Question about the World's Best straddle wire hanger (Tektro CR720)

[Earl Grey]

Just installed my second pair of these lovely bargains from Riv, and
am once again flumoxed by the seemingly superfluous fat philips-headed
screw on the straddle wire hanger.

The two tiny allen headed screws are to arrest straddle wire movement,
okay. Why do you need the third screw? I just looked at the Tektro
site (http://tinyurl.com/4xd38ta) and it seems they are using the fat
philips screw as a resting place for the loose end of the main brake
cable. Is that its one and only intended purpose? Seems like a strange
raison d'etre for a screw, but I guess it works. Any other thoughts on
what it's for?

Cheers,

Gernot

[Shaun Meehan]

Gernot,

I am equally baffled. I've got a pair of those cable hangers on my Atlantis and I removed those screws. Mostly out of spite.

Shaun Meehan

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[Garth]

Yeah .... I don't know why anyone would call it a great hanger ... lol .   The screws are supposed to hold the cable in place. Okay .... try to remove your wheel like that. Yep ... remove the screws.... but frankly ... I prefer the good ol' regular hangers.

[EricP]

I like the hangers, but like Shaun I just don't use the screws.
Prefer the hanger to be able to slide from side to side. It makes for
an easier on-the-bike adjustment to even out the brakes.

Eric Platt
St. Paul, MN

[Michael Hechmer]

I don't own these, but have considered buying a pair of the Tektro brakes for a winter bike.  The Riv photo, with the barkes installed doesn't show the additional screw.  But more importantly how do you like the brakes?  Stopping power?  Ease of set up?

michael

[rcnute]

Super easy to set up and very strong. I have them on all my bikes.
Gotta replace the pads though.

Ryan

[Mojo]

Agree with rcnute, these CR720 is easy to setup and quite powerful especially with salmon pads and the straddle cable as low as possible.

[rcnute]

Another plus is that (for me anyway) they seem to work well with non-
aero levers--sometimes it's hard to make those levers work with
cantis. I have some nice Campy and Mafac levers I wanted to use.

Ryan

[Montclair BobbyB]

My take: I think these are indeed the best straddle hangers out
there. Here's why. You position the hanger for optimum/even pull
from both brake calipers, then you set the screws and secure the
straddle wire so the hanger remains perfectly positioned; without it
the hanger can float and eventually the pull on the calipers will
become uneven.

I use the philips head screw just to hold the straddle wire in place
(in the hanger) enough to unhook it from the caliper and to tighten
the allen bolts (which generally DO require unhooking the straddle
wire to get an allen key on the bolts, particularly with a rear rack).

SO, the allen heads make perfect sense to me, to hold the straddle
hanger in place after setting it up to pull evenly.
The philips head holds the cable in place while you disconnect the
hanger wire, enabling you to then set the allen bolts.

Beautifully designed...

BB

[grant]

The argument that the Tektro hanger is the best...is a funny argument
at some level, because any decent one from the pas 70 years is 98
percent as good as any other, including this. The Tektro *wins*--my
opinion--the final 2 unimportant percent, because if for any reason
(can think of two offhand) your cantilevers aren't opening evenly,
then the set-screws allow you to shift the hanger off-center and keep
it there to compensate. It is a nice-looking hanger, in any case.

Tektro is a neat company. They don't wait, they don't copy, they know
brakes and they innovate. They made the long-reach sidepulls (Silver
and R556) when Shimano wouldn't even respond to the inquiry, and
neither did Dia-Compe. Tektro listened, understood, and DID it---and
figured out the wide-opening q/r that we requested.

[Philip Williamson]

Hmm... what pads do you get? I was disappointed in the Tektros and put
the stock Shimano cheapies back on the rear. I got Yokozuna pads from
Rivendell, but they were really long and seemed to have a shallower
mounting groove than was safe with the Tektros. It didn't look like I
could use them: http://bit.ly/yoko-pads
I am interested in tuning the Tektros - lowering the straddle,
upgrading the pads, etc.

Philip

Philip Williamson
www.biketinker.com

[Ginz]

I'm using Kool Stop Mountain in the front and the Thinline in the
back. I do not like the Thinline with this brake.

I found that I had to RAISE the yoke in the front. I guess different
levers can have a big impact on mechanical advantage even thought they
are all made for cantis?

On Aug 28, 2:54 am, Philip Williamson <philip.william...@gmail.com>
wrote:

[Earl Grey]

Philip,

you are trying to put mountain style pads into a road style brake pad
holder. Get some Yokozuma *road* replacement pads (for side-pull
brakes) and they'll fit perfectly.

