Gut Perception of Speed#

Tue, 04 Apr 2006 13:00:00 +0000

Today I was able to download the GPS track of the Berlin race and have a look at it.

The first and most obvious point is that the GPS will sometimes record badly off-track points which stuff up my max speed and make the route look more interesting than it really is: there are usually only about two or three of these per hour and they're easy enough to delete once in the computer. The picture you see here is after deleting the really badly wrong points, so although I say it's obvious, the reader may be excused for considering it less so. There are still a few that look a bit funny but I left them in because they're not so high above plausible speeds that they break the scaling on the axes.

The second is that it seems to think I fell much later than i thought I fell: the downward spike to zero is at around the 19k mark, where I thought it was more like 15k. Which leads me to suspect that even if I hadn't fallen the end of the race might still have come as a total surprise ...

And then the other noteworthy item is just how much difference there was between the actual trend in speed and my perception of it (based on looking at the GPS on my wrist from time to time); I thought we were picking up the pace a bit in the second half, but it doesn't look that much as though we were. Also my solo pace in the last 2k is basically the same as the pace the rest of the way through: if that really is the fastest I can go, then in the hypothetical situation where I hadn't fallen it might even have made not much difference whether I'd noticed the finish or not - there still wouldn't have been much I could do about it. :-(

I have to admit that my knee would be a lot more comfortable in said hypothetical, though. Road rash makes moving it sufficiently uncomfortable that I really don't want to do it for fun, so I think I may be skipping Tatem tonight.

The Hill of (the) Hill's People#

Sun, 09 Apr 2006 13:00:00 +0000

I'm not an etymologist, but I find this stuff entertaining to play with. -ing is an Old English placename suffix peaning "people of", and "-don" is likewise Old English meaning "hill". So the cycle circuit where we're holding the time trials for the Le Mans fast team is in a place that might plausibly be the hill of the people of the hill.

(But, in fact, probably isn't. It was known as Hillendone when the Domesday Book was compiled, so had no -ing suffix anyway)

Anyway, a bunch of us went there on Sunday to have a look around, skate the course and do some relay changeover practice. This was also my opportunity to find out if my leg is actually skate-safe - which, happily, it is. The circuit is a mile long, less hilly than Eastway (though still hard work up the back straight when there's a headwind and nobody to draft) and the start/finish line is on the downhill straight, so I imagine that one could work up a fairly brisk pace down that if doing more than one lap at a time (we weren't - we were changing over on that straight, so losing time). Will need to work on: right crossovers. Six laps (two warmup, two with gaps for changeover, then two back to back when my partner missed the changeover for his third lap).

Conceded that it was the first time I'd skated since Berlin (in fact, the first time I'd skated in a fortnight except for 40 minutes in Berlin ...) but I was struck by just how much difference a draft - and a flat course - makes. I was pushing harder to get a 29km/h average around Hillingdon than I was in a 32-24k pack in Berlin.

After that, back into town to marshal the Sunday Stroll - or anyway, the first half of it before the heavens opened and gave us a very very wet skate back to Hyde Park. My bearings may never be quite the same.

[ 20k? Something like that ]

It don't mean a thing/if it aint got that (arm)swing#

Tue, 11 Apr 2006 13:00:00 +0000

Bill Begg was in town today, so various LSST people organised an impromptu demonstration/coaching session. I may write that up properly later, but in the meantime be it known that he has six basic principles, and the fifth is armswing. Armswing According To Begg:

• approximately forward/backward motion (I think I've said this before somewhere). Some degree of lateral motion is needed, but not so much that the upper body twists. Bill described it as "more than a quad skater, less than an ice skater"
• the arm fully extended when behind the body
• bending at the elbow as the arm crosses the body, so that the hand ends up somewhere in front of the chest at the end of its travel. Should not be so high as to sock oneself on the chin, nor so much lateral movement that it's crossed outside the body on the other side. Frankly this is easier to explain with a demonstration or picture than in words, so please go and find a picture. Or a demonstrator.
• the arms "drive" the legs (metaphorically speaking: this isn't supposed to imply some kind of mechanical linkage). A too-short armswing will tend to mean that the push was also too short. Hence the importance of having some lateral swing - you can't get the arm very high up behind you without it unless you have really weird shoulders.

