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    Front mechanical disc brake won’t reach rotor

    Hi there!
    I recently bought a set of JuinTech F1 hybrid mechanical/hydro brakes for my gfs gravel bike. The swap of the rear one went buttery smooth – no adapter needed. I mounted the front one using the included adapter only to find out that it's mounted to high and won't really reach the disc rotor. The F1 should be suitable for flat mount and 160mm rotors, which this bike has. Is there some way i can make this work? Would 180mm rotors work here, even tho the F1 aren‘t desgined for those (at least according to the sparse information i found)

    Greatly appreciate your input!

    by Extremist_Enterprise

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    10 Comments

    1. Foreign_Curve_494 on

      Sometimes forks are designed for 160 rotors and the adapter will add 20mm, pushing it out. Does the adapter allow you to flip it the other way? The Shimano one can do 140 or 160, and it looks like you’d need to be in the 140 position

    2. Antpitta on

      Most gravel bikes / road bikes have a 160mm limit for front rotor size. Definitely look at specs before thinking about a bigger rotor as the larger rotor will apply more leverage and the fork needs to be designed to withstand it.

      As for why that brake isn’t fitting correctly there, did the rear come with the same mounting plate and is the rear also using a 160mm rotor?

    4. Extremist_Enterprise on

      Thanks everyone for your input so far, I definitely haven’t done my due diligence properly as this problem is not new as it seems. I’ll try a 180mm rotor and see if that fits (:

    6. glasgow1981 on

      I ran this setup on a Specialized Diverge for a couple of years. I had to run an 180mm rotor on the front to get the Juin Tech GT-F calipers to fully engage.

      Took a bit of head scratching at first but realised it was the only way to get it to work properly.

      Worked flawlessly for me with an 180mm rotor, although the Diverge fork was certified as working with 180mm rotor, so there is that to consider as not all forks will be covered under factory specifications/ warranty.

    7. nateknutson on

      If the rear is 160 you’ve answered your own question. The rear one set up without an adapter. Normal flatmount road/gravel flatmount installations are always either 160 or 140 – you use no adapter for 140 and use the adapter for 160. So what you say can only be true if these are some kind of mutant nonsense flatmount brakes that are actually trying to be 180/160. Just looking at them corroborates this. They’re shaped way different and spaced further out than a normal flatmount caliper. The adapter in the picture is also way different than a normal (ie Shimano) front adapter.

      It doesn’t look like flipping the adapter you have now will help because it will only space it further away. See what happens when you put this brake in the 140 position on a Shimano front flatmount adapter.

    9. FatBoyDiesuru on

      Personally, I’d use this as an excuse to get a 180mm rotor. Looks like it’s meant for that instead of 160mm.

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