Disk brake upgrades, anyone?

DougC said:

I am pondering these as an upgrade to a bike that currently has Avid
[mechanical] BB5's. The front works fine but the rear brake is rather
mushy due to the longer cable stretching/jacket slack I assume.

1) Can I fit other (Shimano/Magura/Hayes/any others?) disk calipers onto
the same frame bracket and rotor?

2) This bike is a long-wheelbase recumbent; do the brake lines com
pre-cut (for a DF)? Or can anyplace make them to length?

3) What problems arise with these braking systems (-considering that it
will be an on-road bike, and I am not likely to use it in sub-freezing
temperatures if that matters-).

4) Alternately, are there any upgrades I could do on the mechanical
system that would help much? It has the OEM Avid levers, probably quite
inexpensive. Do any levers pull "more wire" so to speak? And what's the
best (least-stretchy/least-compressible) conventional brake cable/jacket
out there?

Are you are going to stick with mechanical disc's if you upgrade? If
so you won't find much of a difference between mechanical disc's in
terms of mushiness. If you are going hydraulic then you should be able
to at least use shimano disc since they still use an open line with
non-crimped fittings. Hayes and magura use lines that have a
permanently attached fitting on one end so they are only sold in
certain lengths. One thing that I would find out is if these companies
sell longer than standard brake lines.

Steve Sauter

Quoted message said:

~

"steve" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

DougC said:

I am pondering these as an upgrade to a bike that currently has Avid
[mechanical] BB5's. The front works fine but the rear brake is rather
mushy due to the longer cable stretching/jacket slack I assume.

1) Can I fit other (Shimano/Magura/Hayes/any others?) disk calipers onto
the same frame bracket and rotor?

2) This bike is a long-wheelbase recumbent; do the brake lines com
pre-cut (for a DF)? Or can anyplace make them to length?

3) What problems arise with these braking systems (-considering that it
will be an on-road bike, and I am not likely to use it in sub-freezing
temperatures if that matters-).

4) Alternately, are there any upgrades I could do on the mechanical
system that would help much? It has the OEM Avid levers, probably quite
inexpensive. Do any levers pull "more wire" so to speak? And what's the
best (least-stretchy/least-compressible) conventional brake cable/jacket
out there?

Are you are going to stick with mechanical disc's if you upgrade? If
so you won't find much of a difference between mechanical disc's in
terms of mushiness. If you are going hydraulic then you should be able
to at least use shimano disc since they still use an open line with
non-crimped fittings. Hayes and magura use lines that have a
permanently attached fitting on one end so they are only sold in
certain lengths. One thing that I would find out is if these companies
sell longer than standard brake lines.

Steve Sauter

Quoted message said:

~

Hope can also use hose off-the-reel for sure. The hoses supplied with some
brake kits are pre-crimped but I'm pretty sure most can be fitted with
after-market hoses too. Goodridge will probably be able to provide you with
braided hoses if you want to go OTT.

Skippy
E&OE

DougC said:

I am pondering these as an upgrade to a bike that currently has Avid
[mechanical] BB5's. The front works fine but the rear brake is rather
mushy due to the longer cable stretching/jacket slack I assume.

1) Can I fit other (Shimano/Magura/Hayes/any others?) disk calipers onto
the same frame bracket and rotor?

2) This bike is a long-wheelbase recumbent; do the brake lines com
pre-cut (for a DF)? Or can anyplace make them to length?

Just how long is your cable run? I recently temporarily switched from
hydraulics to cable actuated rear brakes on my FS mtn bike because I was
having problems getting the rear brakes bled properly (it seems I
couldn't get the last bit of air bubbles out so my rear brakes would
fade to nothing far too quickly on descents). My Avid BB7s work just as
well as the Juicys (when the Juicys aren't fading, obviously the BB7s
work much better than the fading Juicys) that they replaced. In fact,
with the speed dial adjustment on the lever I've got it to where it
feels just like the hydraulic brake.

After my next big ride this weekend I'm going to have someone else put
my rear Juicys back on and bleed them. Hopefully a local mechanic will
do a better job at bleeding them than I do.

