A blog about skating and cycling, or vice versa

Arms race#

Thu, 30 Nov 2006 13:54:27 +0000

From further conversations with Mike: the height of the swing at the back is important for cadence, but the bit that actually provides power is when the arm comes forward of the body and bends at the elbow. This is entirely consistent with what I've been feeling, so I might actually be getting it right.

Still haven't thought much about why it works, mostly for the basically trivial reason that unless I'm actually skating I can't visualise which arm is out in front during which part of the push on which leg. So, um.

Knackered#

Sun, 03 Dec 2006 00:01:39 +0000

This is not in any way an interesting post, but ...

As the LFNS was rained off last night I decided I should do some kind of exercise to compensate, and seeing as I have these new weights around, that was the obvious choice. I'm still evolving a routine, but figure that if sport-specificity is the way to go, (1) squats, (2) one-legged squats (occassions for skating on two legs are rare and occur mostly on downhills), and (3) a bit of armwaving and other stuff just to balance things out. But I am being very very careful about how much weight I squat, because my knee complains at the slightest little thing (more so if it's not thoroughly warmed up) and as a result I finished a couple of sets of various stuff feeling that I hadn't done much after all.

This morning I felt slightly sore (which suggests that maybe I had done something after all) but not so much so that it wouldnt stop me skating into town to do route check and some drills on the Beach. This evening, 33km later (plus drills) I'm significantly more sore. More so than I'd expect for what was mostly a fairly lazy day of drills (one-legged skating through cones, which I am better at now than I was this morning, but still can't actually do). I wouldn't go so far as to say I'm hoping for rain tomorrow, but I won't be giving the bike a lot of welly.

Oh, top "learn from my stupidity" tip: dumbbell "bench" press on a swiss ball that's too big is not a good idea if there's other furniture around, because you will hit it when you roll off the ball.

Keys for Kino#

Mon, 04 Dec 2006 23:17:56 +0000

I've just been sorting out some photos for the LFNS site based on bits of video I took on Sunday. Quality is not great, but it never will be given that the camera takes interlaced images.

Anywaym the reason I remark on this is mostly to whine about how the traditional virtue of Unix - scriptability - seems to have been thrown out with the bathwater in this brave new user-friendly world. For each frame I want to save from Kino, I have to

For upwards of 50 frames, this is tedious, and there's no apparent way of automating it without hacking the Kino source directly. And as it uses the Xvideo extension, ordinary window grabbing utilities like xwd don't work either.

So I, uh, hacked the Kino source directly. First the .glade file to add a C-A-s keyboard accelerator to the "save still" button, then the C++ source to bypass the file requester and use a hardcoded pathname. Great, now I have a fork of the wretched application...

Index: src/kino_common.cc
===================================================================
RCS file: /cvsroot/kino/kino/src/kino_common.cc,v
retrieving revision 1.114
diff -u -r1.114 kino_common.cc
--- src/kino_common.cc  17 Oct 2006 07:31:17 -0000      1.114
+++ src/kino_common.cc  4 Dec 2006 23:04:54 -0000
@@ -930,9 +931,10 @@
        }
        else
        {
-               char * filename = common->getFileToSave( _( "Save Still Frame" )
 );
-               if ( filename && strcmp( filename, "" ) )
-                       common->saveFrame( common->g_currentFrame, filename );
+           char * filename;// = common->getFileToSave( _( "Save Still Frame" ) 
);
+           filename=tempFileName;
+           sprintf(filename,"/tmp/kino_still_%d.png", common->g_currentFrame);
+           common->saveFrame( common->g_currentFrame, filename );
        }
 }

Output at http://www.lfns.co.uk/route.php/20061203/1 - see, told you the quality wasn't that good.

Blue in the tooth#

Fri, 08 Dec 2006 02:42:37 +0000

My new phone arrived yesterday, occasioning some monkeying around with Bluetooth. Some notes: :http://ww.telent.net/tmp/med_DSC00014.JPG

1) My USB bluetooth dongle (lsusb identifies it as a "Integrated System Solution Corp. KY-BT100 Bluetooth Adapter") doesn't work when plugged into an unpowered hub. Although lsusb shows it perfectly fine, hcitool scan says Device is not available: No such device. Plug it directly into the computer and it's fine, though.

2) No matter how much I mess around with /etc/bluetooth/hcid.conf (I tried changing the security to "auto", and defining a pinhelper application), I couldn't get phone and computer to pair. The phone would say "Unknown requests access to your items. Allow?", "Allow connection? Always ask/ Always?", "lsip.telent.net-0 Add to my devices?", then prompt me for a passcode, then give a generic and misleading error message. It seems that passcode prompting has to be done over DBus now: if you're running a hide-the-Unix-from-idiots interface like Gnome this is apparently not a problem, but for old and reactionary people like me who actually prefer that the computer do what we_ tell it to, well...

