aerodynamics
2013-05-29
Now you can buy Anna's helmet
It's not cheap!
http://www.uvex-sports.de/en/cycling/cycling-products/?pNavi=11&pModel=uvex+race+4 - 599 euro! But, it's a very fast helmet. A Casco-beater? Maybe Shane can find out for us!
2012-04-12
Making you guys go faster
legally!
Quick notes from Adelaide's professional development week :
Team sprints - it may be faster to be spread out more, but really good at holding the line behind the lead rider - it may be that the slipstream is longer than a "perfect" team sprint needs, but is very narrow. We'll do some fun experiments to work this out, look for a motorbike chasing a rider, with a few bits of welding wire and streamers attached!
Peak torque really does matter.
We can learn a lot from how much speed is maintained (or how quickly it decays) after it hits peak. Ie: the power required to slowly decelerate is much less than that which is required to hold constant speed, timing where we hit peak speed in a flying 200 is even more important than we've been thinking it was. (later is better!) - averages are misleading at best when it comes to analyzing sprint performance with power meter software. Have a look at Anna's data from her old world record. Look at the power put out while speed (slowly) decays. Remember KE = 1/2 m.v^2. Which is to say, momentum matters.
Female sprinters are a long term project - making them strong is a priority for their success in the long term. I am not alone in thinking this. Those of you who are female reading this - if you're not already - GET STRONG and be prepared for it to take a long time to happen. Anna spent 10 years getting strong. It's paying off now in spades. She spent her junior days being kicked in the arse by her sister, but she kept on getting strong and look at her now. Junior stars don't always become senior stars, the quick route to success isn't necessarily the best for long term development, ESPECIALLY for girls, ESPECIALLY where the rules are such that strong kids get handicapped by small gears. (we all know my rant on that!)
Get strong, go fast. Simple!
2011-03-02
Scatto is good
Especially for junior females
Modelled by Emily, I present the 3T Scatto.
Compare to her using the Easton EC90's, which were 38cm c-c :
Much better!
Bear in mind that the camera used to take these shots is a GoPro with a very wide lens, so there is a bit of distortion that makes it look worse than it was with the EC90's
2011-02-20
Big fish, little pond. Little fish, big pond
Or, some days you're the hammer, other days, the nail.
Saturday, Blackburn club championships sprint day. It's blowing a healthy nor-westerly (fast if you know how to use it). 500m ITT first, I use 90". Held starts (we HAVE GATES FFS! USE THE DAMN THINGS!). I ride a 40.03 (hand timed) which I think is a PB. It's fast enough to win MMAS3 and would have gotten me a bronze in JM17(!). Good-o, one in the bag, big fish in a little pond, the other guys I'm racing against are enduros. The Wizard rides 38.something to win MMAS2. Dino wins the 750 at DISC at the Vic Masters on the same day (clashes with BBN's club champs). This will be the last bit of really good news for Dino, who is clearly the fastest MMAS4 in the state of Victoria (big fish, big pond). Emily has no competition, not a single JW17 has shown up to race with her. She rides a pretty good 500 in the circumstances. I'm pleased both for her (win, you can only beat the people that show up to race) and also proud of her. I believe strongly that elite riders should make the effort to race club races when possible, especially things like club championships. It shows the younger kids where they can go and they're part of something and it keeps the elites grounded. Likewise I'm proud of Emerson Harwood (NTID) who also raced.
Next up, flying 200's. It's still blowing a gale, I keep the 90" on. I ride a 13.20, another PB (by 0.1s). That'll do, I'm 0.4s faster than the second qualifier, Richard Stringer, in MMAS3. Emerson breaks Andrew Steel's long-standing track record, with no aero fruit. He rides 11.8 seconds. At Blackburn, that's very fast. Emily rides a much better time than she rode last week at round 4 of the SSS. James Dann rides another PB and qualifies third in JM17.
