the spokes was fortunately directed at the issue I was
concerned about.


There are very few drum brakes which are separate from the hub. I'm
only aware of one, the Arai:
http://harriscyclery.net/page.cfm?Pa...ils&sku=BR5001
This attaches to a rear hub which has threads on the left side.

My feeling is that you *could* mount it as you suggest, but it would be
extremely difficult to get the clearance between the pads and the drums
adjusted properly. This has to be very small so that there's very
little slack in the cable- otherwise, you run out of lever travel
before you get all your braking power.

You could attach one of these to a rear freewheel (threaded) hub and
use it on the front, but there's a bunch of additional considerations.
I've seen it done, and it ain't straightforward.

Jeff


Any information about how well this worked once it was set up? (I
assume they had it set up with a normal brake lever as opposed to using
it as a drag brake?)

  #8  
Old April 3rd 06, 07:18 AM posted to rec.bicycles.tech
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Default drum brakes on non-drum designed hubs

-snip-
JeffWills wrote:
There are very few drum brakes which are separate from the hub. I'm
only aware of one, the Arai:
http://harriscyclery.net/page.cfm?Pa...ils&sku=BR5001
This attaches to a rear hub which has threads on the left side.
My feeling is that you *could* mount it as you suggest, but it would be
extremely difficult to get the clearance between the pads and the drums
adjus ted properly. This has to be very small so that there's very
little slack in the cable- otherwise, you run out of lever travel
before you get all your braking power.
You could attach one of these to a rear freewheel (threaded) hub and
use it on the front, but there's a bunch of additional considerations.
I've seen it done, and it ain't straightforward.


Nate Knutson wrote:
Any information about how well this worked once it was set up? (I
assume they had it set up with a normal brake lever as opposed to using
it as a drag brake?)


They are or were the standard tandem drag brake for years.
SImple effective cheap . Yes compatible with standard ( not
'linear' ) levers.

You would have to widen the fork and get a longer axle to
make this go - very one-off.
--
Andrew Muzi
www.yellowjersey.org
Open every day since 1 April, 1971
  #9  
Old April 3rd 06, 02:45 PM posted to rec.bicycles.tech
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Default drum brakes on non-drum designed hubs


"A Muzi" wrote in message
...

You could attach one of these to a rear freewheel (threaded) hub and
use it on the front, but there's a bunch of additional considerations.
I've seen it done, and it ain't straightforward.


Nate Knutson wrote:
Any information about how well this worked once it was set up? (I
assume they had it set up with a normal brake lever as opposed to using
it as a drag brake?)


They are or were the standard tandem drag brake for years.
SImple effective cheap . Yes compatible with standard ( not
'linear' ) levers.

You would have to widen the fork and get a longer axle to
make this go - very one-off.


Maybe not.

Some decades ago I mouted a disc brake on a freewheel hub, and put it on the
front; didn't need to widen the forks, but I had to pick and choose the
cones to make it fit.


  #10  
Old April 3rd 06, 05:23 PM posted to rec.bicycles.tech
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Default drum brakes on non-drum designed hubs


Nate Knutson wrote:
JeffWills wrote:

You could attach one of these to a rear freewheel (threaded) hub and
use it on the front, but there's a bunch of additional considerations.
I've seen it done, and it ain't straightforward.

Jeff


Any information about how well this worked once it was set up? (I
assume they had it set up with a normal brake lever as opposed to using
it as a drag brake?)


They were used on a couple of Seattle-based homebuilt recumbents.
Seattle's pretty hilly, and both riders are still alive, so I *assume*
they worked good enough for road use.

Jeff

 




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