Juin's 6 Piston Semi-Hydraulic Brakes - Taipei Cycle Show 2024

Mar 6, 2024
by Dario DiGiulio  
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One of these things is not like the others.

The Taipei Cycle Show is known for fielding some of the more unique products that are coming to market, and this year has proven to be no exception. In a field of cool and unusual offerings, some little gems still stand out, whether they're particularly clever or just outright unusual. This GTP-6 brake falls more in to that latter category, with a combination of features that is truly unlike anything else.

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Juin is a Taiwanese manufacturer known for their colorful and budget-friendly brake offerings. The GTP-6 may cast a fairly typical shadow, but it's anything but. These are 6 piston brakes, and though the caliper itself is hydraulically driven, the brake is mechanically actuated. The calipers use mineral oil, and weigh 158 grams apiece.

There are a few mechanically-actuated hydraulic brakes out there, such as the Yokozuna Ultimo and TRP Hy-Rd, but neither is squarely positioned at the mountain bike market.

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Honestly it's a bit hard to tell if the Juin brakes are either, as the tagline "it's about control not power" sends a bit of a mixed message - I tend to prefer to have both if given the option. Shade aside, I understand what they're going for here, and it's cool to see a novel approach.

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Typically, there are some endemic drawbacks to the tightly enclosed hydraulic system used in brakes like this, namely in the form of heat buildup. As descents get heavier and longer, there's nowhere for the heated fluid to go and no thermal chain up the hose to draw heat away, which can lead to more heat buildup and fade.

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Clearly we haven't tested these yet, so consider this all through a speculative lens. I'd be keen to give this system a try though, as there's something charming about the analog nature of a cable brake, though I can't say I ever complain about the newfangled ways of today's amazing hydraulic brakes. If you do decide to try something like these, remember to use compressionless housing, and to constantly tell your friends about how much better your cable brakes are and how you're never going back to fluids.

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If anything, it's an excuse to dig out those old levers in your parts bin.

Though Juin doesn't have a direct sales website, you can find out more information and buy a set on a few online shops such as this one. They retail for about 390 Euro per pair, depending on color and market.

Author Info:
dariodigiulio avatar

Member since Dec 25, 2016
167 articles

130 Comments
  • 87 1
 Add an electronic actuator and you have e-brakes. Which brand does it first?
  • 34 60
flag CaSentLeTabarnakMonHomme (Mar 6, 2024 at 6:17) (Below Threshold)
 While I feel the majority of pinkbike's incel keyboard warriors would disagree with this, I would really like to see wireless brakes. haha.
  • 35 2
 @CaSentLeTabarnakMonHomme: Blake already made some Smile
  • 74 0
 @CaSentLeTabarnakMonHomme: Lots of them on the marker, all hydraulic brakes are wireless Smile
  • 4 2
 This is it. Wireless brakes.
  • 2 5
 @betsie: Well, I was talking about a more developped product like the AXS dropper/derailler not a college project. loll But it's still a good start.
  • 2 4
 @lkubica: that's funny, Dave Chappelle would be proud.
  • 3 0
 @CaSentLeTabarnakMonHomme: you're right, I'd like to see, not to use.
  • 5 0
 @CaSentLeTabarnakMonHomme: what problem do they solve?
  • 2 0
 @Jer3myF: For example no/less bleeding, easy swap and ... 2 extra batteries Smile Would love to run out of power mid-run Big Grin
  • 7 0
 GMBN already did that Smile
  • 12 0
 @CaSentLeTabarnakMonHomme: You think hydraulics don't perform well when things get hot, wait until you see what happens to electronics.
  • 4 0
 Change the safety laws before making this happen because you can't sell such a thing today.
  • 3 0
 @qblambda: I understand there are laws in many countries requiring physical connections between steering, throttle and brakes in passenger vehicles (archaic laws, as if mechanical connections can't fail). Is the same true for bicycles? I dunno.


