For the powermeter - What I am wondering is if I can use my regular wheels with them, because then it's not too bad - i.e. approx. $1,000 for the wireless, but if I then have to get new wheels as well the cost goes up quite significantly. Any insight?

Depends on the power meter you get. You have a few options if you want to roll on your current wheels:

1) SRM - Super expensive, crank based, so not great for multiple bikes
2) Quarq and ANT+ bike computer - cheaper, but still crank based
3) Ergomo - cheaper still, but not very good, and still crank based
4) Polar - Chain based, cheapest "measurement" technique, rather accurate, but permanent to one bike (I'm running the CS600 on 2 bikes, but had to buy a second power sensor, head unit has capacity for 3 set-ups).
5) iBike - calculates power based on bike speed and wind speed. You have to calibrate based on air density, drag coefficient (for which you'll need a real power meter to calculate), rider weight, etc. It's not a true measurement of power, but can be really useful in determining how aero your set-up is.

To the OP: your best options for cheaply improving speed: Clip-on aero bars (~$50 for alloy) will net you 1-2 mph on the flats with a good position, aero helmet (~$100-150) will get you 0.5 mph or so, wheels ($500-$3000) will get you anywhere from 0.2-0.6 mph.

Or, you can not spend any money, train like mad, grab the drops and hammer like cyclists in breakaways, and get to 21-22 mph easy.

Not very scientific, but it may help for comparisons:

I also race TTs, and my previous event in June was finished at 36.0 km/hr average, fairly flat with some rolling hills and a couple of steeper pitches where one almost wants to stand up.

Last week I added in a set of used HED H3C tri-spokes (tubular) and an aero skid lid (Giro Advantage 2) and for this August race I was up to 38.1 km/hr. (~ 23.5 mph)

With no strength training nor any significant interval work between those two events, the engine was more or less as feeble as before. This > 1.0 mph improvement is mostly from those two changes. Worth it? To me, yes, but to many others, likely not. Coming from a biking background these were the next logical steps for me to take, equipment-wise, in my quest to avoid doing the real power training I know is overdue.

Ok, so it seems there are differing opinions on wheels, from what snail male is saying with his wheels over the course of 25 miles he's gaining somewhere between 3-4 min. pretty good savings to me, in fact nearly 5%! Was that with a aero helmet as well? or were both races with aero helmet?

I guess the point I was making in regards to the power meter is that it is a training tool, you don't just put it on your bike and see some better times.

xc800-how affective have you felt the power meter has been in your training? Have you seen a huge gain with using it in a year?

The helmet and wheels were both first used only at the most recent race.
Also, my results were on a 17.6 km course, not a 40km... not sure if/how that would extrapolate over a longer distance.

FWIW every rider finishing ahead of me had The Helmet and only one - an Elite young enough to be my son - didn't have deep wheels. Peer pressure? Perhaps, but at my age, when some of the top riders are above 42 kms/26 mph I reckon I need all the help I can manage!

xc 800 - So obviously you are going to see the greatest gains combining training with better equipment. I am not by any means trying to say you don't need to train, but even you are using wheels and such, do you have any thought to the improvement they gave you upon first racing with them?

Also you talk about 2009 being better for rolling conditions, but worse aero. As I am new to the sport still I know the tire you used this year contributes less to rolling resistance, but does the disc also?

Since we're talking about wheels, I keep seeing the term "true round" come up, specifically to the HED 3C wheels. SOmething about there being a number that the manufacturer puts on the wheel...any explanation for this?

Thanks.

Wow, so glad I caught this thread!

I am in the same situation, wondering where to spend the mad $$$ as far as my bike goes? Tried a P2C, then a P3C but now ride a Orbea Ora TLT (Less spendy bike)

Been wanting to build a HED 3 with a power tap SL as a training wheel/race day wheel, now I'm sold on it from XC800runners notes, I want to be another David Millar with the 475 wattage output (In my dreams)

I'm not cool enough (Or fast enough) to sport the areo dome though, I still get passed by promising soon to be pro riders on their magnificent $6-8K pimped out road bikes for that, its like I'm standing still when they blow my spandex off when passing.

Nope, going with a HED 3 and power tap SL though, about $2500 retail, I'll sport it with my 404 clydesclyde front for now, but would like a Disc/HED 3 on the front like Lance on race day, so sexy!!! Too bad that isn't a do all game ender and one needs a quiver of wheels for diff condtions/race requirements-why I went the Zipp 404 clydes for a first pair of race wheels.

On a brighter note I'm at 206lbs today, I my shed the Clyde title in another 3 weeks if I keep to the program and don't get weak or start dating a drunk/wine-o of a woman.

Maybe that should be my goal, get below the clyde title and reward myself with a HED 3/Power Tap SL as a reward?

Precisely, and that's what I'm trying to get at with regards to the wheel choice. Basically, if you can't put down the power to ride fast, you won't ride faster regardless of the equipment. And your estimates are pretty close with regards to speed/power. On my TT bike, I should have been riding around 26 mph at 290-300W with disc/aero front and no TT helmet. With the aero lid, the speed would be nearer 26.5 mph. But even on training wheels/tires and road helmet, I'm going about 25.5 on my TT bike at 300W. The 24.6 mph race split was done on a road bike with TT bars (albeit a Kestrel Talon, so somewhat aero frame, but road geometry) and accounts for the slower speeds when accelerating out of T1, slowing into T2, and getting stopped behind an interloping SUV at an intersection - Cruising speed was around 25.5 mph during the race. Speed with the training wheels/helmet on the Talon was closer to 25 mph @ 300W. So my position accounts for somewhere around 10W on the TT bike vs. road bike, Aero helmet gives me another 10W, and wheels a final 15W or so. All summed, this 35W savings is roughly 1.5 mph from my Talon with training set-up to my TT bike in full aero. That's broken down into 0.4 mph for frame/position change and reduction in drag, 0.4 mph for aero helmet and 0.6 mph for wheels.

If you want a pretty good break down of where time/power is saved, you can check out this: http://www.bikeradar.com/gear/article/how-aero-is-aero-19273

I've found that my data corresponds pretty well to that found in the article. Cost per W savings for me for aero helmet = $10 and aero wheels = $90. Or, to put it in better terms, I spent $25 per 0.1 mph increase on the aero helmet, and $230 per 0.1 mph on the wheels.

As for training with a power meter this year, I have improved 1.6 mph solely from better training and knowing where my limit is (vs. training with speed only) and the system cost me $500. So, if we're talking finances here: the power meter cost me $31.25 per 0.1 mph increase. Slightly more than a new helmet (at $100) but definitely more financially sound than a new set of wheels.