These mechanical disc brakes are ridiculous! - JuinTech GTF-6
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- เผยแพร่เมื่อ 5 ส.ค. 2024
- These 6 piston mechanical disc brakes from JuinTech might be the most powerful ones I've ever used, but can they justify the incredibly high price?
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I have always had a soft spot for mechanical disc brakes on road bikes. They’re simple to use, easy to setup and maintain, and you can make use of older mechanical groupsets, so are great on more budget oriented bike builds.
I have tested A LOT of different ones in my time, but I've never seen anything like the JuinTech GTF-6. It’s an expensive, oversized mechanical caliper, with 6 brake pistons, that also makes use of large brake pads from an obscure MTB groupset.
So in order to properly assess the performance, I'm going to pit the GTF-6 caliper against the two other mechanical callipers JuinTech offer, the 2 piston F1, and the 4 piston GT-F.
In short, the braking performance was pretty phenomenal, but in light of other options on the market right now, for the average road cyclist, they are just too expensive. Plus, if you watch the bonus clip, the TRP HY/RD calipers are still my favourite!
Semi-metallic brake pads:
amzn.to/4aYxOWb
Timestamps:
00:00 - Start
00:23 - JuinTech overview
02:01 - F1 brake caliper bleed
04:00 - Hill testing
05:10 - Sponsor spot
06:06 - Hill testing cont.
09:57 - Hill testing results
10:31 - Multi-piston caliper discussion
12:16 - Brake distance test
13:36 - Conclusion
15:26 - Bonus clip (TRP HY/RD)
Intro roll:
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Please note:
I am not a professionally trained bike mechanic. There can be risks associated with using products that are unbranded, untested, or come from sources where the provenance is unknown. Please talk to a qualified bike mechanic if you are in any doubt.
In essence, be careful, do your research, and cycle safe!!! - กีฬา
Luke, you are absolutely not ‘a loser talking to himself in his garage’. You are talking to thousands of interested and admiring viewers, creating compelling content of which this vid is another example.
The pistons are all a different color. Worth it.
Cargo bike upgrades fit in there too.
Low maintenance, high stopping power seems perfect for a business oriented cargo bike operator.
With no drop bars involved anything other then full hydraulic system just doesn't make any sense
Exactly what I did (but full hyro). I rarely go over 17-18mph yet 4piston front and rears due to the additional weight.
It's worth considering for Yuba Cargo school run with 25kg of bike, 50kg of kids and 75kg of dad
@@krzysztofkolodziejczyk4335 depends what your bike is doing, I have drums on my commuter, they're awesome
It would have been helpful to compare the performance of the GTF-6 with full hydraulic brakes.
You would have it on a totally different bike set up though so any number of things could cause a lot of variability.
@@Alex-to8es Only different levers needed.
A comparison with the HY/RDs would have been nice too
Be careful about the bike industry's favorite marketing tool-the A / B test. If A is good enough, It does not matter that B is better.
Just think about your car. Would you run out and by a new brake system on your car if an A/B test showed that carbon ceramics stop faster? Obviously not because your current car brakes stop good enough. You don't need to pay for something you don't need. Be aware of the A/B test!!
@@jurekgadzinowski2895have you seen the prices of hydraulic levers. “only” ??? 😂
🥖 🥖 🥖 🥖 🥖 🥖 , 6 one for each piston!!
If I'm not mistaken, the additional braking force afforded by quad (or in this case, hex) piston brakes come from the fact that the pistons are different sizes. Smaller pistons move the pads a greater distance for every millimeter of input at the lever, but squeeze with less force. Bigger pistons do the opposite- they move a shorter distance but squeeze harder.
Heat management is an additional bonus of quad or hex piston brakes.
Fantastic video and research. Well done. I love your work.
Another great review Luke, is good to know the differences between these high ends disc brakes.
that is a great review, thank you Luke It seems like JuinTech makes rather decent brakes. I'll keep that in mind for my next brake upgrade.
