SIDI AERON MTB XC CYCLING SHOES
Engineered for the hardest lines.
AERON redefines XC performance through advanced construction and precision fit.
The ripstop upper with rubber bumpers delivers outstanding protection without added weight,
while dual
NUUN 001C
dials and internal
Firmor X
reinforcement ensure secure,
responsive support. A fast-adapting instep and
UNUM Ergo
tongue provide a pressure-free fit,
complemented by a tool-free heel adjuster for fine-tuned stability.
The outsole, with stiffness index
11
and generous rubber coverage, offers powerful traction
and efficient energy transfer on technical XC terrain.
Technical Specifications
- Upper: Ripstop fabric with rubber bumpers — lightweight, tear-resistant, and protective
- Closure: Dual NUUN 001C aluminum dials — aerodynamic, precise, and secure fit control
- Instep: Adaptive instep linked to dials — molds to the foot for a personalized fit
- Fit System: Firmor X internal support + tool-free heel adjuster — enhanced stability and alignment
- Tongue: UNUM Ergo anatomical tongue — relieves pressure for consistent comfort
- Outsole: X2FC full carbon with rubber lugs — stiffness index 11, optimized for grip and power transfer
- Cleat Setup: Independent cleat adjustment for personalized positioning
- Replaceable parts: Heel pads and dials
Product Benefits
|
STABILITY MEETS AIRNESS
Lateral stability combined with a lightweight, ventilated structure built for XC performance.
|
TOUGHNESS MADE LIGHT
Ripstop fabric and rubber bumpers provide rugged protection without unnecessary weight.
|
|
TAILORED FIT MADE SIMPLE
Adaptive instep system connected to the dials ensures a precise, personalized fit.
|
LOCKED IN
Firmor X support and tool-free heel adjuster keep your foot stable on the most demanding lines.
|
Find Your Perfect Size
To choose the correct number, measure the length of the foot in cm , from the heel to the big toe, as shown in the size chart.
- Place a sheet of paper against a wall and stand with your heel touching the wall.
- Mark the longest toe and measure the distance (heel-to-toe) in centimeters.
-
Compare your measurement with the size chart (EU • UK • US) below.
📱 If you are on a phone, please check the last image of the listing for better visibility. - If you are between sizes, choose the larger size for comfort.
SIDI Millennium Fit - Size Guide
| EUR | USA | UK | CM |
|---|---|---|---|
| 36 | 4 | 3 | 22.5 |
| 36.5 | 4.5 | 3.5 | 22.8 |
| 37 | 5 | 4 | 23.2 |
| 37.5 | 5.5 | 4.5 | 23.5 |
| 38 | 6 | 5 | 23.8 |
| 38.5 | 6.5 | 5.5 | 24.2 |
| 39 | 6.5 | 5.5 | 24.5 |
| 39.5 | 7 | 6 | 24.8 |
| 40 | 7.5 | 6.5 | 25.2 |
| 40.5 | 8 | 7 | 25.5 |
| 41 | 8 | 7 | 25.8 |
| 41.5 | 8.5 | 7.5 | 26.2 |
| 42 | 9 | 8 | 26.5 |
| 42.5 | 9.5 | 8.5 | 26.8 |
| 43 | 10 | 9 | 27.2 |
| 43.5 | 10.5 | 9.5 | 27.5 |
| 44 | 10.5 | 9.5 | 27.8 |
| 44.5 | 11 | 10.5 | 28.2 |
| 45 | 11.5 | 10.5 | 28.5 |
| 45.5 | 12 | 11 | 28.8 |
| 46 | 12 | 11 | 29.2 |
| 46.5 | 12.5 | 11.5 | 29.5 |
| 47 | 13 | 12 | 29.8 |
| 47.5 | 13.5 | 12.5 | 30.2 |
| 48 | 13.5 | 12.5 | 30.5 |
| 48.5 | 14 | 13 | 30.8 |
| 49 | 14.5 | 13.5 | 31.2 |
| 49.5 | 15 | 14 | 31.5 |
| 50 | 15 | 14 | 31.8 |
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About Us
Cyclist's Closet is a virtual cycling store based in Lisbon, Portugal. We provide high-quality cycling gear at competitive prices, helping riders achieve the best performance on every ride.
FROM CYCLISTS TO CYCLISTS — COMMITTED TO QUALITY AND PERFORMANCE
We are an authorized reseller of leading cycling brands such as Sidi, Castelli, Selle Italia, Prologo, Fizik, MET , and many more. All our products are sourced directly from official distributors in Europe, ensuring authenticity, competitive pricing, and trusted service.
Shipping & Handling
🚚 Free Shipping available on most shoes and helmets . For clothing, free shipping applies when purchasing two or more items.
Delivery time depends on the destination country and carrier.
Customs Duties: Depending on your country, your order may be subject to import duties or taxes. These charges are the buyer's responsibility.
Returns
If you are not satisfied with your purchase, you can return the item within 30 days . Returned items must be:
- In the same condition as received
- With original tags attached
- In the original box/packaging
- Without signs of use or damage (including mishandling during return shipping)
Buyer is responsible for return shipping costs, unless the item is faulty or incorrect.
Contact
If you have any questions, please do not hesitate to contact us. We are available 7 days a week to assist you.