BNB

I am looking at replacing my TRP HY/RD cable actuated hydraulic calipers with one of the Shimano caliper models. Amazon has a budget Shimano M375 Post Mount Brake Caliper for $30. My bike is a gravel bike, not MTB. I'm not looking for fancy but I do want decent function. I bought an inexpensive gravel bike with Claris as an experiment in gravel cycling - loved the cycling but those grabby calipers/pads/rotors (not sure which was responsible) almost sent me over the handlebars more than a few times. No need to repeat that. I'm willing to spend more if it's worth it. Any polite thoughts or suggestions appreciated.

shelbyfv

Politely, you are barking up the wrong tree. The TRP Spyre is the best purely mechanical disc brake and the HY/RD is generally thought to be a step above. Replace the pads and clean the rotors for a start.

veganbikes

Why would you downgrade your brakes? If you are having issues with your braking you should practice a little more and if they aren't braking correctly make sure everything is properly cleaned and adjusted.

BNB

I have struggled to replace the brake pads in my TRP Hy/Rd. I could not move the pistons. So I tried a bike shop and they couldn't do it either (in CA). Then tried again with the best bike mechanic i have ever met and he couldn't easily replace the pads - though he managed through some struggle he tried to explain to me. The issue I found is that we collectively cannot manage to move the pistons enough to make new pads work. My cheat was to only replace 1 pad at a time. The bike mechanic in CA couldn't move the pistons inward and sanded down my new pads until the rotor fit. The guy in NH said he used a vice or something to force those pistons over. He told me TRP HY/RD calipers are trouble and he didn't need to convince me. I'm glad they are working for some of you. And I'd gladly sell mine to the highest bidder.

In the meantime I want simple to adjust calipers, simple to replace the pads. I've used Avid bb7 too and might go that route. I just want to know if the Shimanos are OK and what the downside of those calipers is.

edit: the tool the mechanic used and still had a difficult time: hydraulic piston press

cpach

It sounds like there's too much fluid in the HY/RDs, which can be bled even though they need it far less frequently than other hydraulic systems.

That said, if you want to replace with full cable actuated brakes, make sure you use some that are designed for road levers. This gets slightly confusing--basically, MTB/V-Brake levers pull a lot of cables, and conventionally road bikes pull a lot less, but modern Shimano pulls a little bit more than was traditional for road bikes (and Sram/Campagnolo), but generally it's not the largest deal. You probably shouldn't use the M375s--you'll need to set the pads very close to the rotor and it will be grabby. Probably the best full cable disc caliper within reason is a TRP Spyre because (besides playing nice with road levers), among other things, it pulls both pads inwards making adjusting for pad wear more convenient. BB7 road calipers are also a tried and true option.

Also a lot of current generation gravel bikes use flat mount calipers--make sure you match up the caliper mount to the frame/fork mount. You can get adapters to use post mount calipers on a flat mount frame but I'd recommend against it if you're already buying new calipers.

If you want to sort out your HY/RDs (which really are pretty nice): https://trpcycling.com/how-to-bleed-a-hy-rd/ , or a real f'n mechanic. This isn't a quick on the spot thing, they may reasonably may need to look up the video or the service document.

Russ Roth

personally, if you can't the hy/rd working and a good mechanic shouldn't have trouble if they're functional, I'd go with juin tech. They're similar to the hy/rd in that they're a cable pull hydraulic. However the pads don't auto adjust as they wear, just like any of the cable pull brakes you have to adjust the pads as they thin, but I find the stopping power to be nearly as good as full hydraulic road brakes. That's based on having 105 hydraulics, chorus hydraulics, and juin tech set up with 4700 tiagra shifters.

ctak

+1 for trp spyre

BNB

Thanks very much for this information! Much appreciated.

Kapusta

Mech brakes with single-sided activation (like the Shimanos you are looking at or BB7s) work just fine for a gravel bike (heck, I've been fine with them riding MTB in big mountains), but they are tricky to set up right and require a bit of ongoing adjustment for them to keep performing well and not wear the pads all wonky.

Spyres will have the advantage of not only functioning a little better right off the bat, but more importantly they are easy to set of and require minimal fussing with to keep properly adjusted, so they wear the pads in a way that keep them working well throughout the pad's life. I think this is actually the main reason they are considered so much better.

I am very good and working with BB7s and have none of the issues that others do, but if I were buying a new set of mech calipers for my gravel bike (which currently have bb7s) I would pony up for the Spyres.

I can't comment on hydro/mech hybrid calipers.

Koyote

And then work on your technique.

HillRider

Agree completely. If you want to avoid hydraulic brakes, the TRP Spyres are the class act of mechanical disc brakes. They use road/cantilever short pull brake levers so they work with almost all brifters. They adjust the pads individually so alignment and setting the pad clearance is very straightforward and the pads are a standard Shimano design available from numerous makers. They are not the "power brake"some hydraulics are reputed to be but are effective and the lever pull effort is reasonable.

But its me 

Another vote for the Spyres from someone that wore out a set of HY/RDs. Unlike the BB7s, the Spyres are a clever dual piston design. Much easier to install and maintain than HY/RDs, and I find the power equivalent to those. A 3mm hex is all you need to adjust the pads for wear.

I do have a set of Juintech brakes waiting for when the Spyres give up the ghost, but the Spyres just keep on working.

HillRider

Other than periodic pad and cable replacement I can't see how you would wear out Spyres any more than wearing out good quality caliper brakes. The only wear parts are the pads and rotors.