Greg

--
"All my time I spent in heaven
Revelries of dance and wine
Waking to the sound of laughter
Up I'd rise and kiss the sky" - The Mekons

steve said:

Are you are going to stick with mechanical disc's if you upgrade? If
so you won't find much of a difference between mechanical disc's in
terms of mushiness. If you are going hydraulic then you should be able
to at least use shimano disc since they still use an open line with
non-crimped fittings. Hayes and magura use lines that have a
permanently attached fitting on one end so they are only sold in
certain lengths. One thing that I would find out is if these companies
sell longer than standard brake lines.

The only thing I -know- is that I want to keep the disk brakes (I.E. not
go back to rim brakes).

If I kept the mechanical disks, I would want to get better cables and
cable housings for them. If I could find cable that was about twice the
cross-section of the standard generic stuff (and good jacket to fit it),
that fatter cable wold still fit in the same clamps and levers, but have
a lot less stretch.

If I go hydraulic, then I'd need long hoses to be sure, and I don't know
if disk calibers are all interchangeable yet. Used to be you had to get
adapter plates for different brands of calipers.
~

DougC said:

steve said:

Are you are going to stick with mechanical disc's if you upgrade? If
so you won't find much of a difference between mechanical disc's in
terms of mushiness. If you are going hydraulic then you should be able
to at least use shimano disc since they still use an open line with
non-crimped fittings. Hayes and magura use lines that have a
permanently attached fitting on one end so they are only sold in
certain lengths. One thing that I would find out is if these companies
sell longer than standard brake lines.

The only thing I -know- is that I want to keep the disk brakes (I.E. not
go back to rim brakes).

Knowing the advantages of disc brakes on bicycles, great in the wet, if
high probably of killing a rim, great in the mud, great for loaded
touring, curious as to what disc brakes bring to your equation.

Quoted message said:

If I kept the mechanical disks, I would want to get better cables and
cable housings for them. If I could find cable that was about twice the
cross-section of the standard generic stuff (and good jacket to fit it),
that fatter cable wold still fit in the same clamps and levers, but have
a lot less stretch.

If I go hydraulic, then I'd need long hoses to be sure, and I don't know
if disk calibers are all interchangeable yet. Used to be you had to get
adapter plates for different brands of calipers.
~

Qui si parla Campagnolo said:

Knowing the advantages of disc brakes on bicycles, great in the wet, if
high probably of killing a rim, great in the mud, great for loaded
touring, curious as to what disc brakes bring to your equation.

As I have seen it, disk brakes can stop harder than rim brakes.

Ideally I'd like brakes that could lock the wheels even on clean
pavement, but I'd guess only hydraulics would be able to do that.

I've not owned a bike with hydraulics yet but I already know that they
are heavy and expensive. The weight isn't much of a concern, and the
price I would pay if they were durable. It's the other problems I don't
know about that worry me.....
~

Per DougC:

Quoted message said:

As I have seen it, disk brakes can stop harder than rim brakes.

Ideally I'd like brakes that could lock the wheels even on clean
pavement, but I'd guess only hydraulics would be able to do that.

I would not concur.

The reasons for disc brakes are several, but stopping power doesn't seem to be
one of them.
--
PeteCresswell

DougC said:

Qui si parla Campagnolo said:

Knowing the advantages of disc brakes on bicycles, great in the wet,
if high probably of killing a rim, great in the mud, great for loaded
touring, curious as to what disc brakes bring to your equation.

As I have seen it, disk brakes can stop harder than rim brakes.

False under ideal conditions.

Quoted message said:

Ideally I'd like brakes that could lock the wheels even on clean
pavement, but I'd guess only hydraulics would be able to do that.

Also false under almost all conditions. (leaning back)

Quoted message said:

I've not owned a bike with hydraulics yet but I already know that they
are heavy and expensive. The weight isn't much of a concern, and the
price I would pay if they were durable. It's the other problems I
don't know about that worry me.....

They can be lighter and not terribly much more money than mechs.

--
Phil

DougC said:

I am pondering these as an upgrade to a bike that currently has Avid
[mechanical] BB5's. The front works fine but the rear brake is rather
mushy due to the longer cable stretching/jacket slack I assume.

1) Can I fit other (Shimano/Magura/Hayes/any others?) disk calipers
onto the same frame bracket and rotor?

2) This bike is a long-wheelbase recumbent; do the brake lines com
pre-cut (for a DF)? Or can anyplace make them to length?

3) What problems arise with these braking systems (-considering that
it will be an on-road bike, and I am not likely to use it in
sub-freezing temperatures if that matters-).