(When visualising this it helps to remember that when practising it you will be in skating position (i.e. bent) not vertical. Until I remembered this I was having doubts about the range of motion in my shoulders.)

Armswing According To Dan is presently a much more low-key affair: I don't. There's some kind of wacko historical justification for this that honestly isn't that interesting, and prompted by Bill's explanation - that and the sight of a very-nearly-empty Serpentine Road - I decided it really was about time I got to grips with it if I ever want to be able to accelerate. So, practice ensued, and now I think that provided I'm pushing hard while I wave the arms around I've found a swing that (a) feels like it's adding to my speed (this is rare and novel, having happened to me only once before) and (b) doesn't get competely out of sync with my legs in under four strokes. Whether it's correct According To Bill we will have to wait for some future video analysis to find out.

Whether it helps is yet another question, though empirical evidence (there are people faster than me who do it) suggests it seems to in practice. How it helps is perhaps the more interesting question, then. 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.

Top of the Bill#

Wed, 12 Apr 2006 13:00:00 +0000

If you were wondering about the other five of those principles, here's the complete list -

1. Body position
2. Sideways push
3. Weight transfer
4. D shaped recovery, or "looping the foot behind". According to Bill, there should be a moment when only the setdown skate is visible from the front, because the recovering skate is directly behind it.
5. Armswing
6. Setdown: drive the leg forward with the hip flexors and set the foot down gently. The back wheels should (or just "might", I don't know) touch down before the front ones. This gives the usual skating muscles a little extra time to relax.

Mostly this is pretty standard stuff, at least from our perspective in London - perhaps because Mike's been talking to Bill for over a year now and passing the knowledge on. What's quite amazing, though, is just how much he can tell about a skater or a skate just from a brief look: we skated past around him as he watched, and based on looking at a skater in motion for only a second or so he was able to recognise and diagnose good/bad aspects of their setdown, armswing, glide - any of the above, in fact. His frame alignment assessment was similarly swift.

LFNS this week#

Thu, 13 Apr 2006 13:00:00 +0000

It's my turn to lead the skate this week. After last week's ascent (and descent) of Hampstead Hill we're sticking a bit closer to home this week. Partly just for the contrast, partly because I wasn't skating last week and so didn't have time to research very much new.

So I drew up a route by working backwards from the end: I wanted to do some of the roads around Victoria that we missed when we cut my last lead short (Victoria St has fairly recently been resurfaced along its entire length), and I wanted to do the long fast roads by the river (Embankment SW of Westminster Bridge, and Millbank), and Whitehall is a good way to get to Westminster. Then, hey, we can do Haymarket (short but steep) and Trafalgar Square to get to Whitehall. And that gives us most of the second half.

Still needed a first half, though. Starting from Wellington Arch, I appropriated bits of the really nice smooth route to Hammersmith that Etienne originally found in 2004, then looped back around on Craven St to come past Paddington, cross Edgware Road and through some of the Marylebone/Fitzrovia area, round two sides of Manchester Square (I like Manchester Square) then eventually down to Oxford St. That's 5 and a half miles or so, so then we just need to connect that up with the black route - preferably in some way that takes in Hanover Square (greenery is an important part of a balanced diet) - and hey presto, we have a route.

