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Discussion Starter · #1 ·
I just got back into MTB after a 10yr hiatus. I went and got myself a new cannondale and I am very pleased with the bike overall except for the damn TekTro IO disk brakes. I don't by any strech consider myself a pro wrencher but I do have many years of experience doing upgrades and adjustments.
The TekTro's that came with this bike are basically junk and I realize that but I would like to run them for a few months and concentrate on a few other upgrades. But no matter how I try and adjust them they still rub on the rotors both front and back. Is there some trick to adjusting these #$%* things that I'm missing? Any help would greatly be appreciated.
 

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I had a few pairs of these and replaced them with Hydros. While not the greatest, they do work. First, are you sure your rotor is not slightly warped? You can easily see it while rotating the wheels and looking inside the caliper at the pads. If so, slight bending can get you just about perfect. Once complete, turn the inboard pad adjuster (5mm allen key) inward until it's about 1/3 of the way in the opening. BTW, you should have your calper bolts loose at this point. Then grab the brake lever and hold while tightening the bolts. Once tight, release the lever and loosen the inboard pad adjuster a small bit, then give a quick pull on the lever to seat the pads. Now look inside the caliper and spin the wheel. If done right, you should not have rubbing and if you do and it's slight, adjust the inboard pad again slightly. Repeat until perfect. This is very similar to how avid adjusts pads but they have inboard and outboard adjusters. When done right, the IO's can throw you over the bars. Out of the box they feel like stopping on bananna peels...
 

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Discussion Starter · #5 ·
RSabarese said:
I had a few pairs of these and replaced them with Hydros. While not the greatest, they do work. First, are you sure your rotor is not slightly warped? You can easily see it while rotating the wheels and looking inside the caliper at the pads. If so, slight bending can get you just about perfect. Once complete, turn the inboard pad adjuster (5mm allen key) inward until it's about 1/3 of the way in the opening. BTW, you should have your calper bolts loose at this point. Then grab the brake lever and hold while tightening the bolts. Once tight, release the lever and loosen the inboard pad adjuster a small bit, then give a quick pull on the lever to seat the pads. Now look inside the caliper and spin the wheel. If done right, you should not have rubbing and if you do and it's slight, adjust the inboard pad again slightly. Repeat until perfect. This is very similar to how avid adjusts pads but they have inboard and outboard adjusters. When done right, the IO's can throw you over the bars. Out of the box they feel like stopping on bananna peels...
Thanks RSabarse!
This got me closer than anything else I have tried up to this point. The problem seems to be the outboard pad, and adjusting the barrel and removing slack does not seem to have any effect. One thing I did notice last night was that if the quick release is opened the problem goes away. But if I apply the QR the outboard pad continues to rub even if the QR is so lose that it's beyond the safety threshold. Any thoughts?
 

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Sure, did you move the caliper over as far as it could with the bolts? I had that problem on 1 bike, it turned out the rotor must have had a slight dish to it, to I had to light bend the entire thing closer to the hub side. Took about 15 minutes. Good thing these brakes are easy to work on.
 

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I also hate those tektros im running a mechanical Avid BB7 on the front as a replacement and still running the Tektro on the rear - my god! the avid is epic adjustable from both sides and stopping power of a brick wall

as for the tektro - when it wants to work its fine, as soon as a tad of adjustment is required - either spend a few days or buy some avids!
 

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Welp, the problem with the Tektro brakes is that they often come on bikes that need to have their mounts faced parallel with the wheel in order to get them setup real well, since they only have lateral adjustment.

The other thing to consider is properly setting the pad position, which (unfortunately) doesn't happen very often, since it takes a disproportionate amount of time when assembling the bike. In ideal conditions, you want a 1:2 ratio regarding the gap between the left pad and rotor:right pad and rotor. First things first, though...notice on the caliper that there is, on the right side, a large bolt with an opening for a 5mm hex key. This adjusts the placement of the fixed (right side) pad, which will become important soon.

The specific way I like to setup a mechanical disc is thus: 1st, make sure the wheel is firmly in the dropouts, and running true (placing the bike on the ground before closing the QR will ensure this). Next, using the 5mm hex key, make sure you have adjustment room with the right pad, enough to get about a 1mm gap between rotor and pad. To make sure the rotor and pads are parallel, first loosen the bolts attaching the caliper to the mount, then give the adjustment barrel for the cable a few turns, until the left pad is touching the rotor. Likewise, you will use the 5mm key to move the right pad until the caliper is locked on the rotor. It is crucial during this process that you make sure the caliper is still sitting squarely on the mount, and only moving laterally. Tighten the mounting bolts for the caliper, a bit at a time, alternating until both are at spec.

Now, back out the right pad a bit, and screw the barrel adjuster for the cable back in all the way. You should have a small gap between the left (moving) pad and the rotor, just enough for the wheel to spin freely. Using your hex key, you now want to adjust the right pad to the point where the gap is roughly twice as large as the left side.

This all will not make the brakes feel any better, but they will at least work better. As the pads wear, you will need to readjust the brake, using the barrel adjuster and pad adjusting bolt.
 

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I have seen hundreds of these brakes OEM on a particular manufacturers bikes. What I see is that they are over tightened in the factory, indenting the painted surface where the brake mounts to the frame and on the other side where the bolt washer contacts the brake. Take a file and remove the paint from those areas, and you will be able to adjust them properly.
 

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I like to use the concave/convex washers that come on V brake pads. I keep a few around for bikes that have this issue. I install them between the for and the brake, instead of letting the brake contact the fork directly. I have found this gives you a whole lot of ability to then center and adjust the pads.

Just remmeber to properly center them first, then adjust your pads, your problems should be solved.

BIll
 

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Yes, sorry, I meant the disk brakes.

I remember the old shimano brakes, and the big plastic arch used to set them up.

Then they added one adjustment screw which helped a bit, it was only when v brakes came along we finally got an adjustment screw on each side.


I just had a classic bike in the shop with the original shimano canti brakes, lots of fun seeing the old tech and showing it to the young guys.

Bill
 
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