But its me 

Quite true, although I assume the springs will eventually wear out. Might take years, of course. And the Juintech brakes were too good a deal to pass up. New shiny and all.

katsup

I jumped from BB7 to Juin Tech R1 and there was a significant difference in level feel. The Juin Techs were easier to pull, sort of in the middle of full hydro and cable. They both stopped the bike fine.

I am trying Paul Klampers in about a month, but these are out of your budget.

BNB

Good information, here. I have used bb7 on the tandem for years, I know them, they stop a tandem predictably (we're not going down monster mountains with them tho). We did just start having and issue with them ... when we go over a significant bump one pad in the rear dislodges and jams against the rotor; braking is unpleasant when unexpected. The pads are held in by magnet so that seems to be a design issue, best guess, though it's taken years for this issue to start. So I'm looking to try something different. I will replace the pads on the tandem's bb7 and make sure the spacing to the rotor is small which might resolve this issue.

BNB

Just curious what you found was not easy in maintaining the HY/RDs? Were you able to move the pistons in when replacing the pads?

But its me 

I was new to disc brakes, so there was definitely some user error at first. Once I finally figured out how to set up and maintain them (Youtube was most helpful), I still found them finicky. After 10K+ miles, they just stopped being as responsive, and I was just tired of all the maintenance. I was able to move the pistons to change pads, but in time they became sluggish. Tried bleeding them, and it helped for a bit, but the final straw was when cold (10-15F) made them non-responsive. The cold left me with no rear brake and only a partial front brake. Probably (mostly) user error, I'll admit. The Spyres are so much easier to install, set up, and maintain. Yes, you have to manually dial in the pistons with a 3mm hex, but they just work.

veganbikes

We have never had any issues replacing HY/RD brake pads not sure why your mechanics are having such issues. Possibly too much fluid as others have said but that can be easily fixed and probably those mechanics would have tried it by now.

Sorcerer

I've read through the entire thread so far and I see the Shimano mechanicals have not been reviewed.

It is good to read about the TRP and Juin brakes, as I have no experience with them apart from some YouTube video viewing.

Most of my rides have hydraulic brakes. Hydraulic brakes are better overall.

​​​​​​I use Shimano mechanicals on a few MTB single speeds and a drop bar commuter bike and a cruiser commute bike.

​​​​​​THe commute bikes receive daily use in traffic, so the brakes are critical. I have found the Shimano mechs to be excellent for years of use. Yes, I do have to squeeze them harder, but it's not ridiculous. There is one red light at the bottom of a hill that sometimes comes on, which requires going from 33mph to zero, and the brakes never flinch.

They are squealers in the rain.

Although, there is one negative failure to report, which years ago now, where one of the calipers somehow "blew up" with the clamping assembly going loose and dysfunctional. This was on the front of a mountain bike doing an extended steep slow technical trials-like descent where the cable strands successively parted and snapped, which was quite dramatic at the time. Had to jump off and let the bike tumble.

Which reminds me, I should replace the cables again soon!

The cables fray at the pivoting arm.

I've used BB-7s before and they are similar to the Shimano overall. I prefer the various finishes on the Shimano brakes for looks. There's the XT looking light grey, and then there's this sort of polished dark version which really looks nice. I know it's superficial, but the red pad adjusters on the BB7 always looked janky to me.

I've only had the long pull, v brake, version of mechanical brakes. The drop bar bike has Cane Creek long pull road levers on it.

In conclusion, I don't like mechanical brakes for serious mountain biking, and I would seek hydraulics on a tandem. We did have Magura Gustav brakes on an MTB tandem, and they were great, but that's another story.

BNB

Thanks for the reality check. I am also finding my front braking has become sluggish, to say the least. The mechanic who was able to replace the pads with great difficulty (and the tool he used, I found out, is a brake piston press) told me "I basically had no front brake" and he was right. Replacing the pads worked but a few months later and I can move the front wheel by hand with the brake fully engaged.

HillRider

If I were choosing disc brakes for serious MTB use I would also have gone for hydraulics. However, for a mostly road ridden "Gravel Bike", the simplicity and ease of maintenance of mechanical discs was too attractive to pass up and I've been very pleased with my Spyres. I ride plenty of sizeable hills and they have been completely satisfactory.

As to brakes failing from cables fraying, any cable operated brake is susceptible to that and regular cable inspection and replacement is only common sense.

BNB

I've been in touch with TRP, via email thanks to this video, so they're working with me. It would be great to get these expensive (and heavy) calipers working.
to anyone who cares ...
re tandem braking: we're a light team and have never had any problem stopping in any situation over 7 years with bb7.
re hydraulic brakes: ya, I love my mtb hydraulics but switching the other bikes over would be very expensive.

Racing Dan

YMMV as they say .. I have two bikes with those brakes and was never satisfied, always fiddling to get better performance. Finally I bit the bullet and got a set of fully hydraulic brakes and they are Much better.

To the OP. Keep your HY/RD. I get the feeling you just need to figure you how to adjust and maintain them. You can start here:

BNB

As I lost braking power I moved the barrel adjuster hoping to help the situation but it is apparently a "no-no" with these calipers. TRP recommends a bleed too but all worked fine once I put the barrel adjuster fully clock-wise. while this might be obvious to some I sorta think TRP should emphasize that the barrel adjuster should not be moved out beyond 1.5 turns.