Saucony Zealot ISO 3 Review: Between Kinvara and Freedom Lies Bliss! 10 Comparisons.

Article by Peter Stuart and Sam Winebaum

Saucony Zealot ISO 3  
Official Weight:  8.5 oz/241g M9, 7.3 oz/ 207 g W8 *
Stack: 26mm heel/ 22 mm forefoot, 4 mm drop
($130, available now) 

Lateral Side

*Sam's sample size 8.5 had average weight of 8.7 oz/245g (one weighing 241 g, the other 249 g where spec is 241 g). His sample size 9 weighed 8.5 oz 242 g. Note that discrepancies in weight can occur in manufacturing but these difference are more than we usually see. 

Introduction
Sam: Zealot ISO 3 is softer underfoot, more consistent in cushioning feel and more flexible than Zealot ISO 2 (review here).  It officially drops almost an ounce in weight which is fantastic, although we did see discrepancies between the weight of our 2 samples. It has a completely new soft engineered mesh upper with an internal implementation of Saucony's ISO Fit straps with the upper resulting with a  relatively secure yet accommodating fit for a variety of foot types. The new Power Foam midsole is lively yet well cushioned. 
At 8.5 oz or so it has alot of forgiving cushion for such a light weight but does lose a bit of the firm pop off the road of its predecessors. If you like an unstructured more natural ride and a lower drop ride at 4mm but you also want a bit more cushion and comfort then the Zealot is worth a close look. It is for sure one of the finest updates of the year, and a fairly radical one, and is one of the best balances of comfort, cushion, energy and light weight of any shoe I have tested this year.

Upper and Fit 

Sam: The ISO 3 gets a completely new soft  unstructured engineered mesh upper with interior ISO Fit straps replacing the stiff silver outer straps of the ISO 2. The upper is a huge contrast from the ISO 2's. The mesh is open and soft instead of stiff and dense and the same for all the overlays. Gone to are the heavy plastic straps leading to and around the heel counter replaced by a much more minimal and softer construction including a far less rigid but still present heel counter.  I really like how Saucony has evolved ISO Fit. We ask why was this type of upper with maybe a bit stiffer engineered mesh not on the Kinvara 8 (RTR review) with its tortured single Pro Lock strap and stiff saddle mesh?

It has a more relaxed fit than ISO 2, not quite as locked down but should also fit higher volume feet better. I tested both a half size up and true to size. If you prefer a snugger fit or use thin socks stick with true to size. Length was a bit short. At a half size up with thicker cushion socks the fit was more relaxed and voluminous if a touch sloppy even using the rear lace loops. The heel collar at half size up was a bit loose although the heel itself impeccably held in the new less dense more pliable molded heel counter. Many foot types should be happy and comfy here with the half size up option available for those who prefer a more relaxed fit or have more foot volume at mid foot.

The widely spaced and wide green loops and lacing relieve all top of the foot pressure, super effectively an hold the foot quite well but I do think that slightly wider flat laces would make things even better. The strap design surely also contribute sto losing some weight as the ISO 2 had thicker exterior straps.

I like how the area around the last metatarsals and last lace up is open with a minimal last lace loop and no overlays down to the midsole as the ISO 2 had  beyond the logo overlay centered on the upper. Nothing but soft and effective support in this key area also contributing to the improved flex. There is a very slight stiffening of the interior of the upper to create a toe bumper and vertical volume with none of substantial but fairly soft overlay toe bumper of the ISO 2. The ISO 2 front overlay was noticeable so removing it and making the front less structured overall makes for a smoother less pressure free fit, although maybe a bit more slip forward as we felt the front of the shoe in our true to size.

The tongue is less puffy up top and all mesh below whereas the ISO 2 had a patterned embossed surface. 

Two interior straps extend from each big lace green loop diagonally towards the rear attached to the midsole.  This is the new and effective implementation of ISO Fit combining mid foot support, great comfort and flexibility for different foot types. The straps are well covered by the bootie construction tongue, no irritation was noted. I do think they could wrap a bit tighter under the arch where they attach to the midsole.

Peter: Wow is this an improvement from the weird, bulky, bulgy Zealot 2. The upper of the Zealot is great looking, the mesh is light and smooth and the bands across the top add a nice touch for the security of the lacing. This is a simple, elegant upper that laces up, holds the foot and disappears. The ankle collar is nicely padded making the zealot feel plush.

Midsole and Outsole:

Medial Side

Lateral Side

The firmer blue medial side midsole (below) of the ISO 2 is replaced by an entire midsole of a single density of Saucony high rebound PowerFoam, formerly only used in shoes with PowerGrid.

