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Shimano SPD-SL R315 Ultralight Cycling Shoes
The Shimano SPD-SL R315 cycling shoes (about $380 @AMAZON) are a light-weight pro-grade road cycling shoe:
- UPPER: Heat moldable Custom-Fit Technology
- Rovenica* ultra-fine fiber synthetic leather Supple, lightweight and comfortable.
- Excellent Elasticity with high memory.
- Superior durability and high-abrasion resistance.
- Multi-layered moisture control mesh.
- Anti-slip heel lining, knitted with metal fiber.
- Low-profile micro-adjust buckle and dual off-set straps.
- Heat moldable insoles accommodate and support feet.
- LAST: Curved, anatomical last with Custom-Fit precision.
- SOLE: Lightweight hollow channel, ultra-rigid, weaved carbon fiber.

Fit
I bought the Shimano R315 shoes in addition to my existing Giro Prolight SLX shoes because they have a notably wider area for the forefoot and toes. Anyone whose feet are wide as mine are will understand the reasoning here.
The R315 upper is also heat-moldable, which means that riders with oddball feet have a chance of getting a shoe at an off-the-shelf price that has a custom fit.
Build quality
The R315 shoes appear to be very stiff, and very well built— I’d have to say they are a more durable and robust shoe than the Giro Prolight SLX. I have both shoes in size 44.5, and the Shimano is definitely a larger and more commodious shoe, and this is clear when held up side-by-side to the Giro Prolight SLX.
Weight
The Shimano SPD-SL R315 shoes are a larger and longer and more solidly built shoe than the Giro Prolight SLX (even at the same 44.5 size), so it is natural to expect them to be heavier, as they prove to be.
I weighed the shoes on my lab-grade scale. Both weights with Shimano cleats installed for DuraAce pedals:
Shimano R315: 663g (+156g)
Pearl Izumi Octane: 633g (+126g)
Giro ProLight SLX: 507g
Both shoes are very light shoes as shoes go. The Shimano R315 uses a conventional buckle, and is simply a larger and sturdier shoe, and so it is no surprise that it is heavier. The wider forefoot area might be a compelling factor for some riders with wide feet.
Riding feel
TBD— report to be updated with some experience riding them.