Pros and cons of mechanical vs hydraulic disc brakes?

[Duncan Smith]

Feeling somewhat unsatisfied with the V-brake setup on my cyclocross
forks I'm contemplating disc brakes as a solution and am wondering
what the relative merits of hydraulic vs mechanical are?

So far I can think that the mechanical variety are probably cheaper
and easier to fix/adjust at the road-side whereas the hydraulic sort
have more bling and stopping power (maybe - don't know why?)

Also, any recommendations for a 100mm front fork with ISO disc tabs?
So far I've found Winwood and Airborne Aeileron - but both are US
based and don't seem to any stockists in the UK

http://www.jensonusa.com/store/product/FK409C11-Winwood+Dualist+Carbon+Cross+Fork.aspx
http://www.fixedgeargallery.com/2006/nov/JasonElias.htm

Many thanks,

Duncan.

 

[Mike Causer]

On Thu, 15 Feb 2007 05:50:25 -0800, Duncan Smith wrote:

> Feeling somewhat unsatisfied with the V-brake setup on my cyclocross
> forks I'm contemplating disc brakes as a solution and am wondering
> what the relative merits of hydraulic vs mechanical are?

Go to rec.bicycles.tech and find the thread "Mechanical disk brake"
started on Tuesday this week.


Mike

 

[Duncan Smith]

On Feb 15, 2:03 pm, Mike Causer <[email protected]>
wrote:
> On Thu, 15 Feb 2007 05:50:25 -0800, Duncan Smith wrote:
> > Feeling somewhat unsatisfied with the V-brake setup on my cyclocross
> > forks I'm contemplating disc brakes as a solution and am wondering
> > what the relative merits of hydraulic vs mechanical are?
>
> Go to rec.bicycles.tech and find the thread "Mechanical disk brake"
> started on Tuesday this week.
>
> Mike

Thanks

 

[Peter Clinch]

Duncan Smith wrote:
> Feeling somewhat unsatisfied with the V-brake setup on my cyclocross
> forks I'm contemplating disc brakes as a solution and am wondering
> what the relative merits of hydraulic vs mechanical are?
>
> So far I can think that the mechanical variety are probably cheaper
> and easier to fix/adjust at the road-side whereas the hydraulic sort
> have more bling and stopping power (maybe - don't know why?)

My mech/hydraulic comparison is rim brakes rather than discs, but I've
found that...

Absolute power isn't actually much of an issue. If you bother fettling
mech brakes you can lock the wheels up anyway, and if you can do that
then any extra power is moot. What the hydraulics give is a simple
in/out pad motion that means that fettling is (a) far less necessary to
start with and (b) *much* easier to do, and much easier control with
fingertip pressure rather than a monster squeeze of the hand.

Hydraulic rim brakes will fit on existing V-bosses, but you'll be lucky
to find levers that work on drops since Magura discontinued the HS 66 :-(

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 [email protected] http://www.dundee.ac.uk/~pjclinch/

 

[Duncan Smith]

>
> Hydraulic rim brakes will fit on existing V-bosses, but you'll be lucky
> to find levers that work on drops since Magura discontinued the HS 66 :-(
>

Agreed, the normal drop style lever didn't really pull enough wire for
the v-brake, I was thinking of mounting a more conventional mtb style
lever on the bottom of the drop bars (near where the bar end plug
goes).

A bit like this guy's got (except he's got bull bars not drop bars,
but same thing I reckon..) http://www.fixedgeargallery.com/2006/nov/
JasonElias.htm

Any tips for a suitable lever? - my drop bars are over-sized
apparently.

Thanks,

Duncan.

 

[James Thomson]

"Duncan Smith" <[email protected]> a écrit:

> I was thinking of mounting a more conventional mtb style
> lever on the bottom of the drop bars (near where the bar
> end plug goes).

> A bit like this guy's got (except he's got bull bars not drop
> bars, but same thing I reckon..)

