Some limericks

We’re sponsoring Planet Granite Belmont’s Battle for Bolts on Oct. 17th. PG asked all the sponsors to contribute advice for the competitors, and we found ourselves falling into rhyme:

I just met a climber tonight

Who told me, “Here’s how to climb right

your shoes will feel sweet

when they’re fit to your feet,

and they’re laced up So F*#king Tight.”

a more amorous one:

I once met a climber from Boulder

Who had some freaking jacked shoulders

I belayed her up and down

helped her climb around,

but all I really wanted was to hold her.

some real advice:

Did you hear about the climber from Colorado?

Who has such a strange motto:

‘Climb safe, climb hard…

rub your flappers with lard,

and finish all your meals with an avocado.’

for facing strange competition:

I once faced a climber from ‘frisco

Who was powered by purely Nabisco

While not sure to believe him,

To make sure I beat him,

I lathered all the holds with Crisco!

Which one would best prepare you for a 24-hour climbing competition?


Planet Granite Bloc Party

Planet Granite’s Bloc Party, their annual bouldering competition series, is starting up again this Saturday, August 29th. SFT Climbing is donating a pair of custom shoes for the raffle, and we’ll be there all evening with a table and demo shoes to explain how we make custom-fit shoes. If you’re planning to compete, drop by our table and say hi!

Some lessons from the beta program

By working with many beta customers over the last month, we’ve become confident that our algorithm consistently generates last shapes and patterns that correspond to how the designer intended each pair of shoes to fit. Basically, for a broad range of foot dimensions, we know how the shoe will end up feeling on the customer’s foot – where it will have space, where it will be snug, and where any issues are most likely to occur.

What we didn’t expect (though perhaps it’s obvious in retrospect) was the huge range in climbers’ desires for how their shoes would fit. Because there are so many resources on how to fit shoes properly (gear reviewers discuss this, REI and other retailers discuss it, manufacturers put out information urging customers not to undersize too much, etc.), we built a fitting algorithm that was fairly rigid. It takes dimensions, makes assumptions about how much one’s toes should be curled for a given last shape, and produces the last model that fits these inputs.

It turns out we shouldn’t make that assumption about toe curl. For downturned shoes, there is a fair amount of consensus, but different climbers have in mind a HUGE range of different fit styles when ordering flat shoes. For different climbers, “flat shoes” can mean anything from all toes gently curled, to little toes curled/big toe flat, to all toes flat but touching the end of the shoe, to space beyond all the toes!

Clearly, a critical part of our ordering system will be a way for climbers to communicate exactly what they mean when they say “flat” or “downturned.” We’re working on how to help SFT customers make this preference clear. Some possible options are:

1. Have a trained person take the measurements for each order. This person could inspect a customer’s feet in their previous shoes and make notes on the fit and special requests. (This would probably mean partnering with gyms or gear shops around the country and training their staff to become representatives for SFT).

2. Request that each customer photograph their feet in their previous shoes, using their thumb to indicate where the end of their big toe is in the shoe. These photographs would be submitted with the customer’s measurements when they place their order.

3. Have a series of diagrams showing how feet can fit inside shoes, and allow the customer to choose the one that best describes their desired fit.


If you’ve got suggestions on what would be the most convenient way to communicate these preferences, we’d love to hear them. Feel free to comment below or to email



Sometimes, in the mad rush of design/prototype/debug/re-design cycles, you lose track of the progress you’ve made. SFT Climbing just turned 2 years old, and the difference between the first duct tape and sock prototypes Mak and I made and the beautiful shoes we’re finishing for beta testers now is a gulf almost too large to span with a simple anniversary celebration. So instead of toasting the whole journey from barely knowing how to sew leather to creating a digitally enabled (almost) production line, let’s look at a concrete example of how SFT’s tools and command of those tools has improved:

From concept sketch for a new closure system, to a quick prototype to check function, to shoes built with the system for a beta customer,


…in 7 days. Two years ago, I wouldn’t have believed that SFT could pull that off. Thank you to all of you – friends, beta customers, suppliers – who’ve made this possible, and here’s to the continual improvement of SFT’s process to bring customized shoes to rock climbers!

Video: custom last shapeshifting

Because our last model is parametric (its geometry is determined by a stored set of equations and relationships), it can adapt to accommodate different variations of foot proportions. This video shows how the last shape changes for a 5% increase in length and a 22% increase in width across the ball of the foot.

SFT Climbing is taking beta orders for custom shoes.

