TechShop + bike = happy

When I bought the F650GS used, it came with bar risers. Unfortunately, they were already a little too tall for me while I had the normal seat; with the lowered seat, I felt a bit as though the Beemer had ape hangers.

Fortunately, Peter and I have memberships at TechShop in Menlo Park and have taken their Safety and Basic Usage class for the milling machine.

Pardon the crappy pictures; they were taken with a cell phone camera.

The bar risers before:

Setting up the mill to take off a quarter inch:

Milling the bar riser:

One down, one to go:

I installed the shorter risers on the Beemer yesterday morning before my Wind Dancers ride, and I believe the experiment was a success. Even taking off just a quarter inch made my wrists more comfortable. I might take off another quarter inch in the future, but for now, this works.

Hooray for TechShop!

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4 Responses to TechShop + bike = happy

  1. Ken Haylock says:

    Oo-err… I’m a teeny bit concerned with the structural integrity of your revised risers. Sorry if you’ve already thought about this, but…
    The original design had that big locating peg that went into the recess for the original bars, and then the clamp bolts really only had to… err… clamp them down. All the fore and aft forces were then contained by the big solid lump of metal of the peg engaging in the original bottom bar clamp. When you were hard on the brakes, there were almost no forces at all being put on the clamp bolts, and those that were would have been up and down, i.e. in the direction that a bolt is at its strongest.
    Now, though, the riser is free to slide across the top of the bottom clamp, and all that is restraining it – and all of your weight under maximum braking, with the leverage you can apply through those big wide bars, is a couple of quite small bolts. Also, they are shearing forces, rather than the previous forces in tension.
    I’m no engineer, so I couldn’t tell you whether they are now up to that job or not, but you have certainly weakened the whole assembly significantly. Given what is at stake (think of the catastrophic consequences of a structural failure on one side under heavy braking, or even just of bolt stretch causing the bars to unexpectedly rotate), I’d really want to find an engineer and ask them to run some numbers through their calculator before I trusted the modification with my life…
    If you had shortened the riser by milling a centimetre off it but keeping the same profile, that obviously wouldn’t have been a concern.
    I’m sure that with some judicious use of cardboard to make a template for the correct shape and then another visit to the machine shop, you could put them back on the milling machine and re-instate the old shape if necessary…

  2. Nice work. They look very nice. How long did they take to make them? Are they aluminum?

  3. Stephen Lee says:

    Wow. TechShop: What an amazing idea! I think I’m in love. Too bad; I don’t think there are enough builder nerds to support a business like this in most cities. Flashback: remember the little “Dozer” characters on Fraggle Rock? =:-p

  4. Bombauer says:

    Oh my god, that TechShop is awesome! Lucky I live in Mountain View!

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