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On Cloudflyer Multiple Tester Review
By Chief Editor Matt Klein and Senior Contributor David Salas

On Running has been making some moves recently. They have sponsored some serious athletes (Zap Endurance), debuted a carbon fiber racer (review soon) and are in the process (as of this review) of debuting a completely sustainable shoe. Despite these moves, On Running continues to do them in their own way. Instead of full length solid cushioning systems, On uses Cloudtec, hollow cylindrical mechanisms that provide cushioning for both vertical and horizontal impact forces. They have very different upper designs and unique styles. The On Cloudflyer is our first On shoe review and as a unique stability shoe, we are excited to give our thoughts. 

Specifications for the On Running Cloudflyer (per Running Warehouse)
Weight: 10.0 oz (men's size 9), 8.5 oz (women's size 8)
Stack Height: 27mm / 20 mm
Drop: 7 mm
Classification: Mild Stability Trainer


Matt: The On Cloudflyer is On's light stability trainer. Featuring a very comfortable upper, a firmer, mildly stable and uniquely rockered ride. The On Cloudflyer is an excellent introduction to On running shoes with a unique biomechanical design that may provide a different level of protection than other shoes.

David: The On Cloudflyer is a light to moderate stability daily training shoe. The upper is constructed very well throughout with many small details. The geometry is constructed with a rocker design with a firmer midsole throughout. The stability mechanisms are done primarily with geometry and the unique design that On brings to the table. 


Matt: The On Cloudflyer fits true to size in my normal men's size 10. The length did feel slightly short at first try on, but the upper did stretch to accommodate my foot quickly. The fit is wider throughout the length of the shoe.  The heel fits on the wider side and I did have to lace lock the shoe. There is a low external heel counter that did not effect my heel bone at all. The midfoot also fits a bit wider and the slightly thinner laces can be dialed in for a better fit. However, the thinner design can create too much pressure if they are tightened too much. The tongue is the perfect thickness, but is secured by an inner liner on both sides. Despite the security, the tongue did slip laterally a few times until the shoe broke in. The forefoot is wide but secure. The upper mesh is an interesting combination of mildly stretchy but stable. The toebox is very naturally shaped, but not sloppy as long you have a normal to wide width forefoot. There is a mild toeguard that didn't give me any issue. The mesh is very breathable, particularly in the forefoot. For normal temperatures this is fine, but know for colder temperatures you may want thicker socks.

The Cloudflyer fits true to size for a men's size 10. I am a 9.5 and running a half size up so I did have to lace up my shoes tighter. Despite the slight bump in volume and length, the shoe still fits pretty well when locked down. The upper is relatively thick, but padded throughout and breathable throughout. There is a heel counter that is thickened and extended through the calcaneus up until the transition point to the midfoot. The midfoot has plenty of reinforcement and helps give the shoe a good hold and feels stable, even without posting. The lacing has a diagonal lacing pattern starting distally at the tongue for further lockdown and reinforcement. 


Matt: The ride of the Cloudflyer is on the firmer, smoother and rockered side. There is a visual rocker present and the shoe rides like it. This is not a bouncy ride, but a firmer, rolling ride. The design makes the shoe feel far more comfortable landing heel first than anywhere else. The heel, while just a hair soft, transitions into a firmer midfoot and firmer forefoot. The Helion in the heel makes for the more protective landing area. Landing anywhere else makes the firmer clouds up front and Speed Board more evident. The Speed Board does add to additional stiffness from the heel to the forefoot. There is a break in and learning period to both get the shoe to loosen up and figure out how to use it. The heel and midfoot have a bit more stiff landings, while the forefoot does actually have a nice, snappy and smooth toe off. I say stiff, but the shoe does transition you forward fairly quickly (which feels slightly awkward at first). The heel is certainly beveled and does roll you forward. The forefoot does have some toespring, but most of the smoothness comes from the high level of flexibility up front. There is a 7mm drop listed and this is about where this feels. 7-8mm drop shoes are in that sweet spot for me where I don't notice the drop and when combined with the rocker, is never something I noticed. Overall the ride is firmer and rockered.

David: The ride of the Cloudflyer is definitely firmer than some other daily trainers on the market, but still protective enough for daily mileage. The midsole itself has some firmness to it, and the speedboard also firms it up. The outsole has a design that leaves the midline exposed and almost keeps a guiderail by design, with the midline firmed up with the speedboard. The geometry is also has a pretty significant rocker to it which helps keep the transition points smooth. The 7mm drop ratio does feel true, but the rocker also makes it feel very fluid. I agree with Matt with the quick transitions of the shoe. It feels very strange at first with how firm the midsole is, but does grow on you after the first mile. The ride is still firm though, but if someone likes the rockered feel to a shoe and like a firmer platform with some stability this could be a shoe to look into. 


