I've been using folding bikes with varying degrees of satisfaction for a few years now. As I do much of my hillwalking using the rail system it makes sense to have a folding bike as once folded they are (in general, and certainly throughout Scotland) treated as luggage, rather than a bike, and while there are restrictions on bikes, there are none on luggage. A few years back I arrived at Dalwhinnie station to await the southbound train. Shortly after two other cyclists arrived and I asked if they had cycle reservations, which they hadn't. The trains on the Perth line are limited to two bikes, and there were three of us. When the train arrived the guard refused to allow them on board, despite the fact they would have to cycle all the way to Perth! After a hard day when you are cold and wet that's the last thing you need. Since then I've gone through a variety of folding bikes, however most are aimed strictly at the commuting market. There are probably as many Bromptons in London as there are rats nowadays! There aren't that many folding mountain bikes the go though, but one that caught my eye was the Montague Paratrooper. "It's claimed it was designed for the US military and will can be deployed by parachute or helicopter. Having access to none of those I'll take their word for it. I do have access to the mountains of Scotland and have been giving it a good workout, on and off road. It is a full size mountain bike, with 26 wheels, adjustable front suspension, 24 speed Shimano gears and front and rear disc brakes and comes in matt green. It comes boxed and Montague were good enough to throw I a bike bag for it. It required little assembly, needing only to have one pedal fitted, along with one wheel and the seat. If you are happy adjusting brakes, gears and the like you should be able to set it up yourself, otherwise you may want to let a bike shop give it a check over for you. I had to adjust the brakes slightly but the gears were perfect straight from the box. I had a few niggles with the pedals, though that was my fault, and once tightened properly they have fine. The pedals are not of the folding variety. Montague do sell folding pedals but I have never found this type of pedal to be particularly robust, and it's unlikely it will give that much of a reduction in bike width when folded. Folding the bike is straightforward and quick. Open the quick release latch on the front wheel, flick the Clik safety release, and the front wheel is off. Open the catch on the top tube, press down and with a slight pressure the frame opens. It's that simple. You can additionally lower the seat, the whole operation taking easily under a minute. To re-assemble, just reverse the procedure. I find it easiest to replace the front wheel while facing the bike. The bike can be stowed in the bag for transport and this provides a good way of carrying it without getting oil and muck all over other people luggage. I was very impressed with the fact the strap goes into the bag and secures onto the frame of the bike. That negates any worries of the stitching on a sewn strap giving way. I can unfold the bike from the bag and assemble it ready for use in around two minutes. I've found it to be solid enough in use, and had no concerns that the bike may 'open' while traversing rough ground. The pedals have a great chunky grip, as have the handlebars. The thumb controlled trigger shift gears are well positioned, easy to see and index easily. My only gripe is that the handlebars are quite narrow. For a bike designed for the military, where guys tend to be big and broad, it's perhaps surprising, although making it bigger would of course increase packed size and weight). All the replaceable parts such as tyres, gears, brakes, are of the standard type you can pick up in any bike shop, so repairs and servicing can be done easily by you or any bike tech. Retailing around £799 this is not a cheap and cheerful bike, but one to seriously consider for off road use where a folding capability is required. It folds down to a reasonable size and should when folded fit into a reasonably sized car boot. Bike Weight (claimed): 29lbs Weight (actual): 33lbs (15kg) Cost: £799 rrp. Claimed Dimensions (Folded): 36x28x12 Dimensions (Folded): 36x30x15 Carry Bag Dimensions: 36x28x12 Weight: 810g Price: £99 (offers sometimes available- check the small print on the website).