Went out after work last night to skate the bits that I didn't already know. Turns out that the lovely smooth bit of Marylebone Lane is at the other end (and a one-way in the other direction) from the part that we were skating, which is grotty and lumpy. So, strike that out and head down Marylebone St instead. Other than that, I was pleasantly surprised at just how skateable most of it was. Then off to the official route check where we did the full thing with the scout (who'll be directing marshals at junctions and side roads on the night) and six or seven other marshals who came along for a chat and some extra exercise - or so that they know where they're going on the night (allegedly this is the purpose of a route check, but most do it just because it's fun). [ 30k total? Give or take ]

And now I'm off to Tatem for a look around before the club race on Sunday

Wikipedalling#

Thu, 20 Apr 2006 13:00:00 +0000

I got sucked into wikipedia the other day. I hope it's not something I'll be making a regular habit of, but after doing some minor cleanups here and there over the past few months, I found myself significantly revising their article on Double Push. This is a bit silly given that I don't even do it myself (I used to do a sort of "double-steer" poor imitation of it in FSKs - as they naturally steer all over the damned place, it's pretty easy) but mostly got out of the habit when moving to speedskates. Anyway, comments welcome, preferably on the associated Discussion page. Now I have vague intentions to refactor significant numbers of their skating-related pages: see the trail of destruction I leave behind me as I work.

Week as I am#

Thu, 20 Apr 2006 13:00:00 +0000

I'm sure I've done that pun before. Recap on skating since last week, anyway.

• On Thursday I went to see Tatem Park. It's a 227m banked track with two straights and a bend at either end. The bends are exactly the wrong radius - not quite tight enough to crossover naturally, but tight enough that the inside leg never really gets much of a push if skating normally. Been working on Norwegian crossovers ever since - I can do them, kinda sorta, but I don't get any speed out of them yet. Atrociously slow, therefore.
• Friday's LFNS went like a dream - albeit a dream without any temporal distortion, weird non-sequiturs, or running madly around airports missing planes, so perhaps not very much like a dream at all. 'Twas good, though, and on the second half we managed to achieve speeds that although not actually fast as such were at least pacy enough to give the people at the front a bit of a run. (We can't do fast on an LFNS unless the marshals are all really fast, as they need to be able to overtake the pack to block roads before we arrive)
• I missed Sunday's race due to illness (probably something I ate). Let's pass over that without going into the details.
• On Monday we went to Hillingdon and did some relay/intervals stuff. Timed a lap at 3:09, which is an 11s improvement on the last visit (but wind speed and direction makes such a difference). It'd be nice to get below 3 minutes (20 mph average) but I don't think there'll be much of an opportunity before Sunday now. Then in the afternoon, back into town to do Rick's Easter Monday skate
• and yesterday (Wednesday) the first LondonSkate of the season - and the first marshalled group skate I've done this year where I've been in the group instead of one of the marshals. (They're a different outfit from us, although we get along quite well - they've lent us their sound system in the past and we often share marshals). Always interesting to see how other people tackle similar events to the ones that we do, especially if we can steal ideas ... I was going to do this one in my FSKs (would have been the first time back on them since January) but I forgot them when leaving for the office in the morning, so ended up in speed skates anyway.

its been bit of non week mostly#

Wed, 26 Apr 2006 13:00:00 +0000

It's been a bit of a non-week, mostly. Since last post:

• Friday was LFNS marshalling, and actually the first time in a while I've done "normal" marshalling on a Friday for a while (previous three weeks have been leading; skipped due to manky leg; and away in Berlin, respectively)
• I spent most of Saturday asleep in bed. Then on Sunday it rained, so no time trials (rescheduled for Bank Holiday monday). And Monday ws CBA day.
• But I am happy to report a good and productive Tatem session last night. Two 5ks at a pace slightly above what I'm used to (my back was complaining after the first, and it never has trouble at marathon speed) then some relays. Happy to notice that the fast folk were also skating normally around the turns at that speed. Sprints are different: I could see Gav crossing over when sprinting, but it was a fast crossover rather than a deep one - maybe the answer to "I can't get a good underpush" is simply "get back on the other leg asap". My arms hurt now, which is an indication that I'm at least using them for something - whether it's something beneficial to my speed is another matter.

To come this week: WNS if I can stir myself, LFNS, possible cycle ride on Saturday, and Le Mans trials on Monday (ok, that's next week really. But it's a Bank Holiday)