If you're using your bike just to go meet someone at the coffee shop, it's a hassle to have to bring along a backpack, just to carry your lock. You could get a lock-mounting bracket installed on your frame, but the Seatylock presents an interesting alternative – as its name suggests, it's a bike seat that can be removed to serve as a lock.
The actual locking part of the device folds up underneath the saddle sort of like an Abus lock, when not in use.
When you park, the flip of a quick-release lever causes the Seatylock to disengage from an included aluminum adapter that's mounted on the existing seatpost. The plastic-coated hardened steel lock is then folded out, run around the frame and an adjacent immovable object, then secured using a key.
As an added benefit, because the saddle is part of the lock, wandering parts-thieves won't be able to steal it as easily.
Currently the subject of a Kickstarter campaign, the Seatylock should be available in two saddle versions – a streamlined Trekking model, and a fatter-but-cushier Comfort model. Slightly the lighter of two, the Trekking (including the lock) tips the scales at 1.3 kg (2.9 lb). If users wish, however, they can also swap in a third-party saddle.
A pledge of US$85 will get you a Seatylock in either style, when and if they reach production. The planned retail price is $129. You can see a demo of the device in the pitch video below.
For another take on the seat/lock combo concept, you can also check out the InterLock. A successful Kickstarter product that's now in production, it's comprised of a seatpost that houses a cable lock inside.
Sources: Seatylock, Kickstarter
Granit X-plus http://i39.servimg.com/u/f39/18/95/26/68/abus10.jpg
(unknown Bordo) http://i46.servimg.com/u/f46/16/36/60/89/dsc03314.jpg http://forum.tontonvelo.com/download/file.php?id=76327
Not only the same bike but it looks like it has the Seatylock on it as well.
I used to use a real cheap barrel lock on my commuter bike, figuring no one would go to any trouble to steel it. Just wanted to keep someone from just hoping on it and riding off. It was light and convenient. I could even “pick it” in the dark. My time and location for locking up my bike was highly random so I could get by with a cheap lock.
I had considerable experience with locks. I worked in a large bike shop and was the one to get the old locks off the trade-ins. You learn lots of tricks. Salesmen would come in with the latest unpick able lock. Six minutes was the longest it took without causing damage. They are getting better and I am out of practice.
If you have to keep your expensive bicycle exposed in the same place all the time you allow for some determined preparation in order to steel it.
How much trouble do you want to go to to make it too much trouble for someone else? Situation awareness prevails.
Those who don't mind the weight won't like the price.