Archive for September, 2008

A Geekdad Experiment: What Gears Do On a Bicycle

September 27, 2008 2:54 pm

I did this the other day with my kids, and they thought it was a lot of fun.

It’s a simple experiment to do with your kids when they ask what the gears on a bicycle do. You’ll need:

  • A bike with gears
  • Sidewalk chalk
  • A measuring tape or stick
  • Paper for keeping a table of measurements

I started by making a schematic drawing of the two gear assemblies, front and back (we had a 21 speed bike) and numbered them. Then I made a table with a corresponding number of rows and columns and labeled them.

We went out on our low-traffic street after dinner and drew a starting line close to the curb. Next was getting the gears into the first position: smallest wheel in front, largest in back. Then I explained that we would put the front wheel of the bike right on the starting line and make sure the pedal was in its top position (easy to remember). I asked one of my kids to get on the bike and make exactly one whole turn with the pedal, while I held the bike steady during travel (don’t forget the bike helmet!) We then marked how far the front wheel had traveled and labeled the mark with the gear number combination. Now we changed the gear and did the whole thing over until all gears were covered.

During all this it turned out that holding the bike steady was too much work, and we had to be careful not to "coast" without treading the pedal. So I ended up holding the bike myself, turning the pedal while trying to walk alongside, half on my knees. Plus, we had to speed things up because it was beginning to get dark.

Here’s a picture of our markings (from the next morning):


Just by looking at the markings, we could tell that sometimes you can go approximately the same distance with several different gear combinations.

When we were done with all gears and markings, we got out the measuring tape and measured how far each mark was from the starting line. That resulted in the following table:


We then entered this table into a spreadsheet and turned it into a graph:


Sorting by distance, it looks like this:


This is shows that if you want to go smoothly from the lowest speed to the highest, you have to do a lot of shifting. Some steps aren’t doable without shifting both front and back gear, so in essence you won’t be able to go up smoothly.

Anyway, a fun experiment for after dinner or a weekend afternoon.

Exemplary customer service at JanSport

September 15, 2008 6:28 pm

This is an example of how customer service is done right.

We bought a JanSport backpack three years ago or so for use at school. A few days ago a buckle broke, so I contacted JanSport via their customer service web page. I explained the situation of the buckle breaking and not having a receipt and asked if that would be a problem if I’d like to have a repair done. I got a very friendly reply by email the day after, telling me the service center would send me a new buckle if I just gave them my shipping address. I replied back with my address, but also talking about how I wasn’t sure how to thread the buckle back on, could they include some instructions, please.

Well, today I got the buckle with a handwritten note, telling me how to put the buckle back. Not only that, but the buckle in the package had two pieces of webbing threaded through, held together with paperclips to show me how to thread properly. Brilliant!


Thank you JanSport for showing that customer service still exists in this day and age of outsourcing and automation!

CNet picks up BusinessWeek report, seems to do no independent fact checking

September 12, 2008 11:44 pm

Let’s see if anyone cares about this.

CNet posted something about how HP is trying to do an "end run" around Windows. The post seems to quote a BusinessWeek article from last Friday (online edition) and I wonder if anyone did any fact checking.

Now, I’m not about to dignify the speculation around what the future may hold, especially with regards to operating systems and "end runs", with a response, but I can’t stand to see factual inaccuracies about past product development, especially since I was personally involved. You could say this is a matter of personal and professional pride (for better or worse.) The post says this:

HP isn’t confirming the report, but had previously been open about the formation of a new group within its Labs that developed the touch-screen technology and special software used in its TouchSmart PC. The software lets users get around certain features of Vista to do certain multimedia tasks more easily.

Just to be clear: The software came out of the group that designed and developed the HP TouchSmart PC, the Consumer PC division, in conjunction with a few outside partners. Also, the software very much builds on top of things in Vista and couldn’t have been done on XP or any previous Microsoft OS. While it may be true that the software does so, it was not purposely built to let "users get around certain Vista features to do certain multimedia tasks more easily". It was built to provide the user an environment optimized for touch interaction, while providing interesting experiences and useful features at the same time (and yes, we can debate both the word interesting and the word useful, as lots of people have already done.)

CNet, did you check your stories and go back to the sources before posting something like this?

Fix Windows Live Photo Gallery file associations

September 10, 2008 9:35 pm

Not sure this is something people run into a lot, but if you are using Windows Live Photo Gallery and you can’t use it to view files by double-clicking on them anymore, the fix is to re-register the PhotoViewerShim.dll like this:

regsvr32 "%ProgramFiles%\Windows Live\Photo Gallery\PhotoViewerShim.dll"

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