Race time, I get to watch as Alan Dorin and Ben Schofiled fight it out for the chance to race me (4v5). Alan wins that, has a rest and then I race him. I've raced Alan many times over the years, almost always in endurance races and he has almost always been able to beat me. Not today. Sprint is my game and he goes later than I expected him to, gets a small gap which I use as a lay off and I zip past him to take an easy win. Easier than I thought it would be, the standard mode of attack is for these guys to go early and keep jumping (how to beat a sprinter in one easy lesson). Maybe he wasn't 100% fit? I don't know. I'm though to the final. Richard Stringer races Rob Monteath for the other chance to race for first, Richard wins it. So I'm up against Richard in a best of three for the gold.
The first one, I have the lead (I think!), Richard takes it at a jump, gets a small gap but I catch and pass him. One down, that wasn't too bad. He can accelerate and handle the bike well, but doesn't have the top speed to pass me. Good to know ...
Round two and he's got the lead, and jams me right up hard into the fence at 2.5 to go. Jammed so hard I had to grab the fence to avoid falling over! As I grab the rail he jumps and is gone. I chase (it's now a 700m ITT!), wind him back a little, while watching him swerving around a few times (huh?! he's 40m in front and almost in the grass?!) but the gap is just too big and I can't reel him in, I concede and it's 1:1. I'm not pleased about it, but this is club racing and I don't think he meant to jam me so hard into the railing. I'm not going to protest, I do mention it to Doug but he didn't see it, no-one did, it was at the far end of the track and obscured by how we were positioned. I don't think even Richard realised what he'd done.
Round three, this time I resolve to take this one from the front. I have speed on Richard, I don't think he'd be able to pass me at full gas. I have the lead, every time he moves I ramp it up a little, pulling him down off the bank and keeping him under control. No low speed, sudden jumps this time and no way I'm letting him in front to push me around this time. With a bit over a lap to go I accelerate, not 100%, but around 80% or so, not looking back any more, but I will kick up the back straight and again around the final bend, that's the plan anyway. I know he's hard on my wheel but I'll break his timing by changing pace. Up the final straight and I kick again with 40m to go and just wobble a fraction out of the sprinters lane for a brief moment, it's entirely accidental, I think (I didn't see it) it made Richard move off his passing line, I cross first and record a win. There's some discussion about it, I did leave the lane, if the judges think it affected the results I will not be upset and I tell Richard if he wants to protest I will not be upset with him about it (I didn't see if it made any difference but I did do it). He decides not to protest and the result stands.
Ok, club champion for MMAS3 in the TT and the sprint. My first ever. I am pleased!
Sunday, different story. Vic Masters. I'm now the little fish. Here be real sprinters. One guy in our division is a masters world champion and has come down from Sydney to teach us all a lesson. In my opinion, DFL trumps DNS every day. I'm going to put that to the test. My flying 200 is a PB again on 96", at DISC, I ride 12.8something. Beats my previous best by a whole 0.1s! Heh! Anyway, I'm pleased with that, but Gavin (the guy from NSW) rides 11.1 Uhuh .. and He's qualified 1st, I've qualified last (8th) - 1v8. Good-o. This will be ... entertaining ... I have the lead, tactically I do it all as well as could be expected, I keep watching him the whole time, using the bank and speed changes to control position, do the hook-and-drop at turn three with one to go, but Gavin just hits the accelerator and goes whoosh past me. He did everything right, was patient. I'm out 'til the keirin in the afternoon. Still, one better than last year when I didn't get a ride except for the flying 200.
Dino's on fire, he's qualifed fastest and is up against a bloke who's flying 200 suggested his experience at this track was marginal. Dino's lined him up to pass on the finishing straight when he (the guy Dino's racing, loses control and turns right, straight up into Dino with 40m to go. WTF?! Dino comes down hard and breaks his collarbone. I'd like to remind everyone reading of a rule, an important rule. These things happen but that should not have. Dino's put his heart and soul into training for this event and this was just horribly cruel. He gets bundled off in an ambulance with lots of strong drugs.
