Friday, July 11, 2014

Review: Solestar Insoles

The ability to measure left/right pedaling is all the rage in power training right now. The mystical search for efficiency is looking for data to unlock its secrets and make us better cyclists. Here at Peaks Coaching Group we’ve been testing different forms of left/right pedaling measurements for years, and though I’m still a little conflicted about how to use the data for efficiency rating and improvement, I was able to use our research history to learn something I didn’t expect.

Flash back to Interbike 2013, where I met Oliver and his Solestar team. Oliver convinced me to let him make me a pair of custom insoles to help deal with a long-term issue of left/right imbalance that I had always attributed to a hip and pelvis issue I have. After a few measurements, my insoles were ready! I returned home and began my test.

First Impression

I immediately felt what they call “stabilization-delta” in the shoe. The insoles have a unique shape and support that make you think they’ll feel odd as you stuff them into your shoe, but as soon as you put the shoe on your foot, you feel the insoles’ support platform building up and supporting your foot. The insoles were immediately comfortable. I took a few spins around the driveway and from the very beginning felt better connected and more solid in the pedals.

Riding with Solestar

Perfect! I knew by the time I was a mile away from my house that this was going to work for me. I immediately felt more stable in the foot/shoe/cleat attachment. Once I warmed up I was ready to get rolling through the test, but I’d started to notice something. I’m a Speedplay pedal user, and I love the ability to customize my float; I’ve had the same setting for years. Suddenly, however, my left heel wanted to be more out and was pushing against the float limit. I figured that since this was a test, I should test everything, so I headed back to the house, made a quick adjustment to the Speedplay float, and back out I went. I know items like insoles are personal “feel” pieces (like saddles), so I won’t go deep into how they felt to me except to say that they were very comfortable and very stable. I loved the feeling of connection to the pedals. Since that ride I’ve used my custom insoles in my road shoes and the Kontrol version in my mountain bike shoes. Quite simply, I love them.

Data Discovered

So back to my first point. Since that first ride I have noticed another benefit. My initial test ride showed a power balance rating of 50/50. Power balance is SRAM/Quarq’s way of measuring left and right that focuses on power generated on the downstroke segment of each pedaling revolution. There are a lot of confusing claims and measurements regarding left-right pedaling, but I focus more on the change. My balance went from a consistent 47/53 average pre-Solestar to a 50/50 post, and it still averages that today. This aligns with my impression, as my left leg gives me issues and the feeling of better connection to the pedal; now the data supports that (and it always gives me confidence when the qualitative feeling matches the quantitative data). I have charted this in a simple Excel chart that I’ll update soon with a new tracking system that will be found in WKO4, but for now you’re stuck with a vague chart of summary points. This is an average of my daily data recorded approximately every two weeks. Sorry, it’s not perfect science, but it’s a good overview.


For me, the Solestar insoles really work. Great feelings and data clearly demonstrate that they have helped balance my pedaling, as noted by the clear change. I do believe this has helped my efficiency, but it’s really hard to connect to the data, so just take it as a feeling. All I can CONFIRM is that they did change my pedal power balance. I believe their stabilization-delta technology was key to my success, as I was forced to adjust my left heel from day one of using the insole. I now believe that my foot was looking for that support and was leading me to run that heal more in, thus not correcting the issues in my left leg and hip.

Congrats to the team at Solestar, and thanks for letting us in on this great product!


Author Tim Cusick


  1. Sad..
    If you want to earn money by selling useless stuff, just tell some fictional storys and forget about objective studies/data...[]=67

  2. Please re-read the review. I consistently pointed out that this is my feelings and was based on my opinion. For me, and others they work great. Also note I pointed out that insoles tend to be able personal feel like saddles. I can tell you the data is real and actual, so take it as it is.

    PS: Riding bikes and playing with new sh*t is supposed to be fun, you should try it

  3. Peaks Coaching Group has received a response from one of the authors of the study that he'd like us to share.

    "Hello all,

    I am one of the authors of the study "The impact of carbon insoles in cycling on performance in the Wingate Anaerobic Test" (Koch, Froehlich, Emrich & Urhausen, Journal of Science and Cycling, 2013(2), S. 2-5). Since it was quoted here I would like to comment on it and set things into the right perspective.

    The aim of the study was, to prove the effects of the insoles in terms of a higher power output. It is unfortunately true that we couldn't find this effect in our study, though. While the study has a solid research quality (backed by the review of Yeo & Bonanno, 2014, Journal of Foot and Ankle Research, 7:31 ), there are some limitations, which could lead to an underestimation of the real effects. A major point of critique focuses on the adaption time (which is also mentioned in our study). To keep the standardization between the subjects high, the authors of the study decided, that an adaption period is not considered (It is barely possible to control the training load of athletes during an adaption period (e.g. 2 weeks)). Therefore only immediate effects of the insole were measured.

    It takes a fair amount of adaption till the effects on body structure and thereby on the neuromuscular system will occur. Thus in normal settings, an athlete should ride Solestar insoles for 4 to 5 times, about 1 ½ hours each time to gain the full benefit.

    Please be also aware about the fact, that in this study the insole were tested during a 20sec Wingate test and thus the results can not be transferred one-to-one to a ride with steady state pace. Here, more research needs to be done.

    Nevertheless there is already great evidence by the athletes and professionals, who are using Solestar in training and racing. I am myself an active cyclist and a passionate user of the Solestar insole since many years. I can only testify the value and benefits of the insole and I am sure that further research will show the effects in a scientific setting.

    Cheers, Michael"

  4. Sorry about that - just testing ability to publish.
    I agree totally with michael - a 20-30 sec test is hardly going to test improved efficiency over longer periods such as ITTs etc. Quite a rude comeback from review Tim. I think just looking at left right balance does not prove symmetry though - how about angle of peak torque?

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