Another great video Luke. Certainly expensive, but the others seem great. TRP especially. Just built up a Chinese Ceccotti frame with rim brakes but my next bike will be disc with the mechanical TRP1 Saves faffing around with fluid!!!!
I definitely would love to watch some ride vlog, you ride on some amazing places, I would love to see more
Love your channel ! Greetings from Germany !!
Gold standard in DH Mountain Biking are still 4 pistons like the Shimano Saint or the new Sram Maven, 6 is extremely exotic even there. Trend currently is going fom 203mm to 220 or 223 rotors …
This makes me want to couple the hope v6Ti calliper with a new Tech 4 lever to make a ridiculously hard brake
Great video Luke! Just as a potential ‘other scenario’ that people would buy these for. I myself am a juin tech owner, mainly because in 2022 I went from rim brakes to disc, but only wanted to upgrade the frame and didn’t want to buy a whole new groupset (I have a sram red 12 speed axs grupo). So initially I went with the 1 piston caliper, which whilst it worked it felt a little lacklustre. I ended up buying two of the 6 piston in the fetching purple (weighing it up against he Paul klampers which are slightly cheaper)
In my opinion the brake performance offered by the GT 6 is exceptional, and more than what I need for my road bike. What it did mean is that for 400 pounds, I avoided spending over 5x that on a new sram red grupo. And are still cheaper than just buying a sram red pair of Brifters and callipers
A very niche use case I know, but they’ve given me the ability to use a disc brake frame without too many additional costs.
Keep up the great work!
No worries, next time you'll get that pokemon right!
6 piston calipers 😮 they sound really impressive.
Friction is force is F=u * Fn where u is the coefficent of friction and Fn is the normal force applied perpendicular to the frictional surface. Pressure is Force / Area however in a hydraulic system like this the number of pistons would all share the same pressure and hence you'd have n times (6 or 4 or 2) worth of force for the same given pressure. and because friction is proportional to the force and not really the pressure (although it would be the same if you only had one area where force is applied) you should have an increase in force due to multiple pistons. either way great video as always!
Came here to say this. F=PA and there is a greater area for the same pressure. same as tyres
Just to add...that is assuming that the total surface area of the pistons increases between the various calipers ie they don't use much smaller pistons on the calipers with more of them.
Exactly that. You have more pistons doing the "same work" over a bigger area. More = better in this case.
Bought some Sirocco gear with your link. Stuff looks great, cheers! 🤙🤙
Thanks for this, Luke. I'd be very curious to see a comparison between the GT-F6 vs. _Growtac Equal_ calipers.
I really like the bonus clip!
awesome visd again my dude. subbed and liked. thanks for your hard work we appreciate it brother
Amazing episode, when’s the 8 piston version available 😂
Haha this. The piston war begins
Pistons right round the whole disk, now that would be cool... :)
actually sounds like my drum brakes....
@@PRH123 biblically accurate disk brakes.
Nice video Luke .. Just had some F1's fitted and cannot wait to try out 🤞
You're the man we need but don't deserve. Cracking video, Luke (as always)!! 🥖🥖🥖
You need a man? 🥖
There is a small spider on one of the shots from the F1... 🤣🤣🤣... thanks for the great content as always.
Ive had the Juin Tech R1 breaks for a while, post mounted version of the F1. I had no idea these could be bled, thanks so much for that! I'll keep that in mind if the performance drops off at any point. Im using them with compressionless housings. It doesnt feel as good as hydraulic but they break well and reliable, much better than the stock breaks from Cannondale
I really like your channel... you go deeper into the engineering of the products way more than other channels which I enjoy since I'm an Engineer... what is your background? .... also why are your levers have cables coming out the side of them like the cheap ones I've seen...Unless those where all you had for testing your just giving away watts with those even though minimal still counts in my eyes.... again... Great channel... and thanks a million..... 😀
My first bike as a kid had brakes so good I had to plan my stops a street away. These days we are spoilt for choice. Luckily we can choose depending on budget and the type of riding we're going to do. I had the early version of Hy/Rd brakes but the inside piston on both brakes would never retract properly driving me nuts.