Chris Ray wins his sprints and wins Gold. Dino gets a silver by virtue of a disqualification. Not what he wanted and it's awful. Emily collects his medal for him later.
Keirins, I've drawn number 1, I get the motorbike. I'm on 96". Safely on the bike, I lead it out, with one to go the boys behind me kick and I don't have the legs to go with it, first three (of the four in our heat) go through to the final, and they all cruise over the line. Outgunned? uhuh ... anyway, DFL trumps DNS.
Mick Thomas wins the MMAS4 (or 5? Mick?) scratch race AND the keirin!
After some running around with Emily (Dino's not driving anywhere today!) and a solid state team training session in the evening it's time to go home. Phew. A big big weekend ...
2011-02-02
Today it begins in earnest
Yesterday was the women's team sprint, today it's everything!
I'm up in Sydney at the Dunc Grey velodrome as part of the Victorian state team, a pretty minor part, as best I can tell I'm looking after the physical stuff for the guys we've been coaching for the last year. It's a bit muddy, but I'm dogsbody for Hilts and the guys (this is not a bad thing!). It's a great opportunity to see how it all works and gain a lot of very valuable experience. In particular I'm learning (or trying to!) how to fit in and get things done in this team environment without stepping on too many toes. I have much to learn and a few personalities that I need to understand better to get along with smoothly.
But we're here to race, and our athletes are the reason we're here. So on with the real story :
Yesterday we had Adele and Caitlin racing the team sprint. There was five teams in total and our girls had, on the other side of the track, Anna. Welcome to the big time. Adele is no stranger to the big stage but Caitlin was pretty new to this level of competition. For those of you that remember these two girls starting at Blackburn all those years ago, what a journey they've had so far. They're solid friends and they look after eachother. They rode well, not perfectly, but they gave their all and finished fourth, improving their time in the final they made it into by a fraction of a second. Given that they were the only all J19 team I think that's pretty good. I know personally that I'm happy when a rider commits and does their very best. Both girls did that and I'm proud of them.
Along the way yesterday, Jack Bobridge broke the unbreakable world record. Chris Boardman set the pursuit record way back in 1994 I think, with superman position on a space-age bike. Jack beat that record on a BT you can buy yourself using normal aerobars. Wow.... Shane Perkins also rode a blistering 10.05s flying 200.
Today we up the ante, the J19 men do the kilo. The girls do their flying 200 and the 500m time trial. It's going to be intense. Bring it on.
2010-10-03
Practice!
Back on the (old concrete) track
Sunday last (3rd Oct) was the practice day for the Summer Sprint Series. I'd spent a bit of time at the old Blackburn roundy-roundy-drome doing some weeding, burning weeds, chopping weeds, sweeping etc over the last fortnight but hadn't done a lap as any sort of speed since the last round last summer.
With a pesky shoulder injury keeping me seated and spinning, I did a couple of demo rides of the two most common flying 200's with a funky little "GoPro Hero HD" video camera attached to my trusty track bike. These little cameras are brilliant. Cheap enough to not worry too much about if they get damaged, waterproof, high-def (can do 1080p at 30 frames/second!) and with a stack of clever mounts. I slapped the camera under my stem, popped on an 86" gear and did some demo laps for the camera.
Here's the video from those two lines
After that, and a warmup sucking the wheel of the ubersprinter for a few laps, it was time to do some practice. I figured I wasn't good for much, so dropped my gear down to 82" and cranked up the cadence. I rode a 14.4s flying 200, which was about a second off my best at Blackburn, but it wasn't a full gas effort and was way off the sort of gear I'd normally ride (when I can get out of the saddle to get over a bigger gear anyway, bugger it!). I'd probably ride 92" or so if everything was working well, and bigger if I felt good and there wasn't much wind. As it is, I'll be happy if I can hold 86" next week without pain interfering with my ride. We all did a few flying 200's, most of us were way off the times we'd been riding last year. With no aero fruit, fancy wheels or helmets etc and a strong nor-easter blowing it wasn't all bad.
