I picked up a message on an e-mail group the other day about a rider
who crashed on diesel. According to the mail, the amount of diesel
spilled on the road was considerable - several of his mates nearly
crashed too - in fact there was even some talk of the spill being
deliberate. Spills of this size fortunately are not common but the
tone of most of the messages was that diesel "will have you off if
you hit it". Well, it will at very least cause you to slide but most
spills can be predicted and avoided with a little forward thinking.
Clearly diesel is very slippery, particularly in the rain - so the
trick is to stay off it! It's fairly straight forward to spot.
Fresh diesel is very black - wet and shiny looking. In the rain, you
get the familiar rainbow effect as it washes all over the road. Old
diesel which isn't usually slippery is a dull black mark on the
road. Very often though, you can smell diesel before you see it,
particularly if it is a big spill so use your nose.
Think where it will likely be spilled on the road. Consider where
and when lorries and buses operate with full tanks - take care near
industrial estates and bus depots, particularly in the morning. With
our current price of fuel, lorries arriving on ferries are likely to
have tanks filled to the brim. Watch out near filling stations (and
at the pumps themselves too). A broken down lorry at the side of the
road might just have split its tank and dumped gallons on the road.
If you see a line of diesel in an adjacent lane, consider the
possibility that the vehicle trailing it will change lane ahead -
keep back from the car in front so that you can see the surface. If
you see temporary Police warning triangles take care - it may well
be an accident ahead. Be careful at the scenes of accidents - there
may well be diesel, engine oil or antifreeze on the road.
In particular, watch the surface where vehicles change direction -
for example corners, junctions and roundabouts. This is where diesel
will slosh out of a tank with a missing cap. One of our basic riding
rules is that we never travel faster than the speed that allows us
to stop in the distance we can see to be clear, but riders rarely
consider the road surface when applying the rule. Diesel spill
frequently happen on roundabouts where riders go for a bit of "knee
down" action, and as a result are unable to avoid a spillage out of
site on the far side of the island - if you want to get your knee
down, do a sighting lap first!
On a right hand bend a vehicle travelling in your direction will
tend to dump its fuel near the left kerb on the exit which will be
around the corner and out of sight as you set your line up for the
corner. This could be a problem if you run wide yourself, so a safe
line is one that stays towards the centre of the lane and doesn't
take an extreme position on the exit, at a speed that allows you to
change direction if necessary - you should always have a margin for
safety. A vehicle coming the other way will lay it near the centre
white line on your approach to the bend, and is more easily seen on
On left handers, the situation is reversed and the spill you have to
worry about will be on the exit near the white line, again out of
sight initially. Take a safe line that does not rely on extremes of
position and speed.
Use your observation links - if you see diesel on one right hand
bend, the chances are it will be on the next right hand
Petrol can also be spilled. It is just as slippery as diesel -
unfortunately it is almost invisible, and evaporates quickly, so the
If you do find yourself about to ride through diesel, don't try to
steer and don't try to brake. Keep the bike as upright as possible -
in a corner, you may be able to swerve hard to tighten the bend, to
give yourself space to pick the bike up as you cross the spill.
Don't forget that the tyres will still be slippery on the far side
of the spill - give it a moment for the oil to wear off before
flinging the bike on its ear.
Think, scan and plan ahead and diesel should be no more than an
irritant, albeit a dangerous one.