IF YOU'RE PLANNING on soldiering on through the winter, it's a good idea to make sure your bike is prepared for the worst of the weather.
The first thing to do is to treat your motor to an oil and filter change. It's during the first few minutes of running, when it's cold and the internal frictions are at their most vindictive, that the majority of engine damage occurs. During the winter, when the ambient temperature is low, it follows that your engine is going take longer to warm up, therefore increasing the chance of damage. Good quality oils contain additives to protect the engine during cold starts, but that doesn't mean you can skimp on making sure the motor is up to temperature before thrashing it.
If you own a liquid-cooled bike it's important to check the coolant level and make sure there's antifreeze in the system. If the liquid in the expansion tank or radiator is clear instead of blue or green, the system probably contains very little or no antifreeze.
Most dealers sell-ready mixed coolants which contain all the necessary additives. Draining and re-filling the system on most bikes is fairly simple, but if you do drain it then you must remember to bleed the system when you refill it. If you're not confident about what you're doing, it may be a sensible idea to get your dealer to carry out the fluid change.
Without wanting to sound too pessimistic, winter is a good time to fit some crash protection. Crash bungs and an exhaust protector are a good idea year-round, but when the roads are slimy and your tyres are cold you're more likely to have a low-speed spill. Inexpensive plastic crash protection can save you hundreds of pounds in cosmetic damage.
Speaking of tyres, make sure they're suitable and have plenty of life left in them. Sticky track day rubber won't work as well as road-oriented tyres such as Pirelli Diablos, Bridgestone BT014s or Michelin's Pilot Roads. You'll need plenty of tread remaining so as to disperse water, because stopping distances will increase when it's wet. All tyres have a series of wear indicators or bars. When the tread is level with the bars it's time to change the tyre - but, if you want maximum grip in poor conditions, you may want to replace them before that.
Most motorcycles are finished well enough to see off a few rain showers, but none can fend off the effects of salt corrosion. Even the white powder left as the road surface dries out can eat through the toughest show chrome. There are a number of spray-on protective products around, such as Scottoiler's FS365 Protector, a water-based spray. It washes off easily, though, so you'll have to re-apply it regularly throughout the winter. A light penetrating spray such as Würth Ultra 2040 will work just as well, but remember to keep it well away from the tyres, brake pads and discs. Again, it washes off over time, so you'll need to keep on top of it.
On the parts that are unaffected by engine heat, a liberal smearing of grease will give the best protection. Also apply it to any bare threads such as chain adjusters, gear lever tie rods and wheel spindles. The downside is that road dirt sticks to the grease, making your bike look grotty, but after the winter you can easily rinse it off with a degreasing agent.