Cheers,

Gernot


On Aug 28, 1:54 pm, Philip Williamson <philip.william...@gmail.com>
wrote:

[Earl Grey]

Agreed, it is a very nice-looking hanger, and most importantly for me,
it uses a 10mm box wrench and a 5mm? Allen key to adjust. How many of
you carry 2 separate 9 or 10mm box wrenches, which most straddle cable
hangers from the last 70 years require? And how often does one or the
other of those box wrenches slip? holding the hanger in place with an
Allen key is much more secure as you tighten the 10mm nut.

But what is the durned Philips head screw for? What Montclair BobbyB
said? I still think it's a holder for the main brake cable...

Gernot

[Michael Hechmer]

My favorite cable hanger is this one, which I got from Jitensha but are no longer carried.

http://gallery.me.com/mhechmer#100029/IMG_1193&bgcolor=black

They are the best looking I have ever seen and are completely self centering, once installed.  Initial set-up, however is a meticulous, time consuming trial and error process.  I think velo orange now carries something similar.

As to the tectro brake, I was surprised by this comment:

"quite powerful especially with ... the straddle cable as low as possible."

I'm not a physicist but my understanding of levers, and experience setting up canti brakes suggest that the brake will be most effective when the cable and arm approach 90 degrees.  I would set these brakes up with a high straddle wire, like this picture from the Riv site, or even higher:

http://www.rivbike.com/products/show/tektro-cr720-cantilever-brakes/15-153

high profile brake with a high hanger and low profile with a lower hanger. yes?

michael

[Ginz]

My experience with the CR720 requires the yoke to be as high... so
high that I had to use an extra-wide yoke because the straddle cable
wasn't long enough.

[Montclair BobbyB]

Sheldon Brown sez: http://sheldonbrown.com/cantilever-geometry.html

On Aug 28, 12:07 pm, Michael Hechmer <mhech...@gmail.com> wrote:
> My favorite cable hanger is this one, which I got from Jitensha but are no
> longer carried.
>
> http://gallery.me.com/mhechmer#100029/IMG_1193&bgcolor=black
>
> They are the best looking I have ever seen and are completely self
> centering, once installed.  Initial set-up, however is a meticulous, time
> consuming trial and error process.  I think velo orange now carries
> something similar.
>
> As to the tectro brake, I was surprised by this comment:
>
> "quite powerful especially with ... the straddle cable as low as possible."
>
> I'm not a physicist but my understanding of levers, and experience setting
> up canti brakes suggest that the brake will be most effective when the cable
> and arm approach 90 degrees.  I would set these brakes up with a high

> straddle wire, like this picture from the Riv site, or even higher:http://www.rivbike.com/products/show/tektro-cr720-cantilever-brakes/1...

[Philip Williamson]

Aha. My rule-of-remembering has been "high profile = high hanger; low
profile = low hanger," just like Michael's, until I put this brake on
with every mm eked out of the straddle wire and it was still
disappointing. I'll try a long longer straddle wire, and possibly a
wider hanger first. And those Kool Stop pads.

As for the roller hangers, the coolest I've seen was on an old Chrome
Raleigh mountain bike. Super light, and it opened up so you could put
the wire in from the back, instead of threading it through the roller
hole. http://www.flickr.com/photos/philipwilliamson/4301739147/

Philip (off to pick up a replacement S/A nut)

Philip Williamson
www.biketinker.com

[William]

Sheldon (RIP) did a great job of laying out the geometry factors, but didn't really get to the punchline.  

The punchline, in my opinion is that the mechanical advantage of high profile cantilevers is almost constant regardless of straddle cable length.  Brakes like Tektro CR720s and old Mafacs and similar, has a particular mechanical advantage.  You can adjust that a tiny bit, like a few percent, by raising or lowering the straddle wire hanger, but you can't make a major change, no matter where you put it.  The upshot is, if you like how those brakes feel with your lever, then be happy, because there is almost nothing you can do to mess it up.  If you don't like how they feel (probably because of too little mechanical advantage), then you can tinker all day long with straddle position, and it really won't do much.  A different lever that changes mechanical advantage might make a difference.  A different brake pad compound that doesn't need as much force to grab might make a difference, but high profile cantilevers are not very tuneable.  You'll see some folks running their straddle right above the fender, and others several inches higher.  Those two setups won't feel a lot different, all else being equal.  The Riv-ish upside to this is that if you use high profile cantis with a lever that works, you can raise the straddle high to clear your rack, fender, and fat tire, and still get similar braking.   

