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Newbie build questions - tight bottom bracket and fit BBS-HD

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    Newbie build questions - tight bottom bracket and fit BBS-HD

    I am converting one of these...

    It is an entry level 29ER that was sold in a box at a ridiculous price of A$350 from Aldi in Australia.

    First of all my bottom bracket was very tight. It is a brand new bike, very standard bottom bracket. It took all my strength to wiggle it slightly and two hours of sweat to get on. I had to use the securing ring to pull it on using the tread. It is very tight indeed. But it is in place.

    Have a look at how tight it is onto the rear stay (it is a hardtail). I realised it was touching, but in the photo it looks worse, so I think I need to pull it off and add some spacers (which were in the kit from Luna-mate which is the Aussie offshoot of Luna Bikes).

    The issue is that it is so tight on the bottom bracket, that I have no idea how to get it off (haven't tried yet).

    Q1: Should I be adding spacers?
    Q2: How do I get an extremely tight fitting BBSHD out of the bottom bracket ?
    Q3: If I do get it off, should I sand off the paint to make it slide in easily (or other solution?).


    Attached Files
    Last edited by Rodney64; 12-08-2016, 02:45 PM. Reason: Added larger photo

    If it were me, I would remove all of the left side hardware from the motor and use a block of wood to tap out the motor (maybe drill a hole in the block to fit over the square taper spindle). Put a bit of grease on what exposed part of the shaft on the left you can before using a rubber mallet to tap it out. Sanding down the paint and maybe the inside of the frame a bit should help with re-installation. Grease the motor shaft and the inside of the BB shell to help it slide in easier.

    Especially since you have ample room on the threads for both lock rings, I would use enough spacer so that you can just see daylight between the motor housing and chain stay. This way, you know for sure there is no lateral loading on the kit, and its as straight as can be.

    Good Luck!


      You have two main concerns when spacing the bottom bracket... clearing the frame and getting decent chain alignment. Use the spacers that came with the kit or buy a spacer kit to position the motor assembly.
      Check this video for more info on chainring and chain alignment.... It will likely save you some grief due to chain wear and chain derailments. On high capacity cassettes you're going to have a tweaked chain at the high and low extremes but that's the way it goes unless you go with an internally geared hub.