> http://www.fixedgeargallery.com/2006/nov/JasonElias.htm

> Any tips for a suitable lever? - my drop bars are over-sized
> apparently.

Generally when drop bars are referred to as oversized, the oversized part is
the stem clamp - 31.8mm or thereabouts.

Most drop bars have a diameter of around 15/16" (23.8mm) in the part to
which the brake levers clamp. That's far enough from the straight bar
standard of 7/8" (22.2mm) that mountain bike levers don't work well on drop
bars. It's sometimes possible to bodge the clamp, but it's generally not a
nice solution.

The lever in the picture is a Tektro cross lever, designed to be used as a
secondary lever on drops (and therefore with a 23.8mm clamp), and the Avid
mechanical brake is the only one I know of that comes in a version designed
to work with drop bar cable pull.

What gear controls are you currently using? Will you want to keep your brake
hoods?

James Thomson

 

[Simon Brooke]

in message <[email protected]>, Duncan
Smith ('[email protected]') wrote:

> Feeling somewhat unsatisfied with the V-brake setup on my cyclocross
> forks I'm contemplating disc brakes as a solution and am wondering
> what the relative merits of hydraulic vs mechanical are?

Remember that all bicycle brakes are essentially disk brakes. With rim
brakes the disk is bigger and the tyre is attached to it...

If you use a separate brake disk, it's further from the mud so unless
conditions are truly atrocious it doesn't get contaminated. Against this,
it's smaller so has less radiant area to dissipate energy as heat (but at
least the heat doesn't go into your tyres).

Apart from the mud issue, disk brakes are less, not more, effective than
rim brakes, because of poorer leverage and less radiant surface.

> So far I can think that the mechanical variety are probably cheaper
> and easier to fix/adjust at the road-side whereas the hydraulic sort
> have more bling and stopping power (maybe - don't know why?)

Not more stopping power - more sensitivity, more precise control. This
really matters for technical mountain biking but probably doesn't matter
very much for cross.

--
[email protected] (Simon Brooke) http://www.jasmine.org.uk/~simon/

;; All in all you're just another nick in the ball
-- Think Droid

 

[Tony Raven]

Duncan Smith wrote on 15/02/2007 13:50 +0100:
>
> So far I can think that the mechanical variety are probably cheaper
> and easier to fix/adjust at the road-side whereas the hydraulic sort
> have more bling and stopping power (maybe - don't know why?)
>

Power isn't the issue IMO. Its the much better modulation of power you
get with hydraulic discs which give you much better control over your
stopping especially when things are slippy.

--
Tony

"...has many omissions and contains much that is apocryphal, or at least
wildly inaccurate..."
Douglas Adams; The Hitchhiker's Guide to the Galaxy

 

[Duncan Smith]

>
> The lever in the picture is a Tektro cross lever, designed to be used as a
> secondary lever on drops (and therefore with a 23.8mm clamp), and the Avid
> mechanical brake is the only one I know of that comes in a version designed
> to work with drop bar cable pull.
>
> What gear controls are you currently using? Will you want to keep your brake
> hoods?
>

Thanks James, that's good info.. Looks like the Tektro lever with the
avid mech. brakes would be a good combo. Do you have a link to the
avid brakes designed to work with the lever?

My bike's a fixie so no gear controls to worry about!

The brake hoods is a good question - I don't usually run a rear brake,
though I may change my mind after tuesday's ride in the wet... I use
them for pulling up on when climbing hills a lot though. It would be
tidier if I could remove the levers from the hoods, but they don't
seem designed to be removed easily (Tektro). Maybe you can buy some
hoods without levers...?

Thanks,

Duncan.