Low profile cantilevers are super tuneable, but that give you more opportunity to get it wrong.  If you are forced to move the straddle to clear a fender or rack, you may be disappointed at the major effect that had on braking performance..  

[Earl Grey]

Thanks for that explanation, William,

that was enlightening, and jives with my experience. The way my non-
engineer's brain makes sense of this is this:

The main brake cable moves up when you engage the brake. For a high
profile canti to engage you also mostly need to pull up on the
straddle wire, and inward a little. On a low profile canti, you mostly
have to pull *in* on the straddle cable, while pulling up does very
little good. So on a low profile canti the straddle cable has to
change the direction of force from the main brake cable, and yes,
that's easy to get wrong. On a high profile canti, the straddle cable
serves merely as an extension of the brake cable transferring the
brake force to both arms. It doesn't have to change the direction of
the force, and is thus relatively immune to geometry. (I am sure this
explanation won't satisfy an engineer, but it works for me) :)

Gernot

[dougP]

Is this ever a timely discussion! Just back from a tour in Oregon
featuring plenty of hills. My wife's Atlantis is standard Riv build
with the low profile Shimano cantis and Shimano aero levers. It does
have Kool Stop salmon pads. In the past, she's mentioned the brakes
did not seem as good as the dual pivot sidepulls on her old Trek but
was OK with it. This was her first trip with long downhills on the
Atlantis & she's really spooked by the lack of braking.

As a sidebar, I replaced my stock Shimano low profiles with Tektro 720
a few years ago & liked the modulation much better. They are
noticeably more powerful than the Shimano but not as good as the
ancient Shimano high profile canti's on my 80s era MTB.

Now the question: I need to get her more braking power but I doubt
the Tektros are enough. She has small hands & does not have a strong
grip. Are V-brakes a direct substitute? Or do I also need to change
levers?

Thanks for your thoughts on this.

dougP

> > on braking performance..  - Hide quoted text -
>
> - Show quoted text -

[William]

Normal drop bar brake levers do not pull enough cable to actuate typical V-brakes.  There are special levers that pull more cable. and there are inline pulley solutions that correct the cable rate issues.  Small-handed, weak-gripped riders have a significant challenge getting confidence-inspiring brake performance with traditional rim brakes, especially on loaded bikes.  It's non-Rivendell, but you might want to allow her to test ride a bike with disk brakes as you plan out your upgrades.  

[Michael Hechmer]

Doug, you pose the perfect question for me to share my experience with cantilevers and why I continue to believe in hi straddle and hi profile cantis.

My first experience with cantis, after years of good riding with Campy Grand Sport LR brakes and Chorus SR brakes came around 2000, when I bought a SOMA DBL Cross for commuting and had it outfitted with my first Ultegra 9 spd. system and the then new Ultegra Low Profile canti brakes.   The bike and brakes were installed by the best mechanic in VT, including the very short straddle wire supplied by Shimano.  Braking was awful, downright scary for commuting.  I replaced the pads with Salmons and that helped somewhat.  I finally abandoned the SIS brifters, replacing with Cane Creek & Silver shiftes and the braking rose to the level of OK.  Setup, with Shimano Brifters, was also pretty tedious and the brakes needed to be re-centered every time I put the bike into the back of the car or did any almost thing else.  The brifters, which were designed for short reach side pulls, simply did not work together with cants.  I have avoided low profile brakes (and briftes) ever since.

After a poor-braking-near-death-experience, I bought a pair of hi profile Pauls and found that with a very hi straddle wire, as recommended by Paul, I had easy set up and great braking. 

My next experience with Cantis was a pair of hi profile, short arm di comp which came on a 1984 Trek 620 I bought on ebay.  Much to my surprise these brakes also delivered mediocre power, even with salmon pads.

Now my Ram and my tandem have Paul's Racer Ms and Racers respectively.  My Ebisu has neo retros with a hi straddle wire and my now pretty beat up winter bike SOMA has those di comps, which I'm planning on replacing with Tektros and a hi straddle wire.