I did two practice races against Emily, and one against David Thomas, we were all getting the feel for the slacker banking at Blackburn after a winter's training indoors and on the 42 degree timber banks of DISC. It went well, everyone did improve through the session and I'm looking forward to next Sunday.
2010-09-26
This white man can't jump
That is, until my shoulder's sorted, I have to be careful
I've got a tricky shoulder injury I've had for about four months now. Had a few things done to it by doctors and physios, and on the whole I'm confident that it's on the mend. Can't say I recommend having a hydrodilation done for fun, but it did seem to work!
Anyway, one of the issues with it at the moment is that it's somewhat unpleasant to ride hard out of the saddle. Ie: jumping to accelerate is not a good thing to do. Given that there's something else I need to be concentrating on in my own riding more than I have, this is somewhat of a silver lining to the cloud. I've restricted myself to tiny gears and am concentrating on spinning like the clappers. As well as tweaking my position on the bike a bit (up higher, out further at the front) due to a bit of body shape changes (not as much guts in the way!) I can get into a better position which has helped my spin.
Yesterday evening at DISC Em and I teamed up and did leadout entries. She'd done some big gear K1 work on Saturday and was dog tired so we just worked together on leg speed in little gears. I got up to 159rpm doing one of them, at around 58km/h. That's not super-fast by any stretch of the imagination (the kids go faster!) but I'm pleased with it. I was putting out around 640 watts at that cadence, so also a good sign. We were only doing entries plus 50 metres, so there was no endurance in the picture, all just a dive off the bank on the flying 200 line and then hold speed for 50 metres, but I don't think I could have done that this time last year. On all but two of my efforts (we did 6 in total, 1 E+100, 3 E+50's and 2 E+150's) I hit over 150rpm, also an improvement from last year.
My best flying 200 time at DISC is a 12.916, which was done on 98.4" or so with a disk wheel and all the fancy aero fruit, that's 119rpm and 55.7km/h, if I can get that tiny gear going at 58km/h, I reckon once I'm recovered from this shoulder problem I should be able to go a bit quicker than that. My goal for this summer is 12.5s at DISC (57.6km/h) which would be 131rpm on a 92" gear. That's not outside the possible. We'll see ... Long term I want to be able to break 60km/h at DISC (12.0s flying 200). Again, we'll see ...
2010-05-27
Super-slippery
Enter the Kamm-tail
Everything on bicycles is at least 10 years behind motorcycles and cars. The Kamm Tail was originally developed in the 1930's in Germany.
Now it's showing up on bicycles!
Our distant cousins over in triathalon-land think aerodynamics matters, and they're right, but it REALLY matters at 60+km/h in sprints. Will this technology make it into sprint bikes?
2010-03-14
I don't have a motor!
It's official!
Vic masters sprint day on Saturday. No excuses, I have trained all year, gotten stronger, thought I'd gotten faster. Even lost a little bit of weight! To no avail ... Flying 200 was 12.95something, slower than last year (12.91) despite better aero gear. Didn't qualify for the finals. I didn't do the kilo (never again after last year, the kilo sucks!) and in the Keirin I didn't want to get involved in the stupidity happening at the front and gambled on doing a Bradbury when they all crashed.
They crashed in the first run of the race, Turbo got brought down most unfairly and I think no-one was watching it happen, the perpetrators didn't get suspended and from where I was, it was clear that they should have. Modern Keirin does not include pushing down onto a rider who is in the lane and causing them to crash. Maybe back in the 1970's, but not in 2010.
In the re-run, almost the same thing happened again, I sat off the back and watched, then when the pace went on I didn't have the legs to go with it.
So, no better than last year. I think that means, that after a year or so's dedicated sprint training, that I'm not ever going to be any good as a sprinter. I can live with that, I'm enjoying the sprint series, I'll never be any sort of elite, but that's ok, I love sprinting and will keep doing it and keep trying to chip away at my PB in the flying 200. I just won't ever be able to give guys like Lou Pascussi any competition, but that's ok with me. We're all playing with the hand we're dealt at birth and I figure if I can get the best out myself, that'll be enough for me.
