Home > Uncategorized > I always liked sparks

I always liked sparks

August 7, 2010

A friend at work had his bicycle seat stolen this week.  It isn’t a trivial loss either: a $25 seat post, a $40 saddle, a $17 taillight, and an $18 fender.  While shopping for replacement parts, he’s riding on a junk seat that the thief left behind.  Anyway I thought about my bike (and added up the respective cost of those components – a few notches up the ladder from his ride) and decided to hire a sniper to watch the bike racks around campus.

Unfortunately that solution turned out to be impractical for various reasons having to do with the interference of a large Government bureaucracy, so I decided to secure the seat a little better instead.  This I did by pinning the seat tube in the frame.  And what does that have to do with this picture?  This is a view of sparks on the grinding wheel as the carbon-steel pin is shortened to the correct length for the seat tube of the frame. 

In common shop practice, if you want to know (approximately) what alloy a piece of ferrous metal is made of, you touch it to a grinding wheel and observe the sparks.  Some of the patterns are very pretty as well as informative.

(Picture Pentax W60 in macro mode.)

Categories: Uncategorized
  1. August 8, 2010 at 04:46 | #1

    Darn those Feds!  Getting in the way of perfectly good plans to deter thieves.  I wonder if they’d overlook a gentleman in the bushes with a cattle prod.

    The sparks are lovely.  You’ve got a talent for photography and an eye for remarkable beauty in ordinary things that I envy!

  2. August 8, 2010 at 23:47 | #2

    How did you secure the pin? Just drill through both the frame and seat and put in the pin? I think that is a great idea for helping to secure a bike seat.

    And that is a lovely picture Diane!!

  3. August 8, 2010 at 23:49 | #3

    D’oh, wrong post for that last part. That is what I get for late night posting.

  4. August 9, 2010 at 07:26 | #4

    It’s a slotted spring pin – a hollow tube with a slot on one side.  It is slightly larger than the hole, resulting in an interference fit under spring tension.  Isn’t going anywhere.

    Here’s how it looks in the seat post.

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