900 Bike Chain Lock



Made for protecting your bike during long stops.
Highly resistant, high-security bike lock. Perfect for securing the frame and front wheel.

This product is no longer in stock


view all stores

Theft resistantSecurity level rating: 8 out of 10.High-security lock
VolumeUsable length: 90 cm. Ideal for securing frame and wheel to a fixed object.
LightweightWeight: 2.3 kg.
Warranty2 Years
Technical Information

Contrary to what many people may think, no lock is fully tamper proof. A bike lock is there to make stealing the bike more complicated, to delay the thief and therefore act as a deterrent. A good lock has an anti-picking lock mechanism and is made out of materials requiring the use of specific tools, making theft more difficult.
Security rating
The security rating helps you choose the lock that is most suited to your use. To accomplish this, B'Twin defined a test protocol jointly with an independent laboratory, CNPP, based on real-life theft techniques. This unique protocol allows each lock to be given a comparable rating indicating how resistant it is to theft. This rating ranges from 0 (least secure) to 10 (most secure).
Main section
Links made of hardened steel (65 HRC), one of the highest strength levels available for bike locks. Guaranteed resistance to hacksaws and hammers. Covered in fabric to keep it from scratching the bike frame.
Reinforced lock mechanism. Hundreds of different keys to limit the risk of theft. Comes with 2 numbered keys.
Information / Concept / Technology
Structure : 100.0% Acrylonitrile butadiene styrene (ABS)


Sort by:
impossible to unlock
Used for 2 to 8 weeks
this chain lock is really massive and heavy and feels like really good quality for the price. i bought it because i want to be sure that it doesn’t get stolen easily. however, it usually takes couple minutes to unlock it, not very handy when i have to rush. it is stuck and i have to rattle and fight to get it open. so now, after maybe 1 month using it, the lock is stuck and i cannot open it anymore. tried for half an hour and looked like someone who does not know how to use a key, then gave up and walked away. embarrassing! don’t know what to with my locked bike now?? if you have any recommendations how i can unlock it before someone else does the trick with a bolt cutter please let me know..
Terrible product
Used for 2 to 8 weeks
After only two weeks of using this product the lock started getting stuck, making it more difficult to open. At some point I would have to spend 10 minutes on wrestling with the key and the lock trying to open it.
Response of the brand
It is possible that some grit or dirt may have entered the locking mechanism. If you feel the item is faulty, please feel free to return the item to us for a refund or an exchange.
Peter, Cycling Manager, DECATHLON
doesn't work every time.
Used for More than 1 year
Since i bought it it was not good. The lock stuck must oftime and i have to keep wiggle it to make it work. last week the lock doesn't want to open. luckily i couldn't lock my bike so the bike stayed in the bike shelter but now i am unable to unlock and bring it for refund. lost the lock and no refund:)
Response of the brand
Thank you for posting a review of your lock. I'm sorry to read that the lock isn't working as well as it should after 12 months of use. It is possible that some grit may have entered the mechanism causing is to seize. Take a photo of your lock and take it to your nearest shop (drop them a line first) where they can discuss the best option for you.
Peter, Cycling Manager, DECATHLON
Nice lock, can I get additonal keys?
Used for 3 to 6 months

I have used the lock for a few months now, works great.

I've lost one of the keys so I now have only 1 left. Is it possible to get a replacement set of keys to match the lock? I'm worried about losing this one and not being able to get the lock off. Bike locks typically come with 3 keys,

It says in the description that the keys are numbered but htis doesn't appear to be the case, can you confirm this please?

Bike locked forever
Used for 1 week or less
Impossible to unlock my bike... must be an indoor lock as it rusted really quickly. Bike being chained for weeks now. Tryied all sorts of oil impossible to open it.... if anyone at decathlon reads this and has a solutioon i d appreciate.
Response of the brand
Dear sir,
I can confirm that this is a lock designed for outdoor use. I have used the very same one personally for nearly three years outside. Every few months I apply some spray grease in the lock (not WD40 etc...) but one of the most common causes of locks jamming up is grit and grime. Keeping the lock mechanism off the ground for as long as possible is a good tip.
Realistically in your case, the only way will be to saw or cut through the chain with a very large bolt cuter or axle grinding machine as this lock is very strong.
Peter Lazarus, National Cycling Manager, DECATHLON
  • 1
Show results for