Giro 'Prolight SLX' Ultra-light Cycling Shoes

Giro Prolight SLX road biking shoes

Brand-new as of March 2011, the Giro Prolight SLX road cycling shoes offer a considerable weight savings over most standard shoes. They are available in either black or white (I went with black) and they cost about $349.

Giro states:

The Prolight SLX redefines fit, feel and power-to-weight performance in a lightweight shoe. Starting with a select Teijin microfiber upper that shapes to your foot like a second skin, we added an ultralight EVA footbed plus a SuperNatural Fit Kit footbed with adjustable arch support so you can customize the fit to match your needs.

At only 6.5mm thick, the high-modulus Easton® EC90 SLX outsole is exceptionally thin and light yet provides best-in-class stiffness for maximum power transfer. Titanium hardware reduces weight even further. If you're looking for the lightest pro-level shoe without compromise, this is it.

Weight savings

I bought the Giro Prolight SLX shoes at Palo Alto Bicycles, which adjusted the cleats for appropriate knee placement over the pedal spindle, a critical adjustment to avoid knee issues.

I rode a pair of Specialized carbon fiber shoes for years— great shoes. Their weight is similar to current offerings. These weights are with the Shimano cleats installed.

Old shoes: 802g
Giro shoes: 507g = 295g savings (2/3 pound)!

I weighed the shoes on my lab-grade scale. Weights are with Shimano cleats installed for DuraAce pedals:

Shimano R315: 663g (+156g = +5.5 oz)
Pearl Izumi Octane: 633g (+126g = +4.5 oz)
Giro ProLight SLX: 507g

If you’re looking to save 1/4 pound or more, look to the shoes for a very cost effective upgrade versus a ton of money on bike parts! But of course a shoe has to fit and be comfortable too.

Shoes are also rotating weight, which is even more important than static weight. A lighter shoe is less weight to spin tens of thousands of times on your ride.

Why pay $thousands to save a pound on a bike when you can save 2/3 of a pound on your shoes for not much more than a good pair of cycling shoe costs anyway? It’s a no-brainer value for anyone looking for the lightest total climbing weight.

As I wrote this article, I had only one day’s experience with them, and I’ll update my report after a break-in period.

Giro Prolight SLX road biking shoes