I have 2 of these cycle carriers and have used them a fair bit in the last couple of years. Once you are used to fitting them it really doesn't take long to fit them to the roof bars (fitting the bars takes longer). I have had no real problems with them, although the first time of using them took a while to work out the best combination of mounting for the 2 bikes (one has a womans frame). The best solution I have found was to mount one in the normal way and one backwards, so that the arms are both on the inside, this makes putting the bikes on easier and just happens to provide suitable positions for each if the bikes (even with bottle cages). I always use the use the straps to hold the front wheel straight as this makes putting the bikes on much less prone to problems. I have never tried fitting more than 2 but can understand why in would be difficult if not impossible! The pivot point in the middle, whilst making them easier to store, is a bit of weakpoint in the design. Both carriers have cracks in the plastic, although neither has broken (not yet anyway!). Also be careful not to overtighten the wheel straps as the metal bits at the ends are not that strong. They are lockable, both to the roof bars and to the bikes, however I wouldn't like to rely on the locks stopping a determined thief, although they are likely to be more secure than on a boot mounted carrier. Personally I prefer roof mounter carriers as they avoid any problems with lights/number plates being obscured and still allow access to the boot while the bikes are on the car. I am sure there is an increase in fuel consumption when driving with the bikes on the car but have not found it to be that noticeable. All on all, not a bad cycle carrier, but if you can, try them out with your bike(s) first and wait until Halfords reduce them (which they seem to do once a year) before buying.
I purchased this as a second carrier before going on holiday with some friends - I'd already bought a Thule Velo Vise for my own bike, and borrowed an old roof carrier, but needed a cheapish rack which would take a Cannondale with its fat tubes. At first glance this is a fairly normal-looking roof carrier. Two wheel mountings and a pivoting bar which clamps to the bike's downtube. However, in the details it's not quite normal. The most obvious unusual point is the pivot in the middle of the rack, allowing it to fit to curved roofs. In practice it means that if you have a flat roof it's virtually impossible to get the rack straight - not that it really matters. The good thing is that it folds in half so it's easier to store. Fitting the rack to the roof bars is easy enough: place it at an angle, twist the front section on, then secure to the rear bar. Sounds like a good system? Nope. I haven't worked out how you fit more than two to the roof - you need so much space available to turn the thing. Like everything on the rack, they've ignored conventional wisdom and it hasn't really worked. The wheel mounts are pretty good - better than on my Thule. Solid metal levers and webbed nylon straps. Good stuff. The downtube bracket is fairly solid, and will take big or small tubes with the rubber shims provided. Unfortunately even with the supplied sticky pads they tend to fall out quite easily. The bracket could do with opening wider. It rotates so you can set the clamp up at any point on the downtube, but if you have a frame-mounted pump it'll have to come off, and if you have a bottle cage on the downtube life's going to be very awkward. If you have two bottle cages life is very awkward indeed - good luck. The bracket clamp is a clasp-style affair, locked down with a lockable lever. Annoyingly though, the only way to undo the clamp is by pulling the plastic cap which covers the lock . This is a fairly flimsy bit of plastic and isn't up to the job. What was wrong with putting a finger lever in the clasp itself? And the lock is virtually impossible to use if you have a bottle cage in the way. Actually getting the bike into the rack is a bit of a three-handed affair, especially if you have a heavy bike, or you have bottle cages, or you have more than one bike on the roof. Add the three together and it's chaos - make sure you have a handy friend. Overall build quality is ok - the rack feels fairly sturdy, but the blank plastic cover over the front section is loosely clipped on and just crying to fall off at the wrong moment. In short, it wasn't bad value (I got it when it was reduced) but it's really annoying to use. Once everything's in place it's fairly sturdy, but I wouldn't have it as my main rack. If you're a casual user and you need to carry a fat-tubed bike, it's worth a look. If you ride every week, you'll get frustrated.