When I was much younger I would say, "Who needs brakes, they just slow you down!"  Now, medicare not withstanding, I really like having brakes I can rely on.  Intimations of mortality no doubt.

michael

recovering from lower back strain and Irene, in Vermont

 

[dougP]

Michael:

Thanks for sharing your experiences. I plan to try a high profile
canti set-up on my wife's Atlantis as a first measure. Hopefully that
will replicate the braking performance of her old bike. If not, I'll
look into V-brakes & new levers, but that probably has its own
learning curve.

dougP

[Philip Williamson]

I look back on the last 15 years of my cycling life, and I gotta say.
Cantis suck. Single pivot sidepulls suck. The disc brakes on my weirdo
project bike brake very well, but go 'shk shk shk' in corners. The
nicer Avid v-brakes on my 1999 Bontrager have, aside from the initial
squealy pads ("hey, someone set these up without ceramic pads, let me
change that for you")... have been absolutely trouble free for 11
years. I've changed the pads a couple times. They have excellent
modulation, good stopping in wet or dry; I can do nosies on purpose,
but never on accident (well, once).

Cantis for me are a crapshoot. I've set up dynamite dialed-in cantis a
couple times, and as the pad wears, the braking degrades. Sometimes
the canti arm dives under the rim (well, once). I study the charts,
change out the pads (why should you even have to DO this?), finesse
the setup, and then forget everything I learned the next time I have
to set them up from scratch.

I just hate the way v-brakes look on a roadified bike. They look like
ass. I can't imagine putting them on my Quickbeam, but I don't want to
sell a bike just to buy some green anodized Paul cantis.

Actually, maybe I do.

Philip

Philip Williamson
www.biketinker.com

[Michael Hechmer]

Gee Phil, I'm sorry to hear you have had such bad luck with brakes.  We're glad you're still alive.  Some cantis and some canti - lever combinations are indeed more trouble than their worth, but that's not true of all cantis. A good set of brakes will last as long, or even longer than a frame, so those no reason not to spring for really good ones. Pauls cantis have a short learning curve, as do most mechanical things, but once you get it, they are a snap to set up, as are the Racers.  I always set brakes up as high on the rim as I can, and have not had a problem with wear or diving.  I would also argue that single pivot brakes are pretty easy to live with.  You need a 13 mm offset cone wrench to align them, and they can get knocked out of alignment, but it is literally a 5 second job straightening them.  I have a pair of Campy Grand Sports which I bought in the early '80s and a pair of very early Chorus (the pretty ones with the split arms) from the late '80s and they both continue to work as well as they did when they were brand new.  I will admit that dual pivots have a lighter touch but they crowd fenders a lot more than single pivots.  Maybe its like friction shifters, if you didn't start with them it might be frustrating to get up the learning curve.  

Good news, I have no back pain this morning, and a chiroparctor appointment at which I'm hoping to get the green light to resume riding.  Now lets see if I can find some intact roads in VT!

michael

[Earl Grey]

I have always liked cantis, and the Tektro 720s are my favorites. I
have disc brakes (Avid BB7 wit h8" rotors) on one tandem (didn't have
a choice, and thought may as well give them a chance. Every few rides
I need to adjust the pads because they rub. In the rain, they squeal
like crazy. Don't see the advantage over cantis. I have also had the
last generation of single pivot Campy sidepulls. They were fine, but
not as nice as cantis.

V brakes have lot's of stopping power (with special levers) and I
concur that they look terrible. In addition, they are so powerful that
lightweight riders can very easily endo. My 100 lb ex did that once
while cruising at 12mph or so in the park, casually grabbing the brake
to come to a stop on a low-end Cannondale mtn bike. So try some Tektro
CR720s with Koolstop pads before going to V-brakes, and warn your wife
about their grabbiness and high power.

Cheers,

Gernot

[CycloFiend]

on 8/31/11 5:15 AM, Earl Grey at earl...@gmail.com wrote:

> I have always liked cantis, and the Tektro 720s are my favorites. I
> have disc brakes (Avid BB7 wit h8" rotors) on one tandem (didn't have
> a choice, and thought may as well give them a chance. Every few rides
> I need to adjust the pads because they rub. In the rain, they squeal
> like crazy. Don't see the advantage over cantis. I have also had the
> last generation of single pivot Campy sidepulls. They were fine, but
> not as nice as cantis.
>
> V brakes have lot's of stopping power (with special levers) and I
> concur that they look terrible. In addition, they are so powerful that
> lightweight riders can very easily endo. My 100 lb ex did that once
> while cruising at 12mph or so in the park, casually grabbing the brake
> to come to a stop on a low-end Cannondale mtn bike. So try some Tektro
> CR720s with Koolstop pads before going to V-brakes, and warn your wife
> about their grabbiness and high power.

The real rub with V-Brakes (or specifically, linear pull) is that they tend
to be on or off. It's a matter of the pressure your hands are used to
applying, and the more time you spend running canti brakes, the more
ingrained it becomes. You can get used to the difference, but you can also
really hurt yourself - especially when jumping to a bicycle with different
brakes.

Braking 101 Review
Most of the people I've encountered who complain of poor braking performance
have brakes that feel "hard" at the lever. That's the antithesis of power.
It's also about learning how to effectively use the front brake. I was out
at the trails and listened to some "teacher" from a local outdoor shop
carefully explaining to new mountain bikers that they should never use their
front brake, because it would cause them to crash. Piffle and hogwash, to
be sure, but the wrong techniques are out there...

Quick Brake Setup Thoughts
Of course, the main reason the switch to lp brakes caught on was that they
were bone-simple to set up. For shops where you are building a ton of bikes
every day, this was/is important. With cantis, there are a few more
variables, and the problem is that you tend to change one while attempting
to adjust the other. But, when canti designs incorporated the multi-washer
pad adjustment systems of lp brakes, things got better. Here's the
procedure which I found helps mimic quickie-lp setup:

pre - make sure wheel is centered in the dropouts - work on the same side of
the bike as the brake arm unless specified.
1 - release straddle wire. (let's start front left)
2 - cupping the brake pad assembly from below with your left hand, use your
thumb on the same hand to position the arm so it is vertical (i.e. at 90
degrees, i.e. perpendicular to the ground.
3 - while maintaining that position, loosen and position the brake pad so it
is 90 degrees from the arm, and touching the rim (flat is ok at this point)
The trick here is to not move the arm, which should be pretty much lined up
with the fork blade, lock the pad down in this position, which applies the
most power to the rim.
4 - do the same to the opposing arm
5 - connect the straddle cable. If you cannot see if you can change the
straddle relation easily. Otherwise back off the pads a smidge until you
get appropriate clearance
6 - make sure things are even, when viewed from the front.
7 - if you didn't back off the pads, check that they have enough clearance
at this point.
8 - now go back and set toe-in

4 -

--
Jim Edgar
Cyclo...@earthlink.net

Cyclofiend Bicycle Photo Galleries - http://www.cyclofiend.com
Current Classics - Cross Bikes
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-- Robert McCammon, "Boy's Life"

[Allingham II, Thomas J]

Those green ano Pauls stop REALLY well. ;-) http://www.flickr.com/photos/37542512@N04/5645451309/in/set-72157626433454817

Actually, maybe I do.

Philip

Philip Williamson
www.biketinker.com

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[Thomas Lynn Skean]

On Wednesday, August 31, 2011 10:42:07 AM UTC-5, Cyclofiend Jim wrote:

 

....

 

The real rub with V-Brakes (or specifically, linear pull) is that they tend
to be on or off. It's a matter of the pressure your hands are used to
applying, and the more time you spend running canti brakes, the more
ingrained it becomes. You can get used to the difference, but you can also
really hurt yourself - especially when jumping to a bicycle with different
brakes.

 

....

--
Jim Edgar
Cyclo...@earthlink.net

 

Ah-ha! This goes a long way towards explaining why lots of people seem not to like linear-pull brakes. Perhaps It's an area where having a certain minimum amount of mass on the bike and having *less* experience actually mitigates an issue. That is, I've had only linear-pull brakes in my recent riding. And they feel relatively smooth and controllable... perhaps because they are fighting a substantial load (at least me, at 245lbs). I think with my kind of payload, there's a big difference in the hand-effort required to (1) merely engage the brake and (2) stop the bike. Fortunately, I also have strong hands (years of piano lessons). So, while going from (1) to (2) for a lighter-weight cyclist might be startingly quick and difficult control, for me it seems reasonably gradual, easy to manipulate, and never gets too difficult. I've never thought I was missing anything using linear-pull brakes. But I do realize that my current brakes and levers (both from Paul Components) were each an improvement in feel and control. And together they are quite nice. So perhaps after about a year with these I'd feel that my old $20 Tektros or $40 Shimanos, both with Tektro levers, are somehow wanting. Hard to say. But I do know they worked fine for me at the time.

 

Now, as to other comments about the looks of linear-pull brakes... well, to some extent I agree. Not so much that linear-pull brakes are ugly or even particularly unattractive. But some canti-brakes I've seen are works of art. And I like the simple elegance of some sidepull brakes as well. So to me it's more like linear pull brakes are kind of a "lost opportunity" for beauty than an actual blemish. I happen to like the way the Motolite sort of echoes the soldier-y image of the fork crown in front. And in general I like the Paul Components aesthetic.

 

Yours,

Thomas Lynn Skean