September 2, 2008 If there's one thing motorcyclists fear above all else, it's losing the front end under braking. And while the major manufacturers come up with various complicated electronic brake systems like Honda's Combined ABS to tackle the problem, these generally only start working once the wheel starts to lock up. A small aftermarket operation in the US, however, is applying air-over-hydraulics technology - similar to the units that help pull up huge cargo planes on short runways - in a simple and cheap brake mod that fits just about any bike and claims to prevent brake lock-ups before they even begin.

TCB Brake Systems is a small aftermarket supply business based around a single product - a US$90 replacement banjo bolt that slots straight into the brake systems of just about any motorcycle in about 10 minutes. But why so expensive?

Each bolt contains a hollowed-out oversized head, which is sealed off from the hydraulic brake system by a strong and slightly flexible membrane. The theory goes that under high-pressure braking, such as in an emergency stop, brake pads tend to start to lock a wheel up when they grab onto tiny surface irregularities on the disc, sending pressure spikes through the hydraulic system.

The TCB bolt's hollow head contains about a cubic centimetre of air - which is compressible, where brake fluid is not - and the membrane, while not susceptible to flexing under normal braking pressures, has a little give in it at the outside edge of brake pressure, so that when those disc irregularities start sending pressure waves up through the brake system, there's something flexible in the system that's able to even them out.

So, according to TCB inventor Mark Lipski, the unit should prevent many front wheel lock-ups before they even start.

It's a big claim for such a tiny, easily-installed and relatively cheap motorcycle modification - but does it work? Putting compressible, expandable air in as a component of your braking system sounds a bit like what happens when you don't maintain your brakes correctly.

There's only one way to find out what effect this device has - see for yourself as TheBikerGene gives the TCB unit a full test.