Matt: The On Cloudflyer is a very mild stability shoe. The medial clouds are a firmer density than the lateral clouds, there is a plate in the midsole and an external heel counter is present. Most of the mild stability is present in the heel and midfoot, with a broad platform but not measures I can feel in the forefoot. The stability is quite mild and it really is the combination mild density differences (that I almost didn't notice) in the clouds, the plate and the external heel counter rather than any individual factor. In fact I would call this a neutral shoe it is so mild. For those who just want a stable rockered neutral shoe this is a great choice. For those looking for moderate to high stability, this is a shoe you should transition into.

David: The Cloudflyer is a mild to moderate stability shoe. The geometry keeps the transition points smooth, and the outsole has a guiderail like feel to it. The speedboard also creates some rigidity throughout adding some inherent stability. The heel counter is thickened and extended anteriorly as well that helps stabilize some rearfoot movement as it transitions into the midfoot. There is no posting, and the shoe overall runs like a stable neutral shoe with some minor additional stability features like the counter. The upper is very secure and does well with turns and security as well. 


Matt: The On Cloudflyer is meant for easy runs and mileage. The slightly soft heel and firmer forefoot make mild uptempo work fine, but the Cloudflyer does not have the responsiveness required for anything faster. Getting up on your toes feels a bit awkward given most of the weight sits back in the heel. For those used to long runs in firm shoes, this is a good option that will remain consistent throughout the length of the run. However I found the forefoot too thin and the ride to firm for even longer efforts. So for moderate to shorter length runs this shoe is great.

David: I thought with the firmer platform and Speedboard I would be able to push the shoe a little more but had some difficulty with doing so. The shoe feels best at daily mileage efforts and easy days. The weight of the shoe and stiff heel transition do make the shoe feel a little awkward at faster paces, but it can handle a little uptempo if you ask it to. This is definitely for daily mileage however. 


Matt: The durability of the On Cloudflyer is decently high. The upper has remained in great shape, even though I have used this both as a running and walking/clinic shoe extensively. The outsole has done well, except for my normal wear at the posterior lateral heel. At 35 miles, I have not yet chewed into the midsole material but am close. Given the cushioning design, I am concerned about how long these shoes will last before I blow through the clouds at the heel. The cushioning will last as long as the outsole does, so more time will tell on this. The shoe is certainly high quality (even the insole is unique), but the cushioning design may limit durability.

David: The Cloudflyer survived Matt so that is worth something. I agree, the durability is pretty good. I still added some wear after my mileage but overall it is holding up pretty well. I think you can expect right about industry standard on this shoe or slightly above. The midsole so far is holding up well and has actually gotten better with more wear since the firmness has faded slightly. The speedboard should help with maintaining durability though. Good but not great durability. 


Matt: Much of the running industry and the biomechanical literature have focused only on vertical ground reaction forces. If you remember back to your physics and math classes, if you are looking at 2D graph, there is a vertical AND a horizontal axis. In real 3D life there is also a third axis, but for right now we won't go down that path. The point is, when runners land, there are ground reaction forces both in the vertical and horizontal planes. The vertical impact is straight against the ground, but since runners are moving forward, there are horizontal breaking forces, or as a mentor of mine referred to as "shearing" forces. Many cushioning technologies are only based off the concept of vertical ground reaction forces, but a few, like On Cloudtec pods, actually directly address it. The Clouds both compress and shear, decreasing loading rates in both the vertical and horizontal directions. 

The challenge with the Cloudtec design is that it is not full ground contact. For a stability shoe, although there is a speed board in the midsole above the Cloudtecs pods, less surface area means less ground contact and less overall stability. The Cloudflyer is not an unstable shoe however, but the stability elements are more subtle. The clouds on each side of the foot have different rates of compression, with the lateral side compressing more and the medial side compressing less. There is a Speed Board, or plate that is supposed to help transition the foot faster (see ride for more on this). However, with the elements being more subtle, this is certainly a light stability shoe at most. If On is interested in create a higher level stability shoe, a design more similar to the Cloudstratus with a full ground contact outsole may be necessary. 


For an excellent and more in depth discussion on three dimensional impact force loading, please see this wonderful writing by Simon Bartold on Bartold Biomechanics.


Matt: There are many great technologies in this shoe, but I wonder if there are too many things going on. My first suggestion as a stability shoe would be to create a full or increased ground contact outsole for stability. Next, I think the combination of speed board and wedge stability system of the Clouds may be too much. As a stability trainer, I would focus more on a smooth, stable cushioned ride. The speed board component may be better in a lighter weight trainer. If you are not running fast enough to properly utilize plate, it will make transitioning through the shoe harder. Additionally, if this is meant to be a lightweight light stability shoe, an ounce or so needs to be dropped off the weight.

