DIY Sprocket Brake

Discussion in 'Bicycle Repair' started by Tremont MC, Aug 5, 2009.

  1. Tremont MC

    Tremont MC New Member

    I wanted a better brake on the rear wheel. I designed and built this over the last couple weeks. Its got great power, won't lock the wheel though, but doesn't fade either after several repeated stops on a steep grade. What I like is the whole thing cost me 21 dollars for bicyle disc brake pads and thats it. Its got 2 mechanical actuated pushers or pistons behind the primary pad. Check my album for photos.

  2. HoughMade

    HoughMade Guest

    I've seen this in your album. Great idea! Very nice work.
  3. Tremont MC

    Tremont MC New Member

    Thank you. I took this idea from a company called Exile Cycles who build a sprocket brake for aftermarket Harley rear brakes. My objective was a better brake than stock because if you only knew how many different intersections with a stop sign at the bottom of a steep hill I have near my house.
  4. HoughMade

    HoughMade Guest

    Yep, I've seen the sprocket brakes on custom cycles as well.
  5. Luka

    Luka Member

    I have an idea for a change on the brake.

    It looks to me like the weak point in your design, and possibly the reason you can't get it to actually grab/lock the wheel, is that offset shaft you have used, to push on the pads.

    Instead of an offset shaft, to push on the pads, how about a lever ?

    I don't know if I can attach a picture here, but I'll try.

    The lever is green, of course. The pivot for that lever could be in the heart of the aluminum block body, as I drew it, or it could be in a mini-pillowblock, on the surface of the body.

    Attached Files:

  6. Tremont MC

    Tremont MC New Member

    A couple other considerations

    Hi, actually, what I have done with my half ground shaft transmits leverage to the primary pad as efficiently as your design...and in the center of the pad as yours does. The limitations of fitting a brake on this bike are working around the compromises in rigidity of the bike frame (it flexes when brake applied so the power is there), the bearing cones on the wheel itself seem to flex as well as when the brake is applied as the wheel moves away from the frame due to the higher pad pressure on the primary pad. Obviously these issues could be worked around if one was to design the frame/axle/brakes from the ground up and incorporate solutions then. Also space limitations are an important consideration as the sprocket with offset teeth dictate a deeper throat on the disc brake assembly than I would have preferred but was unavoidable on this application. The bottom line is; the limitations are frame flex/wheel bearing cone flex. But I have over 200 miles on these brakes and enough down hill stops on them that I can say they work well within these limits.