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Recreational Cyclocross and Gravelbiking This has to be the most physically intense sport ever invented. It's high speed bicycle racing on a short off road course or riding the off pavement rides on gravel like :The Dirty Kanza". We also have a dedicated Racing forum for the Cyclocross Hard Core Racers.

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Old 03-22-11, 11:02 AM   #1
3373jones
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tektro onyx canti brakes = braking power less than desired.

i'm trying to switch my old mtn bike over to a cyclocross bike. i picked up a set of tektro oryx cantis to use with my 6500 shifters (apparently Vbrakes dont work with STI levers). i'm fairly confident i have them set up correctly. anyway, i tested them out yesterday and the braking power was less than desirable. is this a common problem? what are some cheap solutions? attempt to use the vbrakes anyway? different brake pads?
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Old 03-22-11, 11:37 AM   #2
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A lot of people don't like those Oryx brakes. They are pretty sensitive to setup. There are easier ones to set up, the Tektro CR-720 cantilevers are inexpensive and more forgiving to setup.

But, search on both the CX forum and the mechanics forum and you will find discussions on the Oryx brakes.
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Old 03-22-11, 12:11 PM   #3
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i'm trying to switch my old mtn bike over to a cyclocross bike. i picked up a set of tektro oryx cantis to use with my 6500 shifters (apparently Vbrakes dont work with STI levers). i'm fairly confident i have them set up correctly. anyway, i tested them out yesterday and the braking power was less than desirable. is this a common problem? what are some cheap solutions? attempt to use the vbrakes anyway? different brake pads?
1. Do the brakes feel spongy when you squeeze them? If not - ie if they feel hard and reassuringly definite like V's or dual pivots - you've set them up wrong. Most people make this mistake. Search for previous threads on canti tuning. I'd be very surprised if you've set them up right - confidence that you have is probably a bad sign. Cantis are easy when you have the knack, but the first time should leave you feeling a little doubtful...

2. Almost any set of cantis will give performance with a fork mounted canti hanger; none will do a really job without one. The tuning threads will explain why. Kona make a nice hanger for about 10.

3. This is the least important detail, but fitting Kool Stop Pink Or Swiss Stop Green pads is always a good idea.

Last edited by meanwhile; 03-22-11 at 12:15 PM.
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Old 03-22-11, 04:23 PM   #4
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I had the opposite experience, I tried some CR-720s and they would barely stop. Not fun going into a downhill corner in a pack. One race, and I was happy to slap my Oryxs back on.

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A lot of people don't like those Oryx brakes. They are pretty sensitive to setup. There are easier ones to set up, the Tektro CR-720 cantilevers are inexpensive and more forgiving to setup.

But, search on both the CX forum and the mechanics forum and you will find discussions on the Oryx brakes.
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Old 03-22-11, 05:14 PM   #5
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they are a little spongy (although not excessively)... i'll do a search and see what i'm doing wrong.
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Old 03-22-11, 05:47 PM   #6
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If you want to totally geek out, try this:

http://www.circleacycles.com/cantilevers/

It calculates mechanical advantage based on brake geometry and yoke height.
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Old 03-22-11, 05:50 PM   #7
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If not - ie if they feel hard and reassuringly definite like V's or dual pivots - you've set them up wrong.
Give me the cliff notes version of fixing this!

My TRP eurox feel like this and I think I need to raise the straddle cable.
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Old 03-22-11, 07:37 PM   #8
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I've found that you need to start with the pads set properly. I find older cantis to be a pain to adjust with that post. The inline type pads that come with the oryx are easier. Anyway once you have that set(toe in and all that stuff), the resting position of the canti arms should be close to parallel to each other. so what this means is that whatever you decide for your straddle length, you will need to adjust your yoke so that when the brake is released the arms are held parallel to each other. Trying to get it this close might make the pads touch the rims. What I did was rearrange the washers of the inline pads to create more space.


