With jus a few exceptions, I've seldom been confidant in most ANY of my bike brakes for over 50yrs!!! Some exceptions were a few coaster brakes as a kid, an old road bike of 18yrs use, and a heavy MB of a dozen yrs use. My recent 29er beach cruiser has been the worst of all. Rear brakes will never set solid, and front barely drags me down no matter what I do,.. even at slow pedaling speeds. None of these were disk, although the front MB brake has thrown me a great distance into the air and nearly over the side of an ICW bridge into shark infested waters,... I ate a great deal of pavement instead!
The motor (rear hub) install on my heavy 29er brought a need for some serious brakes. Regen is nice, but on my bike, it's only effective in quickly slowing the bike down from higher speeds to about 12mph. Brake switches for regen are easily adjusted to activate jus before full braking of the wheels. This allows regen to slow the bike saving brake wear (also allows heavy FULL braking from high speed if needed). Below that 12mph,.. the regen is not so good, and I still needed something solid to rely on. I opted for disks,... for several reasons. Number one,.. was the need for replacing my entire brake system, since NONE of the components were effective nor could they be significantly improved. Number two,.. after riding some friends disk bikes, I found them far more effective than ANY system I've previously had. And last,... MUCH easier to maintain, adjust, AND CHEAPER to repair/replace. Weight and momentum generates some tremendous braking forces, often leveraged greater depending on the brake system!!! And rim systems can see some tremendous and costly wear not no mention, expensive replacement that's not the easiest. Pads is pads,... but much easier replacing a worn or damaged disk, than a worn or damaged rim! I also found disks to be smoother and less trouble,... provided headset is adjusted correctly.
BUT CONVERTING TO DISK CAN BE A PAIN!!!! Don't be tempted to use cheap "adapter mounts"!!! If it's cheap,... it'll be costly in the long run. Those cheap front and rear adapters typically clamp or band to the front forks or rear frame chain stay. You'll never tighten them enough. They'll twist and/or bend from those incredibly leveraged forces and will always result in GREAT damage to disks, calipers, spokes, rims AND YOU!!!! I eventually got a front fork with disk brake mounts. And a thick heavy rear bracket mount that BOLTS to the dropout plate. Oh ya,... and new disks, and spokes. Caliper is a bit mangled and ugly, but still usable and good. UGH!
With a new fork, the front disk system is easy,... even with front hub motor. The rear, not so easy,... but like everyone noted, most braking force is on the front. Eventually, you'll consider a different controller more, something with regen braking. They even allow an adjustment of regen braking levels. Very nice with front hubs. I have a rear hub, so I max this setting. And your existing rear rim brake system is likely enough, for most like you. Probably used less than front brakes, so wear and tear is less too. Jus not for me at speeds of 40mph on a heavy bike!!! Your riding style and speed is going be your biggest factors in choosing a setup,.... but if I had long big hills like that, I opt for an additional 30# anchor or grapple hook too!!! :wink:
