Head-to-Head
Glycerin FlexvsAero Razor
The Glycerin Flex is a daily trainer shoe while the Aero Razor is a speed trainer shoe. The Glycerin Flex retails for $170 while the Aero Razor comes in at $140 — a $30 difference. The Aero Razor is the lighter shoe at 6.9 oz versus 9.1 oz for the Glycerin Flex. In our ratings, the Aero Razor edges out the Glycerin Flex — 8.9/10 versus 8.0/10.
| Rating | 8.0 / 10 | 8.9 / 10✓ | |
| Price | $170 | $140✓ | |
| Weight | 9.1 oz | 6.9 oz✓ | |
| Category | Daily Trainer | Speed Trainer | |
| Terrain | Road | Road | |
| Cushion | Medium | Medium | |
| Softness | Balanced | Firm | |
| Drop | Medium | Low | |
| Drop (mm) | 6 mm | 4 mm | |
| Stack | 36 mm | 36 mm | |
| Stability | Neutral | Neutral | |
| Fit | Narrow | Narrow | |
| Energy Return | Low | High✓ | |
| Breathability | Medium | Breathable✓ | |
| Traction | High | High | |
| Shock Absorption | High✓ | Medium | |
| Durability | Good | Good |
