Article by Jeff Valliere and Mike Postaski
Dynafit Ultra 100 ($170)
Jeff V: The Ultra 100 is Dynafit’s ultra distance shoe, featuring a great blend of long distance cushioning, comfort and protection, but unlike many ultra focused shoes, the Ultra 100 is more adept at handling technical mountain terrain with authority, as the Ultra 100 has a firm midsole (though not an abusively so one), a streamlined build, very secure fit and amazing traction.
Pros: Cushion, protection, comfort, agility, traction, secure fit Jeff V
Pleasantly cushioned, compared to Ultra 50 Mike P
Very protective, via high stack/cushion Mike P
Relatively agile for such a high stack Mike P
Cons: Fit not ideal for long distances Jeff V
Takes the cake for most pointy toebox Mike P
Lacing setup, laces seem a bit “light” Mike P
Weight: men’s 10.9 oz / 309 g (US9) / women’s oz / g (US8)
Samples: men’s 11.1 oz / 318 g US10, 11.4 oz / 322g US 10
Stack Height: men’s 32 mm heel / 26 mm forefoot ( 6 mm drop spec)
$170. Available now
First Impressions, Fit and Upper:
Jeff V: The Dynafit looks very euro, with a streamlined, technical looking build, very high quality and is protective looking. As a shoe aimed at 100 milers (based on the naming), I was expecting a bit more of a relaxed fit and was surprised how precise, secure and race-like the upper hugged my foot.
Fit is true to size, with a very secure heel, exceptionally good secure lacing and a somewhat narrow, tapered toe box. I’ll say that for my narrow, low volume foot and preference for technical terrain, I find the fit of the Ultra 100 to be ideal as a daily trainer on technical terrain and excellent for long days in the mountains and running rocky, technical terrain.
While I do like the fit, I think that anyone with wider feet or anyone looking for a shoe intended for 100 milers, may find the fit to be a bit too snug for long distances, not allowing for enough room for splay and swell.
The toe bumper is flexible, but very protective.
There is a lace guard that doubles as a lace garage (difficult to tuck laces in, so I never use it) and helps keep out trail debris.
The tongue is thin at the top and then very thick and well padded lower down, which gives a great comfortable, anatomic fit and feel. While the tongue is not gusseted, it is not an issue and stays in place well because of the way the laces are routed through the tongue. I actually thought it was gusseted at first, but had to really pry to confirm that it is not.
The heel collar is well padded and comfortable.
The heel counter is well built, is anatomically correct, sturdy and features the Heel Preloader, a distinct band that wraps over the back of the heel counter for added anatomical hold, control and stability.
Overall I find the fit to be amazing for my foot and running, generally on technical terrain and not ultra distance, so if you want a shoe that will perform on technical mountainous terrain, you will love the Ultra 100.
If you have a more narrow foot and want a shoe with all day protection, long distance performance for rocky, technical mountain terrain, rock hopping, steep trails and off trail, off camber that can hold up to anything, this is your shoe!
If you have wider feet, prefer a lot of wiggle room for long distances, the fit here might not be ideal, so proceed with caution.
Mike P: Jeff V and I agree on the general feeling of the shoe. Based on looks and shape, it does have a streamlined look which is appealing for me. I tend to favor a narrower on the ground platform, as I find that it helps with agility and even if a shoe has a somewhat high stack. The Dynafit 100 is a good example of this – the stack is noticeably and measurably high, yet the midsole/outsole does not flare out excessively underfoot. Dynafit clearly understands that a narrower platform is helpful for more precise foot placement in alpine terrain.
The next and probably most noticeable first impression for me is the pointiness of the toe box. This is for sure one of the most tapered toe boxes I’ve seen in any shoe, and certainly has a non-natural foots shape in the toe area.
Despite the tapering at the very front, the width across the forefoot is fine for me, so I didn’t have any issues on the run. But it’s definitely a toe box where your toes are pressed together, so that’s a personal preference as to whether it bothers you.
Jeff V covers the details of the upper so I’ll just highlight one key positive point for me which is the heel hold. I’m not sure if it’s the “Heel Preloader” strap itself or just the general shape of the heel, but I found a very, very nice deep and snug heel cup. On the run, my heels feel deeply seated, especially with such a high stack, so that’s a big plus for the Ultra 100 and certainly a contributing factor in why it feels so much more stable and agile than I would have expected in technical terrain.