We’re currently taking a limited number of orders from climbers local to the San Francisco Bay Area. 

If you’ve been patiently waiting for the opportunity to get some SFT custom shoes, we’re excited to finally invite you into our community of beta climbers!

Help us perfect our last algorithm by ordering a pair of custom shoes. Every climber who helps us now improves the speed and flexibility of our algorithm, but for that, we need you to be ready to give us feedback throughout the shoemaking and fitting process.

In gratitude for your help, beta custom shoes are $300 per pair and guaranteed to fit – we’ll work with you until you’re happy at no extra charge (learning your preferences and performance needs is how our algorithm improves).

For those of you who are living the dirtbag lifestyle or otherwise not sure if you can commit to submitting feedback, we plan to offer custom shoe orders with turn-around times of about a week for $400 at the end of June. For updates on availability, subscribe to our mailing list.

If you’re interested now, thanks a ton! You can place your order by emailing

Manufacturing Manifesto

Three months ago, I signed up to give a lightning presentation to a Meetup group in San Francisco that focuses on hardware startups. The day before the talk, I was struggling to put into only two minutes the essence of SFT’s approach to our product design. Of course, SFT means many things to me, since I’m elbow deep in all the aspects of running the company every day. But for any talk, it’s critical to judge your audience’s interests and speak to those in particular. So while this is the Bay Area and therefore some non-zero number of my audience would probably be climbers, really, they and I were there to talk about engineering and bringing products to market, not the details of which shoes are best for smearing or toehooking.

The most pertinent thing about SFT, for the Meetup audience, would be a discussion of how we are leveraging digital manufacturing techniques to bring customized shoes to climbers. Because climbing shoes fit so tightly and human feet vary so widely, SFT has had to rethink traditional shoe manufacturing so that our process can accommodate natural variations efficiently (i.e. to bring custom shoes to as many climbers as possible at the least environmental cost). We are pursuing digital manufacturing because we assume that the shoe fits the climber, instead of stuffing climbers into generic shoes.

When people say “digital manufacturing,” almost everyone jumps to the idea of 3D printing the whole shoe, but right now (due to the materials available, print time, print volumes, etc.), that’s not really feasible. Of course, “shoes” have been 3D printed, but they’re stiff sculptures, not engineered tools that complement the wearer’s biomechanics. Instead of trying force a product into the requirements of one limited manufacturing process, SFT believes in choosing materials and digital techniques suited to the product’s requirements.

Nike Flyknit. Image courtesy of

Nike Flyknit. Image courtesy of

Nike and Adidas’ knitted upper method is a great example of leveraging a digitally controlled machine to obviate the need for part tooling. Here, making rule dies for pattern cutting, cutting the patterns out of sheet stock and wasting some of it, and then stitching it all together has been eliminated or minimized. Critically, by eliminating the need for expensive tooling specific to each shoe style and size, knitted uppers can reduce the pressure to mass-produce shoes.

The shoemaking process has many such pressure points where traditional techniques have relied heavily on fixed tooling. For example, lasts are cut in every size (and left and right) for a specific shoe design. Cutting so many lasts can be expensive upfront, so many manufacturers have stopped offering different widths to reduce tooling costs. However, with a parametric last model and a laser cutter, SFT can make quick-turn, durable, and recyclable custom lasts. When a customer places an order, the last model is reconfigured in a couple of minutes to match the critical features of their foot. In another 2 hours, we can complete a last that’s ready to build a shoe on. By making our lasts on demand, we aren’t wedded to a precut scale of sizes. By making the lasts quick-turn and recyclable, we can make lasts only when needed, storing the digital information necessary to create them.


An SFT laser-cut last resting in its recyclable assembly jig.

Besides the lasts, there are lots of other steps in making climbing shoes which need rethinking to better support customization and to reduce our industry’s waste and reliance on outsourced labor. That’s the stuff that wakes me up in the middle of the night (luckily there’s a whiteboard next to the bed to brainstorm on). SFT’s long-term commitment to digital manufacturing is what I wanted to communicate to the people at the hardware meetup. In the process of compiling my thoughts before speaking there, I realized that SFT has a vision, a manifesto, if you will. This vision of what we can give to the climbing community is what drives us forward:

SFT Climbing leverages digital manufacturing techniques to make shoes that fit real feet. We’re applying the right technology to each step in the manufacturing process so that we can do what’s best for climbers and for the world that we climb in.

The SFT lightning talk on youtube: