Sunday, February 24, 2008

A Great Day with my Boy

Yesterday, I rode with Ian down to the Austin Energy Regional Science Fair, where he had was judged on a poster he put together at his home school coop on water molecules. It was fun to be there with him, but we actually only spent about 20min at the fair. We arrived there at 11:00 ad he was finished being judged by 11:20, and awards were not announced until 3:00. We decided to take a nano-risk of missing anything significant at the awards ceremony and go get cheeseburgers instead.
The real fun, for both of us, probably, was that we traveled to and from the site on bikes, about 30 km round trip. You can see the route profile plotted below courtesy of my new friends at Click here for the route map.
Ian was on the tag-along trailer pulled by me on the Crosstown 7, and at one point on the way home nearly fell asleep. Needless to say, we were both wiped out pretty thoroughly by the ride. I call that just about as perfect a day as you could get.

Friday, February 22, 2008


So, it turns out there's already a nice online tool (Veloroutes) for doing what I did yesterday. Here is a link to a route similar to the one I posted, except that this one does not deliver you directly to my doorstep. I considered that to be slightly imprudent. Here is the profile produced by

With Veloroute, you can export .kml files that are importable to Google Earth, and they already have the elevation data, so you don't have to go through the ordeal of filling in the .kml file. I still want to be able to play with the profile, so my next step is to write an Excel macro to import .kml files. More to come...

Thursday, February 21, 2008

My Route

What started as an innocent curiosity expedition with Google Earth turned into a rather longer journey through data manipulation, which I will explain presently. What I was trying to do was plot an elevation map of my ride to and from campus. Since I commute by bike, elevation changes are important: to be sought out if I want a workout; to be minimized if I'm low on energy. If it was easy enough to do (it was not, with present tools) I was going to plot out several routes and compare them based on elevation profile.
In any case, here is the elevation profile for my route when I ride along Shoal Creek Boulevard:

To get this, I first drew the path in Google Earth and exported the path as a .kml file. kml is the "keyhole markup language", a sort of xml for maps. Unfortunately, and this is a BIG unfortunately, Google Earth does not include elevations in its exports.
It turns out there is a web service for filling in the elevations, though, found here, which is cumbersome, but ultimately useful. I copied out the trip coordinates from the filled-in kml file and reformatted it so that Microsoft Excel could read it. Then, I put in formulas to convert latitude and longitude to distance traveled, and plotted the results.
I know this can all be streamlined, and maybe I'll make a minor goal of posting a one-punch processor for turning Google paths into elevation profiles. In any case, it's kind of cool to see the result. My trip is semi-hilly with about 50 meters net elevation change from school to home. Overall, the ride home has 213 meters of climbing, and the ride to school has 94 meters of climbing.

Friday, February 15, 2008

Mellow Johnny's

I'm very happy to see that Lance Armstrong is opening a commuter focused bike shop, right here in Austin. When I first heard about it I was worried it would be a racing-bike focused shop, of which we have a plethora already. This one is going right into the downtown in a conversion of an old building from the 50's. The idea is to make a bike shop, cafe, bike-storage, shower, and changing-room facility right on the soon-to-be opened Lance Armstrong Bikeway which will provide an East-West corridor into downtown Austin for bikers. This is a great idea that I hope we see more of in the future.
BTW, the name "Mellow Johnny's" is a pun on the French word maillot jaune, for the yellow jersey worn by the Tour de France leader.
Note that I have a newer post on Mellow Johnny's.

The View From Up Here

I think I may have reached the dizzy height of nerd-splendor today in the gas dynamics class when I actually understood Dr. Varghese when he said "This is a five-dimensional hyper-spatial surface subset of our eight-dimensional space." Here are the accompanying equations:

In case you care, this is the development of the distribution of molecular velocities based on intermolecular collision mechanics. Sounds esoteric, but your life depends upon it.
So why am I posting this on my blog? Why would anyone care? In the spirit of Chubby Grum Grum, I'm attempting to at least publicly acknowledge my innate nerdiness and make peace with it, to not take myself too seriously, and to join with you all in a good hearty laugh at the joy I experienced today in wrapping my mind around five-dimensional hyper-spatial surfaces. All together now, ROTFLOL!

