Regular cleaning is far more important for leather than for textile gear because it can be damaged by exposure to airborne pollutants, and it will eventually oxidize to stylish nothingness if not kept clean and moist. Leather is sensitive to ozone, nitrous and sulphurous pollutants. If leather becomes too dry, the fibers will become brittle. In addition, by keeping leather clean and treated, those fibers will have some local lubrication, which means they'll slide past and around one another in flex zones without breaking or chafing.
For regular leather cleaning you may want to try something stronger. There are several brands of leather cleaner on the market, including the popular (and easily found) Lexol. This is a very mild detergent that doesn't pack much power over really caked-on gunk, but it works very well for removing light surface grime. It's made so you won't dry out the leather by frequent cleaning.
Follow the directions for whatever you're using, of course; for Lexol you're supposed to apply the product to a moist cloth and then work it into the leather. If you're using a product for the first time, test it in an inconspicuous area-say, under the arm-to make sure it won't discolor the leather. As with the plain-water route, we've found that Lexol often takes several applications to get the hide really clean. While the company recommends applying and rinsing with the same towel, we've had good luck using a cloth wax applicator for buffing and a plain terry towel for drying. Take your time.
Sometimes, though, the mild approach doesn't cut the dirt. The next step is to mix up a bucket of laundry detergent in warm water. Check the label to make sure the detergent doesn't contain bleach or chlorine. Resist the temptation to use any kind of solvent, even those supposedly benign citrus-based products; they'll eat the dye in short order. First try a soft towel or wax applicator with the detergent. Apply in a small area, work the dirt out, and then rinse with a clean, moist towel. Dry immediately. For really stubborn stains, you can use a soft-bristle nylon brush. But go very slowly. If you think of leather as a skin, you can imagine how it would feel to use the same treatment on your own hide. Use a minimum amount of force to extract grime and rinse thoroughly every time.
Conditioning should always follow a complete washing. Leather will dry out over time, and the washing process accelerates this. Again, follow the directions for the product you've chosen. Generally, though, you should apply the product to another clean towel and apply liberally. (You could spray the conditioner directly onto the leather, but we've found it easier to keep saturation under control by applying it indirectly.) The leather should shine, but it should not be visibly wet.
Allow 30 minutes or so for the conditioner to soak into the leather, more if you're doing this out in the shop in the dead of winter. (In fact, bring your gear inside; it'll live longer.) After that period, wipe any extra conditioner off with another clean towel. Yes, there's lots of laundry involved.
Textile Care
Textiles are a different animal. Most suits are made from a version of DuPont's Cordura fabric, which can be machine-washed under the right circumstances. In fact, Aerostich suggests machine-washing as a primary method of whole-suit cleaning. The caveat is that the inner liner must be washable, and the jacket or suit cannot have leather or suede components, which will not survive the washing in any form you'd want on your body.
For washer-compatible outfits, remove all pads and open all zippers. The first wash should be with a conventional detergent, but again, make sure it doesn't contain bleach. Allow the cycle to complete and then repeat without soap; Cordura can hold soap residue, and the extra rinse cycles will help purge the garment. If wet weather is an issue for you, consider using a wash-in water-repellent such as Nikwax Tech Wash.
Once clean, you can dry most textile garments in a home dryer using low heat. Tumble drying can be hard on zippers and clasps, so consider allowing the garment to hang-dry if you have the time.
Some textile suits shouldn't be machine-washed, and the by-hand procedure is similar to leather's. Wipe off the first layer of goop using a damp towel, taking care to remove the debris without working it further into the fabric. Next you can use a mild detergent in lukewarm water applied with a clean terry towel; as with leather, check for color-fastness in an inconspicuous part of the garment. Clean and rinse with plain water. Tougher stains may require tougher measures, and a few garment manufacturers suggest using a citrus-based cleaner for greasy stains. Again, start conservatively with the agent highly diluted and try it first in an area you won't see if the textile discolors. You can use a nylon-bristle brush to work the worst gunk out of the suit, but repeat gentler measures first, as you may end up grinding the stain further into the fabric. Avoid getting any leather or suede portions of the garment wet, and be sure to treat them appropriately after you've done the bulk of the suit.
Once clean and dry- needless to say that garments unsuitable for machine washing are also unsuitable for tumble drying-consider applying an external water/stain repellent such as Scotch Guard to help keep your newly pristine moto-clothing looking that way.