# OnGuard Mastiff 8123 Bicycle Chain Lock

**URL:** https://aio.lv/en/product--onguard-ong-8123--11417668
**Data updated:** 2026-07-09 14:53 (EEST)
**Category:** Bicycle accessories
**Manufacturer:** ONGUARD
**Manufacturer code:** ONG-8123
**EAN:** 7290001281239
**Warranty:** 2 Years
**Availability:** Available for order
**Price:** 29.99 €
**Prices and availability valid until:** 2026-08-16 23:59
**Price without VAT (21%):** 24.79 EUR
**Can be purchased by legal entities:** Yes (invoice)
**Buy:** https://aio.lv/en/product--onguard-ong-8123--11417668

## Delivery options

| Delivery method | Delivery time | Cost |
|---|---|---|
| Office pickup (2b. Kengaraga str., Riga, Latvia, LV-1063) | 05.08.2026 | free |
| Pickup points | 10.08.2026 | 1.79 EUR |
| Courier delivery to door | 10.08.2026 | 4.99 EUR |

## Summary description

The OnGuard Mastiff 8123 is a high-security bicycle chain lock designed to provide reliable protection against theft. Featuring a durable hardened steel chain construction, this lock offers robust resistance to cutting and sawing attempts. It is an essential accessory for securing bicycles in urban environments, ensuring peace of mind for cyclists who prioritize security and durability for their equipment.

## Long description

The OnGuard Mastiff 8123 bicycle chain lock is a robust security solution engineered to protect your bicycle from theft in demanding urban environments. Constructed with high-quality hardened steel links, this chain provides significant resistance against cutting, sawing, and prying attacks. Its design balances heavy-duty security with practical usability, making it a reliable choice for cyclists who need to leave their bikes unattended for extended periods.
Advantages
The primary advantage of the OnGuard Mastiff 8123 is its superior material composition, which utilizes hardened steel to withstand physical tampering. The chain is encased in a protective fabric sleeve that prevents scratches and damage to the bicycle frame during use. Its flexible design allows for versatile locking options, enabling the user to secure the bike to a wide variety of fixed objects such as poles, racks, or railings with ease.
Suitable for
Securing bicycles in high-theft urban areas
Long-term parking of bicycles in public spaces
Commuters who require a reliable and durable locking mechanism
Protecting high-value bicycles and e-bikes
When it may not be suitable
This lock may not be ideal for cyclists who prioritize extreme weight savings, as the hardened steel construction makes it relatively heavy to carry during long rides. Additionally, if you require a compact lock that fits easily into a small saddlebag, the bulkiness of this chain might be inconvenient.
Key specifications
Hardened steel chain links
Protective fabric cover
High-security locking mechanism
Resistant to cutting and sawing
How to use
To use the OnGuard Mastiff 8123, wrap the chain around the frame of your bicycle and a secure, immovable object. Ensure that the chain is pulled taut to minimize the space available for potential thieves to insert tools. Insert the locking end into the mechanism until it clicks securely into place. Always ensure the lock is positioned away from the ground to prevent leverage attacks.
What to consider before purchase
Weight of the chain relative to your carrying method
Length of the chain required for your specific locking needs
Compatibility with your bicycle frame size
Usage recommendations
Regularly lubricate the locking mechanism with a silicone-based spray to ensure smooth operation and prevent internal corrosion. Keep the keyhole clean and free of debris to maintain the integrity of the locking system over time.

## FAQ

### How much does the OnGuard Mastiff 8123 Bicycle Chain Lock cost, and is it available for purchase?

The price is 29.99 € (valid at the time of publication and already includes all taxes). The item is available for order — 30 pcs. are in stock, and you can place your purchase right now with delivery across Latvia and Europe or choose pickup at the Riga collection point. We offer favorable purchase terms, including the option to split the payment into convenient monthly installments. Availability and price are updated in real time, so we recommend placing your order in advance.

### If I order this product today, when will I receive my order?

If you place your order today, delivery will be as fast and convenient as possible. You will be able to pick up your order on 05.08.2026 at the Riga pickup point or choose delivery across Latvia and Europe. We carefully inspect every purchase and pack it securely for safe transportation.

### What payment options are available?

AiO.lv offers several payment methods: Bank transfer, Bank cards on-line, Apple Pay, Google Pay. All transactions are 100% secure and encrypted.

### Can this product be purchased for a company (with VAT)?

Yes. AiO.lv works with legal entities in Latvia and across Europe. The product price already includes VAT. For certain product categories, as well as for companies from other EU countries with a valid VAT number, a 0% VAT rate may apply. We issue the invoice immediately after the order is placed, support electronic BIS invoices, and automatically generate all necessary accounting documents. You can complete the purchase for a company online — simply select the company profile and choose bank transfer as the payment method during checkout.

### What is the warranty period?

All ONGUARD products come with an official 2 Years warranty. It covers all manufacturing defects and malfunctions that may occur during use. The warranty is valid at all authorized ONGUARD service centers and through AiO.lv

### Can the product be returned after purchase?

Yes, you can return the product within 14 days of purchase if you bought it as a consumer (not a legal entity). Returns are possible without giving any reason — the main condition is that the product retains its original appearance and full set of accessories. We will make the process as simple and convenient as possible: just contact our customer support team, and we will help you arrange the return.

### Where should I contact for warranty service?

For warranty-related questions you can contact the AiO.lv (SIA VSPRO) customer support team. More information about warranty service: https://aio.lv/en/warranty

## Image

https://aio.lv/img/cache/product/11417668/66059459_large.webp