Sunday, March 27, 2011

Last race of the season - race footage.

Last race of the season - went out equipped with a camera on the bike that records in HD (1920 x 1080).

Such a great day out there - one of those rare windless and very beautiful days for racing. Had a blast ... 1st out of the water in my wave, 1st off the bike, then ran up the white flag on the run (as per usual) and finished 6th in A/G. 4th fastest A/G swim and bike - bike time was 30:28, which is probably spot on 40kmh av on the road and about 14 sec at each end mount and dismount to the timing mats.

The camera is a Contour HD which I ordered from the manufacturer in the states, but there are places in Aus you can order online at the same price. About $350. Awesome little camera records in full HD (1920 x 1080) at 30fps (which is almost too much info to process for most computers to play easily) onto a small SD memory card. At 3/4 HD size and 30 fps you can record 1 hr of footage on a 2 Gb card, will take up to 32 Gb card, which could possibly hold a full IM bike at full HD quality.

The 25 min odd recorded on Sunday was about a 1.1 gb file at 3/4 HD res. Started the camera on the bike once I had my feet in and wasn't going to be a danger to anyone. Left it running the whole race and switched off in the rack (would have auto shut off anyway).

Here's a few speed increasing tips and times from the vid you can use to hopefully ride faster as well:

0:25 - 0:50
Get aero as possible on the downhills (even slight ones) - doing so can produce a much higher speed, and by keeping up the power output you can get a good head of steam up that can carry you up the next hill, or further along the course.

1:25 - 1:44
Make sure if you do pass any packs you go over the top with sufficient speed they can't suddenly jump on (may not be that easy!). Remember to hurl appropriate abuse as you steam by.

2:12 - 3:44
Slipstream up behind people, just remember you have 15 seconds to make the pass stick and get out of their draft. Don't get too close or pass too close - a swerving cyclist is hard to miss at full tilt. Also ride in the wheel tracks where the cars have been - they are typically smoother, but may be more prone to potholes (keep an eye out!) Remember to pass only on the right, and move left as soon as you overtake and it is safe to do so. Failure to do so may incur a blocking penalty.

Take it easy on the turn arounds, particularly if it is wet. No prizes for wiping out. Don't blow a fuse building speed on the way out from the turn around - get up to full race pace again without overcooking yourself... it's usually faster than riding out too hard from the turns.

Wave to the draft busters, they are your friends.

5:08 - 5:20
Know the course, and ride the corners hard; get in the right gear beforehand and nail it in, through, and out.

Practice those dismounts and squeeze out your opposition over the timing mat! At least then if they get away on the run you can say you dismounted first.

Time to learn how to run properly over winter...

Oh and if you do end up buying your own Contour HD, you just have to put yt:stretch=16:9 into the Youtube video Tags field to tell it it should be a 16:9 widescreen movie.

Saturday, March 12, 2011

Cervelo's LSWT tests against the Big 4

As published on recently, Cervelo recently tested the big 4 TT rigs against the P4 in the San Diego LSWT wind tunnel, in a long series of pretty significant tests.

These tests are interesting because Cervelo is using their famous DZ (Dave Zabriskie) mannequin - although Dave is super good at sitting in the same position each time, wind tunnel testing is largely a repetitive chore, and I'm sure Dave has better things to do than freeze his goolies off sitting in the same position in a couple of hundred tunnel runs.

< Super Dave - the mannequin.

This means that the test results are actually representative of what we'd expect to see in real world use - ie. someone actually riding a bike round a course, rather than bike only drag figures which are often published from tunnel tests. The second reason this is so significant is because arguably the widely available current best 5 TT bike/frame combos are there being tested, and thirdly, independant observers from Slowtwitch were present during the tests (what level of exposure to tunnel testing they had is unknown however).

Cervelo has stayed quiet on the publication of this material, possibly choosing to release the info via an "independant" third party, rather than publish the test results themselves. Given how much hype surrounds tunnel tests by manufacturers this may be a smart way of releasing the results without incurring the suspicion of "manufacturer bias" prevalent when a manufacturer goes to a tunnel, particularly since their bike comes out either on top or close to the top (depending on the wind angles being tested).

