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Back 10.11.2017

Sebastian Kienle Talks AeroBalance, 858 NSW

As a top pro triathlete and former physics student, German Sebastian Kienle loves the science of speed. That makes him a great match for working with Zipp as a sponsored pro. We invited Kienle to speak this week at the Zipp 858 NSW global launch in Hawaii. His comments underscore the high level of detail top pro triathletes and cyclists pay to not only reducing aero drag, but also to increasing crosswind stability. 

Kienle, the 2014 Kona champ, plans on riding the 858 NSW Carbon Clincher in Saturday’s Ironman World Championship. Below is an edited transcript of his comments on the concept of AeroBalance™ (optimizing aero efficiency and crosswind stability) for faster bike splits.

All photos © BrakeThrough Media

By Sebastian Kienle

The really crucial thing for me, for all the athletes, is staying in the aero position. The most drag is not created by the wheelset or by any other piece of equipment. It’s actually caused by ourselves, by the body. You have this super-optimized position. You spend a lot of time track testing, wind-tunnel testing and so on, but then none of it really matters if you don’t stay in the aero position because of strong crosswinds.

 A lot of people, therefore, choose not as deep front wheel or overall not as deep of a wheelset. With all of the testing with my partners, when you test a wheelset on the track, sometimes a 40mm wheelset pretty much performs the same as an 80mm wheelset. As long as you have 0 yaw (totally still conditions), sometimes there is not that much difference…. Then you go to the wind tunnel and you start to have some yaw (wind angles), and there you have huge differences (in performance between shallow and deep-rim wheels).  

The deeper wheelset actually is getting faster the more crosswinds you have, but the more crosswinds you have the more difficult it is to handle. I think this is what I am really excited about with the new 858 NSW wheelset. No matter what the conditions will be Saturday, I definitely am not going to choose a smaller front rim…. There are some sections on the course where you’re actually coasting and you have to get in a crazy aero tuck. But that’s also a risk for a lot of athletes because bike handling is not that easy sometimes when you have strong crosswinds. (The 858 NSW) just gives me more confidence riding really on the edge and pushing the bike to the limit. 

Especially in Kona where you spend so much time in the aero position you get dehydrated. You are really exhausted…. So the bike handling gets more and more difficult. In a lot of situations, it would not be a problem to handle a bike in training if you have some gusts and crosswinds, but here toward the end of the bike sometimes you try to grab one hand on the aero bar and the other on the back (grabbing a bottle by the seat) and you get a gust and you’re already completely on the limit and that causes some really dangerous situations. 

It’s just good to have a little bit more confidence… from the wheelset. As far as I heard I was the first one who got a victory on the 454 NSW. 

 It’s also great that a lot of the features on the 454 NSW are also on the 858 NSW. The Showstopper Brake Technology is good especially for people who are not used to handling carbon fiber wheels when it’s wet…. And the Cognition Hub (on all Zipp NSW wheels), when you descend down from Hawi there are definitely some sections where you could do some coasting. It’s always amazing when you ride with a couple of other guys and I just make this little rolling test… After a couple meters you’re just slowly moving out of sight!

What Kienle’s Riding at Kona

Wheels: Zipp® 858 NSW Carbon Clinchers

Shifters: SRAM® RED® eTap® Blips™ on underside of extensions and second pair on base bar

Front derailleur: SRAM® RED® eTap®

Rear derailleur: SRAM® RED® eTap®

Cassette: SRAM RED XG-1190, 11-26

Chainrings: SRAM AERO, 55/42

Frame: Scott Plasma