Author Topic: Juin Tech GT-F brake calipers (dual piston)  (Read 17065 times)

diefobo

Re: Juin Tech GT-F brake calipers (dual piston)
« Reply #60 on: September 13, 2022, 09:53:51 AM »
.... prevent tight bends (internal routing) .....

BR Chris

I'm afraid of this in my new build with full internal routing.......

pinaataa

Re: Juin Tech GT-F brake calipers (dual piston)
« Reply #61 on: September 23, 2022, 02:16:34 PM »
I bought the BR-03, after being very underwhelmed by the performance, I got myself the BR-05 for a better performance.

While I tried the brake in road setting (approx 500km) and they are ok, yesterday was my first proper gravel ride and required longer braking down FSRs for a longer period of time. I experienced quite a lot of fading at the end of the slopes where it seems the braking power reduces over time.

This with the announcement in the rotor discussion of the CD-01 and CD-02 that gets discontinued because of issues leaves me wondering if these semi-hydro/Onirii brakes are worth it, or if I should switch to a fully hydraulic groupset (either waiting for Sensah or going with SRAM), or start by switching to different brake pad/rotor combo (recommendation welcomed).

FYI, I have compressionless housing for the rear brake and normal housing for the front brake, and the conditions were very dry.



Queen of Skulls

Re: Juin Tech GT-F brake calipers (dual piston)
« Reply #62 on: September 24, 2022, 02:07:39 AM »
Hey there,

I couldn't say, as I haven't tried the ZRACE.
Here is a review of the ZRACE and Juin F1s.
The GTs are better than the F1s.

If I had to do it over again, I'd go for the F1s, as the GTs just feel like overkill for typical road cycling (no prolonged descents). Confidence inspiring in rush hour traffic though



I don't like this as it appears to be scientific but their are a lot of uncontrolled factors.  Like human reaction, the lack of exact timing, exact pressure put on the breaks,  even the how hydrated he is could influence weight. or How hot the rotors started off between stops.  maybe even how much he trusted the brakes to pull on them.

To accurately test them with repeatability and to eliminate factors.  You would need to make a rig to test them. spin them up to an exact speed, and pull on them an exact amount. and do it hundreds of times. then average out that data. after removing any thing that more than 5% of medium number.

then we are talking about science.
« Last Edit: September 24, 2022, 03:00:51 AM by Queen of Skulls »
Off with your Head tubes...

If the girls dont find you pretty they should at least find you handy...

[color #FE0000]P[/color][color #FDA601]R[/color][color #FFFF01]I[/color][color #008000]D[/color][color #1614E4]E[/color][color #80007E]!!!![/color]

kbike

Re: Juin Tech GT-F brake calipers (dual piston)
« Reply #63 on: September 24, 2022, 04:42:37 PM »
I have 1700 miles on road bike and 750 gravel bike on 2 sets of br-05 calipers.  I have a lot of wear on the 1 set. I need to adjust the calipers so there is less play before engagement.  On my gravel I've only use them on flatter routes.  I kinda expected to here they'd have issues on the tougher descending gravel routes.

I will be buying some upgraded pads off aliexpress to see if they bite better and how long they last.

I just did a full bleed and new hoses on my shimano hydros. The shifters and calipers had zero oil to start.  That ended up taking so much time. I still need to put more oil in to get the feel I want.  The shimano hydro hoses I used were smaller and more flexible the compressionless. That made running the cables easier and faster. I've used these for my scary gravel rides where 45mph happens and you have bends or tight turns during thought downhills.

1Sigma

Re: Juin Tech GT-F brake calipers (dual piston)
« Reply #64 on: September 24, 2022, 06:07:11 PM »
I don't like this as it appears to be scientific but their are a lot of uncontrolled factors.  Like human reaction, the lack of exact timing, exact pressure put on the breaks,  even the how hydrated he is could influence weight. or How hot the rotors started off between stops.  maybe even how much he trusted the brakes to pull on them.

To accurately test them with repeatability and to eliminate factors.  You would need to make a rig to test them. spin them up to an exact speed, and pull on them an exact amount. and do it hundreds of times. then average out that data. after removing any thing that more than 5% of medium number.

then we are talking about science.

Agree, but if you find someone who’s willing to go through all that for the clicks, let me know.
No one in the industry is going to do it (this industry thrives on marketing cherry-picked data and biased studies). So, all that’s left really are highly subjective user experience and uncontrolled experiments…
Better than average - Extra Average

Queen of Skulls

Re: Juin Tech GT-F brake calipers (dual piston)
« Reply #65 on: September 24, 2022, 07:21:19 PM »
Agree, but if you find someone who’s willing to go through all that for the clicks, let me know.
No one in the industry is going to do it (this industry thrives on marketing cherry-picked data and biased studies). So, all that’s left really are highly subjective user experience and uncontrolled experiments…

btw don't get me wrong there are a lot of value in talking about subjective experiences.  Because feel is an important factor in riding. take tire size and the psi even. Feel is as important as performance. Though brakes is something I would want the better stopping and feel( break rub or spoongyness)


For all we know the f1s preform better than the tests because he had trust in them and therefore went easier on them.
« Last Edit: September 25, 2022, 01:49:51 AM by Queen of Skulls »
Off with your Head tubes...

