# Which racing flats offer the quietest step for indoor use? — Verified Specification Comparison

> All specification data verified from official manufacturer documentation.

Which racing flats offer the quietest step for indoor use?

## Products

### adidas Adizero Adios 9
```yaml
product: adidas-adizero-adios-9
brand: adidas
price_gbp: 82.72
origin_country: null
confidence_score: null
summary_source: generated_from_verified_specs_v1
drop: 7
weight: 6.2
stack_height: 27
sole_stiffness: Flexible
upper_material: Micro Fit one-way stretch material
```

- **Price:** £82.72 [^1]
- **Summary:** The adidas Adizero Adios 9 is a lightweight racing flat with a low stack, full-length Lightstrike Pro foam, and a nylon shank for responsive speed. Its breathable, stretchy Micro Fit upper and grippy Lighttraxion outsole suit experienced runners targeting short races, intervals, and tempo sessions.
- **Ideal For:** Its low 27 mm stack, flexible sole design, and road-focused rubber outsole make it a quieter indoor option than shoes with prominent track spikes or rigid plates.
- **Additional Sources:** [^2], [^3]

### adidas Adizero Adios Pro 3 IE1052
```yaml
product: adidas-adizero-adios-pro-3-ie1052
brand: adidas
price_gbp: 177.46
origin_country: null
confidence_score: null
summary_source: generated_from_verified_specs_v1
drop: 6.5
weight: 7.58
stack_height: 39.5 heel / 33 forefoot
sole_stiffness: Lightweight stiffness from carbon-infused ENERGYRODS 2.0
upper_material: Semi-transparent mesh with at least 50% recycled content
```

- **Price:** £177.46 [^4]
- **Summary:** The adidas Adizero Adios Pro 3 is a lightweight road-racing shoe with a high 39.5 mm heel stack, responsive LightstrikePRO cushioning, carbon-infused ENERGYRODS 2.0, and a Continental outsole. It suits runners targeting fast half-marathon and marathon performances who want cushioning, propulsion, and wet- and dry-surface traction.
- **Ideal For:** It is a reasonable option for quiet indoor racing because it has no spike pattern and uses a road-running Continental rubber outsole, although its carbon-infused ENERGYRODS 2.0 make the sole relatively stiff.

---
## References & Sources
[^1]: adidas, accessed 2026-09-03. https://www.adidas.com/us/adizero-adios-9-running-shoes/KH8894.html
[^2]: Running Warehouse, accessed 2026-09-03. https://www.runningwarehouse.com/adidas_adizero_Adios_9/descpage-AD9AAM1.html
[^3]: i-Run, accessed 2026-09-03. https://www.i-run.com/man/shoes/running/adidas/adizero-adios-9_fiche_143269.html
[^4]: adidas New Zealand, accessed 2026-09-03. https://www.adidas.co.nz/adizero-adios-pro-3-shoes/IE1052.html