 

[Ambrose Nankivell]

Simon Brooke wrote:
> in message <[email protected]>, Duncan
> Smith ('[email protected]') wrote:
>
>> Feeling somewhat unsatisfied with the V-brake setup on my cyclocross
>> forks I'm contemplating disc brakes as a solution and am wondering
>> what the relative merits of hydraulic vs mechanical are?
>
> Remember that all bicycle brakes are essentially disk brakes. With rim
> brakes the disk is bigger and the tyre is attached to it...
>
> If you use a separate brake disk, it's further from the mud so unless
> conditions are truly atrocious it doesn't get contaminated. Against this,
> it's smaller so has less radiant area to dissipate energy as heat (but at
> least the heat doesn't go into your tyres).
>
> Apart from the mud issue, disk brakes are less, not more, effective than
> rim brakes, because of poorer leverage and less radiant surface.

Apart from the fact that they're made with material specific to the
purpose of braking, which allows them to run truer, be harder, more
conductive of heat, and use much more abrasive pads, all of which adds
up to a great improvement in efficacy over rim brakes, IME.

A

 

[Paul Boyd]

Simon Brooke said the following on 15/02/2007 16:35:

> Not more stopping power - more sensitivity, more precise control. This
> really matters for technical mountain biking but probably doesn't matter
> very much for cross.

I would suggest that hydraulic discs have more stopping power than cable
discs *for any given input*. Ultimately, both will lock wheels, but my
own experience is that hydraulics do it with far less effort and, as you
say, better control.

--
Paul Boyd
http://www.paul-boyd.co.uk/

 

[James Thomson]

"Duncan Smith" <[email protected]> a écrit:

> Thanks James, that's good info.. Looks like the Tektro lever with the
> avid mech. brakes would be a good combo. Do you have a link to the
> avid brakes designed to work with the lever?

http://www.sram.com/en/avid/mechanicaldiscbrakes/bb7road.php

There's a little more information in the pdf linked from that page. Of
course if you buy that there's no need to change your levers. Or you could
keep the levers you have and add a supplementary cross lever on the bar top.

> The brake hoods is a good question - I don't usually run a rear
> brake, though I may change my mind after tuesday's ride in the
> wet... I use them for pulling up on when climbing hills a lot though.
> It would be tidier if I could remove the levers from the hoods, but
> they don't seem designed to be removed easily (Tektro).

Sometimes the lever pivot is just a press fit in the body and can be driven
out with a punch. Sometimes there's a grub screw holding the pivot in place.
Sometimes the bolt that clamps the lever body to the bars holds the pivot in
place.

> Maybe you can buy some hoods without levers...?

Indeed you can. They're designed primarily for tandem stokers:

http://www.canecreek.com/ergo_stoker_lvr.html

James Thomson

 

[James Thomson]

"Duncan Smith" <[email protected]> a écrit:

> Feeling somewhat unsatisfied with the V-brake setup on my
> cyclocross forks I'm contemplating disc brakes as a solution
> and am wondering what the relative merits of hydraulic vs
> mechanical are?

Apologies - I came in in the middle and have only just read back to the
start of the thread. Can you clarify your present setup? It sounds as though
you've been using V-brakes with road levers. If so, there are cheaper ways
of improving your braking than buying an entire disk system.

The only drop-bar lever that's designed pull enough cable to work with
V-brakes is the Dia Compe 287V. You should be able to get a big improvement
in brake performance by matching your lever to your brake, or your brake to
your lever.

http://www.sheldonbrown.com/canti-direct.html

http://sheldonbrown.com/canti-trad.html

http://sheldonbrown.com/cantilever-geometry.html

James Thomson

 

[Rob Morley]

In article <[email protected]>,
Duncan Smith
[email protected] says...
>
> Agreed, the normal drop style lever didn't really pull enough wire for
> the v-brake, I was thinking of mounting a more conventional mtb style
> lever on the bottom of the drop bars (near where the bar end plug
> goes).
>
Why not just use a pull doubler like QBP Travel Agent?

 

[Rob Morley]

In article <[email protected]>,
Duncan Smith
[email protected] says...

> The brake hoods is a good question - I don't usually run a rear brake,
> though I may change my mind after tuesday's ride in the wet... I use
> them for pulling up on when climbing hills a lot though. It would be
> tidier if I could remove the levers from the hoods, but they don't
> seem designed to be removed easily (Tektro). Maybe you can buy some
> hoods without levers...?
>
They used to be sold as stoker hoods - ISTR Ron Kitching selling the Dia
Compe ones. If you get hold of some old Weinmann levers it's very easy
to remove the blades.

