I've just got my son a mtb for Uni,& he wants a decent lock a `D, type maybe, but shouldn't cost a fortune but do the job!.
Given that any lock can be broken, if they want your bike, just buy whatever your budget can stretch to and tell your son to be careful where he locks it as it can be nicked in 5 mins no matter what lock you use.
£52.49 for a lock that's usually £75. Bargain.
http://www.cyclesurgery.com/kryptonite-evolution-4-standard-lock/d-locks/bikes-components-bikewear/fcp-product/16111
Ditto this. £37.49 for a fifty quid Krypto Evo. Bargain!
For info, the Abus range were always the locks that bike thieves tried to steal to lock up their own (stolen) bikes. 🙂
I'm with footflaps. If you're not going to spend loads I would pick something as small as possible so the frame can be locked tightly to a post and maybe a cable for the wheel if you care about that.
Show your son this video: http://www.nytimes.com/video/2012/03/12/opinion/100000001423494/bike-thief.html
Abus are great and mine is 20 years old and going strong. But so to is my Kryptonite.
I'd recommend one of these Kryptonite Series to u-locks with a cable loop to get your front wheel secured too for £19 [url= http://www.ebay.co.uk/itm/Kryptonite-KryptoLok-Series-2-Std-U-lock-4-foot-Kryptoflex-cable-GK999416-/280920780890?pt=UK_SportsLeisure_Cycling_BikeLocks_SR&hash=item41682ef05a#ht_1481wt_906 ]fleaby [/url]
What's the bike worth. Whatever, it has to be a D lock if you don't want it nicked.
If its not an expensive bike sainsbury's are apparently selling off some D locks for £3 down from £20 at the moment.
Otherwise, Abus and/or Kryptonite.
Abus...hmm, aren't there guides around showing how easily they can be picked?
Kryptonite Kryptolok bare minimum gets my vote.
I'd recommend one of these Kryptonite Series to u-locks with a cable loop
The whole point of using a D-lock and a decent cable lock is that they both require very different tools to defeat, and any theft will now take twice as long (perhaps a minute instead of 30seconds). D-locks with attached cable lock aren't actually a good idea.
Cheap D-lock and a load of reflective tape liberally applied to the frame. The latter puts off 99.9% of thieves and the D-lock stops the 0.1% of colour blind thieves 😉
It has to be a D lock,we use Abus Granit X Plus. Two weeks ago the scum had to dig out the ground anchor and steal the bike ,the lock and the ground anchor.
I think you can do a lot to deter theft.
Don't ride a MTB suspension forks etc. A fully rigid bike, no qr's. Disguise a bike with tape & stickers. Accept you cannot leave a bike unattended in some places and use a ****ing great big lock!!
Its a £300 retail bike! He's not daft & knows not to leave it unattended,but them a us granite locks are £90 nicker.....
Don't know whether it helps but I went shopping for a meaty chain lock recently - the ones 'for motorbikes' were significantly cheaper for a given level of security.
Not sure whether the above applies to d-locks too ....