can not shift front or rear derailleurs

[Jim nocito]

need help. trying to fix my 18 speed bike. freed up the chain and the cables, but can not shift gears. what else can i do?

[Painkiller]

need a tad more info, what kind of shifters do you have? and derailluers. pictures help a ton too. If your cables and housing are freed up then your shifters and or derailluers are at fault. so lets start there.

[Jesper]

(07-27-2020, 11:57 AM)Jim nocito Wrote:  need help. trying to fix my 18 speed bike. freed up the chain and the cables, but can not shift gears. what else can i do?

Welcome to the club Jim,

As Painkiller stated, we will probably need more information and some photos.
If, as you say, the cables are "freed up", but you still cannot shift, then the derailleurs themselves and/or the shift levers must be frozen. How did you determine the cables to be free? I imagine that you disconnected the cables from the derailleurs in order to work on them. If the cables are now reconnected to the derailleurs, you should disconnect them and then attempt to manually move the derailleur cages in and out from the frame, as well as cycling the shifters (whether friction or indexing) through their range of movement.. Grip style shifters seem to be the worse culprits related to "hard" shifting; I won't use them. Aside from tension provided from the springs, everything should move freely without any excessive play. If the overall drivetrain needed work I would remove all of those components and rebuild each one, none of which take much time except the rear derailleur (and probably grip shifters which I throwaway unless working on someone else's bike). If the chain was rusty, then there is a high probability that there is oxidation on the steel and aluminum parts that can effect proper function of same. You can soak the derailleurs in some cleaning solvent (I use gasoline, DO NOT put "plastic"/rubber parts in any solvent unless you know it is safe to do so!), but this will not "clean up" the rust/oxidation which is probably on all the pivot mating surfaces. You will have to dismantle the part and then clean and "polish" those mating surfaces. 000 to 0000 grade steel wool works fine for most surfaces. When working on aluminum, I prefer to use bronze wool (I keep both fine and coarse grades available) due to it being softer than the steel wool and less likely to cause any further a wear/damage. I, in most cases, NEVER use sandpaper on any bike repair/refurbishment/restoration unless absolutely necessary, and that usually means that any damage I might cause is outweighed by the already poor condition of whatever I'm working on.
Personally if there was a fair amount of rust on the bike in general, then I would be doing a complete overhaul on it, to include replacing the cables and housings. You cannot tell what the internal housing condition is so it is best just to get new ones along with the cables; all low cost parts that can make a big difference in the end. A bad housing presents itself upon having cables reconnected with tension on them. They can inhibit cable movement, but cables still feel fine when when manually pulled/pushed in an out while disconnected. If housings looked kinked or bent externally than that will have an effect on the overall operation. Also, cable routing may be incorrect and need to be "re-oriented" to provide smoother operation; this can happen with brand new cables/housings or old ones.
I have loads of techniques/"tricks" to make things work efficiently and at times work better than the original design; but you can only go so far, and sometimes replacing a part will save you a lot of time and effort trying to make that which is "effectively inoperable" be able to function (however poorly) for a short period of time until you have to "repair" it again. About the only exception to that is if you are dealing with rare collectible bikes and components that will never be utilized in a normal manner (e.g. "show" bikes, etc.).

Short "quick fix": blast every pivot point with lubricant/penetrant; keep moving the parts until they work okay, oil up the chain and ride. Of course you are not preventing further internal damage/wear from occurring, but it usually gets you on the road without dismantling or replacing parts. Something I might do for a "dumpster" find just to check it out before doing a full service on it, but something I would never do to on a bike for someone else. Even if that's all they wanted; my safety is exploitable, but not anyone else's safety.