2 cables pulling the same brake?

BigBen wrote:
(clip) 2 cables, one from eachs brake lever, pulling the same cable?
^^^^^^^^^^^^^^^
I can think of two problems you would have to deal with right off the bat.
You would be splitting the cable tension generated by the fingers of one
hand in half. So you would have to squeeze twice as hard, or else change
the leverage of the system. If you double the mechanical advantage of the
brake lever, then you have half the travel at the pads, so they would have
to be kept adjusted closer to the rims, which increases the possibility of
drag, in case the rims are not perfectly true, or if the springs don't fully
retract the pads. You would also have to adjust for wear twice as often.

The second problem is even more troubling. The adjust ment of front and
rear brakes would have to be exactly right, in order to get balanced
braking. Otherwise, whichever one happens to be set closer would engage,
and limit the travel of the cable, holding off the other brake. I used to
have to adjust the mechanical four-wheel brakes on our 1928 Nash, so I know
that problem well.

BigBen said:

Hi All,

Can it be done? 2 cables, one from eachs brake lever, pulling the same
cable? How?

Thanks,
BigBen.

I think a BMX gyro can do this, although in practice, one cable pulls two
cables, but it seems it could go the other way.
--
Phil, Squid-in-Training

Luns Tee said:

In article <[email hidden]>,

BigBen said:

Can it be done? 2 cables, one from eachs brake lever, pulling the
same cable? How?

<snipped>

Quoted message said:

If you're asking what I think, then I think that Profile used to
make an inline combiner so you can operate your front brake with
either the usual brake lever, or a secondary one mounted on an aero
bar. I don't remember what they called it or how you would find one
today, though.

-Luns

If you can get cycling.tv there is currently an interview there with a
Discovery Cannel Team mechanic who demonstrates exactly this on a bike he is
preparing for (I think) Roger Hammond to ride in Paris - Roubaix.
The mechanic has added an extra brake lever to the top of the bars and
joined the two cables to the brake using the kind of block which is, I
think, used in motorcycles to connect the throttle cable to twin
carburettors.

Tom.

BigBen said:

Hi All,

Can it be done? 2 cables, one from eachs brake lever, pulling the same
cable? How?

Tandemists sometimes do it. A shop that specialises in tandems should
have the levers. It's generally not a good idea to pull F&R brakes from
one lever as the rear brake has so much more cable stretch.

BigBen said:

Hi All,

Can it be done? 2 cables, one from eachs brake lever, pulling the same
cable? How?

2 levers to one brake? It's done all the time. Google on "inline brake
lever" or ask a competent bike shop.

Why?

I've sen it both ways. Both brakes to one lever - for a one armed
cyclist. Don't laugh. The guy was strong as hell. NY State ParaOlympic
champ etc.
Also two levers to one brake - common for rough roads, loaded touring
, also for riders with limited movement in elbows shoulders etc.

BigJulie said:

Why?

I've sen it both ways. Both brakes to one lever - for a one armed
cyclist. Don't laugh. The guy was strong as hell. NY State ParaOlympic
champ etc.

That arrangement is also used on tandems sometimes to allow for
operation of three brakes (two rim plus one hub) from two levers.

Quoted message said:

Also two levers to one brake - common for rough roads, loaded touring
, also for riders with limited movement in elbows shoulders etc.

But that's generally done with the addition of a second lever
specifically designed for that purpose, such as the auxiliary lever from
Specialized. The original post sounded like the goal was to use two
regular brake levers to operate a single brake and I still don't see
much point in that.

Why?

I've sen it both ways. Both brakes to one lever - for a one armed
cyclist. Don't laugh. The guy was strong as hell. NY State ParaOlympic
champ etc.
Also two levers to one brake - common for rough roads, loaded touring
, also for riders with limited movement in elbows shoulders etc.

BigBen said:

Hi All,

Can it be done? 2 cables, one from eachs brake lever, pulling the same
cable? How?

Thanks,
BigBen.

I have such a cable system in my HPE Corsa recumbent tadpole. A cable from each of the right and left joysticks run to a common washer that is pulled forward if either of the joysticks is pushed forward. A third cable runs to the rear drum. If only one joystick is pushed, the washer slides forward relative the remaining slack cable. The steering system was patented in US patent 5069469. I believe the drawings disclosed the brake system as well.

Tom Orr said:

The mechanic has added an extra brake lever to the top of the bars and
joined the two cables to the brake using the kind of block which is, I
think, used in motorcycles to connect the throttle cable to twin
carburettors.

Spot on, apparently - I wish to have regular brake levers on the tops
and on the drops, pullling the same brake, on 1 single wheel/rim.

I'll ask around the motorcycle shops ;-)

Thank you!
Big Ben.

On Tue, 10 May 2005 09:32:12 +0100, BigBen <[email hidden]>

Quoted message said:

Tom Orr said:

The mechanic has added an extra brake lever to the top of the bars and
joined the two cables to the brake using the kind of block which is, I
think, used in motorcycles to connect the throttle cable to twin
carburettors.

Spot on, apparently - I wish to have regular brake levers on the tops
and on the drops, pullling the same brake, on 1 single wheel/rim.

I'll ask around the motorcycle shops ;-)

Thank you!
Big Ben.

Hi, those are readily available, they are known as brake lever
extensons. There are many brands, I first saw them on a Specialized
road bike and Tektro makes a nice set.
Here, take a look:
http://www.bikemannetwork.com/biking/p/DMD/BR7312

I just choose the link above, because it came up in Google, and had a
picture. Harris also has them:
http://harriscyclery.net/site/itemdetails.cfm?ID=1679

I have a set on my older bike and they work really well.

Life is Good!
Jeff