Making it stop

This could be tricky...


Since the project started everybody has been working hard to make the bike go faster, but the flip side to that coin is how will we stop the Bulldog?

Some say mechanical brakes are pointless at 400mph (and we should consider them more like a parking device) and that does have some validity, though Gabriel might not feel the same when he’s in the hot seat!

Drag of course has a fairly large hand in slowing things down from high speeds, plus of course we’ve got parachutes, one for high speed deployment, the other for low speed (circa 200mph). But below that shouldn’t we have something half decent to bring things to a halt a bit quicker?

Of course, it’s worth bearing in mind that wherever we make the attempt, we will have 5 miles to speed up, the measured mile, and then another 5 miles to stop. So acceleration and deceleration rates are perhaps not as important as one would expect. With that in mind maybe we don’t need to get excited about the high tech, shiny, multi pot, carbon, ventilated, race brakes, or do we?

At Bonneville for instance, the tractive effort that can be applied through the brakes to stop the bike is limited by the coefficient of friction between the tyre and salt. In the same way as the acceleration is limited by wheel spin, so deceleration will be limited by the wheel locking up.

The shape of the bike and its suspension geometry will severely limit the amount of weight transfer from the rear wheel, and there won’t be too much of that front wheel dive bikers worry about.

In the wide open spaces of salt flats, braking distance isn’t normally an issue (unless something has gone rather badly wrong). But testing the bike, on tarmac here in the UK…the question that arises is how long is the longest runway we can use? RAF Fairford for instance, which was designated as an emergency alternate for the Space Shuttle, is only two and a quarter miles long.

So space is in all practical senses, the final frontier when it comes testing. And without endless amounts it seems like we will need brakes after all…well at least for test runs in the UK and thereafter just for parking.