Bike Forums - Where to start upgrading?

re: used parts:

bottom brackets: so many people do not ride the life out of their bottom bracket. This means that a lot of the BBs out there have plenty of life left in them. People upgrade for all sorts of reasons - need a different spindle length, need a different crank interface, want to switch to external. Whatever the case, most used BBs are just fine. And if they are cheap enough who cares. I am talking about $5 or so. The other reason so have some cheap bottom brackets on hand is for testing out spindle length on crank installs to dial in your chainline or check for ring clearance. Bottom brackets are big heavy units which are hard to bend or mal-form, so they are a pretty good bet. I am talking about sealed BBs here. Loose ball BBs are awesome, really adjustable, quick to change spindle lengths, switch between symmetric and asymmetric, but they are so much harder to work with than sealed that I do not think it is worth it anymore.

headsets: I am wary of buying used headsets. There are too many things that can go wrong removing them and installing them. I would make an exception if it is coming from a bike shop who did a take-off for an upgrade. I would also make an exception for the highest quality headsets which have replacement parts available and which have not changed specs for years and years. The other problem with headsets is that even with an improperly installed headset, the bike is rideable and this is going to trash the headset and fast. One crooked race will really jack the bearings. This means the headset can be removed, look quite new, but be completely trashed.

cranks: be careful of cranks. It is easy to not notice that the square taper is damaged or stretched out. It's also possible one of the spider arms is bent which will jack your ring. But be aware that lots of people upgrade cranks and their old set is just fine. You need to know your interfaces and octalink v1 vs v2 will make you crazy.

seatposts: I would not mess with a used carbon seatpost. Otherwise, this is a good place to buy used. Seatposts are usually marked very clearly for size (diameter) so fit is rarely a question. Other than the seat binder bolt, there is not much that can wear out. Some people can scratch the hell out of their seatposts so be aware of this.

stem: I buy used stems. No problem. Some people might sketch because of cracks or other wear, but I just don't see this is a big enough problem. As with BBs, it is nice to have some different stems around to dial in fit or temporarily change your set-up to deal with an injury.

bars: of course, buy used bars. be aware of clamp diameter. Extra bars are also good to have around, especially for injuries.

saddles: maybe kind of gross? But a lot of people try a new saddle and don't like it so get rid of it before it is used. There are also a lot of take-offs that have never been ridden. Be careful for damaged rails. Not very common, but easy to hide and deal killer.

wheels: most bearings are easily serviceable. trueness is also easy to dial in. big hops are a bigger problem. I don't really want to dwell on wheels because other than having a spare for emergencies, having extra wheels around is not as beneficial as having stems and bars (to me, at least).

brake levers - definitely. Make sure the diameter is correct which is not really a problem for run of the mill road levers or mtb levers (although be aware that those two categories are different) but can be an issue for cross levers. Also make sure the pull is correct for your brake caliper.

brakes - make sure all the parts are there, but these are also an often upgraded component so a lot of the brakes out there have plenty of life.

pedals - I find that most pedals look a lot worse than they are. A pedal might look scraped up but that is only because your face is right next to it. By the time it's on the bike you won't notice. Also, a scraped pedal does not mean it is functionally trashed, again, there is likely a lot of life left. Some are more serviceable than others.