In our Tech Q&A series, we tackle cycling queries big or small, complex or simple with insights from the BikeRadar team and trusted industry experts. Next up, a reader wants to know how they can clean and lubricate their drivetrain without contaminating their rotor. Is there a practical way to clean and lubricatethe drivetrain on my disc-brake equipped bikewithouthaving toremovethebackwheel,to avoidcontaminating the rear rotor? A reader, via email Absolutely,but it requires you to take care. Simon von Bromley points outthatone solution is to simply wax your chain rather than using off-the-shelf lubes,because this cuts out the need for cleaning and re-lubing. But thats not the question weve been asked. While there are items on the market for this problem, there are also workarounds. Tom Marvin / Our Media Digital editor Jack Luke explains there are covers you can buy for brake rotors (fromMuc-Off, for example) or, if you want to save some cash, you can tie a plastic bag over the disc or use a piece of cardboard to shield it. However, these arent strictly necessary. Instead, you simply need to take care not to overspray any aerosolson the rotor. Chain cleaning devices can help prevent contamination. Scott Windsor / Our Media When applying degreaser, either use a brush or spray it downwards so it doesnt find its way into the brakecaliperor onto the disc. Foaming chain degreasers keep things together and prevent them from migrating onto your disc. Scott Windsor / Our Media Using a foaming chain cleaner (for example, Fenwicks) will also reduce the risk of contamination, because the foam settles directly onto the chain and cassette. Its a similar situation when applying lube. Lube should be applied slowly, with only the links receiving drips. Our Media Make sure to hold the bottle close to the chain links and squeeze drips of lubricant onto the rollers as you turn the cranks backwards. You can then use a rag to wipe off any excess.