There are plenty of options out there for carrying your bikes on the car. Unfortunately, bike racks can be pretty expensive, so here's a guide to them to help you work out which will be best for you.

There are four basic options: on the roof, inside the car, on a boot rack and on a towbar rack. Also see the bottom for the summary.

On the Roof

Advantages:
+ Boot is easily accessible
+ Visibility is unaffected
+ No need for a lighting board
+ Quick to fit bikes
Disadvantages:
- Increases fuel consumption by up to 30%
- Bikes get covered in gunge
- Expensive - need to buy roof bars plus one carrier per bike
- You have to remember not to drive into multi-storey car parks, etc...
Overall
Great for frequent use on short journeys, bad for long trips.

The roof-mounting option is in some ways a complete winner. You can leave the rack fitted permanently, and just throw the bikes on when you need to, using the boot as normal. It's fairly popular with pro teams, and most vendors advertise it as 'the professional way to carry bikes'. It's not all sweetness and light though.

One problem is the fuel consumption, which goes up significantly at motorway speeds. Handling can be affected in crosswinds as well. Being exposed to a clear stream of air means that the bikes get covered in dead insects in the summer, and thick layers of oily, salty grimness in the winter.

You'll also need a carrier per bike. This starts to work out expensive. If you go for mid-range kit, you're looking at £60 for the roof bars plus £40 per carrier. If you're going to kit yourself out with Thule goodies, bank on £100 for the bars and £70 per carrier. Having said that, you can transfer the carriers to new cars, and both racks and bars are fairly easy to sell second hand.

It also has to be said that some carriers are much better than others. My favourite is the Thule Velo Vise, which clamps to the fork. This means you have to store the front wheel in the boot, but it makes it infinitely easier to attach the bike. Other carriers clamp to the down tube, meaning you have to lift the bike higher, and it's an awkward process of attaching the clamp. They're also more hassle if you regularly use bikes with different sized down tubes, and are a no-no if you have an odd-framed (eg monocoque or square tubed) bike.

Security: good. Most roof bars and bike carriers come with locks fitted; if not, they're generally available as accessories. A long cable through the frames adds a bit more peace of mind.

Inside the Car

Advantages:
+ Cheapest
+ Easiest
+ Quickest
Disadvantages:
- No fun if you've got a saloon
- Mud in the car
- Less space for people and gear inside
Overall
If you've got the space, this is the easiest way.

The original and still the best. Chuck the bike in and forget about it - no special equipment required.

The problem comes when you have a small car, or a saloon, where it can be tricky to crowbar the bike in. Similarly, if you're travelling with a buddy or two, with plenty of gear, things will get cramped. Plenty of people will tell you tales of getting four people, four bikes and some gear in a Renault 5, and it can be done. But it's not fun.

If you never go on big biking holidays, this lets you get away without buying a rack at all. But you need a big(ish) car to do a full two-week camping trip with the bikes inside.

Security: about as secure as you'll get, unless your car's really easy to break into. But then if you attach the bikes any other way, you can still get your whole car stolen.

On a Boot Rack

Advantages:
+ Cheap
+ Doesn't upset the car's handling much
+ Can actually improve fuel economy
Disadvantages:
- Difficult to carry most full suspension bikes
- You may need a lighting board
- Usually prevents you getting into the boot
Overall
Inexpensive and effective all-round solution.

Probably the most popular way to transport bikes, you can pick up a good rack cheaply (the Halfords Two/Three Cycle Carrier is recommended, at £40-50). You need to take care when fitting them. Set aside half an hour the first time you use it, to get all the straps and arms set up properly, and it should be possible to make it rock solid. Make sure you get a six-strap carrier if possible: the four-strap ones aren't so stable, but still perfectly good enough.

These days, boot carriers generally come with special straps and bungees for holding the bikes. I find these aren't much good, and still use an octopus (three or four bungees connected in the middle with a ring) for holding the bikes down nice and tight. To stop them rubbing each other's paint off (and the car's paint as well), get some foam pipe lagging from a DIY shop. If you've got a monocoque-framed bike, you may have to use cloths or something similar.

Although you'll probably need a lighting board to be road legal, many cars will allow you to mount the rack higher up, as long as you're comfortable with the rear windscreen taking a bit more weight. Or in the case of estates, it makes no real difference anyway. I've done this a lot, and not had any problems with it.

Boot racks are much maligned by some people, probably because it does take a little care to set them up properly. Get them wrong and you won't like them, but get them right and they're a great way of carrying bikes, especially for the cost.

One accusation levelled against boot rack is that they are unstable. Nonsense. Make sure you get the top straps set up correctly, anchored to the top of the bootlid. Then fit the lower straps tightly (some racks recommend anchoring the lower straps to the chassis, but I prefer attaching them to the lower lip of the bootlid. This should reduce stress on the boot, and also allow access should you need it). Then anchor the side straps if you have them. Make sure all the straps are meeting the boot edges at 90 degrees so the clips won't slip when tightened. Once you've loaded the bikes on, retighten the lower and side straps, as they'll slacken with the weight of the bikes. This should be as solid as a rock with at least two bikes on the back, and won't affect your handling.

Depending on where you mount the bikes, generally boot racks will actually make your car more efficient. Why? Well to simplify it a little - normally, at high speeds, your car will punch a big hole in the air behind it. By putting bikes in that hole, they help pull air back into that space behind the car, increasing your economy. So why isn't your car designed to work that well? Simply because it would look untidy. If you want to maximise the effect, mount the bikes close to the car, and remove any wheels which protrude to the sides of the car (since they're in fast-flowing air).

Security: not brilliant, but can be made perfectly adequate - the best idea is to get a D-lock and some cables, including a long one to pass through the rear towing eye.

On a Towbar Rack

Advantages:
+ Cheap if you've got a towbar already
+ Simple to use
+ Strong
+ Can actually improve fuel economy
Disadvantages:
- Need a lighting board
- Expensive to fit a towbar
- Still can't get at the boot on most cars
Overall
A good system if you already have a tow ball, otherwise go for a boot rack.

If you've already got a towbar, this is a pretty good option. Carriers are available for up to four bikes, and some have attachment points at the top and bottom of the bikes for extra stability. Some attach only at the top, in which case you'll need some bungees as per the boot rack.

Like boot racks, towbar racks place your bikes in the low-pressure region of air behind your car and can thus improve your fuel economy at motorway speeds.

Security: a bit better than boot mounted racks, but you'll still want to cable the bikes up.

In Summary

When you can carry bikes inside the car, do. It keeps road salt off the bikes, and doesn't affect fuel consumption or handling. But of course it helps if you have an estate or a van.

If you need to carry outside the car, consider what you'll be using the rack for. If you need it for frequent short journeys (a 20 mile drive every weekend to your local ride, for instance), roof carriers offer quick fit-and-go ease of use, especially the Velo Vise. If you're planning on using it for occasional long journeys (maybe carrying the bikes in the car for the short weekly trips) then a boot rack will be better. It takes a bit longer to get the bikes attached, but once there, the car performs better. And more importantly, a good two-bike boot rack can be had for under £40, whereas decent roof carriers cost £70 each, plus the bars...

Towbar carriers are a great option if you've already got a towbar, since they offer as much ease-of-use as most roof carriers, without the effects on performance.

In short, if you need to carry your bikes on the car and are wondering which system to use, your best bet will probably be to buy a Halfords boot rack, mount it high if you can clear the lights on your car (you shouldn't need their high mount carrier, just run the top straps short), and get some bungees and some pipe lagging. That will sort you for two or three bikes for under £50 and you can use it on pretty much any car.

What do I use? Er - all of the above apart from the towbar!