David: On Cloudflyer did a lot with this shoe when it comes to geometry, upper integration, and the overall midsole. The shoe is still a little firm for my liking however, especially for the design and midline speedboard exposure. They made some good components that help with natural cushioning, but the shoe still comes up a little too firm for the category I think. The shoe also has a lot of potential of being a potentially fast shoe as a lightweight stability shoe, but the weight does negatively impact some of the speed and responsiveness as well. 


Matt: The On Cloudflyer is a light stability trainer the does stability and ride differently. Those looking for a stable ride without having to feel any intrusive posting or wedging will love this shoe. Those who land further back will appreciate the rockered design and protective heel. Those who like a bit of cushioning in the rear and a firmer quicker toe off up front will love the On Cloudflyer. This is a unique shoe and brand that is worth checking out. Especially those who want a rockered shoe without excessively soft or maximal cushioning, this brand will work well for you. We look forward to reviewing more from On Running and watching the brand come out with their new sustainable shoe too!

David: The On Cloudflyer is a light stability trainer for those who like a rocker feel and a firmer midsole. Stability and ride are done uniquely with this shoe and create a guiderail like feel and a snappiness from the speedboard. The upper is constructed very well and is comfortable throughout. There is definitely a market for this type of shoe and with some refinements in weight and midsole this shoe could be a serious player in the industry. On is doing some fun stuff and definitely worth checking out!

Fit                    9 /10 (Nice wider fit, but could be a bit more secure)
Ride                 8.5 /10 (mildly soft heel, firm forefoot with rockered sole)
Stability           8 /10 (May not even qualify as a mild stability shoe, subtle stability components)
Speed               7 /10 (Not great for anything faster than mild uptempo and too firm for long runs)
Durability        7.5 /10 (early wear on outsole, have not chewed into midsole but concerned with Cloud design. Upper super durable)

Fit                    9 /10 (Relatively secure throughout the midfoot, wider forefoot, some extra space in heel though)
Ride                 8.5 /10 (rockered sole feels really nice, though firm midsole and responsiveness could improve)
Stability           8.5 /10 (Stability relies on geometry and some additional components, but still leans closer to neutral)
Speed               7 /10 (Not great for anything faster than mild uptempo and too firm for long runs)
Durability        9 /10 (early wear on outsole, have not chewed into midsole but concerned with Cloud design. Upper super durable)

Total Score: 82 % (M: 8/10  D: 8.4/10)

Thanks for reading!


Find the On Cloudflyer at Running Warehouse here.
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Find other ON Running reviews here:

On Cloudflow 2.0 Review

On Cloudswift 2.0 Review

On Cloudstratus 2.0 Review

Dr. Matthew Klein is a 140 lb male with notable PRs of 14:45 for 5k and 2:32:44 for the full marathon.  He typically runs 70-100 miles per week and trains at a variety of paces from 8min per mile recovery runs to 4:40 per mile 1k repeats.  He prefers firmer and responsive shoes with snug heels and medium to wide toe boxes.  He is particular to less cushioned shoes and close to the ground shoes, but can handle a little cushion when he gets beat up.

Dr. David Salas is a 135 lb male with notable PRs ranging from 3:54 in the 1500m to 1:08:36 for half marathon. He typically runs 60 to 70 miles per week and trains from about 7:30 recovery runs to fast shorter efforts at 4:30 pace. He normally prefers neutral shoes with a firmer ride, but is completely open to other types of shoes.  He is a footwear enthusiast at heart and will always appreciate a high quality shoe when it comes around. For updates on training or testing, IG handle: @docsofrundavid

Editor's Note: As always, the views presented on this website belong to myself or the selected few who contribute to these posts. This website should not and does not serve as a replacement for seeking medical care. If you are currently injured or concerned about an injury, please see your local running physical therapist. If you are in the Los Angeles area, I am currently taking clients for running evaluations.

Doctor of Physical Therapy
Board Certified Orthopedic Clinical Specialist
Fellow of the American Academy of Orthopedic Manual Physical Therapists

Nathan Brown PT DPT MS
Doctor of Physical Therapy 
Masters in Anatomy and Clinical Health Science
Movement Performance Institute Certified in Advanced Functional Biomechanics 

David Salas PT DPT CSCS
Doctor of Physical Therapy
Certified Strength and Conditioning Specialist

***Disclaimer: These shoes were provided free of charge in exchange for a review.  We thank the  people at On Running for sending us a pair.  This in no way affected the honesty of this review. We put at least 35-50 miles on trainers and 10-25 miles on racing flats prior to reviewing them. Currently we have 35 miles (Matt) and (65) miles (David) on our pairs. Our views are based on our extensive history in the footwear industry and years testing and developing footwear. If you are a footwear rep looking for footwear reviews or consultations on development, we are currently looking to partner with companies to assist, discuss and promote footwear models. Partnership will not affect the honesty of our reviews.

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