TOP: Zealot ISO 2 BOTTOM: Zealot ISO 3

TOP: Zealot ISO 2 BOTTOM: Zealot ISO 3

The PowerFoam in the Zealot is also used in the midsole of the just released Ride 10 (RTR review) and is close in feel to Skechers 5GEN, Hoka's RMAT in the Hupana and Salming's new Recoil in the EnRoute, all injected EVA blends with some pop. A bit less bouncy and firmer than RMAT, a bit firmer than Recoil especially in heel, it sits for me somewhere between the 5GEN in the GOrun 5 and GOmeb Razor. It does not have the rebound of Boost or the full Everun midsole in the Freedom but does have less of a sense of side deflection under load and does not require the stabilizing plastic  of Boost shoes to keep things tracking and stable. The overall sensation underfoot is consistent from heel to toe with the outsole providing sufficient structure and stability without any add ons.

Below the sockliner is a thin layer of Saucony's Everun TPU material to add some initial landing softness and supposed energy return. We think it is no longer needed with the softer Power Foam.

Peter: The Zealot ISO 3 has, as Sam mentioned above, a midsole of single density PowerFoam. It's a great simple foam that provides a nice bounce while neither being too soft nor too firm. The outsole is a combination of ibr+ and XT900 foam. There are tons of flex grooves making the Zealot ISO 3 a bouncy, flexible ride.

Outsole

LEFT: Zealot ISO 2 RIGHT: Zealot ISO 3

The ISO 3 flex grooves are deeper than the ISO 2's with more longitudinal grooves in the forefoot  and give the shoe a long, easy flex.
Sam: While all the same color the heel area running to the first deeper flex grooves has Saucony very firm and long wearing XT 900 rubber. Forward is iBR+ rubber with the front toe off area again firmer carbon rubber.   

Ride

Peter: The Zealot has a simple, flexible, easy ride. It may be a touch soft for some, and I'm not sure I'd race fast in it, but it feels really nice to get out and run in. It's the first shoe with EVERUN that I've enjoyed. There's not a ton to say about it, just that it feels good and I keep reaching for it to log miles.

Sam: I agree with Peter. The key words to describe the ride are flexible, soft, yet with good rebound. This is an Easy Riding shoe with an easy, fluid transition and a light one too with plenty of cushion and flexibility. It handles all paces very well and consistently in terms of ride.
Zealot ISO 3 transmits considerably less shock at the heel and especially just ahead of the heel than the ISO 2 as noted during my A/B test one of each version of my feet. The ISO 3's transition is much smoother with less of an interruption at mid foot for me. The cushioning and feel is consistent from heel to toe. The toe off is smooth and flexible.

Conclusions
Peter: The Zealot answers the issues I've had with the last couple of Saucony shoes I've tried. It's more flexible and more fun to run in than the most recent Kinvara--and in many ways feels like a more logical extension of Kinvara 1 and 2 than the current Kinvara. It's as fun as the Freedom, but the Freedom leaves my forefoot feeling a bit beat up. The Zealot sits right in the middle and is a joy to run in.

Sam: This is a very comfortable, quite lively, and very light (8.5 oz) shoe for the cushioning provided. I am thinking it would be an especially good and forgiving marathon racer for the 3:15 to 4 hour racer.  Not just a racer for sure,  it is an excellent daily trainer as well with good manners at all paces and plenty of energetic cushion especially in the forefoot, something I always look for.

In many ways, despite being a more substantial, more cushioned and much more modern shoe I consider the Zealot ISO 3 to be a successor in the Saucony line up to original early versions of Kinvara, as a natural riding low drop shoe. The ride reminds me a lotof the Hoka Huaka but with a far more modern upper, plenty of outsole rubber, and a much smoother front transition to toe off.   While it is a bit less snappy and softer than the ISO 2 it still has that great Zealot pop off the heel to transition, now smoother and less jarring and slightly more dynamic due to the higher rebound cushion from the Power Foam midsole. Quite frankly, I am not sure the Everun layer under the insole is even needed with PowerFoam as taking it out would firm things up a bit.

The fit is quite relaxed at mid foot but secure and should fit a variety of different foot volumes due to the excellent more open ISO Fit and substitution of inner straps for stiff outer ones. Sizing was true to size but a bit short up front. I also tested a half size up and think those seeking a yet more relaxed fit or with higher volume feet and wearing thicker socks could size up half a size. The upper is considerably more comfortable upfront with a  less noticeable overhead toe bumper and wider open stretch mesh at the metatarsals.  The relatively unstructured upper and its soft engineered mesh could use a bit more structure at mid foot where the last laces end and towards the heel. The mid foot is not quite as well held as in the ISO2 but not a big issue.
The light weight combined with excellent cushion particularly in the forefoot make the Zealot ISO 3 a great alternative to

• the now heavier 9 oz plus Hoka Clifton 4 for those also seeking a firmer more stable heel, a touch firmer ride, and more flexibility upfront. 
• adidas Boston 6 fans if you want more forefoot cushion and overall stability and a more accommodating upper 
• Brooks Launch 4 fans seeking lighter weight and a more lively and also slightly softer ride

