What size of D-lock?

[Jdsk]

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" ??

4' bolt cutters, about £30:



Leverage of course increases with length, but at 4' they're getting pretty hard to conceal. It's worth playing with some big ones if you want to understand what security you do and don't have. Ditto an angle grinder,

Jonathan

[mjr]

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?

Not very. Try some bolt croppers on it.

Drain pipes are a last resort for locking to. Many of them come apart in surprising ways that allow locks to be slid off. Probably better to go through a wall bracket on the pipe, which a 290mm D often can, but even then it only adds unscrewing the bracket to sliding it off the dismantled pipe.

Ultimately, a chain is also useless if there is nothing to lock to.

[Stevek76]

I meant to mention the less flexible locking options of a dlock vs chain but clearly forgot it mid post.

You can get chains that are in the "needs power tools" category but mostly they will be motorbike aimed chains and won't be light. Just browsing through the sold secure diamond list any chains are at least 12mm thick and are dual rated also as motorbike gold.

[Cowsham]

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" ??

4' bolt cutters, about £30:



Leverage of course increases with length, but at 4' they're getting pretty hard to conceal. It's worth playing with some big ones if you want to understand what security you do and don't have. Ditto an angle grinder,

Jonathan

Looks more like a 24" set -- but how they're measured isn't the issue -- I have used large 3 foot bolt cutters to cut 8mm and 10mm galvanized chains on sprinkler systems but I know this wouldn't cut the same link if it was a higher grade of chain. What do you think of the kryptonite chains.

I think whatever lock it is it needs to be practical or I'd end up not using it or just not able to go into any shops etc.

Currently I use a heavy stainless cable type combination lock. You'd need a very expensive cable cutter to cut through it. We use a £200 cable cutter at work to cut stainless earth cable but that will only just about cut 10mm square ( not diameter -- there's a big difference ) my lock must be at least 50mm square cable. I find it very easy to use.

I'm only shopping or eating in cafes so not left for long periods of time. When I'm camping it'll be around a tree near my tent -- couldn't do that with a D lock.

[James Up Hill]

On the grounds that a battery-operated angle grinder will go through a D lock in 30-40 seconds, surely all sensible thieves are using those these days?

[Cowsham]

On the grounds that a battery-operated angle grinder will go through a D lock in 30-40 seconds, surely all sensible thieves are using those these days?

Yes if I was a bike thief I'd want to see a D lock I can get good purchase on, with a hand held angle grinder, rather than a cable or chain which would need better specialized equipment to cut.

[DaveReading]

On the grounds that a battery-operated angle grinder will go through a D lock in 30-40 seconds, surely all sensible thieves are using those these days?

Yes if I was a bike thief I'd want to see a D lock I can get good purchase on, with a hand held angle grinder, rather than a cable or chain which would need better specialized equipment to cut.

And presumably not an Abus, which requires to be cut in two places.

[Cowsham]

On the grounds that a battery-operated angle grinder will go through a D lock in 30-40 seconds, surely all sensible thieves are using those these days?

Yes if I was a bike thief I'd want to see a D lock I can get good purchase on, with a hand held angle grinder, rather than a cable or chain which would need better specialized equipment to cut.

And presumably not an Abus, which requires to be cut in two places.

Take two grinder batteries just in case.

[SA_SA_SA]

Why do modern d locks not come with matchingly hardened steel 'barebones' style crossbars that can be slid on to prevent access by jacks?

https://www.ebay.com/itm/BAD-BONES-Bicy ... 2597490843