What you need is a thing called passkey-agent, which is command-line-only. Debian revision creep meant that it was installed on my work machine but has been dropped from the package in whatever version of bluez-utils I have at home. All is not entirely lost, though: one need only 

:; apt-get source bluez-utils
[...]
:; cd  bluez-utils-3.7/hcid
:; make -f ../debian/passkey-agent-makefile 
cc `pkg-config --libs --cflags dbus-1` -DDBUS_API_SUBJECT_TO_CHANGE
  -DVERSION="\ "0.7\"" -o passkey-agent passkey-agent.c
then install said passkey-agent somewhere sensible and ensure that it's started at login.

3) Freaking Nora, but it's slow. I don't know if it's fundamental bandwidth limitations or if there are inefficiences somewhere that make it that way, but pictures transfer from the phone at around 10kB/second.

4) obexftp has possibly the least friendly UI known to Man. So I am hacking up something cheap and nasty and marginally more usable in Perl, using XML::Simple and Term::Readline.

[ edit: you can find it at http://ww.telent.net/tmp/obexftpl.pl if you're interested. It needs the OBEXFTP.pm module which - guess what? - is part of obexftp but not built in the Debian binary package, so pull the source code down and build it yourself. Grr ]

The picture was taken while skating home last night.

Oen off the wrist#

Sun, 10 Dec 2006 02:12:36 +0000

content moved to [[One off the wrist]]

One off the wrist#

Sun, 10 Dec 2006 02:15:23 +0000

:http://ww.telent.net/tmp/armin.jpg

"There ain't no armin it", or, what happens when you attempt to use a wrist-mounted GPS receiver as a wristguard. This sorry specimen has been lying on my desk since I tried that particular stunt back at the [[One Eleven => Fallen in St Gallen]] and hasn't worked since - at least, the screen is bust and although I haven't actually tried plugging it into a computer I don't have many uses for a gps device that's tethered to a desktop computer anyway. Some day I will get around to throwing it away.

Are you thinking what I'm thinking, Pinky? Yes, that's rignt: no hard workout this week. I'm such a slacker. Mind you, I was ill. Weights on Monday, I think.

Next week also marks the last official LFNS and Stroll of 2006

Ob Ex Pletive#

Mon, 11 Dec 2006 17:35:58 +0000

:; perl ~/bin/obexftpl.pl 00:18:13:65:7C:BD
00:18:13:65:7C:BD / > cd Memory Stick/DCIM/100MSDCF/
00:18:13:65:7C:BD /Memory Stick/DCIM/100MSDCF/ > get  DSC00068.JPG
/Memory Stick/DCIM/100MSDCF/DSC00068.JPG at /home/dan/bin/obexftpl.pl line 130.
Received 736 bytes
00:18:13:65:7C:BD /Memory Stick/DCIM/100MSDCF/ > shell ls *.JPG
DSC00068.JPG
00:18:13:65:7C:BD /Memory Stick/DCIM/100MSDCF/ > shell cat *.JPG
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE folder-listing SYSTEM "obex-folder-listing.dtd">
<!--
 XML Coder, Apr 10 2006, 21:03:28, (C) 2001 Sony Ericsson Mobile Communications 
AB 
-->
<folder-listing version="1.0">
<file name="DSC00058.JPG" size="367257"/>
<file name="DSC00059.JPG" size="338048"/>
<file name="DSC00060.JPG" size="320993"/>
<file name="DSC00061.JPG" size="328044"/>
<file name="DSC00062.JPG" size="331203"/>
<file name="DSC00063.JPG" size="376329"/>
<file name="DSC00064.JPG" size="319007"/>
<file name="DSC00065.JPG" size="321540"/>
<file name="DSC00066.JPG" size="310743"/>
<file name="DSC00067.JPG" size="301789"/>
<file name="DSC00068.JPG" size="341402"/>
</folder-listing>

I asked it for a jpeg, it gave me a directory listing - wtf? This is on my work machine which probably has subtly different versions of everything to my home machine. So now I am apt-get dist-upgrading, which even if it doesn't fix the problem ought to fill in the next hour or two until I can go home ...

Swing for it#

Wed, 13 Dec 2006 18:57:28 +0000

I spent an hour or so after work googling for gait analysis papers and watching skating videos in freeze-frame, while preparing a first cut of my long-threatened article on armswing - which was going to say something like "still don't understand, here are some hypotheses about what might be happening". Then I skated home, and - somehow I must have internalised something, because I had a natural two-arm swing for the whole 5k and was barely even thinking about it. From the little I could tell by looking at my shadow it was quite respectable too.