Mercedes used to have a concept that was 100% drive by wire, it looked pretty cool, would be like driving my bobcat Smile
  • 1 0
 @Jer3myF: May be easier to do internal routing? Not needing to install a new barb/ olive and re-bleed if building a frame? Idk…probably not much of a problem for most.
  • 2 0
 @southshorepirate: If bike brakes were wireless, I’m thinking they’d have to have a safety feature where they failed “on”. Like, if your battery fell out, the brakes would slowly apply to locked.
  • 1 0
 @southshorepirate: by some mechanical means that is.
  • 1 0
 @scbullit36: If my mech or hydraulic brakes fail what happens?
  • 1 0
 I'm going to start practicing bar spins now so I'm ready!
  • 4 0
 If the amount of singlespeed rides I’ve done on dead AXS derailleurs is any indication, the I’ll probably die when this comes out.
  • 2 0
 @southshorepirate: I guess that’s a fair point. But I’ve never had a set of mechanical or hydraulic brakes fail if it wasn’t for a crash…when you pick up the bike and realize you broke something or lack of maintenance…which is usually a slow death and you have warning. If you were to lose BT connection between your caliper and lever there wouldn’t be a warning, and it may not be due to a crash. Idk. I guess if someone made wireless brakes, if the f/r shared different BT addresses, I guess if one brake failed you’d still have the other. Then it’d be same same.
  • 1 0
 @scbullit36: I think you answered your own question, how often do brakes fully fail? Surely this would be a much more reliable ANT connection than ol' flaky Bluetooth. Or it could even be wired instead of wireless to reduce that risk. We do have two brakes, so there is built in redundancy in the system.

I am kinda with you, not sure I'd be an early adopter Smile
  • 1 0
 @southshorepirate:

If youre ready for cars costing as much as airplanes, you can have drive by wire.

en.wikipedia.org/wiki/Functional_safety?wprov=sfla1
  • 2 0
 Hell to the no. It's trouble enough keeping derailleurs charged. The practicality and safety of wireless MTB brakes is not something I'd trust. Guaranteed that's why they haven't made them mainstream yet (beyond R&D or random tinkering).
  • 2 0
 @CaSentLeTabarnakMonHomme: front brakes are wireless than rear brakes.
  • 35 2
 Would actually be a potentially good calliper for the slope style crowd to pair with a gyro.
  • 4 0
 that's what I immediately thought - but based on the price vs. how much / how often I need brakes on this bike it's a no-go.
  • 1 0
 Definitely!!!
  • 1 0
 I got a pair on my DJ with gyro, works good.
  • 1 0
 I use the cheap Amazon knockoff version of these on my DJ. The rear wheel locks up like a mofugga
  • 24 3
 Correct me if I am wrong, but isn't one of the biggest advantages of hydraulic brakes that there is actually less friction in the hose, which leads to a better braking feel?
  • 17 3
 That's probably more related to the fact that you can't compress the fluid. Whereas a cable can stretch.
  • 2 0
 I had a much bigger gripe with the maintenance and cable stretch adjustments of those brakes than I did with the friction associated with the design.
  • 7 3
 @Canadmos: The fluid is nearly incompressible, yes. However the hoses can stretch. Standard hoses are not dramatically stiffer than brake cables in tension.

The main difference is indeed the much lower friction in the fluid vs the cable.
  • 1 3
 @rideordie35: Please show me the documents that support that claim, I'd love to read them.
  • 3 2
 i know in mx and supercross many riders prefer a cable actuated clutch to a hydraulic setup because it has a more "connected" feel.
  • 14 8
 @Canadmos: cables don’t stretch. Housing and their stops compress.
  • 8 5
 @jankslayer: Steel cables can and do most defintely stretch. Not sure what your logic is on that point
  • 7 3
 @jankslayer: exactly. Squeeze the lever and you can see how housings compress and move. After a while you can pop off a ferrule and see how the innards are squeezing out because the housing compressed and the cable stayed the same length. Colloquially people call this cable stretch because you have to tighten the cable as the adjustment mechanism but it's not true.

