How a classic motorcycle is stored through the winter months has a direct and significant bearing on its condition when it is brought back into use in spring. The damage that accumulates through a poorly managed lay-up — degraded fuel, discharged battery, internal corrosion, deteriorated rubber — is preventable in its entirety with the right preparation. At South Wales Classic Motorbikes, we have stored and recommissioned more classic motorcycles than we can count, and want to share the full process that we follow.
Fuel System Preparation
Modern ethanol-blended petrol begins to degrade within weeks, leaving varnish deposits that block carburettor jets and damage rubber components. Before laying up, either drain the carburettor completely by opening the float bowl drain screw and running the engine until it stops from fuel starvation, or treat the remaining fuel with a quality ethanol-resistant stabiliser. If the tank will contain fuel over winter, use E5 super unleaded with stabiliser and ensure the tank is full to minimise condensation on internal surfaces.
Engine Oil Change
Change the engine oil before lay-up, not in spring. Used oil contains acidic combustion by-products and contaminants that continue to attack internal metal surfaces throughout the storage period. Fresh oil left in the engine over winter is dramatically less damaging. After the oil change, run the engine briefly to distribute the fresh oil throughout, then switch off. The oil in the sump at lay-up is the oil protecting the engine through winter.
Battery Care
A lead-acid battery left unattended through winter will self-discharge and may be permanently damaged by deep discharge. Connect the battery to a quality smart charger — CTEK, Optimate, or similar — that will maintain charge without overcharging throughout the storage period. If mains access to the storage location is not possible, remove the battery and store it in a frost-free location, connecting it to a charger whenever convenient to maintain charge.
Corrosion Protection
Apply a light film of ACF-50, WD-40 Long Term, or a similar corrosion inhibitor to exposed metal surfaces, particularly chrome and any bare steel areas. This displaces moisture and leaves a protective film that inhibits rust formation during the damp winter months. Do not apply to brake discs, pads, or tyre surfaces.
Tyre and Suspension Care
Where possible, keep the machine off its tyres over winter — either on a paddock stand or with the machine resting on a purpose-made stand that keeps both wheels clear of the ground. Prolonged static load on tyres in cold conditions can cause flat spots that take time to round out. Check and adjust tyre pressure before storage — cold air will reduce pressure through winter.
Cover and Storage Environment
Store the machine under a breathable cover in a dry, ventilated space. A non-breathable cover traps moisture against the paint and chrome, accelerating corrosion. A damp, unventilated garage is worse than no cover in some respects — moist, still air is ideal for rust formation. Plug the exhaust outlet with a rag or purpose-made bung to prevent rodents from investigating.
For advice on winter storage for your specific machine, contact South Wales Classic Motorbikes on 07966 296269 or visit southwalesclassicbikes.com.