I think it's good time that my Brompton had a service and the main two things I'm looking at doing are:
- Servicing the brakes.
- Cleaning up the drive train.
What's the best way to go about these tasks so I don't end up breaking anything?
(Brompton doesn't provide any detailed pictures or component data on their web site, so I'm working from the crummy little pictures I can find.)
Basic service is no different from any other bike, with a few twists.
You can get yourself a "chain washer" (and accompanying solvent) to clean the chain, wipe dry with a rag after cleaning, then apply a good chain oil (from a bike shop -- don't use ordinary motor oil or "3in1" oil). For convenience choose a "dry" oil (the bike shop will know what you mean) unless you regularly ride in the rain -- the "dry" oil will stay cleaner. Work the oil in by cranking/riding a minute or two, then wipe off the excess with a rag.
However, using the chain washer on the Brompton chain may require that you partially fold the rear wheel to gain enough slack in the chain to do the wash. Probably hanging it from something by the seatpost, with the wheels still touching the ground, would give you enough slack.
If you don't use the chain washer, just wipe the chain as clean as possible, douse in chain oil, then wipe again -- not perfect, but should be good enough.
In daily use, ideally clean the chain weekly, and after every ride in the rain. (Though I personally stretch these intervals considerably.)
The sprockets don't generally need cleaning unless they become really cruddy, at which point scraping them is the simplest approach.
Keep the chain tensioner clean (wipe with a rag) and well-oiled with chain oil. If it gets really cruddy you can spray it with WD40, wipe dry, then oil, then wipe again, then oil again, then wipe again. (Keep WD40 off the tires and finish.)
The bikes apparently come with a 1 or 2 speed front sprocket and a 1 or 3 speed rear hub. Both (if not single speed) will need adjustment after riding for the first 100-200 miles or so. This should probably be done at a bike shop, since it takes a bit of skill. Once adjusted (after this break-in period) they shouldn't need further adjustment for 1000-5000 miles.
The chain with the single-speed front sprocket will likely need to be replaced roughly every 5000 miles, and maybe every 2000 with the 2-speed front sprocket. But it depends on how hard you ride it, and in what conditions.
The brakes (which appear to be relatively standard caliper brakes) similarly should be adjusted after 100-200 miles. Brakes do wear, of course, and further adjustment may be needed every 200-1000 miles, depending on how you ride the bike. This is something you can do yourself, but exactly how you do it depends on the style of the brake -- there are generally adjusters somewhere along the cable path that you unscrew to tighten the brakes -- you want the pads to be fairly close to the rim without touching. If the brakes get off-centered, where one pad is much closer to the rim than the other, you should probably have a shop adjust them. And when the pads wear down to the point that the metal holders threaten to rub the rims, the pads will need to be replaced (at a bike shop).