A thank you for making this video and offering your personal opinions.
Man i like your style! Amazing presentation! I want to become a presenter like you!
Good test, thanks
I never know that there are hydraulic brake heads on the market, i feeling like a n00b after 20 years of riding. I need to investigate this cool STUFF! Thank YOU for pointing me on it!
Luke, I'm mainly a mountain biker, used to race DH and even on DH bikes they only run 4 piston brakes. Hope brought out some 6 caliper brakes like 20 years ago but they stopped selling them years and years ago. As you've said, pad material and the power and modulation in the system is more important.
Love the channel though, keep up the good work 🥖🥖🥖🥖
Thank you Luke!
Luke = Legend in making! Awesome video as always! But :D Adding more pistons does increase force behind brake pad. We can say that max pressure in caliper chamber is equal for all calipers, but difference is in surface area exposed to hydraulic pressure ( more pistons more surface area ) F=P*A F-Force P-Pressure A-Surface area.
Those GTF-65 might be good for my old'school MTB. Juyst the front thouygh.
The 6 pots would be worth having on an electric scooter.
Nice video - a lot of creators struggle to give an apple-with-apples comparison but you've done a great job. Great explanations plus you've got a really engaging presentation style 👍👍
My question comes from the downhill mountain biking perspective so might not apply to road-cycling...
Would the reduced volume of fluid mean that potentially there's a greater chance of brake-fade from the fluid overheating (compared to fully hydraulic brakes)?
The Juin Gtf-6 would be great for a disc brake tandem bike!!
Great video! It's good to see options in the mechanical-disc world. Personally, I like the simplicity of mechanical brakes. An Achilles heel of mechanical disc system is the housing. Compressionless housing will dramatically increase the power and feel of even cheap mechanicals. I threw compressionless housing on my 2019 Radwagon, which has inexpensive Tektro mechanical discs. I can now easily lock up the rear wheel, with much more control and power compared to the old housing. I strongly suspect GOOD mechanical discs and GOOD housing or compressionless housing will significantly decrease the gap in performance between a mechanical and hydraulic system. I also suspect that there is overlap in performance-would it be "better" to have JuinTech, Growtac, TRP or Paul Klamper mechanicals compared to some entry-level hydraulic brakes? The answer is probably yes. These hybrid-style brakes are an interesting option.
The 4 piston pad looks the same as my saint/zee pads. I remember hope made some 6 pistons hydro brakes in 2003 called the mono 6 Ti
This also reminds me of a funny old MadTV fake commercial for a *_20_*_ blade_ razor -- the Spishak Razor
This is cool. I'm not as interested in bikes and riding them, although I'm Dutch and of course use my bike a lot to go to places, but this video was interesting. The thought of a system like this once occurred in my head as an idea, but never looked into it.
This pressure is transmitted through the hydraulic fluid to a piston, which can be used to exert a larger force. The mechanical advantage of a hydraulic system is determined by the ratio of the area of the piston on the output side to the area of the piston on the input side.
This is the google result when you search hydraulic mechanical advantage. The surface area of the plunge of the master cylinder and the surface area of all the surfaces that it will push onto,(which in this case is the back of each of the six pistons )are critical for understanding the pressure applied. A six piston brake caliper should have three times the clamping pressure of a two piston brake caliper.
Your understanding of surface area and friction was really good, though. Thank you for making these videos. I've been thinking about upgrading my brakes and wasn't sure how much of a difference it would actually make?
As someone else has already highlighted, hydraulics kind of change the way this work. That’s because in the hydraulic system, you have a certain amount of pressure. The thing is that while you would have the same amount of pressure in the system (PSI), you have more area across more pistons. Because it’s a hydraulic system, the more surface area you have (by adding more pistons), the more pressure you have acting on the brake pad.