This might not be the right way, but it worked great for me and my stopping power is excellent!
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Old 03-22-11, 09:49 PM   #9
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Of note: I am running two pairs of oryxs on two different Konas. On the Major jake I have them toed pretty aggressively with a stem mounted cable hangar. On the JTS they are hardly toed at all but there is a fork mounted hanger. The JTS is HANDS DOWN the better stopper! I am not sure the pads are the exact same but neither are cool stops. Both sets are standard v-brake pads.
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Old 03-23-11, 05:16 AM   #10
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I added some Koolstop cyclocross pads, huge difference even without being tuned correctly. Also, I have been using a straddle cable on the cable, which also made a big difference. the brakes are good enough for me
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Old 03-23-11, 01:04 PM   #11
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Quote:
Originally Posted by Andy_K View Post
If you want to totally geek out, try this:

http://www.circleacycles.com/cantilevers/

It calculates mechanical advantage based on brake geometry and yoke height.
+1 on that reccomendation, and read the accompanying paper with his analysis of cantilever geometry. http://www.circleacycles.com/cantile...i-geometry.pdf

In short, for medium to low profile cantilevers such as the oryx, a shorter (lower) saddle cable will always produce more mechanical advantage. Spacing the pads so that the arms are swung out more open can possibly change the mechanical advantage but results are rather unpredictable, measure then play with the on-line calculator to see. High mechanical advantage will result in more braking force, a squishier feeling brake lever that requires more lever movement to actuate and less mud clearance at the pad. If you need more clearance for mud at the rim or you bottom out your lever travel against the bars during hard braking, then lengthen the saddle cable to decrease meachanical advantage.

Last edited by GrayJay; 03-23-11 at 01:19 PM.
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Old 03-23-11, 08:17 PM   #12
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The brakes are awful imo. I'm thinking of getting something different. I can't stand the spongy feel.
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Old 03-23-11, 08:29 PM   #13
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so wait, spongy is good? my problem with canti's is I can pretty much bottom out the levers. maybe a cm before the bottom, the pads hit the rims, but I can still squeeze and it feels like I'm not getting any more stopping power.
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Old 03-23-11, 09:19 PM   #14
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Spongy feeling levers indicate that the brakes have enough mechanical advantage to make enough force to distort the rim, pads, levers, cables etc. Suppose it could also just indicate that the cantilever arms are way to flexible. Excessively stiff feeling levers indicate the opposite- that there is insufficient force being generated by the brakes to distort anything. It might mistakenly feel comforting to have more force on the lever but that is more a sign that the cantilevers are doing little to slow you down.
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Old 03-23-11, 09:30 PM   #15
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so wait, spongy is good? my problem with canti's is I can pretty much bottom out the levers. maybe a cm before the bottom, the pads hit the rims, but I can still squeeze and it feels like I'm not getting any more stopping power.
You might first try setting your pads a bit closer to the rim. If you have narrow or medium profile cantilevers, you might experiment with lengthening the saddle cable to raise the saddle hanger position, this will provide less mechanical advantage so the pads move-in faster and contact the rim sooner and leave you enough travel at the levers so you don't bottom out. All the mechanical advantage in the world is worthless if you don't have any lever travel left to apply more force.
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Old 03-24-11, 05:07 AM   #16
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All the mechanical advantage in the world is worthless if you don't have any lever travel left to apply more force.
good point. especially when I'm using my interrupter levers on the tops it almost feels like the cable is slipping in that additional squeezing after the first contact doesn't appear to slow me down at all, but the next time I brake the pad contacts the rim at the same amount of pull on the levers so you could be right about the bending of the cantilever arm or the straddle. I'm getting some new brakes to test this theory. Sorry for the mini-threadjack OP.
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Old 03-24-11, 09:02 AM   #17
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Give me the cliff notes version of fixing this!

My TRP eurox feel like this and I think I need to raise the straddle cable.
Fit the fork mounted canti hanger!!! Then -

You really need to see http://www.sheldonbrown.com/cantilever-geometry.html

But in summary -

- The closer the angle between the yoke wire and the horizontal is to zero, the more the force from the brake lever is multiplied in moving the pad inwards (the mechanical advantage aka MA) but the less it will move inwards for a given amount of lever movement

So a flat straddle wire brake can be easier to use if you have low hand strength (perhaps from exhaustion after lots of braking)..

