Topo Athletic ST-6 Review - Flexible and Minimal, But Size Up

In short, the Topo Athletic ST-6 is a good update from the ST-5 — more usable, easier to recommend, and a solid transition shoe into barefoot running. But it still has issues with sizing, width, and that slippery heel material.

When I first got my hands on the ST-6, I was curious whether Topo had addressed the problems I had with the ST-5. The short answer? They’ve made steps in the right direction. The heel fit is improved, the arch support is dialled back, and the flexibility is genuinely barefoot-like. But this shoe still has a few rough edges that you need to know about before buying.

At a Glance: Topo Athletic ST-6

• Best For: Runners transitioning to barefoot who want flexibility with a little cushion; those wanting a breathable summer shoe
• Skip If: You have a super wide toe box, wide midfoot, or need a secure heel lockdown
• Stack Height: 14mm | Weight: 182g (6.4 oz) | Drop: Zero
• Overall: 6.5/10 — A flexible, lightweight transition shoe with good ground feel and minimal cushion, but sizing runs short and the heel material slips
• Price: $125 | Prices on Amazon

Fit

Does the Topo Athletic ST-6 fit true to size?

The ST-6 runs slightly short — go half a size up. In my usual US 9 (same size I wear in most Altra shoes), my toes were too close to the end. The big toe side rounds off and becomes restricting, which means you’re losing usable space up front.

Half a size up is the move here. It’ll give you more room in both the toe box and midfoot, which this shoe desperately needs.

How wide is the toe box?

The toe box is roomy, but it’s not as wide as you might expect. It has decent splay room, but the shape rounds off on the big toe side rather than squaring off. That rounding creates a pinch point that limits the space where you need it most.

The midfoot is where things get tight. It’s quite narrow — similar to the problem I’ve experienced with the Altra Lone Peak, where my foot falls over the side of the shoe. Your little toe also gets squished in here. Going half a size up helps, but if you have a genuinely wide midfoot, this shoe might not be for you.

Does the shoe have a good heel lock?

The heel fit is much better than the ST-5, but the material lets it down. Topo raised the top lace eyelet from the ST-5, which allows a better lace lock to pull the heel in. That’s a real improvement — the ST-5 had a very flexible heel with a slightly wrong shape that left things loose.

Here’s the thing — the soft, silky neoprene-like heel material is a problem. When forces are applied or your foot goes at different angles, there’s slipping in and out. The material just doesn’t grip well enough for a secure lockdown. It’s frustrating because the structural fit is improved, but the material choice undermines it.

Feel

Is the 14mm stack height good or bad?

The 14mm stack delivers a minimal feel with a soft cushion underneath. Good ground feel underfoot. This is a stack height I personally love — it’s comparable to the Bahé Revive Adapt. You get enough cushion to take the edge off without losing that connected feeling to the ground.

The ZipFoam midsole strikes a nice balance. It feels minimal overall, which is exactly what you want in a transition shoe.

Is the shoe flexible?

This is a very flexible shoe. It bends in every direction with only a little torsional stiffness. That’s a good sign for barefoot-like movement — you want your shoe working with your foot, not against it.

The flexibility is one of the ST-6’s strongest features. If you’re coming from traditional running shoes, this will feel dramatically different underfoot. Good different.

Lacing and tongue

The lacing system is simple but effective. Fabric loop lacing that could be cranked too tight if you’re not careful. The tongue has two loops on either side that keep it straight and in place — works really well.

The tongue itself is thin but does its job. It cushions the laces from your foot without adding bulk, which contributes to that minimal feel. No complaints here.

Durability

How long before the outsole wears out?

Don’t expect much longevity from the outsole. There’s partial rubber in the right locations — forefoot and heel — which helps keep the shoe lightweight. But that rubber will wear through to the midsole foam over time. The good news? There isn’t much foam to begin with, so the soft foam packing out isn’t a major concern.

Will the upper develop holes?

The upper is light and breathable, but that comes at a cost. It’s a great summer shoe — very airy and comfortable in warm weather. But the thin material will scuff and rip easily. Expect it to thin out quicker than some shoes over time.

This is a trade-off. You get excellent breathability and a lightweight feel, but you’re sacrificing long-term durability. If you’re after a shoe that lasts multiple seasons, temper your expectations.

The Bottom Line

The Topo Athletic ST-6 is a solid step forward from the ST-5. The improved heel fit, reduced arch support, and genuinely barefoot-like flexibility make it easier to recommend than previous versions. It’s a good transition shoe for runners moving toward barefoot — you get that connected ground feel with a little cushion as a safety net.

But it’s not without issues. The sizing runs short, the midfoot is narrow, and the heel material slips when it shouldn’t. These aren’t dealbreakers for everyone, but they’re worth knowing before you buy.

Choose the Topo Athletic ST-6 if:

• You’re transitioning into barefoot running and want flexibility with a little cushion
• You want a lightweight, breathable summer running shoe
• You prefer a minimal feel with good ground contact
• You liked the ST-5 but wanted better heel fit and less arch support

Skip the Topo Athletic ST-6 if:

• You have a wide midfoot or need a truly wide toe box
• You need a secure heel lockdown without any slipping
• You want a shoe that’ll last multiple seasons of heavy use
• Your feet are between sizes and you can’t go half a size up