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TRP Hy/RD - To bleed or replace? Disk brake help needed

Scoob84Scoob84 Posts: 76
edited July 2018 in Workshop
I just recently come back from the alps where i lent my brother in law (who is not a cyclist) my genesis croix de fer so he could join me to watch the tour go by on the top of the Col de Romme. That part went great and we had a lovely time. Next came the other fun part, descending back down to the valley to the car. There was a lovely section of road between the Romme and Columbier which was a beautiful decent which zero traffic. Long story short, i thought he was being a bit of a censored going so slowly and not making the most of the open roads like I was. Turned out when we got to the bottom, he was only riding with one brake as the rear disk brake had ceased to work and i couldn't hear him over the noise of the wind rushing by. Ooops. Good job i had replaced the front pads days earlier, but still a concern.

Anyway, my initial thoughts were that he had worn the rear pads out which I was aware were slightly worn, but not knackered. But having just replaced these yestewrday with new, they still don't work.

The brakes are TRP hy/rds, they're a couple of years old and came with the bike that I inherited from my dad, so I'm not really what sort of life they had under his tenure, as he downplays everything.

The cables are fine, fairly recently replaced (compression-less) a pull on the lever pulls the little lever all the way on the brake. There is little piston movement, but not enough to generate any meaningful friction, which leads me to think they may need bleeding.

I don't own a bleed kit so weighing up my options. Do i invest in one (£15-30 but no guarantee it will solve the problem) pay Evans cycles to fix in the hope they can (£30 but no guarantee), or throw these out and buy a news (£60-100 guaranteed fix)

Is there anything else that i have may have overlooked?

How often should you bleed brakes?

Apologies in advance, if this has already been discussed to death on this forum.

Posts

  • DeVlaeminckDeVlaeminck Posts: 7,312
    New fitted yourself wouldn't be a guaranteed fix if you messed up the installation. I'd get a bike shop/mechanic to sort them.
    [Castle Donington Ladies FC - going up in '22]
  • timothywtimothyw Posts: 2,482
    I suggest watching this and making up your mind if this is something you can manage (bleeding):
    https://youtu.be/FFgrHBrO_00

    However, since you mentioned the cables being replaced recently, are you sure it was set correctly? If (when not squeezing the lever) you can't screw in the little arm bolt, then there is too much tension on the cable and they haven't been able to reset themselves.

    Further possibility, some early Hy rds were defective and didn't properly adjust for wear anyway - worth looking into as you might be able to get a free replacement that way.
  • Scoob84Scoob84 Posts: 76
    TimothyW wrote:
    I suggest watching this and making up your mind if this is something you can manage (bleeding):
    https://youtu.be/FFgrHBrO_00

    However, since you mentioned the cables being replaced recently, are you sure it was set correctly? If (when not squeezing the lever) you can't screw in the little arm bolt, then there is too much tension on the cable and they haven't been able to reset themselves.

    Further possibility, some early Hy rds were defective and didn't properly adjust for wear anyway - worth looking into as you might be able to get a free replacement that way.

    Seems easy enough.

    I'll check the little arm bolt in a bit. But i'm confident the cables are fine, as they've been fine for a while since i replaced them. I can push in the lever on the caliper end, and the pistons will move slightly, but they'll barely grip the disc. would an air bubble cause this?

    I'm interested in knowing how often should these brakes should be bled?
  • meanredspidermeanredspider Posts: 12,337
    edited July 2018
    I very much doubt they need bleeding. People bleed full hydraulic brakes far too often. These aren’t even full hydraulic. From what you describe, my money would be on early faulty design (not compensating for wear) or incorrect installation after cable install (which even LBS do)
    ROAD < Scott Foil HMX Di2, Volagi Liscio Di2, Jamis Renegade Elite Di2, Cube Reaction Race > ROUGH
  • I'd fully recommend ditching TRP's and replacing them with the Giant Conduct hydraulic brake system if you can find some for sale. The beauty of this system is that you retain your cable shifters, keep the upgrade cost sensible yet the result is 99% of a fully hydraulic setup.

    I did just this only six weeks ago, buying them direct from Giant, however their website now shows them to be out of stock https://www.giant-bicycles.com/gb/conduct-hydraulic-disc-brake-upgrade-kit

    It might be worth ringing around a few giant dealers to see if they have some in store or checking here https://www.pedalon.co.uk/acatalog/giant-conduct-hydraulic-brake-conversion-kit.html Just make sure you order the correct kit as there are two versions of this kit, post mount and direct mount brake calipers. I don't know which version pedalon are selling via that link.

    The braking performance difference between the TRP Spyres which I replaced and the Conduct brakes is huge, like the difference between night and day.

    Oh, for what it's worth my Giant dealer only charged me £25 all in to fit the kit.
  • Scoob84Scoob84 Posts: 76
    I'd fully recommend ditching TRP's and replacing them with the Giant Conduct hydraulic brake system if you can find some for sale. The beauty of this system is that you retain your cable shifters, keep the upgrade cost sensible yet the result is 99% of a fully hydraulic setup.

    I did just this only six weeks ago, buying them direct from Giant, however their website now shows them to be out of stock https://www.giant-bicycles.com/gb/conduct-hydraulic-disc-brake-upgrade-kit

    It might be worth ringing around a few giant dealers to see if they have some in store or checking here https://www.pedalon.co.uk/acatalog/giant-conduct-hydraulic-brake-conversion-kit.html Just make sure you order the correct kit as there are two versions of this kit, post mount and direct mount brake calipers. I don't know which version pedalon are selling via that link.

    The braking performance difference between the TRP Spyres which I replaced and the Conduct brakes is huge, like the difference between night and day.

    Oh, for what it's worth my Giant dealer only charged me £25 all in to fit the kit.


    I love a decent curve ball suggestion. But i'd i'd have to replace my (old style) tiagra shifters if i were to go down this route, adding further cost. Attempted two TDF stage 9 cobble sectors on these horrible devices and got 3 torn blisters on y hands.

    £120 though, good going when a single replacement hy/rd brake costs £100+
  • timothywtimothyw Posts: 2,482
    Which tiagra are you on? If it's ten speed they're fine, that's what I have on my Giant conduct setup (tiagra 4600 rather than the newer also ten speed 4700...)
  • Scoob84Scoob84 Posts: 76
    TimothyW wrote:
    Which tiagra are you on? If it's ten speed they're fine, that's what I have on my Giant conduct setup (tiagra 4600 rather than the newer also ten speed 4700...)

    4600 - I find them uncomfortable and incredibly ugly. But other than that they're great.
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