Disc brake adjustment question / TRP HY-RD brakes

[54ny77]

Just picked up a bike (tandem) with TRP HY-RD disc brakes and running Ultegra triple 6700 levers.

Issues that I could really use some help with, as discs are all greek to me:

1) Despite getting all the cable slack out of system, I can still pull lever all the way to the bars. I've followed the TRP install instructions to the letter. Front is so-so, rear is not good, can barely skid. Not enough grip to give me confidence in a full panic stop esp. if coming down a quick hill.

2) Front disc rubs ever so slightly and the sound (chatter/squeak) drives me nuts. Rear is fine, no chatter.

Pic of disc brake model attached. Thanks for any help!

[Hilltopperny]

I usually set these up as tight as I can with the barrel adjuster set up so that I can loosen it until comfortable. Then as the pad wears I can use the barrel adjuster to tighten things up.

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[tellyho]

Assuming compression less housing? That was crucial for me. Trp wants you to set up in a very specific manner, that has worked for me. But yes, I found the lever travel problematic. There is a cable routing hack that shortens the pull. I eventually replaced mine.

[leftsidedrive]

These brakes aren’t amazing, and you’ll find when the pad wears down approximately 50% you will lose all braking power. Barrel adjusters essentially do nothing. My advice would be to run some trp Spyres. I apologize if I come across as negative and unhelpful, but these brakes are truly awful.

[54ny77]

Good to know, thank you. I have some avid disc brakes on another bike that are mechanical, using 105 levers, and they work just fine. It sounds like the answer is to get rid of these and I will do so ASAP. Thanks for the advice.

[vertr]

Originally Posted by leftsidedrive

These brakes aren’t amazing, and you’ll find when the pad wears down approximately 50% you will lose all braking power. Barrel adjusters essentially do nothing. My advice would be to run some trp Spyres. I apologize if I come across as negative and unhelpful, but these brakes are truly awful.

Yeah I had the same experience with the hy/rd post mount version. You have to set them up against their guidelines for them to work like normal brakes. I switched to a cheap pair of Juintech hybrids from amazon and it was a world of difference.

[54ny77]

Do you like the Spyres? Have they worked great? What kind of levers are you using?

Originally Posted by leftsidedrive

These brakes aren’t amazing, and you’ll find when the pad wears down approximately 50% you will lose all braking power. Barrel adjusters essentially do nothing. My advice would be to run some trp Spyres. I apologize if I come across as negative and unhelpful, but these brakes are truly awful.

[catchourbreath]

I raced cx for a couple seasons on them. Using sintered pads and compression less housing makes a huge difference

[mjf]

You likely need a brake bleed.

The barrel adjuster should only be used for picking up slack in the cable and nothing else. Adding tension to the cable otherwise is depressing the plunger further into the master cylinder of the caliper, preventing the pads from advancing as they wear.

[54ny77]

what does a brake bleed do on a mechanical system? i totally get it on a hydro system (i used to do same on my moto years ago), but don't understand how that works on a hybrid system with cable actuation.

i'll look into this as well as replace pads. i looked at a trp video and they show how to do all of that.

eventually i prefer to keep things simple and will replace with mechanical discs.

thanks for all the suggestions/info.

Originally Posted by mjf

You likely need a brake bleed.

The barrel adjuster should only be used for picking up slack in the cable and nothing else. Adding tension to the cable otherwise is depressing the plunger further into the master cylinder of the caliper, preventing the pads from advancing as they wear.

[mjf]

Originally Posted by 54ny77

what does a brake bleed do on a mechanical system? i totally get it on a hydro system (i used to do same on my moto years ago), but don't understand how that works on a hybrid system with cable actuation.

i'll look into this as well as replace pads. i looked at a trp video and they show how to do all of that.

eventually i prefer to keep things simple and will replace with mechanical discs.

thanks for all the suggestions/info.

The way that I like to think about these brake calipers is where the cable attaches to the caliper can be considered a brake lever when compared to a normal system, but there's no hose in between the "lever" (cable attachment) and hydraulic caliper. The only thing that the cable is doing, is pulling on the "brake lever" at the hydraulic caliper.

Remember, these are cable actuated, hydraulic calipers. The cable portion of the system only exists to actuate the plunger at the hydraulic caliper.

But yes, get some new pads, especially if the ones you have are worn since that'll likely push the pistons back into the caliper. While that should fix some of the sponginess you're experiencing, a brake bleed will very likely be a necessary course of action.

These are VERY good brake calipers, but they're often misunderstood for how they're supposed to be set up and maintained, leading to the same problems that you're having.

[54ny77]

got any good pad recommendations?

i ordered a bleed kit.

Originally Posted by mjf

The way that I like to think about these brake calipers is where the cable attaches to the caliper can be considered a brake lever when compared to a normal system, but there's no hose in between the "lever" (cable attachment) and hydraulic caliper. The only thing that the cable is doing, is pulling on the "brake lever" at the hydraulic caliper.

Remember, these are cable actuated, hydraulic calipers. The cable portion of the system only exists to actuate the plunger at the hydraulic caliper.

But yes, get some new pads, especially if the ones you have are worn since that'll likely push the pistons back into the caliper. While that should fix some of the sponginess you're experiencing, a brake bleed will very likely be a necessary course of action.

These are VERY good brake calipers, but they're often misunderstood for how they're supposed to be set up and maintained, leading to the same problems that you're having.

[tellyho]

What does a bleed kit for these look like? I have replaced the fluid in mine: pop off the reservoir top, empty, fill. I don't believe there's any other procedure but happy to be corrected. Ask TRP to send you new silicone bladders.

[54ny77]

tellyho: this is what i found online in terms of protocol.

i just ordered a bleed kit that said it was compatible with trp.

[mjf]

Originally Posted by 54ny77

got any good pad recommendations?

i ordered a bleed kit.

For a tandem? Metal sintered would be my go to in order to deal with the extra weight. They use the generic Shimano B01S pad shape, so options are essentially infinite.

Few options that I like
https://trpcycling.com/products/sintered-2-piston
https://www.discobrakes.com/?s=0&t=0&c=14&p=100&tb=001 - Whatever composition you feel like.
https://mtxbraking.com/product/gold-label-brake-pads/ - Shimano Deore GL111 variation

Originally Posted by tellyho

What does a bleed kit for these look like? I have replaced the fluid in mine: pop off the reservoir top, empty, fill. I don't believe there's any other procedure but happy to be corrected. Ask TRP to send you new silicone bladders.

Full vid here

https://www.youtube.com/watch?v=BcZKtFI8Els

https://youtu.be/BcZKtFI8Els?t=60 - At roughly here for the next minute the tech discussed how improper usage of the barrel adjuster and push rod, which causes the push rod to enter too far into the master cylinder, causing the timing port to close, and preventing the pads from advancing properly.

The is very likely the problem that leftsidedrive has, and shows a very common misunderstanding of relying on the barrel adjuster when trying to use and maintain these calipers.

Originally Posted by 54ny77

tellyho: this is what i found online in terms of protocol.

i just ordered a bleed kit that said it was compatible with trp.

https://www.youtube.com/watch?v=BcZKtFI8Els Full vid and explanation here.