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I've got a typically squeally back brake on my gravel bike (GRX800). I've tried swapping the transfer port O-ring but to no avail - leave the bike a couple, of days and lots of noise, no stopping. Drag it down a big hill to get it b*st*rd hot and it behaves again for the rest of the ride. Then rinse and repeat.
The bike is a) secondhand b) just over 2 years old - so warranty isn't doable. Rather than throw more money at Shimano so they can carry on profiting from producing rubbish, I'm thinking of going the RX4+ route. Bar the hilarious price compared to Shimano (esp as I'd need to buy a matching pair, not just replace the leaky one), any downsides?
I run Hope brakes on my mtbs so well used to bleeding and setting them up.
Thanks!
Why do you need to buy a pair - no/one is going to notice they’re mismatched if both black?
I’ve been running an RX4 on the rear a while to replace a micro leaky Shimano caliper. Still running the Shimano on the front - waiting until it dies or I get a new bike with a difference standard fork (currently has flat mount rear / post mount front - because Cannondale).
RX4 doesn’t feel too different - but you can get spares / the seals actually keep the oil in.
Was a fiddle bleeding the thing initially and it took quite a while for the power to build but they’re good once bedded in.
I have been using them for several years with no problems. The only downside I know of is that the non direct mount version did not fit easily to my bike. The bike shop had a lot of problems fitting the brakes to my Genesis CDF. If you have direct mount it should be easier.
Why do you need to buy a pair – no/one is going to notice they’re mismatched if both black?
I'll notice! Would do my nut in, that!!
I found the RX4+ mated to a GRX lever to be a lot more difficult to set up with the 4 pots and then had issues with leakage. It would be fine for a few rides and then next time I took it out it squealed like it was contaminated & that's because they were somehow. So very similar experience to yours.
It was a press/review bike though so I have no idea how it had been treated before I had it.
It has put me off RX4+ completely though.
I’ve got RX4/RX4+ with GRX and Duraace on 4 different bikes. No issues with any of them in years and 10s of thousands of km.
RX4s with GRX levers on my Ragley Trig are amazing. RX4s with Ultegra levers in my roadbike are a nightmare... difficult to bleed, loads of lever throw (more than 2x the GRX equivalent). Been trying to get them right since the summer and can’t decide whether to switch road bike to GRX levers or to swap back to Shimano calipers. Not sure that helps, as when they’re good they’re VERY good, but some times they’re not
That's wierd. I've RX4+'s with Ultegra shifters and they're fantastic.
There's almost no free stroke and they are supremely powerful. I bled them from the bottom (ahem) and they were definitely less aggro than Juicy's which have the accolade of the most needy brake - ever...
I’ve been running an RX4 on the rear a while to replace a micro leaky Shimano caliper. Still running the Shimano on the front
Everytime you post this I wonder why you'd not put the hope on the front and swap the non leaking Shimano to the back.....
I’ve been running an RX4 on the rear a while to replace a micro leaky Shimano caliper. Still running the Shimano on the front
Everytime you post this I wonder why you’d not put the hope on the front and swap the non leaking Shimano to the back…..
2 reasons - the main one being the rear is flat mount and the front is post mount. And then the RX4 is front and rear specific too.
Actually another reason is neither caliper is more powerful than the other. The bike is running 160mm rotors too - so generally no lack of power. Although I accidentally got organic pads instead of sintered when I needed to replace the Shimano pads and that was a mistake. The organic ones felt like they faded on longer descent and generally felt a bit crap vs the standard sintered ones.
👍 makes sense when you put it like that, thanks.
Hang on the Hope are £80 and come with 2 sets of pads an end vs £50 for shimano that will leak again and one set of pads.
I’ve got a typically squeally back brake on my gravel bike (GRX800). I’ve tried swapping the transfer port O-ring but to no avail – leave the bike a couple, of days and lots of noise, no stopping. Drag it down a big hill to get it b*st*rd hot and it behaves again for the rest of the ride. Then rinse and repeat
Same here with GRX600 levers and GRX400 calipers. Rear brake only, but I haven't had the caliper apart. It only suffers in damp conditions for some reason, no problems over two summers. Weird!
The rear rx4 on my bike has developed a micro leak.
I've one on the front of my cross bike to replace the leaky GRX one. I really like it and will replace the rear when that one goes.
Just to note that I got 2 pairs of pads with my RX4 caliper which does help justify paying £100 for a caliper.
Check that it's not the hose going into the caliper. Mine started to weep a little bit, but a quick nip up and has been great since.