So to results:

Firstly, the graph of Bikes, with Super Dave on, and trying to get the fastest possible ride - ignore-hydration-do-whatever-it-takes-to-win. This run sweeps from -20 yaw to +20 yaw, also important, because the drive train side affects the run numbers (if you look at drive side and non drive side in isolation you can get an idea, but not the full picture of what is going on.)

What does this show? Well by and large the P4 with a bottle on is certainly better than its competitors in the narrow range of -7.5 to +7.5 degrees of yaw. So if it is a low (or no wind) day, it could be hard to hang onto that guy on the P4 that just came steaming past. At 0 yaw the P4 is an average of 100 grams less drag than the average of the competitors - or around 5% better which is a significant reduction in drag. Between -15 to -7.5 and +7.5 to +15 the bikes chop and change in results, with the P4 being worse than all competitors in -10 to -15 yaw. Strangely, the P4 is again better than all competitors at less than -15 or greater +15 yaw. All competitors to the P4 test faster with a bottle OFF, making the P4 the only bike to go faster with the bottle on (whether you can actually get at that fluid while staying relatively aero is another matter - if you have a P4 you should be racing with the bottle in, regardless of what it contains).

The second part is to compare these results against the Trek Speed Concept white paper that came out last year. This is also available from Slowtwitch. In those tests, they did use a mannequin similar to super Dave, but only published limited data for tests with a mannequin. Most of their published data was without rider... which isn't a problem here as we have without rider data from the Cervelo tests too. Now this data was collected by 2 companies that have years of experience in tunnel testing, from the same tunnel (LSWT). The only apparent difference between these tests is the use of a H3 front/Hed disk rear in the Trek study, compared with Zipp 808 front/Zipp disk rear in the Cervelo study.

Cervelo results:

Trek results:

OK, so we have to confine ourselves to 0 to +20 deg yaw, but WTF? How is it possible that these results are so dramatically different between these tests? Admittedly, we only have 2 identical bikes in both tests: Trek Speed Concept and the P4 - but even these figures themselves are widely different for each set of results. If we take the data for P4 and Speed Concept from both tests and overlay it against each other we get:

The Trek data (solid line) is markedly different to the Cervelo data (dotted line), and given what I know about the 2 wheelsets (including independant tunnel tests and field tests), I'd be very surprised that either wheelset is the primary contributor to this margin of difference. Given the large (and consistent) gap between P4 and Speed Concept in the Trek data - I'd say "please explain, Mr. Trek".

Dan Empfield (Slowtwitch) does have the following conclusions:

Other bike companies might argue that the superior straight-on performance of the P4 is: 1) Somewhat due to the superior 0° yaw performance of the Ventus (the minimal drag of the pursuit position seems intuitively to be optimized for straight-ahead winds; and, 2) The most important yaw angles are those between 7.5° and 15°. As to the latter point, that's above my pay grade.

What is nevertheless undeniable, based on the results of this test, is that the P4 is the equal, or near equal, of every other bike in the test at these greater yaws, and better yet when as the bike points directly into the wind.

I'm betting the performance of the P4 in low yaw won't vary that much regardless of what bars go on that machine. As to the idea that yaw angles between 7.5 and 15 degrees are more important, that only works if you're a mere mortal spending the majority of your time racing in wind lower than about 10 kmh (6 mph). Once the wind strength goes above 10kmh (6 mph) you'll be seeing a wide range of yaw angles depending on the direction you're pointing, so you need a bike/wheelset that works well across a wide range of yaw. And if race day dawns calm and still, I hope you've got a P4 hanging on the wall of your garage!

Saturday, February 26, 2011

Going faster in shorter races - esp. if you are of larger build

A mate from my local forum hangout [steamroller] recently asked a couple of questions regarding going fast in shorter races, particular for the bigger blokes.

Q. I was wondering what the benefits would be for each piece of technology, specifically in relation to bigger bodies over a sprint distance triathlon.

