replacing center pull brakes with direct pull ones ?

Howdy - I am working on friends bike - it is an old MTB with center
pull brakes.
Old brakes seem serviceable. Should I attempt to put direct pull
brakes on it?
What are advantages of such move (if any)? If I understand Sheldon
correctly
I would need new set of levers too?

Woland99 wrote:
Howdy - I am working on friends bike - it is an old MTB with center
pull brakes. Old brakes seem serviceable. Should I attempt to put direct pull
brakes on it? What are advantages of such move (if any)? If I understand Sheldon
correctly I would need new set of levers too?

you would need a new frame too, as the pivots are in the wrong place (u
brake pivots are above the rim, V-brake pivots below. Diameter can be
different too)


--
/Marten

info(apestaartje)m-gineering(punt)nl

On Jun 20, 1:06 am, M-gineering wrote:
Woland99 wrote:
Howdy - I am working on friends bike - it is an old MTB with center
pull brakes. Old brakes seem serviceable. Should I attempt to put direct pull
brakes on it? What are advantages of such move (if any)? If I understand Sheldon
correctly I would need new set of levers too?

you would need a new frame too, as the pivots are in the wrong place (u
brake pivots are above the rim, V-brake pivots below. Diameter can be
different too)

--
/Marten

info(apestaartje)m-gineering(punt)nl

Hmmm... orginal brakes are traditional center pull - not u-brakes
so pivots are below the rims - just like in v-brakes. But i did
not check diameters yet - I assumed those were standarized.

Woland99 wrote:
On Jun 20, 1:06 am, M-gineering wrote:
Woland99 wrote:
Howdy - I am working on friends bike - it is an old MTB with center
pull brakes. Old brakes seem serviceable. Should I attempt to put direct pull
brakes on it? What are advantages of such move (if any)? If I understand Sheldon
correctly I would need new set of levers too?
you would need a new frame too, as the pivots are in the wrong place (u
brake pivots are above the rim, V-brake pivots below. Diameter can be
different too)

--
/Marten

info(apestaartje)m-gineering(punt)nl

Hmmm... orginal brakes are traditional center pull - not u-brakes
so pivots are below the rims - just like in v-brakes. But i did
not check diameters yet - I assumed those were standarized.


Ah, semantics. It's more usual to call them cantilevers. These are
interchangable

--
/Marten

info(apestaartje)m-gineering(punt)nl

On 20 Jun, 06:12, Woland99 wrote:
Howdy - I am working on friends bike - it is an old MTB with center
pull brakes.
Old brakes seem serviceable. Should I attempt to put direct pull
brakes on it?
What are advantages of such move (if any)? *If I understand Sheldon
correctly
I would need new set of levers too?

If the existing brakes work then there's no really good reason to
change them - cantilever brakes are fine for most situations. But if
you do change the brakes then yes, you will need to change the levers
as well.

Colin

Colin MacDonald wrote:
On 20 Jun, 06:12, Woland99 wrote:
Howdy - I am working on friends bike - it is an old MTB with center
pull brakes.
Old brakes seem serviceable. Should I attempt to put direct pull
brakes on it?
What are advantages of such move (if any)? �If I understand Sheldon
correctly
I would need new set of levers too?

If the existing brakes work then there's no really good reason to
change them - cantilever brakes are fine for most situations. But if
you do change the brakes then yes, you will need to change the levers
as well.

not necessarily - depends on whether they're mtb direct pulls, or road.
they have different leverage ratios.

On Jun 20, 8:30 am, jim beam wrote:
Colin MacDonald wrote:
On 20 Jun, 06:12, Woland99 wrote:
Howdy - I am working on friends bike - it is an old MTB with center
pull brakes.
Old brakes seem serviceable. Should I attempt to put direct pull
brakes on it?
What are advantages of such move (if any)? �If I understand Sheldon
correctly
I would need new set of levers too?

If the existing brakes work then there's no really good reason to
change them - cantilever brakes are fine for most situations. But if
you do change the brakes then yes, you will need to change the levers
as well.

not necessarily - depends on whether they're mtb direct pulls, or road.
they have different leverage ratios.

OK - I should have said "replacing cantilever brakes with direct
pull ones". The reason I thought about doing it is that my friend
was complaining that old brakes did not work very well.
Do I understand it correctly that you can exert more force on rims
using direct pull brakes?

I think that the new ones I got are MTB direct pulls. These are
Avid Single Digit 5.

In article ,
Woland99 wrote:
On Jun 20, 8:30 am, jim beam wrote:
Colin MacDonald wrote:
they have different leverage ratios.

OK - I should have said "replacing cantilever brakes with direct
pull ones". The reason I thought about doing it is that my friend
was complaining that old brakes did not work very well.

Cantilever brakes take more work to setup properly, but once
that's done they work as well as any in my experience. See
Sheldon Brown's page on cantilever brakes.

Do I understand it correctly that you can exert more force on rims
using direct pull brakes?

No, they are just a lot easier to setup.

_ Booker C. Bense

On Thu, 19 Jun 2008 22:12:18 -0700 (PDT), Woland99
may have said:

Howdy - I am working on friends bike - it is an old MTB with center
pull brakes.
Old brakes seem serviceable. Should I attempt to put direct pull
brakes on it?
What are advantages of such move (if any)? If I understand Sheldon
correctly
I would need new set of levers too?

It's very likely that a new set of pads and a little attention to
adjustment will make the existing brakes as effective as they need to
be. Although you can mount direct-pull brakes in place of cantis,
unless you replace the levers at the same time, you'll find that the
brake adjustment gets very touchy, the need for proper wheel truing
gets even more critical, the hand lever travel gets quite long, and it
may become distressingly easy to unintentionally lock the brakes.

Before doing all that, I'd try swapping to a new set of brake pads.
Make sure that you check the rims for wear first, though. If the bike
has a lot of miles, and the rims are aluminum, then the sidewalls of
the rims may be worn enough that it may be new wheel time. Steel rims
generally don't wear enough to worry about, but braking is nowhere
near as effective in wet conditions with a steel rim, either.

--
My email address is antispammed; pull WEEDS if replying via e-mail.
Typoes are not a bug, they're a feature.
Words processed in a facility that contains nuts.

On Jun 20, 10:38Â*am, Woland99 wrote:
On Jun 20, 8:30 am, jim beam wrote:



Colin MacDonald wrote:
On 20 Jun, 06:12, Woland99 wrote:
Howdy - I am working on friends bike - it is an old MTB with center
pull brakes.
Old brakes seem serviceable. Should I attempt to put direct pull
brakes on it?
What are advantages of such move (if any)? �If I understand Sheldon
correctly
I would need new set of levers too?

If the existing brakes work then there's no really good reason to
change them - cantilever brakes are fine for most situations. Â*But if
you do change the brakes then yes, you will need to change the levers
as well.

not necessarily - depends on whether they're mtb direct pulls, or road.
Â* they have different leverage ratios.

OK - I should have said "replacing cantilever brakes with direct
pull ones". The reason I thought about doing it is that my friend
was complaining that old brakes did not work very well.
Do I understand it correctly that you can exert more force on rims
using direct pull brakes?

AFAIK, you lose mechanical advantage with cantis as the lever is
pulled towards the handlebars. That said--they can be set up to brake
nicely. The high mechanical advantage of linear pull brakes comes at
the disadvantage of needing to keep the brake pads very close to the
rim and thus the wheels very true.


I think that the new ones I got are MTB direct pulls. These are
Avid Single Digit 5.

You'll need new levers that pull the appropriate amount of cable.
About $15USD for some decent models by Tektro or a suitable
equivalent.