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Inline barrel adjusters for mechanical road discs?

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Inline barrel adjusters for mechanical road discs?

Old 11-21-20, 07:45 PM
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keithdunlop
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Inline barrel adjusters for mechanical road discs?

SRAM recommends that when road levers are used with mechanical road disc brakes that inline barrel adjusters be installed to "remove cable slack." Road levers don't have the built in adjusters that MTB levers do.

But, is this really necessary? BB7 calipers already have dual pad adjusters and cable slack can be handled with pre-stretching cable and using a third-hand tool during installation, with future adjustments as the system wears in.

Or am I wrong about the usefulness of inline adjusters.

Per Park Tool: "Do not use the barrel adjuster to move the pads inward as they wear. This will eventually move the lever arm to a position where it is contacting another part of the caliper, preventing the pads from contacting the rotor. The barrel adjusters should only be used to take out cable slack as the cable and housing system settle in."
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Old 11-21-20, 08:14 PM
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There is an easy to follow simplicity in having no cable adjuster. Unfortunately for those who pay attention to details this simplicity is a fools economy. Funny but I think of our country's current political issues as a metaphor... Andy
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Old 11-21-20, 08:26 PM
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Originally Posted by Andrew R Stewart View Post
There is an easy to follow simplicity in having no cable adjuster. Unfortunately for those who pay attention to details this simplicity is a fools economy. Funny but I think of our country's current political issues as a metaphor... Andy
Ummm . . . what?
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Old 11-21-20, 09:17 PM
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Originally Posted by keithdunlop View Post
Ummm . . . what?
Having more adjustment range to handle the set up and wear and tear is a good thing. Planning for future change and allowing some flexibility is future abilities is a good thing. Choosing a path that polarizes parties, reduces options and compatibility with others is generally a short sighted path. Andy
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Old 11-21-20, 09:23 PM
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My bike doesn't have in-line adjusters, just the barrel at the calipers. It has inline adjusters for shifting and I don't like them. So I wouldn't put them in the brake cables. My riding style allows me a few seconds every month to get off the bike to make adjustments while cycling. I agree that one should adjust the calipers at home or in the shop as the pads wear.
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Old 11-21-20, 09:26 PM
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Uhmmm, I'll just leave this on-topic post here. No, no need for inline barrel adjusters, if you adjust the brakes by pulling cable you'll kill all the leverage(power) in the system and it won't work at all. Everyone knows my feelings on cable stretch, but housing does definitely compress when new. Attach the cable, squeeze the crap outta the lever a bunch and then pull the slack at the anchor. No need for any 'adjustment'. As the pads wear you adjust by moving the adjustable piston.
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Old 11-21-20, 11:08 PM
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I was sure that I read not to use barrel adjusters, for the reasons others stated. I use bb7s with road levers abd even on long trips, it's been very infrequent that I had to adjust the dials to move the pads in as they wore.
I'm pretty certain that I only had to do this once during a 3000km two month trip.
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Old 11-21-20, 11:35 PM
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Originally Posted by keithdunlop View Post
SRAM recommends that when road levers are used with mechanical road disc brakes that inline barrel adjusters be installed to "remove cable slack." Road levers don't have the built in adjusters that MTB levers do.

But, is this really necessary?
Nope. If the calipers are aligned correctly, rotors disks are true, and pad adjusters don't get lose by themselves, you shouldn't have to adjust the brakes during even long rides.

Per Park Tool: "Do not use the barrel adjuster to move the pads inward as they wear. This will eventually move the lever arm to a position where it is contacting another part of the caliper, preventing the pads from contacting the rotor. The barrel adjusters should only be used to take out cable slack as the cable and housing system settle in."
What Park Tool said about lever contact is true. A very dangerous situation to be in because sometimes, the mechanism will "jump" before the lever even contacts other parts of the caliper, effectively losing brake effectiveness quite suddenly.

One effective way I found to avoid it is to adjust the caliper so that the caliper housing is closer (as close as possible) to the rotor at the side of the pad with barrel adjustment. This way, the pad with barrel adjuster is about fully recessed into the caliper while the other pad is more exposed. This adjustment will move the lever as little as possible from the non-tensioned position.