..But you'll have to trade off rim clearance, because the pads will move less for a full lever squeeze

...And/or you'll lose absolute braking maximum power - because the further the cantis move the more pads are squashed and it is the degree of squash that determines absolute braking power at the rim. I.e. there is a conflict between the ease with which you can get maximum braking power, and what that power will be.

So it there isn't a single optimal angle but a continuum, reflecting demands for ease of braking, maximum force at the rim, and clearance. The retro mountain bikers who still use cantis tend to go for a low straddle low rim clearance set up with high MA and high maximum braking. My impression is that crossers tend to go for lots more rim clearance - because cross races are traditionally very muddy - and much less MA.

If you do go for a low straddle to maximize MA, then you should probably fit one of those fork widgets that catch the straddle cable if there's a break - otherwise the straddle can catch in a knobbly tyre and that can be the endo you. So to speak.

Finally, more power to stop the rim can easily be more power to skid rather than brake - narrow cross tyres have much less grip than 2" mtb tyres and grip is the real limit on braking. People confuse mechanical advantage and braking power all the time, but it is actually at least two steps removed.

As Sheldon Brown says, a common mistake is to think that cantis should feel hard and definite. The opposite is true. Brake levers connected to cantis should feel soft and squashy. The squashy feeling comes from the brake pads being squeezed between the canti arms and the rim of the wheel. The more the pad is squashed - the squashier the lever will feel - and the better the braking will be. Never try to adjust your cantilevers so that they feel hard!

Last edited by meanwhile; 03-24-11 at 09:10 AM.
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Old 03-24-11, 09:05 AM   #18
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so wait, spongy is good? my problem with canti's is I can pretty much bottom out the levers. maybe a cm before the bottom, the pads hit the rims, but I can still squeeze and it feels like I'm not getting any more stopping power.
The brakes should feel spongy when set correctly. But not all cantis that feel spongy are set correctly! Fit the hanger, follow the guide. With decent pads and a decent cable path - no stupid kinks! - you'll get jaw dropping modulation and power.

Are your brakes squealing? If so and you're not getting enough stopping power, or good modulation, it's because of the tension-and-release cycle in the cable that a fork mounted hanger prevents. Your brakes grab, this causes the cable to twang releasing the brakes for a fraction of a second, the brakes come back on... The fork mounted hanger fixes this.

Last edited by meanwhile; 03-24-11 at 09:13 AM.
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Old 03-24-11, 09:10 AM   #19
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Also: we're going to have a canti sticky soon. Obviously I'll reference Brown, Bontrager, and Zinn. And I'll copy past posts on mini-vees and travel agents - unless someone else wants to take care of any of these topics, which would be nice!
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Old 03-24-11, 02:19 PM   #20
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The pads that come with the Oryx suck. Koolstop MTB Dual Compound are awesome (I use them on both my Linear pulls and Oryx Cantis)

If you'd really like to use the Linear pulls (frankly they're easier to setup, quieter and offer more power) get some Problem Solvers Travel Agents (w/ the adjuster)
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Old 03-24-11, 06:02 PM   #21
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Fit the fork mounted canti hanger!!! Then -

You really need to see http://www.sheldonbrown.com/cantilever-geometry.html

I think I may have to go the fork mount (like I have on my geared bike) since my issue may be the angle of the housing going into the hanger below my stem.

I've read Sheldon etc. but frankly it just confuses me more!
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Old 03-25-11, 06:23 AM   #22
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Shorten your straddle cable as much as possible.
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Old 03-25-11, 07:41 AM   #23
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I think I may have to go the fork mount (like I have on my geared bike) since my issue may be the angle of the housing going into the hanger below my stem.

I've read Sheldon etc. but frankly it just confuses me more!
Ignore the link and just read my attempt at a guide; let me know how it works for you.
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