I am a BOP [Back of Pack] participant and will probably always be down that end. In saying that I would still like to get faster over the sprint distance. Prior to everyone saying do more training and lose weight, I already understand that and have taken steps in that direction. I am specifically talking about improvements in transitions and also the use of technology i.e aero helmets, wetsuits etc.

I have read the stuff that fishboy did regarding the aero helmets,wheels etc but was wondering if the results he got would be significantly different based on greater weight and width regarding shoulders stomach etc.

I think steamroller was referring to: when he asked his question.

So how can we squeeze a few savings off a short race time without actually doing much for it, particularly if you're bigger than the average bear?

I'm big-ish, but not Clydie* big - 81kg (180lbs) and 186cm (6 ft 2in), 55cm shoulder width, 100cm chest circumference. However, big enough that first time in the wind tunnel I was worse than an average triathlete (CdA 0.265-0.275 seems to be pretty on the mark average for someone with aero lid and bars, I was 0.285 with aero lid and aero wheels, and not much changed in the course of that wind tunnel session 1).

[* Clydie = local dialect for "Clydesdale category" (after the horse), in which the triathlon participant must be over 100kg (221 lbs).]

Being bigger means you have more frontal area that you have to either hide or somehow disguise as a slippery-as-a-fish shape.

Sprint is all about high speed racing... therefore being aero, and powerful as well, is crucial to success on a Sprint bike leg (20km or 12.4 mi of pain). Forget comfort, find the smallest possible slippery shape you can squash your body into, train to adapt to that shape and deliver race power in that position. Learn how to unpretzel yourself off the bike and "still run good" (I haven't quite mastered that bit yet).

You can throw tech dollars at the solution, but getting the body aero is usually the single biggest thing you can do followed by an aero helmet.

The time savings below are based on a 36kmh (22.5mph) average sprint bike speed using the same power, if you do just that *one* thing listed below.

Unfortunately you can't add all the time savings together - it doesn't work like that.... as you go faster, you save less total time.

Aero lid (fishboy mandatory, and independent of body size): Steamroller had possibly the best aero helmet (Limar Chrono), but hadn't actually used it in a race!! Get it on the road son: wear it, you will PB next race.
A good aero helmet can make about 1.0kmh (0.6mph) speed difference: 54 sec (at 30kmh (18.7mph) the difference in speed is about 27 sec.)
A not so good aero helmet will increase your speed around 0.5kmh (0.3 mph): 27 sec saved over a road helmet - still a cool saving.
Below 26-28kmh (16.8 mph) the benefit of an aero lid is relatively negligible, and you may probably start feeling just wear your road lid if you feel like riding that slow.

Aero bars (or getting away from road position into TT position, this is dependant on body shape, flexibility etc) will generate a 1kmh (0.6 mph) speed increase: 54 sec saved

Aero wheels (independent of body size): 30-45 sec
Simkins aero brake (independant of body size): 8 sec saved
No front brake (illegal but what the hell) (independant of body size): 16 sec saved

So in essence you can get an array of bike time savings by just investing $$$ independant of body size.

You will however need some assistance to fine tune a larger body to go quick.
Though it sounds expensive, if you can get into a wind tunnel with someone who knows their schizzam from their elbow, or do field testing with power (also expensive if you have not a power meter) this is probably the best way of return on investment (see graph in the article mentioned above, you can spend loads of $$$$$$$ on bike bling and not be much faster than you already were).

Based on my starting and final aero setup I've saved 1:51 over 20km (12.4 mi) based on same input power, by tweaking body position and some specific aero hardware bits.

For me, a wetsuit saves about 6-8 sec/100m, and takes ~8 sec to remove. Given a bit slower running in the wetsuit the break even point for me is around 300m swim (0.18 mi). Longer, than that I'll definitely have a suit on. If you are big, and sink like the proverbial, it may save more you than this.

