What size of D-lock?

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ratherbeintobago
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What size of D-lock?

Post by ratherbeintobago »

Need a new lock, I think, as my existing one is too big.

What size of D-lock is big enough? I think a 230mm one will be fine, the other option is a 300mm

What does the panel advise?
Jdsk
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Re: What size of D-lock?

Post by Jdsk »

The ones that's always with me is 280mm outside length. I also carry a cable.

Leaving it with as little clearance as possible seems to be a good idea. I don't expect either to withstand a determined attack.

250 mm might be a bit small to go round the frame and eg a lamppost.

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mjr
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Re: What size of D-lock?

Post by mjr »

Jdsk wrote: 8 Jul 2021, 3:23pm Leaving it with as little clearance as possible seems to be a good idea. I don't expect either to withstand a determined attack.

250 mm might be a bit small to go round the frame and eg a lamppost.
Be very cautious about lampposts. Some of them are hinged or unpluggable for ease of repair and then the thief can just slide your lock off the post. Any metal fences (and the thick posts, not the bars or palings) nearby are usually better.

I also have a 280mm D. I agree on leaving little clearance. If I'm parking on a typical bike stand, I usually fill the D with stays, crank or wheel, as needed. I also use an alarmed cable to deter attacks on the front wheel (even though it takes me 5 minutes with tools to detach the brake and guards and remove it on my usual bike!)

I wonder if the 300 is really an optimistic outside measurement of a 280mm one.

As to which you need, measure your bike and some typical parking objects.
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Paulatic
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Re: What size of D-lock?

Post by Paulatic »

mjr wrote: 8 Jul 2021, 3:41pm Be very cautious about lampposts. Some of them are hinged or unpluggable for ease of repair and then the thief can just slide your lock off the post.
I’m no expert on lampposts as it’s not an item I see many of. You’ve baffled me though and I can’t work out how a D lock can be slid off a hinged post. Can you explain please.
I’m also wondering are these detachable posts you mention really light so one person can easily lift off.
We do have some posts in my village but they were changed to LED some ten years ago so easy access isn’t a priority as no maintenance has been needed.
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Mick F
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Re: What size of D-lock?

Post by Mick F »

I suppose the question is aimed at someone who wants to lock their bike to an immovable object.
Size is dictated by that object, Shirley?

I have a D lock that's not been used in years. I used it when locking my bike to railings opposite my ship, or outside my office but the people near and on watch, knew very well whose bike it was and kept an eye on it. Also had a big tally on the lock with my name, rank and number. I was lucky, I know.

I've locked bikes outside supermarkets over the years, but used the D lock and/or a cable lock as well as a Kabrus Alarm lock.

It all depends on how long you want to leave the bike for, plus where it is left. Size (and strength) of D lock depends on many many things.
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mjr
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Re: What size of D-lock?

Post by mjr »

Paulatic wrote: 8 Jul 2021, 4:01pm I’m no expert on lampposts as it’s not an item I see many of. You’ve baffled me though and I can’t work out how a D lock can be slid off a hinged post. Can you explain please.
Fold the post down, slide the lock horizontally along the post (most get thinner "higher") and then wrangle it over the lamp head, which is probably much easier with modern flat LED ones. I suspect the thief wouldn't even need to smash the lamp head like they used to. Then take the bike away by van and cut the lock in privacy.
I’m also wondering are these detachable posts you mention really light so one person can easily lift off.
Yes, they're typically the shorter lampposts used in some parks and town centre pedestrian zones. I'm not sure if one person can remove/reinstall a faulty/vandalised lamp because our council parks workers seemed to work in pairs, but that might have changed with covid. I don't think a tall A road post would be unpluggable. Those are more likely hinged because I rarely see them working on lamps at height on A roads any more. I wouldn't like to bet against motorists driving into a cherry-picker! Safer to fold them down along the pavement and then the incompetent motorist will hit the pole stub first, causing damage but hopefully not injuring the workers.
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Cowsham
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Re: What size of D-lock?

Post by Cowsham »

I saw one today which fitted neatly inside the frame triangle and seemed to be bolted to the seat tube. Maybe they're all like that -- I haven't got one yet.
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DaveReading
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Re: What size of D-lock?

Post by DaveReading »

Cowsham wrote: 8 Jul 2021, 6:42pm I saw one today which fitted neatly inside the frame triangle and seemed to be bolted to the seat tube. Maybe they're all like that -- I haven't got one yet.
I use a Kryptonite mini-D that fits that description.

While I could use it to lock the crossbar to the horizontal part of a Sheffield rack, I much prefer to put it through the chainstays and wheel and lock to the vertical bit of the rack, leaving no room for a thief to get any kind of leverage inside it.

I didn't like the frame holder attachment that came with it (the lock wobbles too much), so it normally travels bungeed to the rear carrier on my tourer.
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Cowsham
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Re: What size of D-lock?

Post by Cowsham »

DaveReading wrote: 9 Jul 2021, 8:28am
Cowsham wrote: 8 Jul 2021, 6:42pm I saw one today which fitted neatly inside the frame triangle and seemed to be bolted to the seat tube. Maybe they're all like that -- I haven't got one yet.
I use a Kryptonite mini-D that fits that description.

While I could use it to lock the crossbar to the horizontal part of a Sheffield rack, I much prefer to put it through the chainstays and wheel and lock to the vertical bit of the rack, leaving no room for a thief to get any kind of leverage inside it.

I didn't like the frame holder attachment that came with it (the lock wobbles too much), so it normally travels bungeed to the rear carrier on my tourer.

The one I saw looked very rigid to the seat tube -- don't know what make it was only saw it briefly.
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Cowsham
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Re: What size of D-lock?

Post by Cowsham »

What advantage has a D lock over a chain and padlock?
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scottg
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Re: What size of D-lock?

Post by scottg »

Cowsham wrote: 13 Jul 2021, 8:20pm What advantage has a D lock over a chain and padlock?
Takes longer to cut thru.
https://altorlocks.com/collections/saf-lock
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Cowsham
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Re: What size of D-lock?

Post by Cowsham »

scottg wrote: 13 Jul 2021, 8:29pm
Cowsham wrote: 13 Jul 2021, 8:20pm What advantage has a D lock over a chain and padlock?
Takes longer to cut thru.
https://altorlocks.com/collections/saf-lock

2021-07-13_15-28-31.jpg
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Stevek76
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Re: What size of D-lock?

Post by Stevek76 »

D lock generally lighter for the same level of protection. The 8/10mm links of chains will generally yield to 4' bolt croppers. 16mm+ dlocks (also abus's 14mm square profile) will generally need an angle grinder.

On the flip side, if you don't fill the lock properly, dlocks are vulnerable to jacks etc and chains are a bit trickier to angle grind.

Mostly of course it's about not leaving expensive bikes locked outside!
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Cowsham
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Re: What size of D-lock?

Post by Cowsham »

I think -- what use is a D lock if you've nothing to lock to. ie there may not be a convenient bike rail/rack and only a cast iron drain pipe which my chain will wrap around. What about stainless chain and lock? Wouldn't that be hard to cut through?
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Cowsham
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Re: What size of D-lock?

Post by Cowsham »

Stevek76 wrote: 15 Jul 2021, 9:52pm D lock generally lighter for the same level of protection. The 8/10mm links of chains will generally yield to 4' bolt croppers. 16mm+ dlocks (also abus's 14mm square profile) will generally need an angle grinder.

On the flip side, if you don't fill the lock properly, dlocks are vulnerable to jacks etc and chains are a bit trickier to angle grind.

Mostly of course it's about not leaving expensive bikes locked outside!

4" ??
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