Wide bottom bracket cartridges: how is chainring attached?

Discussion in 'Bicycle Repair' started by Max-M, Nov 8, 2011.

  1. Max-M

    Max-M Member

    When a wide bottom bracket cartridge is used to gain pedal clearance (like the 206mm sealed BB in the attached pic from the Sick Bike Parts site), how is the chainring attached to the BB's spindle? I imagine you'd slide the chainring to the correct position on the right side of the spindle, and then use some sort of set screw arrangement to tighten the chainring to the spindle (maybe with a milled flat on the spindle to hold the set screw in place). That seems to be the way that the chainring in the attached picture works.*

    Is this how it's done?

    Also, does anybody know of a vendor of chainrings that would attach to the spindle this way?


    * The chainring pic came from King's Motor Bikes' site. The chainring is part of a wide pedal crank kit that they sell. But I can't get any information from them ("Josh," the "tech guy" doesn't call back. I've spoken to "Tiffany" twice, but she has to defer technical questions to Josh). Anyway, they say that the wide pedal crank kit would take "two to three weeks" for delivery, so King's is out of the equation.

    Attached Files:

    Last edited: Nov 8, 2011

  2. 5-7HEAVEN

    5-7HEAVEN Member

    When you buy the cartridge from SBP, they can also supply you with the aluminum crank arms. Both arms have square peg holes, which slip onto the cartridge and bolt on. The chainring side also has male threads around the hole, upon which the freewheel screws onto. Custom chainrings have mounting holes matching the 4-bolt/5-bolt freewheel. The chainring sprocket bolts is secured to the freewheel w/4 or 5 long bolts. Spacers separate and align the inside bicycle sprocket with the rear wheel sprocket.

    They might have pics on SBP website.
    Last edited: Nov 8, 2011
  3. Max-M

    Max-M Member

    Thanks, 5-7HEAVEN

    When you mention the freewheel, I'm assuming that you're talking about a build which uses a jackshaft to drive the bike from the front, adjacent to the chainring. I'm using a traditional chain drive setup from my EZM Q-Matic's clutch sprocket to a 56-tooth sprocket that's hub-mounted on the rear wheel of the bike.

    But, I'm hoping that I can use SBP's 206mm bottom bracket, and attach the chainring (the type in the attached pic) to the proper position on the spindle with a set screw or pin mount.

    Does this sound viable?