Scores 

Peter 9.8/10

-.02 very slight instability at heel
Sam 9.75/10
-0.10 I wish they had a touch firmer midsole for a bit more response and heel stability
-0.05 mid foot hold just back of lace up could be a touch more supportive.
-0.1 for weight discrepancies between shoes in a pair one being 0.3 oz / 8 grams more than spec. at half size down from spec size 9 weight

Comparisons

Hoka Huaka (RTR review) 8.9 oz

Sam: The 2014 Huaka at about the same weight is still one of my favorites of the last several years is the closest comparison for me as the rides seem quite similar in their energy and feel. The Huaka's RMAT midsole in many ways runs similarly to the Power Foam in the Zealot. While the Huaka was a bit more versatile as it could do both trails and roads its upper just doesn't compare, it had a minimal outsole and its toe off was wide, stiff and more awkward than the Zealot's on the road.

Saucony Kinvara 8 (RTR review) 7.8 oz

Sam: The Kinvara is lighter but quite frankly dated and awkward in its fit and ride. I found the heel had tendency to bottom out and the mid foot upper is very secure but not comfortable. Clearly the Zealot ISO 3 is a successor to the Kinvara in low drop more natural Saucony rides and has a superior midsole. 

Peter: The Zealot is what I wish the Kinvara was--much closer to the enjoyment I got out of Kinvara 1 and 2. In my opinion, the Zealot is smoother, more fun and a better overall shoe.

Saucony Freedom ISO (RTR review) 9 oz

Sam:The Freedom is fun to run but a harder beast to tame for me given its lack of upper structure, no real heel counter, thin forefoot and Everun bouncy midsole relying only on the outsole for stability. The Freedom is more interesting to run but for me only shorter run and not day to day. Most runners will find the Zealot more versatile

Peter: Am I the only person who feels like the Freedom has too little in the forefoot. Between the relative softness of the forefoot and the lack of stack height, the Freedom starts to hurt after 8 miles for me. The Zealot, on the other hand, stays good for miles and miles and miles. 

Saucony Ride 10 (RTR review) 9.8 oz

Sam: Really in a different class as a heavier classic daily trainer and one of my favorites to date of 2017, the Ride is snugger, slightly less agile, heavier, less flexible, and less energetic even though it shares a Power Foam midsole. 

Hoka Clifton 4 (RTR review) 9.35 oz

Sam: While the Zealot has a touch less cushion, 2-3mm and is somewhat firmer than the Clifton it is a far livelier more stable shoe with more road feel and agility, greater flexibility and lighter weight. Still very well cushioned the Zealot gets the nod 

Peter: No comparison here. The Zealot is much more fluid and natural to run in. 

adidas adizero Boston 6 (RTR review) 8.4 oz

Sam:Things get interesting with this comparison. Very close in weight and heel cushion feel, the Zealot has superior forefoot cushioning but is a touch less snappy and agile.  It is more versatile as a long racer less so as a trainer due to its thin forefoot and snug upper.

Nike Zoom Elite 9 (RTR review) 8.2 oz

Peter: This is actually one of the closest shoes to the Zealot. The Zealot is a bit more cushioned and may be better for easy runs, while the ZE 9 picks up the pace a bit better. I'd race in the ZE 9, but probably wouldn't do so in the Zealot. 

Hoka Hupana (RTR review) 8.2 oz

Sam: Another close comparison the Hupana was my 2017 shoe of the year for its energetic very smooth ride due to being 100% RMAT (same material as the Huaka) with no outsole at all. The addition of a substantial outsole and its firmness in the Zealot gives it more pop off the road, and durability. Hupana is a bit more fun to run but Zealot is more versatile.

Hoka Clayton 2 (RTR review) 7.75 oz

Sam: The Clayton 2 is firmer and has a more awkward fitting upper than the Zealot and is of stiffer materials. I wouldn't dare run it barefoot due to the arch blister issue but would the Zealot. Underfoot the lighter Clayton is stiffer all around and slightly more stable. It has slightly more stack height. I find it harder to roll through to toe off than the Zealot but overall it is more responsive. In a longer race when tired I would lean towards the Clayton, for every day training with race versatility I would lean towards the Zealot.

Altra Escalante (RTR review) 7.8 oz

Sam: The lighter Escalante has a firmer, more dynamic ride. For me it is more of an uptempo shoe than the more relaxed underfoot trainer focused Zealot with his 4mm drop vs. zero for Escalante and higher by 7mm heel and 3 mm forefoot. The Escalante upper does get a slight nod. 

Skechers GoRun 5 (RTR review) 7.5 oz

Peter: The Zealot and the GoRun 5 feel like a pretty similar level of cushion. The GoRun is lighter, and a simpler shoe overall. I might go longer in the Zealot, but the GoRun is super fun. Get both!

Zealot ISO 3 was provided at no charge. The opinions herein are entirely the authors'.

Comments and Questions Welcome Below!

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