 

[Ian Smith]

On Thu, 15 Feb 2007 16:35:49 +0000, Simon Brooke <[email protected]> wrote:
>
> Apart from the mud issue, disk brakes are less, not more, effective than
> rim brakes, because of poorer leverage and less radiant surface.

But potentially more effective because of fewer conflicting material
selection issues.

regards, Ian SMith
--
|\ /| no .sig
|o o|
|/ \|

 

[Ian Smith]

On 15 Feb 2007, Duncan Smith <[email protected]> wrote:

> Feeling somewhat unsatisfied with the V-brake setup on my cyclocross
> forks I'm contemplating disc brakes as a solution and am wondering
> what the relative merits of hydraulic vs mechanical are?

Only thing I've not seen in the discussion to date is that mechanical
are prone to cables frrzing if they get wet in them and it becomes
cold. Presumably hydraulic don't (until it becomes very cold? What's
the freezing point of the fluid?

regards, Ian SMith
--
|\ /| no .sig
|o o|
|/ \|

 

[Duncan Smith]

> Apologies - I came in in the middle and have only just read back to the
> start of the thread. Can you clarify your present setup? It sounds as though
> you've been using V-brakes with road levers. If so, there are cheaper ways
> of improving your braking than buying an entire disk system.
>
> The only drop-bar lever that's designed pull enough cable to work with
> V-brakes is the Dia Compe 287V. You should be able to get a big improvement
> in brake performance by matching your lever to your brake, or your brake to
> your lever.
>

So, the bike came with some sleek carbon forks which only allowed up
to 28mm width tyres. Cycling to work on un-gritted icy back roads
made me a little twitchy, so I let the LBS fit some cross forks and
either canties or a v-brake - they went for Vee in the end - Shimano
Deore. I did mention about the 287V, but they thought that the front
cable was short enough that it wasn't necessary - and kind of isn't,
at least for one of my wheels. The other wheel has a slight, slight
buckle that means I just have to slacken of the v-brake a little, but
the result is that by the time I pull the lever (standard road lever)
so that the pads bite the rims, there isn't all that much free travel
left before touching the bars, which in the wet is definitely sub-par.

The idea was that it would be quick and easy to swap the wheels over
depending upon the weather, one with a 28mm tread, the other a 35mm
studded tyre, but that didn't really work out because the rims are
different widths - and it takes longer to **** with the vees than it
does to change the tyre over.

Strictly speaking I could probably make do without, but I wouldn't
mind trying out some discs anyway. Never had discs before.

Regards,

Duncan.

 

[Tony Raven]

Simon Brooke wrote on 15/02/2007 16:35 +0100:
>
> Apart from the mud issue, disk brakes are less, not more, effective than
> rim brakes, because of poorer leverage and less radiant surface.
>

I have cable and hydraulic rim brakes and hydraulic disk brakes and I
can't believe that anyone who has ridden all three extensively could say
what you have just said.

--
Tony

"...has many omissions and contains much that is apocryphal, or at least
wildly inaccurate..."
Douglas Adams; The Hitchhiker's Guide to the Galaxy

 

[Anthony Jones]

Duncan Smith wrote:
> The idea was that it would be quick and easy to swap the wheels over
> depending upon the weather, one with a 28mm tread, the other a 35mm
> studded tyre, but that didn't really work out because the rims are
> different widths - and it takes longer to **** with the vees than it
> does to change the tyre over.
>
> Strictly speaking I could probably make do without, but I wouldn't
> mind trying out some discs anyway. Never had discs before.

My guess is that it would be cheaper and easier to replace one of the wheels
so that you have a pair with similar rim width, and then either get a 287V
lever or switch to cantis. I wouldn't want to deny anyone the pleasure of
spending money on bike-bling though.

Anthony