Review : Juintech GT-F

Recently I built my first disc brake bike. Yes, I'm very late to the disc brake game. Every time I plan on buying a new bike, the thought of not being able to reuse all my old parts makes me think twice.

Anyway, coming back to my choice of disc brakes, I was very clear that I was opting for mechanical discs for the simple reason of serviceability at home. I repair and put together all my bikes myself and try to avoid LBS if I can. Not needing to fuss around with hydraulics and getting a whole bunch of new tools makes it enticing.

So what were the options? Top of my list, I had Paul Klampers, Yokozunas and Juintechs.

Doing a search on the Web, this list shouldn't surprise anyone and I was dead set on getting a pair of Klampers. However, there were a couple of show stoppers. First, the Klampers were mighty expensive and they only offered really expensive shipping options to Singapore. With the Klampers, you would also need to purchase additional mounts and bolts for rear brakes. My brand-new bike was still in transit and the rear stay measurements weren't easily available, so that was an issue. Another thing I was concerned about was the bulk of the Klampers. I'm not sure if it would fit well on the bike. It just looked risky for the price I was gonna pay and all the potential caveats.

The Yokozunas and Juintech were hybrid mechanical brakes which meant they were supposed to feel like a hydraulic system would but they were cable actuated. I was intrigued by the potential best of both worlds approach. Since the Klampers is now off the list, I had to decide between both of these.

Like the Klampers, the Yokozunas were expensive and hard to ship to Singapore. While everyone raves about the Yokozunas, there weren't many reviews despite passing mentions that they were great. If Yokozuna reviews were rare, Juintech reviews were near impossible to find. Having said that, there were many positive reviews about Juintech in public forums, but hardly any were found on blogs or YouTube. The only upside being in Singapore, getting a pair of Juintechs was easy and the fact that it shipped out of China. Juintech accessories were amazing. It came with multiple length rear bolts and an additional pair of brake pads.

It was a no brainer so I pulled the trigger on the high end Juintech GT-F that came with 4 pistons!

Shipping was quick without any drama and everything was delivered as stated in the box. Next came installation. The user manual might as well have been in Greek. It was absolutely useless and generic. After mounting the brakes on the bike and the wheels on, it was time to tune it. Based on the various comments on the forums, everyone mentioned that it was a breeze. Plug and play!

Installation

That was so far from the truth. The first issue I had was rubbing on the rotors. No matter how I tried to adjust the dial, I just couldn't get the rotors to not rub. After removing the brakes and pads, I realised that the pistons were not fully retracted. I pressed on the brakes and saw that the pistons weren't compressing equally. Some were further than the other. I suspected that being in the box or in storage for a while, the piston walls probably needed cleaning.

Having 4 pistons made it challenging and that all 4 shared the same reservoir made it tricky. After a lot of messing around, I finally got them all to compress at similar rates. Not perfect but close. Reinstalled them on the bike and went again. It was rubbing slightly less and was annoying enough during a ride that the rider next to you could hear it.

Disassembled it again and pulled everything out. I suspected that perhaps there had been too much oil in the hydraulic reservoir. So, I used a bleed block to hold 2 pistons in place while I pushed the other 2 pistons back and reset them. It then became clear that it wasn't possible. It is highly likely that the pistons were not properly reset when hydraulic oil was bled into the system at the factory.

These brakes were not meant to be bled and there were warnings about opening up the bleed port. Since I can't see how these brakes will ever work, I gently opened the bleed ports. The moment the screw was loosen, mineral oil speweed out. Almost a clear indication that there was too much oil in the system. Once the screw was out, with a kitchen towel over the bleed port, I reset all the pistons to their original positions. Kitchen towel absorbed a lot of fluid.

Put the screw back in place, cleaned up the system with brake cleaner and back on the bike it went. Immediately, no more rotor rubs! Success!

Ride impressions

Took it out for the first ride and tried to bed in the pads that came with it. I must say my initial thoughts on the pads were disappointing. It didn't perform better than Swissstop Black Knight rim brakes on my carbon wheels. It just didn't bite and these were supposed to be resin pads.

After deliberately braking hard over a couple of rides, the pads are now performing well. The performance far exceeds any typical rim brake setup. Modulation feels like an improved version of rim brakes but still way off from true hydraulic setups. On my last ride, as the pads heat it under heavy braking it started to squeal.

I have yet to try it in the wet, but I'm certain it will do better than any rim brakes in that regard so I'm not overly concerned.

Summary

As with any Chinese-made product, quality control is sometimes hit and miss. If you are not handy with bikes, it's generally not a great idea. However, if you are comfortable handling tools and have an understanding of how bikes work, they are pretty reasonable value for money. They often perform equally as well as their branded counterparts.

Despite the installation and initial setup issues, it's been largely trouble free and I'm extremely happy with it. One key thing to note about installation is the fact that the rear brakes are aligned natively to fit 160mm rotors. What this means is that there is no need for an additional adapter to fit a 160mm rotor in the rear but if you had a 140mm rotor like most road bikes in the rear, you will run into an issue and you will need to change your rotors. This was not explicitly spelt out anywhere unfortunately.

I would definitely recommend the Juintech GT-Fs but if I had to do it again, I might consider the 2 piston model.