If the girls dont find you pretty they should at least find you handy...

[color #FE0000]P[/color][color #FDA601]R[/color][color #FFFF01]I[/color][color #008000]D[/color][color #1614E4]E[/color][color #80007E]!!!![/color]

ChrisB

Re: Juin Tech GT-F brake calipers (dual piston)
« Reply #66 on: September 25, 2022, 11:32:03 AM »
I bought the BR-03, after being very underwhelmed by the performance, I got myself the BR-05 for a better performance.

While I tried the brake in road setting (approx 500km) and they are ok, yesterday was my first proper gravel ride and required longer braking down FSRs for a longer period of time. I experienced quite a lot of fading at the end of the slopes where it seems the braking power reduces over time.

This with the announcement in the rotor discussion of the CD-01 and CD-02 that gets discontinued because of issues leaves me wondering if these semi-hydro/Onirii brakes are worth it, or if I should switch to a fully hydraulic groupset (either waiting for Sensah or going with SRAM), or start by switching to different brake pad/rotor combo (recommendation welcomed).

FYI, I have compressionless housing for the rear brake and normal housing for the front brake, and the conditions were very dry.

After longer use (1000km plus), I found the break power of the BR-005 to be lower compared to the Juintech F-1.
I also experienced fading especially in warm temperatures.... after changing the break pads to alternatives, the break performance improved consdiderably. I do not know yet if this also cured the fading on long downhills.

I changed to these Cooma break pads:


BR Chris

ChrisB

Re: Juin Tech GT-F brake calipers (dual piston)
« Reply #67 on: September 25, 2022, 11:38:17 AM »
btw don't get me wrong there are a lot of value in talking about subjective experiences.  Because feel is an important factor in riding. take tire size and the psi even. Feel is as important as performance. Though brakes is something I would want the better stopping and feel( break rub or spoongyness)


For all we know the f1s preform better than the tests because he had trust in them and therefore went easier on them.

No scientific tests from my side, however over 2000km on my Titanium Gravel bike with Juintech F1's including downhill on Swiss mountain passes.
I use the BR-005's on my second gravel bike for commuting and after about 1000km I found a big difference in break performance, a big part seems to be related to the sub-par original break pads on the BR-005's.

BR Chris

bamboo_mountain

  • Guest
Re: Juin Tech GT-F brake calipers (dual piston)
« Reply #68 on: September 25, 2022, 12:50:10 PM »
I am also finding that braking performance, while initially good, is deteriorating with stock pads on the BR-005. Thanks for sharing your findings.

kbike

Re: Juin Tech GT-F brake calipers (dual piston)
« Reply #69 on: September 25, 2022, 01:21:57 PM »
Agree, but if you find someone who’s willing to go through all that for the clicks, let me know.
No one in the industry is going to do it (this industry thrives on marketing cherry-picked data and biased studies). So, all that’s left really are highly subjective user experience and uncontrolled experiments…

There is a guy that does amazing testing just need to get him interested. He also buys all the products for testing. He's built and tested gas bicycles.  If anyone would test brake calipers he would.

https://youtube.com/c/ProjectFarm

Serge_K

Re: Juin Tech GT-F brake calipers (dual piston)
« Reply #70 on: October 26, 2022, 04:45:53 PM »
Will Juin tech brakes work the same using SRAM / Shimano road shifters? I know that different cable pull ratios mean you shouldn't mix shimano and sram shifter-brake, but Juin Tech doesn't make a Sram version and a Shimano version AFAIK?
If you have a choice between Shimano and Sram with a plan to use Juin Tech brakes, what should you do?
Fast on the flat. And nowhere else.

carbonazza

Re: Juin Tech GT-F brake calipers (dual piston)
« Reply #71 on: October 27, 2022, 01:34:53 AM »
Will Juin tech brakes work the same using SRAM / Shimano road shifters? I know that different cable pull ratios mean you shouldn't mix shimano and sram shifter-brake, but Juin Tech doesn't make a Sram version and a Shimano version AFAIK?
If you have a choice between Shimano and Sram with a plan to use Juin Tech brakes, what should you do?

Shifters need a precise move for each shift.
But they will just brake more if you increase the force on the lever, I don't think there is a special ratio to have.

FWIW Sensah levers work well with F1 brakes.
And are a SRAM like actuation with Shimano shifter pull ratio.

s3si1u

Re: Juin Tech GT-F brake calipers (dual piston)
« Reply #72 on: October 27, 2022, 02:57:39 AM »
Shifters need a precise move for each shift.
But they will just brake more if you increase the force on the lever, I don't think there is a special ratio to have.

FWIW Sensah levers work well with F1 brakes.
And are a SRAM like actuation with Shimano shifter pull ratio.

F1 works with SRAM levers as well can confirm.
Agreeing with what you said, though. Any road lever should work fine.

zerstorer

Re: Juin Tech GT-F brake calipers (dual piston)
« Reply #73 on: April 29, 2023, 03:04:28 AM »
It is confirmed that there are 2 versions of the BR-05 in existence. But all new production post Feb 2022 should be using 32mm pads instead of 26mm.
This info is stated on taobao.