4) Alternately, are there any upgrades I could do on the mechanical
system that would help much? It has the OEM Avid levers, probably
quite inexpensive. Do any levers pull "more wire" so to speak? And
what's the best (least-stretchy/least-compressible) conventional
brake cable/jacket out there?
~

Make sure the pads haven't had overspray contamination from lubing the
chain. It's very, very easy to do this... always use drip lube with
disc-equipped bikes.
--
Phil

DougC said:

Qui si parla Campagnolo said:

Knowing the advantages of disc brakes on bicycles, great in the wet, if
high probably of killing a rim, great in the mud, great for loaded
touring, curious as to what disc brakes bring to your equation.

As I have seen it, disk brakes can stop harder than rim brakes.

Ideally I'd like brakes that could lock the wheels even on clean
pavement, but I'd guess only hydraulics would be able to do that.

Good V-Brakes are every bit as good as hydraulic disc imho. The
advantages lie elsewhere, bling being at least one of them. For me,
seperation of the wheel and braking surfaces is desirable. Lower
maintenance as well, but I'm sure others who know better will be along soon.

<snip>

DougC said:

Qui si parla Campagnolo said:

Knowing the advantages of disc brakes on bicycles, great in the wet, if
high probably of killing a rim, great in the mud, great for loaded
touring, curious as to what disc brakes bring to your equation.

As I have seen it, disk brakes can stop harder than rim brakes.

Ideally I'd like brakes that could lock the wheels even on clean
pavement, but I'd guess only hydraulics would be able to do that.

I've not owned a bike with hydraulics yet but I already know that they
are heavy and expensive. The weight isn't much of a concern, and the
price I would pay if they were durable. It's the other problems I don't
know about that worry me.....
~

i've ridden shimano hydraulic disks on my mtb for years now, having
previously used cable disk and rim brakes. these hydraulics are
unquestionably superior. they offer firm braking, good modulation,
excellent stopping power [wet, dry or muddy], no detectable difference
in lever feel between front & rear, and above all, are very resistant to
fade. they wear reasonably well too. maybe not as well as a rim brake
in dry conditions, but /way/ better than a rim brake in muddy conditions.

as to stopping better, in ideal conditions, hydraulics should be able to
lock the wheels just as well as well adjusted rim or cable disk. in
reality however, the self-adjustment of hydraulics, good wear and
ability to cope with all conditions load the dice heavily - and you
/can/ say that hydraulics stop much better on average. i'd never go back.

DougC said:

I am pondering these as an upgrade to a bike that currently has Avid
[mechanical] BB5's. The front works fine but the rear brake is rather
mushy due to the longer cable stretching/jacket slack I assume.

1) Can I fit other (Shimano/Magura/Hayes/any others?) disk calipers onto
the same frame bracket and rotor?

2) This bike is a long-wheelbase recumbent;

beware mounting tab position and dropout style. a friend had a 'bent
with the tab mounted so that:

1. it didn't [couldn't] grip the disk fully.
2. it was [badly welded] to the front of the fork making it a prime
candidate for fatigue.

in addition, the dropouts didn't have lawyer lips. all in all, a shabby
combination.

Quoted message said:

do the brake lines com
pre-cut (for a DF)? Or can anyplace make them to length?

3) What problems arise with these braking systems (-considering that it
will be an on-road bike, and I am not likely to use it in sub-freezing
temperatures if that matters-).

4) Alternately, are there any upgrades I could do on the mechanical
system that would help much? It has the OEM Avid levers, probably quite
inexpensive. Do any levers pull "more wire" so to speak? And what's the
best (least-stretchy/least-compressible) conventional brake cable/jacket
out there?
~

DougC said:

I am pondering these as an upgrade to a bike that currently has Avid
[mechanical] BB5's. The front works fine but the rear brake is rather
mushy due to the longer cable stretching/jacket slack I assume.

If you have already eliminated other possible causes of poor rear brake
performance (bad pads, greasy pads, poor adjustment, fouled cable,
kinked housing, etc), then consider switching to a set of levers that
have adjustable mechanical advantage, e.g. Avid Speed Dial or Dia Compe
PC-7 EXA. Then you can set the front and rear MA on each lever such
that they provide uniform feel and they resist bottoming out.

Chalo