Time can be had left, right and centre if you practise, practise, practise. None of these seem to be body shape dependent. Here's a bunch of stuff that I've worked out is faster for me. It might, or might not be for you. ;)

1. Walk through all transitions before the race. Work out swim entry, bike exit, bike entry, run exit and shortest distance, and physically walk/jog round them all so you see what it looks like in the race (nothing like seeing it before hand). Look for shortest route and landmarks. Remember aisle row markers "I'm between 13 and 14". Getting lost is sure fire way to add seconds.

2. Set up your gear carefully, in the same setup as you practice your transitions with (not practicing transitions? - tsk - better get on that too). Mine is towel folded, running shoes at bottom of towel, helmet top side down at top of towel, straps out in the right orientation for pick up and straight to head. Sun glasses open inside helmet ready for straight to head. Shoes clipped on bike (R shoe on R pedal and L shoe on L pedal, not as I have done once the other way :blush: ), appropriate gear pre-selected for bike exit.

3. Practice getting out of that wetsuit: get out of water, get running for a bit (recover from shock of standing up, and move faster for a bit), then try to remove wetsuit top - after top is down remove cap and goggles and finish run to bike. Practice removing wetsuit quickly after every open water practice swim - experiment with oil/glide substance on calves and feet to get feet out easier. As you arrive at bike, bend down pushing wetsuit as low as possible on legs, grab glasses put on, grab helmet and put on; at the same time stomp feet alternatively to remove suit; once helmet clipped, use hands to remove any last bit of suit and get bike off rack and go. A good 20 sec to be had here with practice.

4. Shoes on bike, run barefoot. Easily 15 sec saved in transition, you may give up some on the road getting your feet in, but you are at speed (yes, accelerate up to at least 30-35kmh before trying to put feet in, to go fast enough to minimise time loss).

5. Practice mounting. Keep running till the road is clear enough for a fast running mount, sometimes this may be past the mount line - run through the slower traffic, get to the front, quick mount and away up to speed before trying to get feet in. Another 5 or so sec saved.

6. Practice dismounting. Feet out of shoes resting on shoe tops in last 300m, hands on brakes decelerating on approach to line, swing leg over before you get to dismount line and leap into run on the dismount line. If you race long, and have bottles on the back - take 'em off - you don't need that much fluid, and it is a lot more aero without them, and worse, rear bottles can be a serious dismounting hazard as you swing a leg off the back of the bike.
If coming in overcooked, use a bit of brake and support a bit of weight on the front wheel between strides to get down to an actual running speed that your (now detonated) legs can cope with. I find acknowledging marshal at dismount line by nodding that you understand that you will be dismounting (or attempting to not crash and burn) leads to less yelling on their part. Very satisfying when you come in hot and they're gobsmacked you can actually be off the bike and through dismount that fast. Another 8-10 sec saved.

7. Get running quick - try and stand up as tall as you can and keep cadence high as you (try) to get into decent run form. It's hard, and I suck at it. There are many other better qualified runners than me that might have a few more pointers there.

There is no magic bullet (or else I would have found it by now). Sorry.

Actually - make sure you put glide or vaseline on parts of your feet pre-race you are prone to blister in... I wouldn't use socks in Sprint or Olympic race, but would for a long course or half ironman.

So there you have it, a few time savings that you can (hopefully) squeeze out of your next short race, independent of the fact you block the sun from most people standing next to you. Enjoy!

Friday, February 4, 2011

New Pioneer power meter pic

Aaah those tricky Japanese... we've seen a few hints, schematics and press releases but here is some concrete evidence of a new Pioneer power meter.

Who knows how good it is, but more people riding with power can only be a good thing ;-) And I'm pretty sure that is an ANT+ logo on the device.

Thursday, February 3, 2011

New QR CD .01 - Reviewed

New Quintana Roo CD .01 reviewed, looks interesting.

QR CD .01 Review

Thursday, January 13, 2011

Interesting post on A2 wind tunnel with Chris Boardman and Rory Sutherland

Aaah. Boardman. Probably more aero testing than any other cyclist. Holder of the world hour record. Sir. Still involved with cycling, helping our Rory Sutherland in the A2 tunnel.