Another test is put big weights on the cables and measure them after days, weeks, months and see that the cables do not stretch. An old shop I worked at did this, a few engineering students I knew did this in college, etc. Same results, cables don't stretch in a meaningful way.
  • 2 0
 @Struggleteam: even on cars you can really feel the difference.
  • 2 0
 This product is actually a bit more relevant in road bikes, as full hydro disc brake shifters are incredibly expensive. Those half hydro setups are great way to save at least a few hundred bucks on a build without compromising on performance that much. Idk why they are going 6 pot now, but I'm very interested how well they will perform. (The stated price is kinda ridiculous tho)
  • 2 0
 @Canadmos: Fluids and even solids are compressible. Even if fluids were incompressible, the brake line would still expand under pressure.
  • 2 1
 @endoplasmicreticulum: brake lines with woven outers don't expand under pressure. Hope V4 DH and Trickstuff brakes are the only OE examples of this in the bike world and I'm pretty sure Hope moved away from the woven outer since it was too fat to fit in most internal routing tubes. You can still get Goodridge brake hose kits for most brakes if you want the added power and have external routing.

In other hydraulic applications there are internal braids or external woven covers that resist expansion from fluid pressure. Most bike hydraulic brake housings all expand under pressure and it's a bummer.
  • 2 0
 Hydraulically driven pistons also have the advantage of "self adjusting",
i.e. automatically moving in with pad wear,
which fully mechanical brakes do not.
So this Juin system gives you that advantage.
It also allows you to activate both sets of pistons.
Most mechanical disc brakes have a fixed side, while the other side is activated by the cable.
TRP Spyre brakes are a rare mechanical design that activates both pads;
Ask anyone who has installed or maintained Spyres, and they'll tell you it's a headache.
So yes, it's not going to give you the silky feeling of full hydros, but it's a nice in-between option, when you don't want to deal with hydraulic systems.
I personally buy cable activated dropper posts for this reason (which are sometimes hydraulically driven)
I just effing hate setting up hydraulic lines (in other words, I'm bad at it)
  • 2 0
 @GTscoob: @GTscoob: You can still get the new Tech 4 brakes from Hope with steel braided brake lines, I have them. And the current steel braided brake lines have the same outer diameter as the kevlar lines. I mostly got them for the bling factor, I couldn't feel a difference between them.
  • 1 0
 @blcpdx: If I recall correctly, the Juin brakes don't have a reservoir like the TRP HY-RD and therefore can't compensate for pad wear.
  • 2 0
 @GTscoob: I agree. In my extensive shop experience, it's the housing itself and the housing seating into the end-caps that makes it feel like the cable is stretching.Whenever I install new cables and housing I'll always add tension to the cable and then rotate/wiggle the housing at the ends so that it seats firmly into the end-caps.
  • 1 0
 @ToastLover: 10-4, thanks for the clarification.
Auto adjust is a clearly listed feature on TRP HY-RD product page, whereas Yokozuna only notes "Simple one knob pad adjustment", which, to be fair, is a benefit vs mechanical disc brakes, which often require adjusting the fixed side with a tool, and the active side with a barrel.
  • 1 0
 @GTscoob:
Brake lines do expand under pressure, since the materials youngs modulus is finite.

It might not be much, but the sum of your brake line expaning, the seals compressing and the caliper spreading all add up to significantly reduce the stiffness of your brake way below the fluids bulk modulus. Otherwise you couldnt move the lever a millimeter after your pads made contact.

Just a few weeks ago, we had someone at our hydraulic lab measure the effective bulk modulus for steel braided brake line filled with HLP, and while I cant tell you the exact numbers, it was more than HLP alone.

