Guide to roof bars: Steel or aluminium bars

We usually have a range of steel and aluminium bars for most cars.

Steel bars are rectangular box section (32mmx22mm) and are usually steel with a black plastic coating. Steel bars are usually the cheapest option, but are not as aerodynamic, so they will be a bit noisier.

Aluminium bars (also known as aero bars) are typically about 80mm wide usually have a wing shaped profile. They are more aerodynamic than steel bars and they will be quieter in use. 

Steel Bar summary

• Usually the cheapest option
• Noisier than aluminium aero bars
• Less aerodynamic
• Most but not all of the bar can be used to mount accessories
• Good option for occasional use

Aluminium(aero) Bar summary

• Best option if you need to fit lots on your bars
• Quieter than steel bars
• More aerodynamic
• The full length of the bar* can be used to mount accessories
• Best option for regular use
• Usually more expensive than steel bars

Gear usually attaches to steel bars using 'U' bolt fittings. You position the product on top of the bar and U bolt goes around the bars and attaches to the product with wing nuts.

Aluminium bars have a channel running along the top edge, usually filled with a rubber strip, we call this a T-track slot. You often attach gear to this type of bar using T-track bolts - a T headed bolt that sides into the channel. This allows use of the full length of the bar.

We have a guide to the different roof bar fittings. See the link below.

Guide to roof bars: Attaching items to roof bars