Jeff V: The EVA midsole provides a supportive and protective ride, with ample cushioning, soft enough to feel well cushioned and comfortable for long distances, yet firm enough to feel supportive, stable and predictable, which is particularly advantageous in technical terrain.
Protection under foot is amazing and sufficient for any terrain, no matter how rugged and rocky. While the Ultra 100 is not necessarily intended to be a fast, responsive shoe, they are ideally suited to efficiency over the long haul. If you are having a good day and feeling fast, I have found that the Ultra 100 can certainly rise to the occasion and performs very well.
Mike P: The EVA midsole does feel quite substantial underfoot. There’s a sure sense that there’s a lot of foam between your foot and the ground, and also the feeling that you’re high up off the ground. The feel, as Jeff notes, is soft but not overly soft – the foam does not feel unstable in moderate/technical terrain. An Ortholite insole is used here, so that also contributes to the soft feeling underfoot.
As far as the drop is concerned – it’s a quite comfortable and balanced 6mm. It feels just right for long, ultra distances. The level of midsole foam feels about even from the ball of the foot through the rear of the shoe. Then there’s a big toe rocker up front, so you really get the feel of a very full level of cushioning throughout the entire foot, until you get into that toe rocker portion of your stride.
The toe rocker is much more pronounced in comparison to the Ultra 50, which felt flatter, starting from the ball of the foot. The Ultra 100 midsole and geometry seems more oriented towards absorbing long miles, while utilizing that front rocker to keep your stride rolling along.
Jeff V: The Vibram outsole features 4 mm chevron traction lugs with the nice little Traction Lug nubs to provide that little bit of extra grip in loose terrain. I have run on a variety of terrain in Colorado, Oregon and Washington – steep, loose gravelly off trail and trails, mud, roots, slabby rocks, talus, scree, dirt roads, buffed singletrack, etc…. and traction is always confidence inspiring. I have not had much opportunity to run them in the wet, but what little I did, I found wet traction to be average. With about 50 miles on them thus far, durability is above average.
Mike P: Another outsole with the Vibram MegaGrip Traction Lug technology. This seems to be a standardized setup for many trail shoes these days across many different brands.
I had no issues whatsoever with traction in a wide variety of terrain. I took them up to the Sawtooths of Idaho for a solid, varied mountain run and I had all the traction I needed. I went through several stream crossings without issue, although I haven’t had an opportunity to test in rainy, wet rock terrain. It’s very, very dry out here at the moment.
But Vibram Megagrip is of course a known quantity so I would expect performance to be fine. I was able to get a bit more water testing earlier in the season with the Ultra 50 and those performed well, although they use Dynafit’s Pomoca outsole and not Vibram. Vibram should be an upgrade here. Jeff mentions he found wet traction to be average, and I’d say looking at the lugs, there’s not a big amount of surface area, so that would likely be a limiting factor.
Ride, Conclusions and Recommendations
Jeff V: I’ll admit that I didn’t love the Ultra 100 right away and it took me a while to appreciate them. At first I think I was thrown by the name and trying to figure out the best use for them and how they fit in.
I am not sure if they would be my pick for a 100 miler, probably not, which is mostly because of the precise, narrow tapered toe box, for which I would prefer a shoe with a bit more breathing room.
That said, the Ultra 100 is plenty capable of long distances with great cushion, protection and an overall smooth and efficient ride. This is a shoe that really shines for long efforts when the going gets rough, as they are sturdy and well built, with great cushion, protection, a protective upper, excellent foothold, stability and fantastic traction.
Jeff V’s Score: 9.6/10
Ride: 9.5, Fit: 9.5, Value: 9.5, Style: 9.5, Traction: 9.5, Rock Protection: 10 😊😊😊😊😊
Mike P: It took me a little bit of time to warm up to the Ultra 100. I intended to test them much earlier – bringing them along with me during the Boise Trails Challenge during mid June. But I tried them on somewhere around the midpoint of that event (1-2 days, 100+ miles in), and the very narrow and tapered toe box was a complete no-go at that point. I had to shelve them for a bit until that event was complete and after some recovery time.