Iam not trying to start an argument about semantics, but saying it doesnt expand is just wrong.
  • 1 0
 @nickfranko: Please compare the young's modulus of hardened steel and plastic with fiber reinforcement and the respective cross sectional areas. It's pretty simple engineering analysis to find the relative stiffnesses. It varies widely between different products though so that's why I kept my first statement general.
  • 1 0
 @GTscoob: Correction, they will expand less under pressure. Still enough to measure with calipers for example.
  • 1 0
 @bman33: when talking about bike cables they do not stretch. They are so much stronger than the housing, you can see the ferrule pulling the housing apart when changing out your cables and housing. This is why you have to tighten the system over time.
  • 19 0
 At $425 it would be hard to pick that over a conventional hydraulic system. If it was dirt cheap it would be fun to try but that’s getting into Dominion pricing.
  • 3 0
 Yeah I clicked the link and thought "I dont know what 360 euros is in Canadian but that sounds like a lot!"
  • 12 3
 Juin Tech is Taiwanese, not Chinese. The Yokozuna Ultimo's mentioned in the article are rebranded Juin Tech M1 brakes. This article makes Juin Tech sound like some sketchy Chinese AliExpress brand but they are a reputable Taiwanese brake manufacturer.
  • 2 3
 Typical anti-china brainless turd, never heard of Republic of China(ROC), Taiwan province?
  • 2 0
 @marktofh: You really created a new account for this huh?
  • 12 0
 That logo looks vaguely familiar, almost juicy.
  • 14 0
 I can still recall the sound of the brake that shell not be named
  • 3 0
 @pakleni: no need for a bell to alert bears or hikers with those howling stoppers
  • 9 0
 @pakleni: gobble gobble gobble
  • 1 2
 Chinese manufacturers just can't help themselves in the copycat game. Look at their auto show and you can see even copies of Ferraris. Last week's PB article on those Trickstuff wanna be brakes... etc. This logo and the brakes levers might as well just be old Avid stock rebranded ...
  • 2 1
 @bman33: It's that Chicom philosophy that's to blame...
  • 3 0
 " "it's about control not power" sends a bit of a mixed message - I tend to prefer to have both if given the option."
This line cracked up lol ....

Anyway, if this is somewhat reliable, it would potentially be a great option for the Slopestyle Dudes since they could run a cheap cable gyro and then still have ample power out back.
  • 1 0
 Well I think no slopestyle rides is gonna put that anchor on their bike
  • 2 0
 @kanioni: great for fufanu's
  • 3 0
 As far as I know, Juin Tech brakes are quite good and reliable.
Few years ago I built 2 travel bikes (29" Genesis Longitude) for a couple who travelled 12000km in South America. They reported zero issue with their brakes and had all the power and reliability they needed. Just an experience I share...
  • 3 0
 I was also puzzled by this product and who the intended customer could possibly be. Most of these cable/hydraulic conversions are for road and gravel bikes where a customer already has mechanical brifters but wants to upgrade their calipers to something more powerful. But Juin Tech already offers that exact product in the M1 brake/Yokozuna Ultimo, which is a four piston brake that uses Shimano Saint brake pads. I don't know that many road or gravel riders who need 6 piston braking power, and this doesn't make sense for an MTB customer when there are already so many great affordable full hydraulic brakes available.

So I think this six piston brake is probably intended for commuter ebikers. A lot of cheap entry level commuter ebikes come with bad mechanical disk brakes, and this product allows them to replace their brakes with something significantly more powerful without having to replace levers or bleed anything. If you go to the Amazon review for the Juin Tech M1, almost every review is written by someone with a cheap commuter ebike who replaced their underpowered mechanical disk calipers. That makes a lot more sense.
  • 2 0
 How is a cable driving a hydraulic more "analog" than a full hydro? Full hydro is way smoother, inputs directly relating to outputs with no discrete independent levels to move through. It completely removea even the potential for cable drag adding slight notchiness as the irregular surface of the cable slides through the irregular housing, causing a feeling of discrete levels of force transmitted, the literal definition of digital.
  • 5 0
 Opens the doors and minds to more widespread headset cable routing.
  • 5 0
 Probably the opposite. The big push for headset/aero routing for road bikes is also partially responsible the hydro disc and electronic shifting push. You simply can’t get good, low friction cable actuation with the majority of headset routing. The cable actuated bikes with headset routing have sluggish shifting and a lot of brake lever friction.
  • 1 0
 @BikesBoatsNJeeps: I was postulating that it would reduce the problems with having to open/bleed the brakes when front end changes are made, but you make a good point on how the hydro systems allow for more bends.
  • 1 0
 I'd love to hear the reasoning behind using 6 pistons instead of 4 or 2. The only thing other than the obvious "more pistons = more good" I can come up with is that the master cylinder assembly was so long that they decided that they might as well use that space and add more pistons.

