I need some advice. I currently ride zipp 404’s and I am doing Ironman Canada this year. How much time do you think could be gained, if any, by getting a disc? My current bike p.r.'s are 5:01 IMPC and 5:28 IMUSA…thanks.
anyone?
anyone?
Bueller?
This disc will be faster - you could check http://www.analyticcycling.com to see if you can estimate the time.
A LIGHT disc (such as a Zipp) would be faster. A heavy disc will be a challenge up Richter, Yellow Lake, and the rollers after Richter.
I’d choose 404s over a Renn. I’d choose 909s over 404s.
Cheers,
Jonathan C. Puskas
A LIGHT disc (such as a Zipp) would be faster. A heavy disc will be a challenge up Richter, Yellow Lake, and the rollers after Richter.
I’d choose 404s over a Renn. I’d choose 909s over 404s.
Cheers,
Jonathan C. Puskas
Sorry for the useless post above. Anyway, you can’t be serious about the importance of light weight of 404s vs. the aero factor of a Renn disc on the IMC course. The climbing isn’t that steep, and even if they were there are certainly more gains to be made from advantages of a disc on the descents, rollers, and flats on that course.
If you’ve got a disc, definitely run it at IMC. The climbing isn’t such a huge deal.
There is more than 4,000 cumulative vertical feet of climbing at IMC. Yes, there is also 4,000’ of descending…It’s your choice.
I’m just saying that at 145 lbs, I’d choose not to drag extra weight around the course.
I’d definitely choose Zipps over Renn. Not because I’m anti-Renn or pro-Zipp, but because I’m anti-extra weight and pro-lightweight (it works for me as a lighter rider).
Trust me, I know the value of a disc. I used one at IMCdA last year and WF last weekend.
When it’s all said and done, we’re talking about less than a minute’s difference with either choice. If you are really concerned about $$$, just enjoy the 404s and save the money from the Renn altogether. If you want to “pay for the minute,” buy the Zipp disc and enjoy BOTH lightweight and aero benefits.
However, IMC IS a hilly course (by IMNA standards) and weight is a reasonable variable to consider.
I’d love to see the numbers, but don’t have a subscription to Kraig’s site. Maybe the weight matters more proportionately at 145 lbs.
My advice for saving weight on the IMC course is to make sure you empty all non-essential water bottles before the climbs. Seriously, there are enough aid stations that you can do just fine with a full Jetstream at the bottom of Richter or Yellow Lake. I even recall there being an aid station in the middle of the Richter climb.
You don’t need a subscription to see the Redlands article at
http://www.bike.com/template.asp?date=6%2F5%2F2002&page=2&lsectionnumber=6&lsectionname=Tech+Smart&lsectiondirectory=techno.
Judging from the article it looks like a cut and dry case. Disk wins over even lighter deep dish rims.
I get a roughly 3.8% average grade for Richter Pass based on the course profile on the IMC site. That’s not steep enough to negate the advantages of a disk wheel.
The cost of buying an extra wheel for the few chances you have to race on it is another question altogether, but if you’re five minutes or seconds away from a Kona slot it could be money well spent.
The difference between the Zipp and Renn is about 200g.
I’ve been reading here and at bicyclesports.com for a failrly short time, but the question of “to disc or not to disc” has come up at least a dozen times. The disc will be faster, whether it’s the Renn or the Zipp.
John Cobb, from his forum at bicyclesports.com: “I continue to be amazed that racers don’t use rear disc. If you get a good lightweight one they really work and will give you more than 5+ minutes over any other rear wheel”
The disc will be faster. Read this analysis from Kraig Willet’s site. And while you’re there, read has wind tunnel test comparing a Zipp disc against a $59.95 CH Aero disc cover.
Sorry, almost forgot Kraig’s url
Don’t forget that this depends a lot on the weather and your bike handling skills. If it is windy and you have to hit the brakes descending, your advantage with a disc will be wiped out in no time.
The Renn disk (tubular) comes in at 5 1/2 oz over the Zipp disk. By the start of the Yellow lake climb, one has swum for an hour more or less and biked 60-70 miles (3+ hours for us mortals). I have to think that despite the best nutrition and fluid plan followed faithfully, most everyone will have lost a minimum of 2-3 pounds (I’m 5’4 and 142 lbs) and 5 lbs or more for those approaching or graduated to Clydesdale class. Now, put this insignificant weight difference in perspective by the technical analysis in the article on the Cervelo site (quite interesting to me at least) and one sees that weight differences really don’t amount to beans even up to 5 lbs, unless one is a very slow rider. Furthermore, time lost on hills is easily made up if the weight gain is traded for aerodynamic improvement. Why am I telling you all this??? It is on the Internet if you look, I am doing IMC this year and I am giving valuable help and assistance to the competition. Shut up already!! Oh yes, I also have a Renn 575 tubular disc on order that I intend to ride at IMC. I couldn’t justify the price of the Zipp, even after having gotten my wife’s approval. Doh! I just did it again, more info to the competition. Goodbye already.
Looks like a cool website, not sure how to use it.
I don’t know anything about the IMC course, but I do own Zipp404’s and a Renn 575 and I know the Lake placid course. For any race that is mountainous I deffinately use the Zipp rear wheel. If you are talking about a Zipp disc go for it. If it’s a Renn, save your money. The Renn is a great wheel but it has it’s place. Most people don’t realize how light the Zipps are and what a pleasure they are in the mountains. I’ve tried dragging the Renn through the mountains around Woodstock NY and there is no way I wanted to run after that ride. Use your Zipps, your legs will thank you on the run. Good luck and have a great race!