Bournemouth & Wessex Advanced Motorcyclists

Wet Weather Riding

Introduction

This is a subject that doesn't come up that often since it can be difficult getting people to ride their bikes when the rain starts coming down. However, riding in these conditions can be challenging and fun. Here are some points you may wish to consider the next time you are riding on wet roads.

The main objective for avoiding unwanted slips and slides is to ride smoothly. This involves developing your riding plan early so that rapid braking, accelerating or quick changes in direction are not required. That's wet weather riding taken care of....OK, maybe just a few more points.

Cornering

Your machine is most stable when travelling upright in a straight line at a constant speed with the engine just pulling. To maintain maximum stability when negotiating a corner we should endeavor to comply with as many of these elements as possible. 'Upright' and in a 'Straight Line' is out (I hope) so what we have left is 'Constant Speed' with 'Engine Just Pulling'.

If you negotiate a bend on a motorcycle and maintain the throttle position that gave you 'Constant Speed' on the straight, you will slow down as you go through the corner. To maintain 'Constant Speed' through the corner you must roll-on the throttle. Your motorcycle was designed to drive through bends. Applying the throttle early settles the suspension, unloads the front and enables the rider to feel more accurately what the machine is doing. With the correct amount of roll-on the machine should be operating in the mid-point of its suspension travel with approximately 40% - 60% weight distribution front to rear. This complies with the elements described and allows your suspension to work effectively in order to maintain maximum stability. On wet roads this roll-on should be smooth, even and constant through the corner.

All braking and gear changing should be done on the approach when the machine is upright. To drive the corner the bike will be slowest at the entry. Sounds obvious, but having to roll the throttle off on a corner blows away our 'Constant Speed', loads up the front and unsettles the bike, thus compounding the chance of an unrecoverable front-end slide.

Developing the habit of selecting an entrance speed that allows you to drive all bends pays dividends as follows:

Road surface is obviously of paramount importance in the wet, especially through a corner. Recognising slippery surfaces early is preferable. Patches of shiny tarmac, drain covers and mud are obvious ones but also just as problematic are surface changes. The high grip surface used on some roundabouts is a good example. The speed and lean angle you may have chosen for the traction available on said roundabout may be safe while it lasts but, when you exit, the high grip surface usually reverts to the normal, black and 'slippery when wet' stuff. Think about that one.

Roundabouts

Negotiating roundabouts on a motorcycle is great fun. However, they also provide some potentially dangerous conditions, not least of all fuel spills. So where is it? It's going to be where the vehicle has dumped its fuel through the hole where the filler cap should have been. You need to bear in mind that not all vehicles have their filler caps on the near-side and not all of them have them on the off-side. Basically it's a case of visualising where the fuel has been spilt and avoiding it if possible.

Something else to consider is that some roundabouts are designed to give a positive camber. This can provide a 'lip' on the road surface as you exit. Riding over this lip while the machine is banked over can unload the tyres and at the same time provide negative camber, a good recipe for a loss of traction.

Overtaking

As previously mentioned, abrupt use of the throttle should be avoided. This means that overtaking in the wet needs to be planned so that it can be carried out smoothly. The technique of 'elastic-banding' comes into it's own in slippery conditions.

Regaining your side of the road after the overtaking manoeuvre can be especially dangerous in the wet. White lines, overbanding and debris brushed into the center of the road provide a very slippery surface to cross. In this case, regaining your side of the road on a closed throttle is best avoided. It is not desirable to have the bike's weight biased on the front tyre while crossing this slippery section. Waiting for an overtaking opportunity that allows you to drive the machine over the crown of the road is much safer.

Braking

We should all know brake bias percentages for front and rear in slippery conditions. Extra emphasis should be placed on the smooth operation of the controls. Under braking, as the weight of the machine and rider moves forward, the front tyre makes the transition from unloaded to loaded. Make this change too quickly and the front won't be able to cope with the sudden requirement for additional traction. Taking up the 'slack' smoothly and then applying pressure progressively will allow you to brake harder and also feel the amount of grip you have to play with. Using the back brake settles the rear and plays a large part in how the weight is distributed during braking - which should only be done in a straight line!

Due to the loss of braking ability, good forward observation is even more important. Also, choose the best section of road to brake on. Think about where traction will be compromised. e.g. traffic lights - the centre of the road is sometimes very slippery due to engine oil dripping from stationary vehicles.

What Else?

Plan your ride and think about some of the conditions that you can expect to encounter on your journey. For example, if you go on a ride up to Shaftesbury via Zig-Zag hill on a wet autumn day you can expect some interesting conditions. Wet leaves, mud and gravel washed from the banks, but its autumn and its raining - what did you expect?

Some other things to consider:

In addition to your wits and ability some other assets are also required for optimum safety on wet roads:

Conclusions

You may notice that all the points that have been mentioned concerning riding in wet conditions also apply, and are desirable, in dry conditions. Riding in the wet develops good habits because it demands good technique. I hope that the next time you have a ride planned and it rains, you won't put it off, rather treat it as an opportunity to show off your advanced riding techniques.

Nigel Jones
Senior Observer

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