Monday, February 11, 2008

How Cool is That?!

Today was one of those days that I live for at school. Full of excitement and adventure and really cool things. The coolest thing of all (if you grok the engineering mind) was that I got to use a Scanning Electron Microscope to examine some of the diesel soot particles exhaled by my dear Thumper. You can see the zoom-in in the series of photos below. The magnifications go from 200x to 10,000x. For reference there is a little bar that shows a distance scale. 1µm is a thousandth of a millimeter. For reference, one of your hairs is about 50µm across. The fibers you see in the pictures are glass fibers that make up the filter paper I trapped the soot in. We're zooming progressively in on the particle slightly left of center in the first image.

Incidentally, the smaller soot particles less than 2µm across (the individual clumps in the last image) are perfect for delivering carcinogenic compounds deep into your lungs. When they clump together like the one shown above, then your nose filters it out, but if they remain small (and hard to see, which is good for visibility but bad for lungs) they pass right on down and deposit all sorts of wonderful benzene and other toxics straight into you most sensitive tissues. This is actually a special concern for bike commuters, who tend to breathe deeply right next to the exhaust pipes of trucks and buses. For that reason I try to ride on road where the diesels don't go...
I guess that sort of explains part of why I'm doing what I am in graduate school. Hope you thought this was a neat as I did.

Friday, February 8, 2008

Answers to the Ultimate Question

...because the weather was beautiful: clear, sunny, cool; I had spent way too long in the cave, I mean lab, breathing diesel fumes with Thumper; and finally, in a stroke of wonderful coincidence, I passed a line of 42 cars waiting for the stop sign at Shoal Creek and 45th.

Now, what was the question???

While we're talking about why we like to be outside so much, check out this pic of our happy family enjoying the great outdoors last weekend. Hannah commented on this on her blog...

Tuesday, February 5, 2008

Dynamic Crosstown 7: A Review at 1200 miles

Last summer, I had to retire my old faithful commuter with something like 12k miles because it need about $400 worth of new drive train, wheel, hub, etc. Having paid about $400 for it 12 years ago, it was time to check out the market and replace it with a new bike.
I looked around at several options, and I ended up choosing the Dynamic Crosstown 7 over the Bianchi Milano, Bianchi Bergamo and the Breezer Uptown. This time around, I wanted reliability, low maintenance, and a good balance of cruising speed and comfort. Having had enough of cleaning dirty derailers, I was sure I wanted to get an internally geared hub. I ended choosing the Crosstown 7, a shaft-drive bike with the Shimano Nexus 7 internal hub.
I made my choice based on rides of the Bianchis at Ozone Bikes and reading the reviews of the Dynamic online. gave a good review on their site. Many of the people who write in to the Dynamic website are hard core year-rounders in the sticks of Maine who ride through snow and summer rain alike. I took that to be a pretty good endorsement. The shaft drive had strong appeal to me since I have long ago tired of sprocket tattoos, greasy fingers, chewed up pants legs, and expensive drive train replacements. The shaft drive has no exposed moving parts, does not need to be cleaned, and is an $89 part when and if I have to replace it. (Dynamic estimates its lifetime at about 10k miles.) How many chains, gearsets, and derailleurs have I been through on my previous bike in 12k miles? At least $300 worth... :-\ Daring to be a little different, I took the plunge.