If you have 100 PSI of pressure in the hydraulic system, and you have 1 square inch of piston surface area and two pistons, you would have 200 pounds of force acting on the brake pads/brake rotor. If you have the same amount of pressure, but 6 pistons each of the same side, you will have 600 pounds of force instead, because you have a larger surface area that the pressure can act on. The thing that you end up losing is travel. The 6 piston caliper will only be able to move the piston 1/3 the distance of the 2 piston caliper.
That’s why they felt so much stronger - they are literally applying more force because they have more area that the hydraulic pressure can act on. They’re not going to be 3 times as strong as the two piston calipers, since the other pistons are smaller, but that’s why they were stronger.
How do you find the Darevie gloves you are wearing??
Just love your work Luke. I really hope this TH-cam thing is working out for you.
What would you suggest is the best rotor size for a 6 piston setup.
Will a 140mm work, or are you limited to 180 or larger if it's a flat mount?
TRP Hy/Rd auto adjusts pad distance for wear. For the Juin-Tech you manually adjust the pad distance.
Good video! Did you use compressionless housing?
I have the yokozuna ultimo (same as juin tech gt) and just recently purchased the juin tech gtf-6 for front and f1-s for rear for more stopping power on my bikepacking rig. Sounds like I made a good decision. I feel the 4 caliper are lacking the power.
Great content 😀
This mans crazy doing a Vs, Vs, Vs and paying for it himself... god damn.
Great video thanks. Do you know if the Juin Tech GT-P are the same as Yokozuna Ultimo?
They do look very nice!
I have Hope RX4 four piston hydraulics on my LOOK endurance bike and they are excellent. I also have Paul Components Klampers on my Gravel / bike packing bike. I've got to say that the Klampers are phenomenal, but like the Juin Tech they were expensive at £200 a calliper but are truly exceptional and mean I can sort any issues off the beaten path if need be.
Best outro ever!!
Great Luke, I like your methodology. You are quite right that friction is proportional to normal load (pressure as you called it) so for the same size rotor, with the same pad material, then you should gat the same braking for the same hand pressure regardless of pistons and pad area. However it friction ceoficient that can change. Pads can out gas during use due to the heat reducing ceof. leading in the extreme to fade. That is well understood. However there is another effect which can make a difference and that is shear stress in the pad marerial. Less area leads to higher stress which makes the fibres in the material lean over more and so reduce coef. Thats on a tiny scale of course but can in some manner explain some of the difference.
I would recon that the hy-rds will compensate for pad wear better (because of the resevoir) so performance at max wear will be much the same as new.
Great testing Luke, keep it up.
Small point, off topic, is that cable operated hydraulic calipers are like the old magura (I think that was the brand) with the remote hydraulic block on the stem but more integrated.
This is the only explanation that seems to make sense. Since otherwise there isn't any reason for the normal force or the coefficient of friction to change as Luke had stated
@@ranitbose9609 Typically 4 piston brakes have more hydraulic leverage (ratio of caliper piston area to master cylinder piston area), so the normal force is changed when compared to 2 piston models. You could of course increase the hydraulic leverage on 2 piston brakes too, but that runs into issues at some point (e.g. short and wide pistons will have a tendency to get stuck and spoke clearance is limited, master cylinder pistons can only become so small while still being strong enough), so at some point it becomes easier to add more pistons.
The pokemon bit had me 😂
Cool review as always! Thanks a lot!
By the way, nice googles as well. What's that?
Had him tech brakes on my gravel for years bloody brilliant way way better than any cable discs
How is the clearance to the pads? Do more pistons mean the distance the pads move is less, and therefore the gap is smaller? For example I tried hope rx4 hydraulic calipers and I was disappointed with how narrow the setup margin is, went back to Shimano.