[[Once upon a time => It don't mean a thing/if it aint got that (arm)swing]], I wrote

Note to the "unlock the power of gravity" people: there's no net gain on the action-reaction principle from throwing your arm away from your body behind you. Unless you sever it while doing so, sooner or later it will reach the end of its travel and have to be brought back. So, we're probably looking for some mechanism that makes it sufficiently worthwhile to get that extra oomph at a certain part of the push that losing it again at some other part of the cycle is a price worth paying.

which I now believe, surprisingly enough, is exactly what happens - though it's the lateral component that's important. Swing your arms left (left arm back and outward, right arm forward and inwards) to impart a rightwards force to the torso at the same time as pushing with the right foot. This will counteract the leftward movement of the torso due to pushing, so that you get a longer time to push before your leg straightens. So it doesn't matter that there's no direct energy gain from swinging your arms one way and then back again, what matters is that when you're swinging them one way it gives you longer to put force down with the leg.

Secondary issues:

Now that I think I've worked it out (ICBW, quite easily) it all seems bloody obvious, of course. It probably is.

Thank you for the daze#

Fri, 15 Dec 2006 02:11:02 +0000

I think the loss of sleep last week (due to being kept awake by my teeth) probably caught up with me.

Happier news: I finally replaced the wheels on my skates: they were V profiled, worn by probably about 8-10mm, and starting to crack. The new ones are not actually new, but they've only been used for races - at least they're still elliptical. Not that I expect that to last long if I skate them in traffic.

The London Friday Night Skate#

Fri, 15 Dec 2006 17:46:50 +0000

I note that I keep saying "LFNS" and haven't yet expanded the acronym. Tonight is the last skate of the year (we kick off again on 6th January), which prompts me to say a few words about it. From the forthcoming web site

The London Friday Night Skate is a ten to fifteen mile street skate around London, every Friday (hence the name). We do a different route every week - one week we might take in famous central London roads and sights, another week we'll head for some long fast downhills in Camden or Putney, or even a trip to the countryside out at Barnes. The roads are blocked as the skate passes by our expertly co-ordinated volunteer marshals (on skates), and we even have our own portable sound system on a bicycle

The LFNS is not a protest! We're nothing to do with any political organisation, we're not environmental protesters, and we're not Critical Mass. We're faster than Critical Mass.

Well, the bit about the sound system is not strictly accurate right now: for the moment we have a loan of a sound system on a bicycle from the LondonSkate, which is the other major marshalled street skate in London (they do Wednesdays, we do Fridays & Sundays). And we only go to Barnes in summer when there's enough daylight to get there and back: those country roads are dark.

It was through doing the Friday Night Skate (or more accurately, through going to the pub with everyone after doing the Friday Night Skate) that I first started meeting people in the skating community. After a while I started marshalling, then I started planning and leading routes, then I was elected to the Marshal's Committee, then ... - it really has been a slippery slope.

Ich bin keine jelly doughnut#

Wed, 20 Dec 2006 00:48:56 +0000

Back from Berlin half-marathon. Yes, I did get my feet cast for new boots, and yes I was able to enter the race. Which was nice. In the interests of ecological soundness (and the secondary purpose of being able to find it more easily later) I have recycled the rest of this entry from what I posted to the LSST forum. More post-race analysis to follow some time when I've caught up a bit.

So, this was my first race where I was able to use pacelines as anything more than temporary windbreaks to skate downwind of. My 41.50 halfway time in Berlin full marathon last September got me into block B (in which there was a wide range of talent as it contained everyone less than 50 minutes who wasn't in a pro team) and i soon found myself in the second half of the front pack there, where the pace was comfortable or perhaps even a bit slow. It took me about 7k to be sure it was the front pack - seeing Hans further up it was the final piece of the puzzle - and then I started to think about heading up the line to play. Before I got that far, though, Hans dropped back past me with a cramp and I became the only LSST skinsuit in the vicinity.

Over the next few k I percolated gradually up the pack anyway, and even took a couple of pulls - the second being more sucessful than the first, in which I neglected to check whether anyone was following me and found myself skating alone ahead of the pack for a while. Still. it wasn't as if I didn't offer ...

By about 15k or so there seemed to be two groups forming within the pack: the pace at the front had crept up to 33-34k, which made me a bit happier, and I'd pretty much decided to dig in and see what happened nearer the finish.

