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Gravity DeadEye 29 with BBSHD and Sturmey-Archer RS-RK3

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    Gravity DeadEye 29 with BBSHD and Sturmey-Archer RS-RK3

    So here she sits, mostly complete aside from the shift sensor I'll plumb in to keep buddies from shifting under load, and eventually a nice Manitou Machette Comp fork to soak up the bumpies.

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    I chose the Deadeye 29 because it was a single-speed bike with horizontal dropouts that would take 27.5+ tires, and looked like a nice platform to re-create a Luna BABE. Initially I envisioned this as a replacement for the Kawasaki Ninja 250 I sold a couple of years ago, as I moved 2 miles from work and it didn't even have a chance to warm up on the commute, so mostly an all-weather commuter. As the design, planning, and build progressed I became interested in doing some mountain biking, too. I think I really put too much emphasis on the horizontal dropouts. There's nothing wrong with a chain tensioner! And once I swapped in the Sturmey hub I couldn't even use the motorcycle-style chain tensioners that came with the bike. I also dropped $50 on a very cool, very heavy double-kickstand that I may still use if I end up doing a lot of commuting and need to park in a garage at the office. I'll also make a secure, steel box with a motion-sensor alarm in that case, but as of now since nobody is working from the office but me I can just park it inside.

    So on to the build!

    For starters, I removed the non-drive side of the bottom bracket without issues, but found that the cheap BB tool I'd bought was inadequate, so my LBS helped out with the drive-side removal.

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    Then I cut a couple of strips from an old inner tube and hot-glued them to the top of the BBSHD to act as a downtube bumper.

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    As it turns out, this was unnecessary. First off, I'd put the rubber too high up on the top of the motor, and, secondly, the stock motor mount positioned the motor so that it sits just a few mm away from the downtube, already. Keeping it tight should be enough to keep it from moving around.

    Say what you will about the DeadEye, it's a near-perfect fit for a BBSHD with the stock 46t chainring. No spacers required, and the chainring clears the chainstays with just a couple mm to spare.

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    Chainline to the single-speed 18t cog was nice out of the box, as well.

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    Rode it in single-speed for a couple of weeks and found that the 18t rear cog is a little tall, making it tricky to pull away from lights, so I ordered up a 24t cog for the 3-speed, but that turned out to be too torquey, and even in 3rd it wouldn't hit 25 mph, so back to the18t. Had no end of trouble getting the SA adjusted until I realized that I'd installed the shifter arm incorrectly. Once I got it lined up right it worked a charm!

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    I'll probably drop down to a 42t chainring just to improve the chainstay clearance and make 2nd gear a little easier to pull away in. Haven't plumbed in the gearshift sensor yet, but I should before I let anyone else ride and try to shift under load.

    I'm also having an issue with the Sturmey half-twist shifter interfering with the throttle. The throttle mounting ring is really thick. Trying to minimize use of the throttle, anyway, but it would be nice to be able to reach it from my usual grip position. Maybe I'll find a way to extend the thumb lever to the right a bit.

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    Need to replenish the budget a bit before considering a suspension fork, but I've got my eye on the Manitou Machette Comp, which fits my 1-1/8" steerer and will accept a 27.5 x 2.6 tire.
    Attached Files

    #2
    Easy throttle fix is upgrade from that $10 throttle to the $20 horizontal throw throttle ...it extends much further . They have a right hand version I think

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      #3
      Sadly, only comes in Lefty. There is a right-specific throttle, but it's a different design and doesn't extend as far as the left side model. Thanks, though!

      And, to be honest, as I'm over 100 mi into my e-bike journey I find my riding style evolving to the point that I rarely if ever touch the throttle. Mostly it's a mater of getting the right gear and PAS combo for the conditions. This has been a fantastic project, and ongoing adventure!
      Last edited by DCErik; 09-23-2020, 10:51 AM.

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