In the front I'm not sure yet. Hub brakes could be an option, but I was thinking to get a segmented fork for it sometime, then run v up front. But yeah until then probably drum up front and coaster in the backAre there pictures of this mythical beastie? Sounds like you are playing in my sandbox now. I've been planning an internal geared hub built on an old Canadian frame. Do you plan to use pedal actuated braking in the hub, or will it be rim brakes?
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I agree, there are some severe limitations when it comes to off-road comfort. No way around that. Where I live, in Denmark, I ride mostly flowy single-track and gravel/fireroads. So I think it'll be okay, but I honestly wouldn't want to ride coasters like fellas did in the mountains, I'm too much of a chicken and sucker for comfort. But I like the simplicity, and they are incredibly functional brakes that just work, albeit at the cost of actual modulation and, as mentioned, pedal comfort.My main issue with coaster braking on trails is foot position, you can't simply back pedal to place your feet where you want them. It just requires a little bit of thinking in advance and eventually you adjust to it. The other is modulation, coasters like to lock up, which will really mess up the track and make enemies of trail builders