---
product_id: 295858795
title: "Castelli Undersaddle XL, Black, OSFA"
brand: "castelli"
price: "$377.35"
currency: USD
in_stock: true
reviews_count: 5
url: https://www.desertcart.us/products/295858795-castelli-undersaddle-xl-black-osfa
store_origin: US
region: United States of America
---

# Water-resistant materials Secure internal pocket Stain-resistant design Castelli Undersaddle XL, Black, OSFA

**Brand:** castelli
**Price:** $377.35
**Availability:** ✅ In Stock

## Summary

> 🚴‍♂️ Gear Up for Adventure!

## Quick Answers

- **What is this?** Castelli Undersaddle XL, Black, OSFA by castelli
- **How much does it cost?** $377.35 with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.us](https://www.desertcart.us/products/295858795-castelli-undersaddle-xl-black-osfa)

## Best For

- castelli enthusiasts

## Why This Product

- Trusted castelli brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Built for the Bold:** Designed to withstand the elements while complementing your active lifestyle.
- • **Adjustable Fit for All:** Equipped with an adjustable hook and loop attachment strap for a customizable fit.
- • **Secure Your Essentials:** Features a water-resistant zipper to keep your belongings safe and sound.
- • **Smart Storage Solution:** Includes an internal storage pocket for organized access to your essentials.
- • **Stay Dry, Stay Stylish:** Crafted with water and stain-resistant materials for the modern adventurer.

## Overview

The Castelli Undersaddle XL is a versatile and durable storage solution designed for cyclists. With water and stain-resistant materials, a secure water-resistant zipper, and an adjustable attachment strap, it ensures your essentials stay protected and easily accessible on every ride.

## Description

CASTELLICastelli Undersaddle XL, Black, OSFA

## Features

- Water and stain resistant materials
- Water resistant zipper
- Water resistant construction
- Adjustable hook and loop attachment strap
- Internal storage pocket

## Images

![Castelli Undersaddle XL, Black, OSFA - Image 1](https://m.media-amazon.com/images/I/61MEcbrMaZL.jpg)

## Customer Reviews

### ⭐⭐⭐⭐ 







  
  
    Good quality but I think if it was just a ...
  

*by T***Y on Reviewed in the United Kingdom 🇬🇧 on 3 June 2016*

Good quality but I think if it was just a centimetre or two longer and centimetre wider it would be perfect,it has strength and looks nice,it has a mesh compartment on the outside which is stretchy and I use it for my mini pump but in my opinion an additional strap for this mesh which is open ended at both ends would make it safer because if you store something in it you could find it working loose,the straps that tie the actual bag to the bike do not really prove useful in securing whatever is in the outer mesh compartment.

### ⭐ 







  
  
    Fell apart mid ride.
  

*by K***N on Reviewed in Canada 🇨🇦 on 20 January 2021*

The adhesive holding the strap together didn't last more than a season. It fell apart while I was descending and went flying at oncoming traffic.The shop I bought it from said it happened to someone else. Too bad, it was great while it lasted.

### ⭐⭐⭐⭐⭐ 







  
  
    XL is relative.  Consider this a mini.  A very nice mini.
  

*by L***D on Reviewed in the United States 🇺🇸 on 12 March 2018*

Had a micro bag for my skinny-wheel road bikes.  Found it handled a tube, patches, multi-tool, and levers without a lot of wasted space, and could grab the saddle nicely.  And then I got a new ride with 28s. Maybe up to 32s eventually.  Squeezing that bigger spare tube into my trusty old micro bag was just too much, so, time to shop. Saw this reviewed somewhere, then found it here at Amazon. Sadly, unable to find the Castelli Undersaddle in the shops I checked, so, there I am, reading online reviews and mining for specs on this thing.  First off:  don't let the "XL" label fool you.  This is any other company's mini. And that's good. Wasn't sure I liked the 'boxy' design, but then noticed the pump sleeve on the bottom, and that was it.  Ordered.  Fits my larger tube and all the other stuff with a little space to spare, while holding on tight and not looking huge.  And offers what I consider the nicest mini-pump option.  Kudos to Castelli for thinking outside the box on this one.

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**Shop now:** [https://www.desertcart.us/products/295858795-castelli-undersaddle-xl-black-osfa](https://www.desertcart.us/products/295858795-castelli-undersaddle-xl-black-osfa)

---

*Product available on Desertcart United States of America*
*Store origin: US*
*Last updated: 2026-06-07*