Redshift Switch Aero System

Few things bother me more than putting aero bars on road bikes. It's rarely a good idea, and tends to create more problems than it solves. For all but the very long torso'd athletes, putting aero bars on your road bike will create too much reach, force you into an uncomfortable position on the front of your saddle, and generally not be very efficient. That is until I found the Switch Aero System from Redshift Sports...

The Switch Aero System allows you to comfortably and efficiently add aero bars to your road bike while still maintaining an excellent road position. This is not a review of the system itself, but instead a quick investigation into it's biomechanical merits and aerodynamic advantage.

Seat Post

The meat of the system is the seat post, which is hinged with a 4-bar linkage to allow a saddle to move 5cm forward from it's original road position. By moving forward, you're allowed to rest on the arm pads of an aero bar much, much better than if you were to try to do the same without the movement. The added beauty of the post, though, is that it not only moves you forward, but also up slightly. Why is this important? Well, when you move your pelvic structure forward you're actually shortening the length of your pedal stroke. Move forward enough and you've compromised your optimal knee angle significantly and, in so doing, you lose power. The slight upward movement of the saddle maintains your knee angle from the road position. Assuming that angle was optimal to begin with, you've now placed yourself in an aero position without compromising biomechanics. Nice. Click the below short video to see how it works...

We measured a few athletes using the Switch Aero System to determine if, indeed, the seat post worked as described. Each was measured utilizing our Retul system; the results were as follows:

Athlete #1 (female)  
Extended Knee Angle (bottom of pedal stroke) with saddle in regular road position 43°
Extended Knee Angle (bottom of pedal stroke) with saddle 5 cm via Switch Aero System 43°

Athlete #2 (male)  
Extended Knee Angle (bottom of pedal stroke) with saddle in regular road position 43°
Extended Knee Angle (bottom of pedal stroke) with saddle 5 cm via Switch Aero System 44°

So, this is not particularly shocking. The fine gentlemen at Redshift are accomplished engineers, and simply did the math and designed accordingly. Still, it's great to know they got it right, and that your optimal knee angle will be maintained when moving the saddle into the forward position. Cool.

The seat post is very solid. The movement is easy, and can be adjusted forward and aft while riding. It's not so easy that it will accidentally move itself, and I actuated both a new and early version of the post which had been used hundreds, if not thousands of times, and really couldn't determine the difference between the two. In other words, the linkage does not seem to wear and become overly easy to move. The quality is apparent.

Aero Bar

Since this isn't an actual product review, I'll refer you to DCRainmaker.com for a thorough review of the entire system; however, I would like to point out a few features which really stood out to me.

First, the bars are quick release. Within seconds you can have the bars (arm pads and extensions) on and/or off. It's simple and easy. This is great because often once you put aero bars on your road bike, taking them off can be a bit of a pain, so you end up leaving them on even when you don't want/need them. Problem is, they take away real estate at the top of your bars, which is quite a nice hand position to be missing. Oh, and the quality of the bars is evident here as well. Once clamped into position, the bars are solid and worthy of all your trust.

The adjustability of the bars is also quite impressive. There's plenty of fore/aft adjustment, and the ability to put spacers under the arm pads should you need more height. I doubt most people would want that...in fact, I would likely place a lower-stack set of clip-ons on my bike if I were using the Redshift system. I could do so because the forward movement of the seat post would allow me to go lower with plenty of comfort. That's off-topic, though. The point is, these bars offer a great deal of adjustment for most anyone.

Aerodynamics

It comes as no surprise that there's an aerodynamic benefit to being in aero bars vs a regular road position, but just how much of an advantage is it? As you might imagine, we tested to find out. Each athlete tested multiple times. Below are the averages from the tests...

Athlete 1

Position CdA Wattage Savings*
Hands on hoods of the road bars .3327
In aero bars with seat moved forward .2851  39.2 

Athlete 2

Position CdA Wattage Savings*
Hands on hoods of the road bars .3619
In aero bars with seat moved forward .2989  38.5

What do those numbers mean? Well, if you look at it another way- Athlete #1 would save themselves 2.7 minutes for every 25 miles ridden, and Athlete #2 (pictured right) would save 3.7 minutes for every 25 miles ridden. Not bad considering they get to ride faster in a more comfortable position!

The other question you might ask is, how close is this to a full aero position on a tri-specific bike? Well, we haven't tested that a lot, but the one test we did complete showed a 50 watt savings (50.1 to be exact) when going from the the base bar to the aero position. In other words, The Swtich Aero System works pretty darn well in getting you most of the way there.

Additional aero savings can be had by using a lower stack aero bar like I mentioned earlier. A Vision or 3T clip-on would put the arm pads and, therefore, you, a few centimeters lower. This would reduce your CdA even further resulting in more time saved.

There's more to consider than just time saved in aero. The beauty of the Redshift system is it allows you to keep your regular road position so, when the road angles up, you have your nice, comfortable, efficient road position at your disposal for climbing. Oh, and by the way, when that road begins to drop down from the summit of your climb, you have your stable road position so you can descend with confidence. Nice.

Applications

The obvious use for the Redshift Switch Aero System is triathlon. Very simply, it allows you to have a good deal of aero benefit with your road bike so, if a new tri bike isn't in the budget, you can be comfortable and aero for a lot less money. For climb-heavy tri's, an athlete might consider using a road bike instead of a tri-specific bike if they can ride a faster bike split with a bike which likely climbs, and descends, quicker overall.

There are other uses for Redshift. Recreational cyclists who enjoy riding centuries and longer endurance rides would do well to adopt the system. The added position is not only faster, but more comfortable, to ease the tension of the some of the more flat, monotonous, miles.

There's been one surprise use for Redshift - Mountain Biking. This was initially brought up by the Redshift crew. They mentioned a user had been testing it on his mountain bike with good results, and when I thought about it, it made sense. Consider this: when climbing an extremely steep hill, a rider tends to slide forward to the tip of the saddle in order to keep the front wheel on the ground. This movement is coupled with pulling back and down on the handlebars to help produce sufficient power to ascend some very steep terrain, and it works quite well. Still, it's not a very comfortable nor sustainable position. The other problem is that, by sliding so far forward on the saddle, you shortened the length of your pedal stroke quite a bit, and are in a far less efficient position to produce power. Moving the Redshift seat post forward as you approach a steep hill allows the forward movement you need while maintaining the correct knee angle for maximum power.

I was intrigued by the mountain bike angle, so I decided to test the Redshift seat post myself. In a very non-scientific manner, I did short hill repeats up both a moderately steep climb, and a severly steep climb (20+ degrees). Both inclines were enough to bring me forward on my seatpost - two things became immediately clear:

  1. Power was higher. Ranging from 20 - 50 watts for each run with the saddle forward!
  2. It was much easier to handle the steep, twitsting, rocky section of the 20+ degree climb because I was not forced to the tip of the saddle, but was seated normally.

Pretty interesting stuff. For both climbs, I had a short, flat area right before the start which allowed me to switch the saddle position on the fly with ease. I'm not sure how realistic it is to move the saddle on trails that are less smooth, but the results were tough to ignore.

Conclusion:

There's no doubt the Swtich Aero System is beneficial to anyone who wants to place aero bars on their road bike. Both biomechanically and aerodynamically, it makes perfect sense. For bike fitting, it takes the headache away from doing so, and it could very well be a better, faster solution for climb-heavy triathlons.

Setup is easy, quality is high, and there's no doubt a benefit to using the Switch Aero System. ERO highly recommends it's use.

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