With my feet and legs somewhat back to normal, my initial runs in the Ultra 100 were uninspiring. At 11.4 oz shoe in my US10 can tend to do that, especially on somewhat worn-out legs. But after a few more runs, including a trip to the Sawtooths, they started to grow on me. I appreciated the much more voluminous cushion underfoot compared to the previously tested Ultra 50. They also felt surprisingly stable the more terrain I threw at them.
The toe rocker up front was quite a bit help in moving along that 11.4 oz and really making them feel not all that heavy – at ultra-type paces. The feel of the shoe on the run is somewhat reminiscent of a Scott Supertrac – with that similar combination of full cushion from the ball of the foot back, plus effective toe rocker. Both brands’ shoes tend to run lighter than their weight would suggest.
The pointy toeb ox wasn’t an issue on any of my runs, but it was noticeable. Having my toes pressed together is just not something I like, and would definitely not want that for a long ultra. Foot swelling would be a problem for me. But if you have a narrower shaped foot, or perhaps your “toe box” had been adapted to dress shoes and/or pointier shoes over time, these could work fine or even be ideal for you.
I agree with Jeff V’s overall assessment that the Ultra 100 is a great training shoe for long miles in any type of mountain conditions. The only thing holding it back for me from being a racing option is the toebox, and probably it could lose just a little bit of weight. But overall, a solid, alpine, mountain, long distance option.
Mike P’s Score: 9.08 / 10
Ride: 8.5 – Not super dynamic, but stable and relatively agile – built for long mountain miles
Fit: 9 – Very good and secure upper, great heel hold. Full point deduction for pointy toe box
Value: 9 – Should be durable for many mountain miles
Style: 10 – I think they look very sharp, especially with some mountain grit worked in
Traction: 9.5 – Very good, lugs are not overly deep, but that’s nitpicking
Rock Protection: 10 – I never felt anything get through to my feet
Index to all RTR reviews: HERE
Hoka Speedgoat 5 (RTR Review)
Mike P (10.0): The SG has a tapered toe box, but not nearly as much as the Ultra 100. But I find the SG5 squeezes my forefoot more than the Dynafit, making them much more uncomfortable. But if the fit works for you, the Hoka offers a similar all mountain, long distance package at about 3 ⁄ 4 oz less in weight. The main difference I’d say is that the Hoka has a much wider ground platform which some runners may prefer for stability. Personally I favor the narrower style of the Dynafit which feels more maneuverable for me.
Saucony Xodus Ultra 1 and 2 (RTR Review)
Mike P (9.5): I’ll focus on XU V2 here – there’s quite a big difference in weight here with the Saucony almost 1.5 oz lighter in my size. The Saucony may feel a touch softer underfoot, but both feel equally cushioned. The Dynafit’s foam may feel just a little firmer and more stable. Both uppers are nice and secure with a bit too little space in the toe box for my tastes. Heel hold in the Ultra 100 is deeper and better. I feel more stable in the Dynafit even though it’s probably a little bit higher stack. The XU V2 “rides’ ‘ higher to me – there’s just a touch more “wobble” and I don’t prefer them in technical terrain.
Brooks Caldera 6 (RTR Review)
Mike P (9.5): I tested the Caldera 6 but wasn’t a big fan. It’s just way too much underfoot for me, with one of the most excessively wide platforms, on par with the GS:TAM. Both shoes were so wide that I felt like they altered my footstrike too much and were uncomfortable. I think the Caldera is a better fit for larger and/or heavier runners. I find the Dynafit a much better option in technical terrain due to the much easier maneuverability and more even feel underfoot. The Caldera has too much squish and bounce underfoot.
Brooks Catamount 2 (RTR Review)
Mike P (10.0): As you know from my prior reviews the Cat 2 is one of my faves, It is way lighter, and has a much faster and responsive ride. It’s a go-fast shoe for a much wider range of short through ultra distances. Some may find the Cat 2’s cushion a bit thin, and it is relative to a shoe like the Ultra 100. But it works just fine for me as a lighter runner and I’ve taken them 123+ miles in 24 hours. I feel more stable in the Cat 2, especially at faster paces since it’s lower and closer to the ground. It’s a great training and racing option, where the Ultra 100 feels more like a training shoe to me.