And then I clipped a skate and went down. Traditional Superman dive on palms, taking skin off knee and elbow. I got up again as soon as the pack had passed and started pushing to catch up, getting slightly closer on each straight and quite a lot on each turn (as with the September marathon, there were a lot of people coasting around corners) until, when I was less than fifty feet from the back of the pack, we turned left and I noticed a lot of people sprinting, a lot of spectators cheering, and the clock at the finish. Drat.

I crossed the line at an indicated 40:30, but afterwards I found that my actual time was 0:39:17 or maybe 0:39:10 (I think the first is from when my block was started and the second from when my chip actually crossed the start mat) so a bit happier to be under forty minutes after all. Still could have done better if I'd stayed upright, though.

Merry Christmas#

Wed, 27 Dec 2006 22:29:55 +0000

V. little skating lately, due to (a) a cold, (b) Christmas. Now back from (b), and (a) is gradually clearing up though not nearly as fast as I'd like it to: I've had this sore throat for a week now.

Probable 2007 happenings: another blog software rewrite, and this time likely to be in Lisp: it doesn't look like Ruby is much more resource-light than SBCL, and I do actually rather like interactive development.

Borne slippy#

Thu, 28 Dec 2006 11:48:13 +0000

:http://ww.telent.net/tmp/dirty-wheel.jpg

Bethnal Green Road has the strange property of being the last road in London to dry out after rain, so when I look out of the window in the morning to decide whether to skate into work, I don't pay much attention to its surface unless it's under sheets of water: I'll be back on dry land a mile down the road anyway.

Today was different, though: ultraslippery all the way round. Very little traffic, though: I think the City workers must be all on holiday still, because there was practically no congestion anywhere along the route.

Later this week I will recap on the current weights status, but for the moment please just note that my quads are sore.

"First, they came for the cyclists ..."#

Thu, 28 Dec 2006 12:30:02 +0000

Not that I cycle much (any more), but if cyclists are forced off the roads it's not going to make life easier for us even crazier skaters ...

Dear Mr George Galloway MP

I write with regard to the DSA's consultation on their proposed new draft of the Highway Code, and its likely impact on cyclists.

The new draft carries the advice to cyclists that they "should" use cycle facilities where provided. Although on the face of it this seems reasonable, in practice there are many occasions when (whether due to traffic conditions or to roads to which cycles facilities have been added without appropriate consideration of the actual needs of cyclists) it would be impractical, inappropriate or in some cases actively dangerous to use a provided facility. For example, it would be an extremely foolhardy (some would say suicidal) cyclist who would cycle up the inside of a "bendy bus" at a junction, yet many cycle lanes encourage exactly that behaviour.

I acknowledge that many cyclists will of course be aware of these dangers and will filter the Highway Code's advice through the benefit of their own experience. My concerns, however, are two-fold. First, that not all cyclists are that experienced, and these are exactly the people who may be led astray by well-meaning but bad advice from sources that they ought reasonably to be able to hold to a higher standard of reliablity. Second, the issue of contributory negligence: although the Code does not have the force of law, it is often held as the arbiter of responsible behaviour on our roads, and will be looked to as an authority in disputes between road users - thus the spectre of a cyclist being held to have contributed to his own plight when hit by a motor vehicle, because he "should have been on the cycle path". One remembers the recent case of the 9 year old boy who was permanently brain-damaged by a negligent driver. The driver's insurers subsequently claimed that the boy's parents bore liability for their son's severe injuries, as they had not made him wear a helmet. In a collision with a motor vehicle it is unlikely that a polystyrene helmet would help materially anyway!

I would like to echo the CTC's call for the following changes to the draft, which I reproduce below

  • Remove all words which could give rise to unwarranted "contributory negligence" claims against cyclists;
  • Include clearer advice to drivers on interacting safely with cyclists and other road users (for example, on leaving sufficient space when overtaking a cyclist);
  • Ensure that its advice to cyclists (particularly that on negotiating roundabouts) is in line with the Government-backed National Standard for cycle training and;
  • A recommendation that anyone wishing to improve their confidence and safety should undertake cycle training to the National Standard

The current direction of the consultation draft seems to be to foster an "us and them" attitude and squeeze cyclists off the road. As we both know, the numbers of cyclists in London have increased dramatically in recent years, with concomitant benefits in lower pollution and congestion and better health - and these cyclists are largely amicably sharing the road system with all the other road users in our city. The proposed Highway Code changes would almost certainly be deletorious to this welcome trend.

I look forward to your response

Whether it'll make any difference is another question. He's possibly not the best advert ever for men wearing Lycra ...

⟪Nov 2006 Jan 2007⟫