From what I’ve read, one doesn’t reap much benefit from aero stuff until your speed is up around 23-25mph. I’m doing IMC this year, and my goal is to average slightly over 20 mph for the course (5:30ish split). Knowing that it’s a hilly course, would I really benefit much from a set of slightly lighter, way more aero wheels? I’m currently riding Velomax Circuits (clinchers, 1650 grams, 28mm rim depth) and I’m looking at the HED Carbonlites (tubulars, 1400 grams, 50mm rim depth).
If not, what setup would you recommend given my goal average speed and the IMC course? I’m 6’ and 155ish lbs on a QR Caliente.
one doesn’t reap much benefit from aero stuff until your speed is up around 23-25mph.
Not true. You’ll definitely see some benefit, although I can’t give you exact numbers (you can try analyticcylcing.com and biketechreview.com) Whether it’s worth the $$$ is up to you.
I went from ritchey 32 spoke wheels to bontrager 16 spoke xlite aero wheels last year. I think the bontragers are moderately aero compared to H3’s and Zipps. The bontragers definately made a difference on flats and downhills, sometimes up to 1 or 2 mph. They are not much lighter than the ritchey’s so i didnt notice much when climbing. It was a worthwhile investment.
i had the same wheel question about a month ago…one guy e-mailed me and made my decision real easy:
race wheels will give me approximately 1 mph gain in speed over my “non-aero” ksyriums. this translates to approximately 20-30 minutes less time that i have to spend on my bike at an ironman distance race.
if money is not an object, i’d go with the race wheels. why sit on your bike for 5.5 hours, when you can be done in 5 hours?
Is the primary benefit from the aero wheel or reduced weight? When I add up the numbers comparing my current set-up and a HED Carbonlite setup, there’s only about 100grams difference (assuming that I need to carry two extra sewups with the Carbonlites compared to two extra tubes with my current clinchers - that’s about a 300gram difference right there). I figured that weight would be a big issue as the IMC course is known for being hilly.
In the book (GOING LONG) it states one can benifit as much as 1 to 1.5 mph faster with race wheels. I tested the theory and low and behold it was correct. I found at the same heart rate I was a little over 1 mph faster on my Zipp 404’s over my Kysrium’s.
So if your looking at a 5:30 bike split, that would be alot of saved time…
Great article. Thanks a million. Reading this, I should lean toward a disc (assuming it’s not windy) and an H3 front as opposed to, say, a lighter, less aero setup. Do people ride discs at IMC (anybody know)?
Discs are allowed, so there will be people using them. Looking at the course profile you can see there are 2 significant climbs with corresponding descents. Weight-wise, drink most of your fluids at the bottom of the climbs and refill at the next aid station, and don’t worry about a the weight of a disc.
Plenty of disc wheels at IMC–I don’t profess to know what is optimal, but would love to ride a disc down the long decent from yellow lake. It’s all about aero at that point. Occasionally serious cross winds once you are in sight of Skaha lake, but I think it’s your front wheel you have to worry about not the back.
Wheels especially of the aero variety are one of the only areas where you can BUY speed. Remember rotating weight is very critical, and aero wheels make a difference at even the lowest speeds, they are much more efficent at higher speeds, but the combonation of aero spokes, aero rims and lower spoke count benifits at all speeds, albiet not much at lower speeds. In this case, something is more than you had before.
There are actual and psychological advantages to having a pair of race only wheels.
Here’s what I would advise:
Train on a set of heavy non-aero clincher rims with heavy bomb proof tires. On race day slip on the aero, lightweight tubulars and You will be amazed at how fast your bike will go. My purly anectdotal observations are that when I did this I was able to ride in a 1 -3 cog teeth bigger under the same conditions/effort. That would clearly indicate that I was going faster.
Hed still has their slightly out of true H3’s listed, don’t know if they have any tubulars left. The Renn disc is $400. That’s $710-760, depending which H3. Some sites have good prices on Alps. (for the front)
Is the H3 really better than the Alps or Stinger 5.0? They’re all the same at yaw angles of 0 and 5, (see http://www.biketechreview.com/tunnel/uncertainty.htm) the Alps and Stinger are better at 10deg while the H3 is better at 15deg.
You could do a brand new Renn disc and Stinger 5.0 front for ~$820.
So I guess my question is, how much of a difference in performance does the .031-.035" runout make? Are we talking noticable wobble, or simply “not quite true”? I don’t think I’ve ever had a bike that I’ve managed to keep the standard wheels completely true on, so will I notice a difference, or is it one of those things where I won’t notice it unless I’m going 45 mph on a big downhill?
i rode a ksyrium front and a renn rear last year. this year i will be riding a tillium front and a renn rear (assuming i can qualify again). also looking for a 5:30 bike split.
all the top pros had discs. lots of the top ag’ers had discs. It’s not THAT hilly that having a disc for the flats wouldn’t make a difference…there was a nice headwind coming back last year that i think the disc made a difference for.
Unlike other so-called “aero gear” that I have found to be of dubious advantage, race wheels are a very good idea for several reasons:
They should be lightly used, therefore true and the tires and cassette should be in good shape (just make sure you clean your chain well before the race). Economically it makes more sense to use tubulars for races wheels and they offer me some distinct advantages on race day, namely lighter weight and increased resistance to pinch flats. Because they are moving so fast relative to your speed, they do offer an advantage (the deeper the rim, the greater the advantage) to people with slower average speeds.
I have tried to “buy speed” with Vision aerobars and a Cervelo P2 frame, and found they made no discernable difference. My disc and front zipp though, did seem to make me faster. I don’t know if I would go so far as to say 1 full m.p.h. though. I think people should be going faster on race day because it is a “race” and therefore the effort is there that you just can’t duplicate in training, not because they have faster wheels.