The buying experience was good overall with minor hiccups. Since they are fairly small volume, there are not local dealers, and my order was over the phone but the sales rep was helpful, knowledgeable, and willing to customize the order. They swapped the cheapo pedals and seat for a good cycle computer, and I added fenders, too. With the added delivery charge, the total came to about $750, delivered to the door. Their website estimates 3-5 days delivery to Austin. I ordered late on Friday, and it took them until the following Wednesday to put it in the mail, and five business days later (Monday) it arrived. From order to arrival was actually 10 days.
Assembly was straightforward: the shaft drive poses no special difficulty, and I was eager to take it for a spin. I noticed right away that the shaft drive was not silent but growled a little bit, especially right before shifts. Otherwise everything felt good.
I did quickly develop two beefs, though, that are pretty much inexcusable for a bike of this cost. First, out of the box, the front wheel had a wobble large enough to brush the front brakes. >:( I cured this with a spoke wrench and wheel alignment rig, discovering in the process that three spokes were way loose. How this got past quality control, I have no idea, but this was a disappointment. ??? The other beef is that the crank was a little loose and creaks embarrassingly when I stand on the pedals. :-[ This has been largely resolved by using clipped pedals and shoes (no switching torque direction) and a quick tightening of the crank arms, but I would expect the cranks to be appropriately seated and tightened to avoid the noises. Again, this is minor and relatively easily fixed, but with no local dealer offering a free first tuneup, and for the price I paid, I would expect it to be ready to go straight out of the box. :(
In any case, that was 1200miles ago, and quickly forgotten. I have five months riding it, in cold weather and hot. I've changed flats, and spent a lot of time in the saddle (The trip computer estimates about 100hrs.) So here are my well-worn impressions now:
In Re: the growling, a shot of grease to the front crank case completely solved the problem. I would have expected it to be done more thoroughly out of the box, but this was not a big deal. Properly done, it is totally silent. The bevel gears and drive shaft add a very small amount of friction relative to a brand new chain, but I think this would reverse for an older chain, and as I expected, the drive has gotten smoother with after a short break-in. On average, I've been adding grease to the front crank on a more or two less monthly basis. I ride a lot and more vigorously than some, so my greasing interval is slightly shorter than the recommended by Dynamic. I can tell it's time to add grease when the drivetrain gets a little growly. It's really very easy to do and takes me all of 15 seconds to do, so this is a HUGE improvement over the messy chain cleaning process I used to dread.
I definitely enjoy the lack of worry about pant cuffs, grease marks, and having been through the rain a few times this week and have not at all missed needing to clean the chain and derailleurs, etc.
I love the Nexus 7 hub, and highly recommend it: the shifts are precise and instantaneous. The gearing is well suited to my commute, which is moderately hilly (mostly along Shoal Creek from Anderson to campus). Anything hillier, and I'd recommend the 8-speed, whose extra gear is at the bottom of the range, for climbing. It took a little bit of time to reprogram my muscle memory since its grip shift is setup in the opposite sense from a derailleur's. I.E. twist forward to shift down and backward to shift up. At first I had to think about; now it comes naturally. Regardless, I love the ability to shift without pedaling, a huge help for hill starts.
The geometry is, for me, the right compromise between being far enough forward for speed and power but upright enough not to stress my wrists and lower back (especially with a backpack: I prefer not to use a bike rack). I saw a complaint online about the aluminum frame being too stiff, but I find it very comfortable and not too jarring, and I appreciate the lighter weight. In addition, the aluminum frame displays some beautifully well done TIG-welds, for those who appreciate that sort of thing.
Regarding flats, it's not a big deal to remove the rear wheel, although it is certainly more of a process than on a bike with a chain and quick release skewers. I keep two extra tools that I would not otherwise: a stubby flat-head screwdriver, and a thin wrench to fit the bolts on the rear axle. The main problem with getting the rear wheel off is actually the fenders. With the rear-open axle drops, you really have to remove the fender to get the wheel off. That makes it more involved than a conventional setup, so in order to minimize that problem, I replaced the Kendra tires it came with with some Maxxis urban tires with a Kevlar lining (and a reflective sidewall). Since putting on those tires, I've not had a single flat, and removing the rear wheel hasn't been an issue. Better tires are an option that Dynamic offers, and I would recommend paying the extra money for them.
Overall, I'm pleased with the purchase and would characterize it with one word: smooth. I look forward to putting lots more miles on the bike. In general, the build quality and components are good (with the above noted exceptions), and the Nexus 7 really shines. The shaft drive is pretty transparent and noticeable only because of the annoyances it doesn't give. I think I'll appreciate it more and more as I don't have to tune it, oil it, clean it, replace it, or hide my greasy pants legs. I hope that shaft drives become more accepted in the mainstream in the future. I think that would be well justified, especially among the bike-as-transportation community.

Sunday, February 3, 2008

Ride on Mr Francis!

I saw this guy biking up Shoal Creek Boulevard today and found him to be inspirational. I present to you Mr W.B. Francis, on his way to the grocery store, on a tricycle. We should all be this active in our 80's.