Last Thursday I took a ride to help me prepare for the upcoming NYC Century ride. My route was as follows.
In reply to my previous post, Park Avenue South and then Park Avenue proper is the least unpleasant option. It’s only two lanes below 42nd, which is probably the biggest determinant of comfort. I go left at 42nd and up Vanderbilt Avenue, then right at 46th and back onto Park. This section is wider, but there’s so many cars pulling up to the curve and turning that nobody really has an opportunity to pick up a lot of speed like on a wider, staggered-light street. They should put a bike line along the median and get rid of one lane of traffic. I also rode all the way cross town to the Hudson path on a different trip; this was slow and unpleasant and added 5-10 minutes to my ride, which is a big percentage increase.
I have an excellent downtown route. Yesterday I made it to 25th & Lex from my house on the Upper West Side in 19 minutes, stopping only a handful of times. I go down Columbus Avenue to 77th Street, where I make a left and get into the park. I then take 7th Avenue south through Times Square (shitty, but I want to stay near Broadway. It’s really not so bad: it takes maybe 3 minutes to get through) — it would be awesome to go from 59th to Times Square on Broadway instead, but note that you’ll have to avoid the pedestrian plaza by getting on 7th at 46th or 45th. At 42nd, I go left and get back on Broadway. Then at Herald’s Square, I go down the extended sidewalk on 6th, cross 34th on the east side of the street and then ride in the gutter against 6th avenue traffic to get back on Broadway. Then it’s smooth sailing again down to 26th, where I make a left, go to Lex, make a right, and done!
The beautiful part of this route is that at no point are you really being overtaken by cars. The Columbus Avenue section is downhill, so I can keep a pretty good pace. The 7th Avenue section has proven quite empty (since 7th starts below the park!), so most of the time I have the road all to myself. Broadway is shunned like the plague these days and has a separated bike line – you have to be more wary of pedestrians walking wherever they damn well please.
I’m back in New York again, and I’m trying to take my bike everywhere. It’s a little different from Cambridge, to say the least.
I’m at school in Midtown on the east side, and live on the Upper West Side, so my natural route to school is to go through Central Park, down 7th Avenue through Times Square, down Broadway, and then cut east a few blocks at Madison Square. This is a pretty nice route, as the street portion of the ride is through low-volume areas, some even with good bike lanes. (However, the separated path in the 30’s is unusable, since it is basically an extension of the sidewalk.)
The trip back home is not so easy. The 40’s and 50s on almost every single uptown avenue are terrifying. I have ridden on 3rd, 6th, Madison, and 8th, and every ride has near misses. I will give Park a try today, I think, although the lack of staggered lights makes me nervous. Also, 2-way traffic means lots of people zooming across my lane without looking for bikes.
My question is, is there are a way not to risk death on the way home without diverting to the Hudson River Bikeway (an exhausting diversion)?
I thought I’d fill in a few rides I have done just for completeness.
1. The Ashuwillticook Rail Trail was beautiful. It runs along the water, not very close to the road, not many road crossings. My only wish was that it had a swimming hole, too.
2. When I got my fixed gear back last month, I just went out around Boston in any old direction. At the time, I couldn’t even find all the roads on the map. However, when I went to Jamaica Plain a few weeks ago, I was able to place everything much better. I still am not sure of the second half of the ride (starting with Stony Brook and going until Boston College), but here’s the route anyway (with notes to jog my memory). It was hot. It was on big roads. There isn’t much to recommend it; I probably should have stuck with my original plan to go on Jamaica Way.
3. This isn’t a single route, I just wanted to reflect on how lovely it is to ride around Cambridge and Boston, especially late at night. At least half a dozen times I have taken the bike out after midnight and ridden the nearly empty streets of Cambridge and of Boston. As much as I don’t like nighttime activities in general, these have a special charm; after a certain hour, you get to see such interesting characters with their guard down. Some favorite roads and places are Broadway and Cambridge Street, Cambridgeport (which always confuses me) and Downtown and the Financial District. For a while, Beacon Street just out of Inman Square was cursed; before my bike got its spiffy upgrades, I consistently lost my chain at the top of the hill there. During the daytime, I am a fan of the Somerville Community Path east of Davis Square, which is the extension of the Minuteman Route.
As I indicated in my previous post, I’ve been learning how to get my chainring straightened out. The internet, as far as I can tell, basically only has Sheldon Brown’s useful (but slightly cryptic) explanation of how to do this. However, now that I have dealt with it, I understand the issue better.
Recall that the role of the chainring is transfer energy from your feet (by way of the pedals and crank) to the chain and eventually to the back tire. Because every ounce of energy your feet put into the pedals is meant to be transferred into the chain, getting very low resistance makes a huge difference in the feel and performance of the bike. When there is too much slack in the chain (low tension) or the chain binds at any point (high tension), that is energy that should be going from your feet to the wheels, but is instead being dissipated by inefficiency in the system.
Following up on my previous post about my new bike, everything has been going quite peachy. Who knew that buying everything new helps?
Well, it’s no silver bullet. If there’s anything I have learned about fixed gears so far, it is that you have to get the crank bolts just right, and check them frequently. There should not be any noise, and there should not be any binding of the chain. When I first got the repairs done, there developed an awful rattling in the chainring; it turns out the bolts were too long and weren’t able to be tightened enough. After a couple weeks riding around with a new set of properly sized bolts, the rattling came back. I got a wrench and discovered everything had come loose. I tightened, and the chainring went back to being almost totally quiet.
I have been using R for a few weeks now, and now that I have a feel for how to get things done, I am starting to explore how to get those things done faster. On the suggestion of a friend, I picked up Data Manipulation with R by Phil Spector. Once you get the hang of R syntax, it is a great book to show you how to actually get things done; I am most of the way through it, and would highly recommend it.
One thing he introduces in chapter 9 tangentially is the “system.time” function; feed it a code block, and it will tell you the amount of real and system time elapsed. So, it is the perfect test bench for which of two methods runs faster; he uses it to show you how you get a 4x speedup using the built-in “colSum” function over “apply”. Using vectorization, a loop is just as fast as “apply”, however without vectorization, you get a 60x slowdown using element-by-element looping.
This points to the key to R-speed: don’t lie to R. Tell it everything, so that it can allocate memory efficiently, which is by far your slowest task. Take this example for applying “rbind” across a set of data frames. Previously, I had thought “functional programming”, and naturally went with “Reduce”. However, this book motivated me to find the “do.call” solution. Observe the results.
> df <- lapply( 1:1000, function(z) data.frame( runif(1000 ))) > system.time( a <- do.call( cbind, df )) user system elapsed 0.54 0.01 0.59 > system.time( b <- Reduce( cbind, df )) user system elapsed 40.16 0.80 42.61
That’s right, the “Reduce” method took 80x longer than the “do.call” method. I am going to change some of my code right now…
I work in Acton, and I live in Cambridge. Given that the driving distance is about 20 miles, and the biking distance about 25, it was only a matter of time until I rode the route. This week I did it in both directions, although not on the same time. All I can say is, thank goodness for the minuteman bikeway.
Finally, a picture of my bike. Love it! The bag under the seat has my flat fix kit, keys etc. That’s a cable lock I have stuck on the handlebars.
I had everything below the frame replaced. See my last post.
Push on pedals A to rotate chain ring B, driving chain C, rotating rear cog D, and pushing wheel E forward.
This is actually very limited advice on bike repair. But first, the background.
