Any recommendations on a good yet lightweight bike lock. I've had a decent d-lock for a long time which has been a great buy but it's a bit hefty to lug around with me. Security obviously more crucial than the weight though.


pjay [254 posts] 6 years ago

The lighter locks get the less secure they become. It's a fact of life, unfortunately.

Stofish [61 posts] 6 years ago

This one has served me well, get the slim version.

PeteH [151 posts] 6 years ago

oh, another thing worth saying is that I took out some bike insurance recently and the insurance co linked the rating of lock they require (gold, silver, bronze etc) to the value of the bike.

So that might give you a decent metric as to the what the smallest/lightest lock you can get away with for the value of your bike.

They said:
- sold secure bronze up to £250
- sold secure silver up to £1500
- sold secure gold over £1500 (no maximum value)

These are just their numbers but they might help give an indication. This was British Cycling insurance.

PeteH [151 posts] 6 years ago

Been thinking of the same thing myself, something a bit lightweight that I can take on longer rides when I might feel like parking up for a while and going for a wander.

Smallest one I've seen is the Kryptonite Evolution Mini (http://www.amazon.co.uk/Kryptonite-Evolution-Mini-Lock-Bracket/dp/B000AMPRG0/ref=sr_1_1?ie=UTF8&qid=1324071492&sr=8-1) which is silver sold secure. Have seen these on other bikes but not felt how heavy it is, but presumably small size and weight is what they're trying to sell. Its true that they're popular with messengers.

I currently commute around London wearing one of those Fahgettaboudit u-locks (and a chain), ideal for there, but very very heavy and would not particularly want to carry on an 80-mile weekend jaunt.

You might want to visit lbs and just feel the relative weights

Simon E [3300 posts] 6 years ago

Security obviously more crucial than the weight though.

You'll be sticking with the D-lock, then.

Flexible locks, usually cables, are very easily broken. Even those big, fat chains that weigh a ton can be easier to break with hefty bolt croppers than the D-locks.

For nipping to the shops I take a cheap combination lock that coils up in my pocket but for longer time away from the bike in town it's always the Kryptonite D-lock. The bike's not worth a lot, but it is to me - I would be upset, and have to walk home, if it was nicked.

The Evo Mini would be OK if it can secure your bike adequately, but I find the extra depth of the standard Series 2 means I can get the lock around a post or stand and through the rear wheel & seat stays. It's a visual deterrent too.

Sold Secure is an industry sponsored cop-out / self-interest scheme and not the best way to evaluate a lock's performance. It's only of relevance if your insurer specifies that standard as minimum for paying on a claim.

Bikeradar's lock tests appear pretty good. I had pages from an old C+ group test where they discussed their methods and it was a good way to compare the locks' ability to resist attack.
If you have the time this is one of many discussions on security at LFGSS:

trikeman [309 posts] 6 years ago

I Don't want to throw a spanner in the works here on D locks, but at work we witnessed one of the fastest bike thefts imaginable, viewed after the event on the works CCTV. The bike, a reasonable scott was D locked to the specific cycle 'hoops' then along came the thief. On full display he produced a small scissor jack, the type in old car boot's, put it in the D lock and put a small 'screwdriver' in and turned it a few times - 'bang' the lock was on the floor and he was away. We couldn't believe how quick it was. The CCTV footage was given to the Police and the owner got a crime reference number.
I had a look at the lock base after (thief took the U bar bit) and that was a silver sold emblemed one and it looked like the lock's bar / U bend just sheared the anchor pawls within the bottom - after all, the little jack can lift a ton or two if it can lift cars - food for thought. I know whatever we use the determined thief will have an answer, but it just looked so simple, an action we all said even if it was in the wide open to the public just looked like the 'ownwer' leaning over and unlocking it until we looked closer. Good end to the story though, he got a new bike and a better later upgraded model to boot from his insurance (there is the biggy - insurance). Hope it helps.
Regards Trikeman ;o)

PeteH [151 posts] 6 years ago

That Bikeradar article is good Simon. Its worth a read if only because there are quite a few expensive locks there that are rated as crap. (Might try looking at the fixie thread but generally find that site a bit hardcore!)

trikeman I think it just goes to show that the main purpose of locks is to delay and deter - I don't think any of them can be relied upon to prevent. The advice I was given when I first had a bike in London was to put two different types of lock on it, the reason being that the attack for chains is different to the attack for d-locks, so a thief needs to have the tools to do both. It sounds like a reasonable argument although if a thief is determined...

dave atkinson [6371 posts] 6 years ago

I use one of these around town:


you can't lock your wheels up with it, just the frame. but it's really well built and half the weight of a normal u-lock. it'll fit in your jeans pocket too.

some locks are better at resisting the old scissor jack than others. it's not something that you'll be able to gauge from the sold secure rating though, as it's not something that they test for (i don't think)

Simon E [3300 posts] 6 years ago

Thanks for the link Dave.

When I was choosing a lock I got the dimensions of the Kryptonite Series 2 variants (there are three of them) and worked out which would fit without leaving too much room. If I get time tomorrow I'll take a pic of my locked bike and upload it.

I obtained internal dimensions for each of the Kryptonite locks I was considering:
Evolution Mini: 8.3 x 14cm (730g)
Evolution Series 4: 10 x 23cm (1700g)
Series 2 Std: 10 x 23cm (1100g)
Series 2 ATB: 12.7 x 23cm

On Series 2 v Series 4 I decided that if a dedicated thief was able to break the slightly lighter and less portly Series 2 lock he'd get through the heavier Series 4 easily enough. I don't know how accurate it is buy Kryptonite use a scale of 1 to 12. The Series 2 score 8 while the Series 4 get a 9.
LFGSS is certainly hardcore but threads like the one I linked to helped me decide on the best option for me.

You can probably tell I spent a while gathering all this info  3

Edit: a link I saved.