Any other explanations?
  • 1 0
 More pistons more modulation. I had Clarkson climb8s 6 pots back in the day and my dirt jumper has hope mono 6s.they feel really nice but ultimately power is controlled by piston size. I'm also not sure why you'd make a cable actuated 6 pot but someone will buy it
  • 1 0
 @briain: How would more pistons improve modulation? (And what is modulation anyway?)
  • 1 0
 Whenever I think of 6-piston calipers I'm reminded of the 6-piston calipers that Suzuki used to have and then stopped. The way I think of it - if 6-piston calipers were the wave then you'd see them in MotoGP - newsflash - they aren't there.
  • 1 0
 @finnspin: So modulation is fine adjustment. It's why most brakes are 4 pistons now the original Saints were 2 piston super powerful but very hard not to lock them up.
  • 1 0
 They already make 2-piston and 4-piston versions, so this isn't an "instead of" situation.
  • 1 0
 @briain: I still don't see how more pistons improves fine adjustment. I think what most people consider "modulation" (hate the term, modulation is something the rider does, not a property of something) is the relationship between brake lever travel change and braking force change.
Unless I'm missing something, more pistons does not necessarily change that, or at least it's not the only way to influence it.
Meanwhile I think: more pistons, more problems will hold true, more chance for unequally moving pistons and inconsistent brake feel..
  • 1 0
 @finnspin: So I'll try to explain how a disc brake works which is not the piston and pad clamping the disc they actually deflect the disc and my understanding is more pistons give you more control. So the way to test this is to hold a wheel with your hand parallel to each other and have someone try and turn it and try again but this time with your hands offset from each other. Hope that vaguely makes sense
  • 1 0
 @briain: I think I get what you are trying to describe about deformation, but it does not line up at all with how brakes are designed and therefore does not make much sense. If that was the case, why would we have pairs of pistons directly opposed to each other and not offset? And why does everyone (except Magura) use a single brake pad with a very rigid backing plate for each side? Deformation of the disk can't be the goal.

The only way I can see multi piston brakes improving "modulation" is the ability to have different size pistons, so that one side of the pad contacts first, avoiding a harsh "first contact" and reducing the grabby feeling.
  • 1 0
 I don't know about this. One of the biggest things with full hydraulic brakes is the preciseness and smoothness of the levers. That was the first think that struck me with the Juicy 7s back in the day. After I got those brakes, I was instantly sold on hydraulic brakes.
  • 1 0
 Semi hydraulic disc brakes have been there before, haven't they? I recall a riding buddy had them back in the day though I didn't see the point. Obviously Magura had semi-hydraulic rim brakes for road bikes as road bikes have the brake and shift levers integrated and Magura doesn't make shifters.

