July 2, 2012
Lacking those newfangled power-metering hubs, I am reduced to boring calculation. 400lbs gross vehicle weight, up at hill that peaks at a 10% grade (maybe more hard to tell), minimum speed 4mph, faster in the not-so-steep parts. That’s 320 watts, my huffing-puffing not-much-fun power output over a period of several minutes. 400 = 220 (me) + 110 (passenger) + 65 (bike, tools) + 5 (backpacks). Plus a few watts for the always-on lights, plus a few watts for rolling resistance.
The waste heat output (we’re not that efficient) is almost a kilowatt. Yes, I was quite warm.
June 30, 2012
June 28, 2012
It worked much better than I had expected. Yet another thing it turns out you can do on a bicycle.
June 21, 2012
Do not buy a bike with “mountain bike” handlebars. Those are the ones that are essentially a straight piece of metal tubing, maybe with a little bend. If the bike store you are buying from attempts to tell you that these are good for anything, find another bike store.
The specific problems with these handlebars are:
- For riding in traffic, they are too wide.
- They provide only one hand position; notice all the aftermarket nonsense to help add positions?
- That one position that they provide is pessimal, especially if you are older, especially if you have had problems with your wrists (e.g., carpal tunnel) in the past.
- They don’t work well with baskets.
- When you go to replace them, either because your hands hurt or are going numb, or because you want to use a basket, you’ll discover that the one-piece brake+shifter lumps do not play well with the new handlebars, and you’ll need to replace that, too.
- Even if you don’t replace them, that one-piece brake+shifter lump will go bad; the shifter on one side or the other will start to not reach all the gears. The guys at my local bike shop said: “spray it with lots of WD-40 and work it back and forth, and it might get better, otherwise, there’s no point trying to fix it”.
Some positive advice: for retrofitting a mountain bike for civilized use, I recommend replacing the bars with Velo-Orange Left-bank or Porteur bars (22.2mm lever diameter), an appropriate shifter (Falcon thumb-shift is cost-effective, though not indexed; SRAM twist 7, Shimano 7, or Shimano 6), and Tektro brake levers. There are 8-speed options at Amazon. The Velo-Orange cork blend grips are comfortable, durable, cheap, and black (which goes with everything and does not show dirt). To install them, be sure that there is room on the bar to push them all the way on, get their insides wet, and push them on quickly. If they fit loose, a little bit of tape on the bar that runs the length of the grip area and curves around into the end will help (if it doesn’t curl around the end into the inside, it can get pulled loose and bunch up as the grip slides on). Spurcycle grip rings, when available, are another nice choice (I bought some on Kickstarter, and they work quite nicely, especially when trapped at both ends by a lever and end-cap).
June 3, 2012
Very often when returning home from work, Lowell St in Lexington is a parking lot, though it clears out towards Arlington. Last Thursday I decided to count how many cars I passed, and vice-versa. I passed 60, then 25 passed me. There was a little pass-me-pass-them-pass-me at one intersection that counted as only one pass-me. The last car to pass me, was a motorcycle that I passed at about #30, then I crossed into Arlington.
March 23, 2012
Try this experiment. Take a bicycle out to a bike trail with any significant traffic at all. Pull off to the side, and start fiddling with your bike. Every third person will stop or call out to see if you need any help.
Next, try putting the hood up on your car, parked on a busy street (Massachusetts Avenue, Arlington, in particular). Stand next to the car facing traffic with some jumper cables in your hand, out where drivers can see them, almost as if you needed a jump to start your car. Dozens of cars will drive by and many minutes will elapse before anyone will stop to help (at least, that was my experience today).
Draw your own conclusions.
March 11, 2012
I can’t quite put my finger on it.
It’s the Vassal-Huron-Sparks-Brattle-Hawthorn route from Fresh Pond to Harvard Square. My other gripe is that the return route does not use the same roads (because of one-way streets, among other things). If Lake View Avenue was made two-way-for-bikes, the to/from routes could be mostly the same, and it would have only two stops and one light.
To be fair, my favorite route to Concord Avenue (the one I recommend to other people) also includes five stops and a stop light.
February 20, 2012
I’ve spent way too much time and money tinkering with bicycle electronics, but I am so incredibly pissed at off at the high price and mediocre quality that you get if you buy retail instead of DIY. I had a clever idea yesterday that would allow easy, simple combination of a USB charger with a cheap, brain-dead rectifier/doubler.
February 14, 2012
It has to digest a wide range of input voltages, and it has to be efficient enough to deliver 2.5 watts of power.
This version has several flaws (spec’d wrong buck diode, holes were not large enough; needed to bias D+ and D- to make iDevices happy about charging), but with some tinkering, it works (tested with iPod Classic and Nano). Further research needed to figure out why it won’t charge my Motorola phone. Further research: mini-USB is a 5-pin connector, and pin #X (they call it that) is shorted to pin 2 and connector to pin 4 (GND) with a 200k resistor. For now, I will just buy a cable that claims to work for this purpose.