Everyone else had a good day. Dino and Mick were the best of the Vics at the sprint and keirin respectively, I still don't know why Queenslanders and Tasmanians are allowed to enter, and win, the Vic state titles, I'm sure there's a reason for it but I don't know what it is. Chris Ray rode his best kilo in competition (after a F200 and a bunch of sprints) and got 3rd in the sprint and I think placed in the Keirin as well? Craig rode well given his very upset year with a lot of personal stuff to contend with too, and on the Sunday Cam and Mick rode scorchers too.
2009-10-11
Equipment, return to sender
Unfit for purpose!
I wrote in my last blog that, amongst other things, it's not about the equipment.
Except sometimes it is ...
It is when the equipment is a limitation.
If you don't trust your equipment, especially in a sprint situation which demands 100% commitment, you cannot perform at your best, and then it is about the gear. When your equipment is a significant limitation, change your equipment.
I have an FFWD 5 spoke front track wheel. It is being returned to the local distributor for a refund. I don't trust it. The first one I got about a month ago, Pete and I glued on a Tufo S3 lite tyre, I took it to DISC and jumped on after some quick photos for Ride magazine. It immediately launched into a resonating tank-slapper as I got onto the bank. I took it off, put on the old Bonty front and got back to training and coaching for the day. Later, Nathan Larkin and I pulled it apart and found that the bearing/axle fit was fractionally loose, and there's no way to adjust it. Ok, send it back to FRF (local distributor), they send me another one. This one's still got a little bit of play, but it's better than the last one. Glue it up, wind it up at Blackburn at round one of the aSSS for my flying 200, I'm 100% committed to this effort and am going absolutely as fast as I can in almost perfect conditions.
At full speed, it does the same thing the last one did, almost putting me over the fence. I was very lucky not to crash.
We had a look at it afterwards and the bearing/axle interface has play, enough to allow a resonance it seems. What a seriously brain-damaged design this is. A ~$3,000 retail wheel which has no way to alter bearing tightness. The Mavic iO has adjustable bearings, which means manufacturing tolerances (and wear!) can be adjusted out. Not so this design. It's a POS. Don't buy one unless and until they redesign the hub such that you can adjust the bearings.
Not that you probably need one anyway, I don't need it, I need something I can trust, which isn't this wheel. If you're thinking about it, think again.
2009-09-09
We don't dabble in aerodynamics, but ...
Just to show that aerodynamics is a very fickle and often counter-intuitive thing ...
Roadies don't care much about aerodynamics, most of the time they're drafting. MTB riders aren't going fast enough to care. Time trialists and sprinters care a lot. At aboc, we don't pretend to know much about aerodynamics, we prefer to claim that the only way to tell if something is aerodynamic is to test it and that many things that look fast aren't necessarily so.
So, here's something that took me by surprise. Pedaling makes very little difference to drag, at least within the confines of this test (~13m/s, ~45km/h). Here's a paper on it. Intuitively, it seems obvious that pedalling faster would add more drag to the bike.
Pedaling cadence showed little effect on the measured aerodynamic drag, with only a 1% variation between test conditions. Thus, any desired pedaling cadence can be used for wind-tunnel testing.
The drag measured for a rider when pedaling is not influenced in a significant way by the speed of pedaling, in the 40-100-rpm range. The drag measured while the rider is pedaling turned out to be a little smaller than the average of measurements taken with the rider's feet stationary at various positions around the pedaling circle. We do not know the reason for this difference, but it is quite small. We conclude that it is valid to take wind-tunnel drag measurements with the rider pedaling anywhere in the 40-100-rpm range.
So there you go. 40rpm, 100rpm ... no big difference in drag. Not what I would have thought! Aerodynamics ...