Either way, I can't see how these could possibly perform better and be more simple than a fully hydraulic system. It isn't even cheaper than a decent hydraulic disc brake system.
  • 1 0
 AMP/Rockshox brake was a cable actuated set up. Had them on a AMP B-3.
Bonus was the rotor mounted w/ 3 bolts (so lightweight..!)
  • 1 0
 @NWintheUSA: Yeah, I think it was an AMP brake indeed!
  • 2 1
 @dariodigiulio Is there any evidence that your full hydro brakes heat up the fluid and hose up to the lever? I think most heat in a brake system goes into the pads, caliper and rotor, but not much further. The fluid in a brake system does not recirculate, so little chance to move the heat around like a coolant system. I would imagine a large 6 pot pad and caliper, with well insulated Ceramic pistons, and ideally large rotor and pad with heat sinks (eg shimano ice tek) would be pretty thermally tolerant.
  • 1 0
 Where would journalism be without baseless speculation?
  • 1 0
 The real advantage of hydros is efficient and precise mechanical transfer of the force at the lever to the clamp force at the caliper. More power and far better modulation. Cables have loads of friction that mess with this, especially if there are bends and such.
  • 1 0
 Some people posting here have said they don't see the point in having a cable-hydraulic hybrid, as the friction in the cable of such a system negates the advantage of hydraulic fluid. However, I am a long-time user of fully cable brakes (go ahead, shoot me), and want to point out that in fully cable systems, the cable is one source of friction, the other being the ball bearings on ramp internals of the caliper. Hybrid systems eliminate the latter and replace it with lower friction hydraulic internals.
  • 1 0
 For road/gravelbikes that want to use existing mechanical brake/shifters or dirt jump bikes with gyros it makes some sense, you get some of the automatic adjusting of hydraulic disks and maybe the lower internal friction while keeping the cockpit setup.
6 pistons is just an odd choice for that market, since they are typically not very interested in maximizing braking power.
  • 1 0
 This product is just weird, because the only guys I know that run cable actuated disc brakes, including these hybrid versions, are hardcore retrogrouch roadies who refuse to learn how to bleed hydraulic systems. This crowd would not be caught dead on any mountain bike, let alone a downhill-oriented mountain bike.
  • 3 0
 To every Rad E- Bike customer with the crappy Tektro mechanical set up …… we’ve got your ultimate upgrade!
  • 1 0
 This is a product designed for heavy, cable-brake e-bikes. Pinkbike has a tendency to spotlight products designed for other types of cycling just for the high engagement factor of their viewers.
  • 9 5
 Srams gonna need 10 pistons before they get close to my TRPs
  • 5 0
 This reminds me of the razor wars where companies like Gillette kept adding more every year.
  • 1 0
 don't trp have a cable/hydraulic drop bar brake thing? never ridden one
  • 1 0
 @johnny2shoes: It's astonishing how prophetic that article was
  • 3 0
 This falls under the mantra: "Just because you can make it, doesn't mean you should".
  • 1 0
 "I tend to prefer to have both if given the option."

No shit. The point is that it's almost always not an option to have both, for a reasonable cost, there is pretty much always a trade-off.
  • 1 0
 I have Juin Tech something-or-others on my winter road bike and they are trash. Impossible to bleed, nowhere near enough adjustment for pad wear, and sticky pistons. Never again.
  • 2 0
 Who else is excited that there some sweet aftermarket levers for my Avid Mechanical discs?
  • 1 0
 That was my thought, those look pretty nice for my BB7s.
  • 4 1
 the parts bin ? more like the parts room ; )
  • 1 0
 It this can feel as good and have the power of normal hydraulic brakes, I love the idea of a simpler system/lever for frame swaps and I can only assume simpler bleed etc.
  • 3 0
 Hope did it better
  • 2 1
 Hayes did it first?
  • 4 1
 Rock Shox did it first.
  • 4 0
 @hohmskullkrishten: Actually the Rock Shox brake was a rebranded AMP unit.
  • 1 0
 Gott in Himmel - will it never end? Back to the workshop to invent an 8 piston caliper before dinnertime
  • 1 0
 At a certain temperature which is not going to be hard to reach on a long descent the braking power will be 6 X 0.
  • 1 0
 Call me crazy but I won't buy any product if they can't even get their left to right anodizing to match.
  • 1 0
 hmm I dunno man, it only has six pistons and all it does is brake?
  • 1 0
 good for DJ an touring etc but MTB? nah
  • 3 2
 They will go down a treat on the Wheelie Kids bikes.
  • 2 0
 those look super cheap
  • 1 0
 Oh, is that what they're known for?
  • 2 0
 $4.50 on Temu!!!
  • 1 0
 My eyes! Why aren't these pink calipers blurred like the others.
  • 1 0
 imagine these and a gyro plate on a full suspension. ultimate slopeduro
  • 1 0
 Dig up the levers? I'm still using them.
  • 1 0
 finally a linear lever that has a hinged/removable clamp
  • 1 0
 Cough too hard near the front brake lever and instantly OTB
  • 1 0
 Nothing new. Italian company Grimeca made this back in 2000 !
  • 1 0
 Do they come with ABS?
  • 3 0
 Nope. I don't come with abs either.
  • 1 0
 repost trp did it first
  • 1 1
 As seen on Temu.







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