Cleaning, Detergents and WD40

WD40 (Water Displacement 40)

As this stuff comes up regularly in discussion about cleaning and maintenance, I thought I should give it a mention. I use WD40 if I come in very late on a wet night and don’t have the time or inclination to clean and lube my chain. I’ll remove my chain, drop it on a plastic tray and give it a coating to push the water from the links, always with a view to a proper clean/dry/lube the next morning. This is the only time that WD40 touches my chain. Same goes for GT85; way too thin to be an effective lubricant on your chain.

In terms of bicycle maintenance, WD40 is probably best used for its solvent properties. It’ll break down new and old grease fairly easily, especially if you introduce a brush or cotton bud to the task, so it’s very good for the initial cleaning of parts, although I’d recommend doing so away from the bike. Another potential problem with WD40 is that it tends to be most readily available in spray form. Because of the relatively close proximity of things like wheel rims and brake rotors to derailleurs and chains, the potential for troublesome overspray is obvious. As well as rendering disc brake pads useless in a flash, WD40 will also help turn to a watery mess the thick grease which your hubs, headset, BB and suspension bearings all need to operate effectively.

Whether you’re a disc brake user or not, if you intend to use WD40 for its solvent properties you should consider Isopropyl Alcohol (IsA)* a necessary part of your tool kit and always use it to clean the WD40 away. Remember that any degreaser/solvent left on a component (not just WD40) will not only ‘dilute’ the fresh lube that you apply, but it will also prevent it from bonding effectively to the working surfaces that you are trying to protect. Fresh lube should really only be applied to clean, dry surfaces, otherwise it’s more or less a waste of time.

* for some important info on Isopropyl Alcohol, click to ‘Rotor Cleaning‘.

As for it being a lubricant (it’s still popular for some reason as a chain lube), the oil in WD40 is far too thin to serve any useful purpose on a bike. Also, the oil that remains after the solvent carrier has evaporated is extremely sticky, so it will always attract a lot of dirt. All of this dirt will combine with the oil and mix into an excellent abrasive paste which will considerably reduce the effective working life of any drive-train. If you’re using WD40 as ‘working’ lubricant on your bike, I’d suggest finding a nice, quiet corner, sitting yourself down and having a word with yourself…

Detergents and Cleaners

For the most part, I also try to keep household detergents away from my bike as they all contain salt to some degree or another. Not only will salt promote quicker rusting of steel (if that’s not your frame, it’s almost every nut and bolt on your bike), but it will also cause rubber components (like fork seals) to harden and, eventually, crack. It’s a long process and will happen anyway over the years but I don’t see any point in speeding that process up. Detergents also break down oil and grease, two substances that keep parts like chains, hubs, headsets and bottom brackets running smoothly. Same philosophy as the salt on rubber, plus you’re just making more work for yourself having to re-grease or replace hubs way before time. If the dirt is set on, then I’d recommend something like Muc-Off, Finish Line Bike Wash or Hope’s Sh*t Shifter which come with a spray-top to ‘aim’ where you’re spraying. This will soften the dirt before rinsing off without getting into unwanted places.

If you do need to wash your whole bike down, there’s no amount of muck that a couple of buckets of clean, hot water and a small brush won’t sort out. It’s the frame you’re washing down, not your components. A hosepipe is wasteful, so too is a pressure washer. The latter could also force water deep into your bike’s bearings, even the sealed type, and so should be considered unsuitable for cleaning your bike. Especially if you don’t intend to clean and re-lubed it, it’s a good idea to remove the chain before washing your bike down. The less water your chain sees between cleaning, the better.

I use a short brush which I bought from an auto accessories shop. It was designed for cleaning alloy wheels on cars so it’s flexible and is soft enough for bike paint. A toothbrush is great for any hard to reach places, like behind a chain device if you have one or around suspension. No matter what you’ve been riding in, the dirtiest part of your bike is always going to be the area around the bottom bracket (BB) as it’ll catch dust and water/mud spray from both wheels. Keep loading your brush with clean water and start working your way down from just below the seat-post clamp. By the time you’ve reached the BB a lot of the muck is going to have gone, or been sufficiently loosened. If the whole frame is coated in mud then obviously it’ll all need washing down. If you just have a concentration of dirt around the BB stop short of the head tube and headset as this area can be cleaned with a wet cloth later. No need to go splashing water all around the headset bearings. Use a clean cloth to wipe dry the frame, paying attention to the BB area and crank arms.

Again, unless they’re caked in mud, I use a wet cloth for both fork lowers and the chain/seat stays. This means that I’m not splashing more water than I need to around the hub bearings.

It’s usually at this point that I bring my bike indoors and turn it upside down, remove both wheels and finish wiping down the underside of the frame.

Cleaning wheels is rarely necessary for disc-brake users. Cleaning of wheel rims is covered in the rotor/brake cleaning page.

As you can see, cleaning the important parts of your bike can generally be done without using any water at all, at least while they’re still attached.

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