Salomon S/Lab Genesis (RTR Review)
Mike P (9.5): This is fast becoming one of my favorite shoes. It’s a similar do it all trail shoe as is the Catamount 2 – but leans more towards technical terrain and has a bit more cushion for longer distances – so similar to the Ultra 100. The Genesis upper is just as secure as the Ultra 100, but features a nicely wide and shaped toe box. There’s also a massive difference in weight with the Genesis over 2 oz lighter. It’s a bit pricier, but for me, very much worth it as it’s a much better shoe across the board.
Salomon Ultra Glide 2 (RTR Review)
Mike P (9.5): The UG is Salmon’s cushioned, long distance cruiser. But it doesn’t perform nearly as well as the Dynafit in moderate/technical terrain. It has more of a full longer rocker as opposed to the Dynafit’s noticeable toe rocker. I found the UG2 works well to cruise in smooth and level terrain, but struggles beyond that. It’s lighter than the Dynafit though, and with a nice and secure upper – it’s probably a better shoe if you primarily run in tamer terrain.
NIke Zegama Trail (RTR Review)
Mike P (9.5): This is likely the closest comp as both shoes feel very similar on foot. Full cushion through most of the foot with a toe rocker up front ( the Dynafit is more pronounced). The Dynafit upper is more secure, but the Nike toe box, while shallow, is still more comfortable. The Dynafit’s Megagrip gets the edge in traction, especially in the wet. But if dry, the Zegama performs just as well. I think the Zegama is a more comfortable and equally performant option in dry conditions.
Nike Ultrafly Trail (RTR Review)
Mike P (9.5): Nike’s newest super shoe just took 2nd and 3rd in the men’s Western States. It’s way, way softer underfoot, and way faster than the Dynafit. But for me all that soft cushion is a bit unstable, so I’m not sure what the right conditions would be for me to race them. Major difference in the toebox – the Ultrafly has a huge, voluminous toe box, while the Ultra 100’s is narrow and overly pointy. The Dynafit has a clear win in heel hold though, as there can be a bit of slippage in the Ultrafly if you have a low volume heel. I’m not sure how much overlap there is between these shoes, including price as the UF is $250l.
VJ Ultra 2 (RTR Review)
Mike P (10.5): The VJ is an ounce lighter, closer to the ground, and handles technical terrain at faster speeds. The VJ’s rock plate is also more noticeable,while the Ultra 100 relies on cushion for protection. The Dynafit is really a long distance cruiser, while the VJ Ultra 2 is a better option for any type of technical terrain – at faster paces. The VJ also has a quite tapered toe box, and I have to go a full size up to get a comfortable fit.
Jeff Valliere loves to run and explore the mountains of Colorado, the steeper and more technical the better. He has summited all of the 14ers in the state and can be found on mountain trails daily, no matter the weather, season, conditions or whether there is daylight or not. On the side he loves to ski (all forms) bike and hike, often with his family, as he introduces his 12 year old daughters to the outdoors. Jeff was born and raised in New Hampshire, but has called Colorado home for over 25 years. He is 5’9” and 145 lbs.
Mike Postaski currently focuses on long mountainous ultras – anywhere from 50K up to his favorite – 100M. 5’10”, 138 lbs, midfoot/forefoot striker – he typically averages 70 mpw (mostly on trails), ramping up to nearly 100 mpw during race buildups. A recent 2:39 road marathoner, his easy running pace ranges from 7:30 – 9:00/mi. From 2022-23 Mike has won the Standhope 100M, IMTUF 100M, and Scout Mountain 100M trail ultras. He also set a course record with 123.74M at the Pulse Endurance Runs 24H and completed the Boise Trails Challenge on foot in 3 days 13 hours, besting the previous record by 7 hours. Mike’s shoe preferences lean towards firmer, dense cushioning, and shoes with narrower profiles. He prefers extra forefoot space, especially for long ultras, and he strongly dislikes pointy toe boxes.
Dynafit Ultra 100 is available now from our partners
Samples were provided at no charge for review purposes. RoadTrail Run has affiliate partnerships and may earn commission on products purchased via shopping links in this article. These partnerships do not influence our editorial content. The opinions herein are entirely the authors’.
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