Bicycle: Frame locks

Old locks, some history of Axa and frame locks in NL

I've used a number of different frame locks on most of my bikes. I'm not sure what locks there were if any on some bikes I had in my youth, but after that locks were a standard requirement for anyone to use, for the bicycle you would use to go to school for example, and to leave it at shops, or to leave it locked when you would go to a sports club. The evolution of these locks is quite clear. I know that in the 1980s, 1970s such locks were barely more than some sheet metal, you could probably saw through those with a standard small 'Puk' metal hand saw in no time.

In the 1980s Axa also made better locks, usually white with a red knob, these are hard to saw through which I know from having spent some time many years later sawing through one of these 1980s locks on a bike from a relative of which we couldn't find the key. Sawing through such locks was already very difficult and time consuming, and it is not really practical at all with frame locks these days. Angle grinders however cut through anything in no time. There are no safe locks! The only locks that may be somewhat safe are those that are incorporated into the frame, which means almost certainly damaging the frame to open to lock. That still leaves the possibility of thieves taking components, such as wheels. In any case you can only consider any lock as a delay to a thief, no permanent security.

A few relatives used later Axa locks such as the SL-7 and SL-9. These could be hacked (simply opened) with a blank key that you could order from a bike shop... See in Dutch this page: That made these locks rather useless and I wouldn't buy one of them and I would replace them on any of my bikes. Locks are not expensive, just buy a recent good one!

Recent frame locks: Axa Defender, Axa Victory, Abus 5850, Trelock RS 453 and issues hitting the knob and/or key with your heels

1. Axa Defender: I used the Axa Defender frame lock on I think 2 of my bikes, but at some point I read an article about the Defender being easy to open, which mentioned that video surveillance from an Ikea in Delft showed someone breaking these locks without much effort (see This made me decide to go for the Axa Victory from then on.

2. The Axa Victory is a nice lock but has an annoying plastic piece that hides the bolts after you mount it. This comes off pretty easily when you take out the wheel and then hit the plastic piece with the tyre. It got bent the first time this happened to me... This is a pretty bad design decision! In the Defender and other locks there are usually 2 plastic pieces that fit over the bolts, one on each side and there is zero chance that they will come off from contact with the tyre.

Email to Axa: I wrote an email to Axa about this experience but also suggesting, related to the issue to be described next paragraph, to put the key more to the inside by changing the cylinder or rotating it slightly upwards (there could perhaps be an issue in rainwater coming in, so sliding it over a bit and perhaps shortening it a bit would be better then). I got a rather meaningless reply stating it would be passed on to the relevant department. That sort of reply usually tells you that you'll never hear anything more about this, whichever company it is you contact.

Issue with hitting the key or knob with your heels (an issue with many frame locks): With my Cannondale touring bike I had an issue of hitting the key with my heel with the defender and other locks. This is from a smaller frame size M that I chose which I like because of not wanting to have a long top tube, which you get esp. with Cannondale frames of size L/XL, which gives a rather stretched out position. This means the frame is fairly small (and I use a long seatpost with it) and the lock is rather low, and right in the circle where my foot goes when pedalling. If the frame were larger or smaller this wouldn't happen...

3. The Abus 5850: This lock, as all Abus locks, has a knob that sticks out quite a bit. I hit it regularly with my heel on the first ride with the touring bike with Rohloff hub that I bought, so I ordered a Trelock RS 453. I could have ordered another Axa Victory but I wanted to see how well the Trelock lock works, as with the Victory that stupid plastic cover for the bolts that comes off far too easily is rather annoying. I made a picture of how much the Abus sticks out, to be added shortly.

4. Trelock RS 453: Abus locks were not an option due to the knob sticking out with all of their locks, so I ordered the Trelock RS 453 in the version with key that you can remove at any time. So importanly also when the lock is open thus giving space for my heel. This works well, though it may be just a bit wider than the Axa Victory. Ca. 15.0 cm total width vs. Axa Victory ca. 14.5cm? I need to take the Trelock off the bike and measure it then.

Estimates confirmed when measuring off the bike... I decided to get another Axa Victory just to compare and use on the 2nd bike too to see if I like it more for being slightly narrower and perhaps other reasons (perhaps a more or less smooth key action for example, I've not yet compared this).

Some data on these locks:

With 'effective width' I mean the width the lock would have when looking at half of it, taking the half that sticks out most, then double that. So if the knob sticks out a lot more than the key (esp. of note with a lock that has a removable key), then how much that knob sticks out will determine the effective width. You won't then be hitting both sides, but 1 side is enough and that is the problem hitting either side with your heel.

For use of version with keys that are not detachable when the lock is open:
- Axa victory: Effective width with knob and key: 145.8 mm, as the key does not stick out much (and only there where the lock is narrower) and the knob barely from the ring and only where the lock is already narrow. Still, despite nothing sticking out the version with removable key is better is it has a smaller section where the lock is 'wide' and your heel more easily glides past the ring if hitting it, than the key... Here the removable key adds a little bit to heel clearance.
- Trelock RS 453: Effective width with knob and key: 159 mm as the key sticks out quite a bit. here the removable key is essential for good heel clearance.

Plug in chains from Axa and Trelock:

The plug-in chains for the Trelock locks have a longer pin. They will fit into (and then actually get locked in) the Axa locks, and they are exactly the same shape at the end so this makes sense, but the Axa plug-in chain does not lock into the Trelock LS 453 without some modification as the exposed metal part is too short. You could cut off a bit from the plastic at the pin of the Axa chain to make it work with the Trelock locks (removing some plastic from the Trelock lock is not going to be enough considering the difference in lenght of the exposed metal of the pin that goes into the frame lock.
- Axa RL-100: 724 g, 6mm thick chain links, length from the notch in the pin to the inside of the last link of the chain: 95 cm
- Trelock ZR 355: 928 g, 6mm thick chain links, length from the notch in the pin to the inside of the last link of the chain: 103 cm
- Trelock ZR 455: 1800 g, 8mm thick chain links, length from the notch in the pin to the inside of the last link of the chain: 97 cm

The Trelock ZR 355 is my choice due to slightly longer, working with both Trelock and Axa locks, and not too heavy. The ZR 455 is one I would take only when going to or living in a big city for a little bit more safety.


I can't really say much about the locks in regard to being lockpick resistant nor simple brute force resistant (which the SL-7, SL-9, Defender aren't), and I haven't seen any negative experiences about this on the internet, so the issues with the knob sticking out and whether or not to get an always detachable key are the most important choices to make. I would choose the best lock in the range of any given manufacturer, not a cheap lock, for any bike, as the price difference is very small (prices range from ca. 20-40 euros), which means that economising here is not really useful unless it is a very cheap 2nd hand bike that your mindset is "I will buy another 2nd hand bike if it gets stolen". However, that means wasting your time and more money on buying another bike, so I would still recommend the best in the range of the manufacturers.

Of the locks I used the Axa Victory gives the most heal clearance and is the lightest, is also the best in heel clearance in versions with not always detachable key, the Trelock is in the middle and the Abus 5850 is the worst in all aspects I discussed above. I occasionally do touch the Trelock 453 with my heel but glide past it, the Axa victory is barely narrower but I will try it on this bike too to see if the 5mm total (so just 2.5mm per side) narrower is noticeable in my case.

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