These jiun calipers can have different internals so I'd like to know if they maintain nice clearance
Absolute LOL to the Pokémon ad-break guessing game reference. Touché sir.
What is its effect on the disc rotor and the hubs? Would you recomend on a more powerfull disc rotor and hubs?
Those centerline rotors? Aren't they on backwards?.... NM just saw it addressed in the bonus clip. Love that lead in BTW👍
Funny he says it doesn’t make a difference, I’ve once put a centerline on backwards and under heavy braking you most definitely can tell, I was chasing a weird vibration forever, then flipped the rotor to the right way and it was totally fixed. The spokes are designed so the rotor is stiffer in one way and helps a lot with vibrations
Luke, after all the improvements of sensah shifters, which one would you prefer for budget 11 speed shifters? Micronew or Sensah?
the shoulder straps you mentioned are the "bib" in bib shorts, just as a note. without they are just called shorts or cut shorts.
Great video
On the topic of brake pads. I really hated how the factory juintech pads squeal in the wet. I’ve since switched to (disco brakes) ceramic pads. But they’re not quite as powerful. Do semi-metal pads squeal less than the factory juintech ones do in the rain?
Is the modulation better with the 6 piston? Quite worrying that mechanicals can't lift the back wheel - my old shimano and sram hydraulics will flip you over the front and not feel guilty about it
Is it will exploades when you are in down hill with too much braking?
Great video. What glasses are you using while doing the testing?
For an electric bike, where you have lots of cables running into the frame, in a crammed space, having mechanical cables and hydraulic calipers would make assembly and maintenance much faster and easier.
Fairly sure multi pistons are more powerful because the total piston surface area is larger, so the hydraulic leverage is greater. The same can be achieved if they increase the size of the single piston, but the packaging would be kinda ass.
As I understand it, with a typical full hydraulic system you aren't increasing the piston surface area much going from 2 to 4. What you do get is (1) more brake pad surface area and (2) more even pressure on the pad. Ultimately you are limited by the size of the master cylinder, especially for road brifters. However, with a hybrid brake it is possible to have a substantially larger master cylinder and therefore more piston surface area.
@Sierramike524 is correct
That is, if you increase the piston area, force will increase proportionally but the distance that the pistons travel will also decrease proportionally. 10% will probably not cause a huge loss of clearance, but if the pistons were 100% bigger (2->4 pistons of same size), that's definitely liable to require very very true rotors. If you want to keep the same clearance, you would lose pressure on the brake pads.
Are the pads proprietary to Juin or are they the same firm factor of common pads like promax and shimano?
I’m a mountain biker and despise the pavement but your videos are very entertaining.
🥖 like your vidz... how fast were you going for your braking tests?
as an aging flatland freestyle rider, i love cable operated brakes... never seen a hydraulic "detangler"!
lol, my highschool project was a freestyle bmx with disc brakes... 25 years ago, before they become so ubiquitous...
Let me ask you what are the distances in milimeters (they look the same) between the caliper mount points also the distance between the flat mount points on the flat mount brackets that come with them? I need to evaluate before I buy if I can put the on a Salsa Journeyer with Microshift SWORD group set which beggers another question are they short pull?
That's some really thorough, extensive testing Luke. Nice job. 👍🏼
Honestly. I think it's good for those who have a giant bike who used their own 'hydro' system but you can't find the parts made anymore. You don't have to throw away your shifters.
Pretty impressive!
But I really like my fully hydraulic brakes. As these are hybrids, is there any way to convert them to fully hydraulic brakes?
@tracevelo Have you tried bleeding your HyRds yet? My front has a bit more lever pull than the rear but I’ve got double the amount of bolts in it than in the TRP bleed video! I think it’s so you have a top and bottom port for the caliper/reservoir no matter if it’s front or rear so you don’t have to remove it but I’ve been too scared to try yet!!
Can you use thicker rotors? How thick was his rotors?
