There is more plastic on a bike than you might think: mudguards, chainstay and chain guards, e-bike battery covers, baskets, caps, light mounts and bottle cages. Strong summer sun fades plastic and turns it grey, while dirt, moisture and winter de-icers leave it dull, rough and more prone to cracking.
Regular cleaning and a thin protective layer of silicone restore a neat look, repel water and dust and slow down ageing of the material. The whole job takes less than half an hour.
What you will need
Important: Silicone makes surfaces slippery. Never apply it to handlebar grips, the saddle, pedals, brake discs, pads, rims or tyres. Before the first treatment, test the product on a hidden area of plastic.
Step 1
Clean the plastic parts
Wash dust and dirt off the mudguards, covers and guards with warm water and mild shampoo. Use a soft sponge rather than a stiff brush so you do not scratch glossy plastic. Pay particular attention to the inside of the mudguards, where road mud builds up. Rinse off the shampoo with clean water.
Step 2
Dry the surfaces
Wipe the plastic with a dry microfibre cloth and let the bike stand for a few minutes. The protective layer goes on best over a clean, dry surface, and leftover water underneath can leave streaks.
Step 3
Apply the silicone
Spray WD-40 Specialist Silicone onto a cloth or directly onto the part from 15-20 cm. Spread it evenly over the whole surface so no patches are missed. Near the brakes and contact surfaces, apply it to the cloth only to avoid overspray.
Step 4
Buff and remove the excess
Give the product a few minutes to work, then go over the surface with a clean, dry cloth. This removes the excess and leaves an even sheen. A thin film remains that repels water, dirt and dust and protects against fading.
Step 5
Do not forget the rubber seals
Use the same product on rubber plugs, dust boots and seals on e-bike covers and mounts. Silicone keeps rubber supple and stops it drying out and cracking. Apply thinly, using a cloth.
Tip: Treat the metal bolts that hold mudguards and guards separately with
WD-40 Multi-Use. They will undo easily even after winter, and the plastic around them will not crack under the force.
What next
Repeat the treatment monthly during the season and after washing the bike. If your bike lives on a sunny balcony, treat the plastics more often and move it into the shade for the winter.
These uses come from the experience of WD-40 users in many countries. Always follow the instructions and warnings on the product label.
More guides in «How to use».