You still need to use the barrel adjuster as the pad wears BUT the pad with non-barrel adjustment takes priority as per Park Tool advice.
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Old 11-22-20, 08:16 AM
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Originally Posted by cubewheels View Post
Nope. If the calipers are aligned correctly, rotors disks are true, and pad adjusters don't get lose by themselves, you shouldn't have to adjust the brakes during even long rides.



What Park Tool said about lever contact is true. A very dangerous situation to be in because sometimes, the mechanism will "jump" before the lever even contacts other parts of the caliper, effectively losing brake effectiveness quite suddenly.

One effective way I found to avoid it is to adjust the caliper so that the caliper housing is closer (as close as possible) to the rotor at the side of the pad with barrel adjustment. This way, the pad with barrel adjuster is about fully recessed into the caliper while the other pad is more exposed. This adjustment will move the lever as little as possible from the non-tensioned position.

You still need to use the barrel adjuster as the pad wearsBUT the pad with non-barrel adjustment takes priority as per Park Tool advice.
the person asking the question has BB7 Avids, as I do, and I am sure that they specifically say NOT to use the barrel adjusters as pads wear, but to dial in both the adjustable dials for each pad.
This is what I have done, and like I said, it is something that has to be done rarely, so not an issue, and done with the right torx tool. I have one on my multi tool.
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Old 11-22-20, 08:33 AM
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My TRP Spyre mechanical disc brakes have barrel adjusters on both calipers and, even fully extended, I can't see how they could move the operating arms far enough to go "over center".
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Old 11-22-20, 08:36 AM
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I wasn't clear, I thought he was referring to barrel adjusters on the brake handles. I'm certain Avid says not to use these as pads wear.....but I realize we are talking about road levers, so what I wrote was thinking barrel adjusters up near the levers, not on the calipers. My BB7s only have the two dials though, one for each pad, no barrel adjusters on caliper.
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Old 11-22-20, 08:37 AM
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You don't use the barrel adjuster to compensate for pad wear. Let me repeat that. You DO NOT use the barrel adjuster to compensate for pad wear. Use the pad advancement dial. It's located on the caliper. The only use of the barrel adjuster on mechanical disc brakes is to remove the small amount of cable slack when initially setting up the brakes.

I hope it doesn't need saying that hydraulics don't need a barrel adjuster.
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Old 11-22-20, 10:50 AM
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Thank you all very much (even Mr. Stewart) -- question resolved.
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Old 11-22-20, 12:39 PM
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All of these recommendations may depend on the brand and model of brake caliper being used. I'm using juin-tech cable operated hydraulic calipers with SRAM AXS levers. I have one bike with the F1 and one with the GT model. No inline cable adjuster is needed because the calipers have a built-in cable tension adjusting knob. It is necessary to adjust it initially and periodically, as the pads wear. If that's not done, then the brake levers will eventually bottom out on the handlebar and not offer full braking ability.

I found that the calipers must be centered before attaching the cables because the very stiff compressionless housing will not allow the calipers to move freely and center properly, at least with the internal cable routing on my Cinelli Superstar frames. I even had some problems centering the front without the cables attached. I ended up placing a .007 inch feeler gage between the outer pad and rotor, while actuating the lever by hand and tightening the mounting bolts. That left the pads well centered and the amount of brake lever travel kept to a minimum. I use the SRAM small hands feature adjusted all the way in, which reduces the available travel.
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Old 11-22-20, 12:41 PM
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Originally Posted by cubewheels View Post
Nope. If the calipers are aligned correctly, rotors disks are true, and pad adjusters don't get lose by themselves, you shouldn't have to adjust the brakes during even long rides.



What Park Tool said about lever contact is true. A very dangerous situation to be in because sometimes, the mechanism will "jump" before the lever even contacts other parts of the caliper, effectively losing brake effectiveness quite suddenly.

One effective way I found to avoid it is to adjust the caliper so that the caliper housing is closer (as close as possible) to the rotor at the side of the pad with barrel adjustment. This way, the pad with barrel adjuster is about fully recessed into the caliper while the other pad is more exposed. This adjustment will move the lever as little as possible from the non-tensioned position.

You still need to use the barrel adjuster as the pad wears BUT the pad with non-barrel adjustment takes priority as per Park Tool advice.
No. No. Let me repeat...no.
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