Force is Pressure/Area so, at the same pressure, you would expect more force with the larger contact area.
Is there a carbon bike frame that is both built to accommodate both fully self contained hydraulic disc brakes such as the ones featured in this video that also accommodates mechanical brake levers, (with stainless steel brake cables). Second question, is there an electronic groupset that features mechanical brake levers, (to couple with these self contained hydraulic brakes)??? Thanks for you answer. Thanks for you videos and your chosen subject.
Im intrigued by the different piston sizes, I wonder what effect that has compared to pistons of equal size. They do look big when on the bike.
Thanks for your video. It was very interesting to know that a roadie brake can do 6-pistons. It's a perfect for us here with Steep Hills in Hong Kong.
I got a few questions if you won't mind:
1. Can it do 180mm rotor or even 200mm?
2. Can I use my existing SRAM AXS group set for this brake?
3. Weight of the caliper compared to say SRAM calipers?
Believe it or not the taping part of the bleed is usually necessary as it tends to get a few small stubborn bubbles out of the system.
"Get orf moy laaannd! Release the hounds!" 😂
Did you installed front rotor incirrectly? You need to turn it
My SRAM centreline rotors look exactly like these and are mounted the other way around, I don't know if this would make any difference though.
How easy is it to get replacements for those massive pads?
Who needs these GTF-6 calipers? I have an older tandem with cable operated disc brakes. They work OK in the flat lands, but are not very good in the hills. Retro-fitting to a Juin Teck would give me/us much more braking power, heat control, and ease of installation. Tandems can get pretty heavy with 2 riders and several bags of gear. Fully loaded our tandem is over 400 pounds!
6 pots used to be all the rage in motorcycles in the 90s and early 00s, especially in the modified community.
And mountain biking
So what is better..hybrid or full hydraulic ? I need to order something today reguardless of cost .
Can you also try premium fully mechanical disc calipers? (Like growtac equals)
Do you fit any bigger rotors on your bike? It could be interesting if you test 140-160-180 mm rotors.
I have an TRP brakes which were stock on my Triban and after around 3 years I had to switch them out to mechanical breaks, because even tough I switched out the brake pods and the disc rotors, bleed them they lost so much power I was afraid to commute to work. These 3 piston Juin Tech's look really good but seem to me overkill.
The former head of Trickstuff once told me that the larger a piston is or if you have two in a row instead of one the brake pads won't twist as much. The result is a more equally distributed force on the brake pads. Think back when we had V-brakes. Maybe you remember how a worn pair of pads looked like - the front of the pad still had material left while the rear was completely gone. Now that I think about it the brake pads of my old two piston (having a small diameter) brake the same happens there as well.
yeah this is true about more brake pistons, its really no different than car brakes or big brake kits. on your stock standard car you have one piston on each side of the rotor pushing the pad into the rotor, this is nice and works well but your not utilizing the pad well enough and can often get inconsistencies in brake performance or brake fade. inn comes the big brake kit, a big brake kit tries to solve two problems, heat and consistency, the increased amount of pistons in the calipers allows you to run bigger pads distributing the pressure more evenly over it, this will make them more efficient not building up the same concentrated heat that makes brakes fade, this should give you more consistent braking and since you distribute the pressure over a larger surface and there is more material for the heat to soak into, in addition to this most big brake kits have larger ventilated and drilled or slotted rotors that will aid in cooling as well. the main goal for bigger brake calipers is not stopping distance but consistent performance when your brakes are hot.
Love the review - as we do all of yours. But a question: if you think it too niche and too expensive, what, in your opinion, fills this spot in the market at a better pricepoint? Paul Clampers? Or..? 🥖🥖🥖🥖🥖🥖 (one baguette per piston)
With that mustache Luke look's like a 80-90's police officer from the coast of Miami or something like that.
Downhill racers on the steepest tracks still running quads, how much power do you need on a road bike, on a flat road??