Originally Posted by dddd

Any "repair" to the seatstays is only going to be cosmetic, but no worries as that piece of tubing isn't butted so will never fail at the hole.

Look for a bottom bracket spindle dimension stamped into the spindle near the seal, it likely would carry an OEM-type size/offset code such as D-NL, but in this case I think you can assume (but do verify) that the correct bottom bracket for this RSX crank is 118mm, no offset. You really don't want to increase the driveside protrusion of the frame, so better to be accurate here than to "play it safe" with a longer or more heavily-offset spindle. A UN-55 model would seem like the best choice for low money.

If this bike fits, it should make a good all-around bike for where the triple compact gearing setup would be useful. There are 11-28t and 12-28t 7s cassettes that will give lower-yet gearing, but the11-24t was a standard RSX offering and features a nice, smooth progression of gear ratios.

Two thoughts on the right shifter, sometimes it takes a long time, or heat, to get the lightly-spring-loaded pawls inside to move, after an appropriate penetrating lube has flooded the shifter's insides. Once any relatively thick lube has filled the crevices, a more-aggressive penetrant may not be able to penetrate readily into the gummed pivots of the spring-loaded pawls.
Keep in mind also that if the unresponsive lever is moved VERRRY slowly, that the spring may then be able to overcome the gummy resistance of the thickened grease, and which may then create enough movement along the freeplay of the pawl pivot to help finally force the penetrant in. So after getting the lever to engage through a perhaps 2-minute-long early stroke, to where it actually catches/engages the cable spool teeth, a second engaging lever action may then take half as long and so on. Heat is your friend here, so perhaps use a hair drier or leave the lever under your car's hood for 20+ minutes before testing the levers again very slowly. It is almost rare to have actual mechanism damage causing an unresponsive lever on such a low-mileage bike, so don't try taking it apart or forcing anything.

Those calipers will be a nuisance when it comes time to remove the wheels if wider tires are used, so don't increase tire size unless a wider rim is also used, or until you replace those cheap calipers.

An LP-26 bottom bracket this old will usually have thickened grease that resists turning, but I have found that they continue to provide solid service for some years despite this. I wouldn't really expect it to free up much on it's own. There is I believe a thin locknut under a plastic cover that covers a keyed washer and cone, so disassembly is possible. The bearing retainer must be pulled straight out after the cone is removed, to allow the balls to be displaced to one side of the spindle so that the spindle can be withdrawn, so this is far from a standard rebuild procedure and I haven't rebuilt one of these in probably 20 years. Their bearing quality is quite decent though these are heavier and rougher-feeling than the UN55 that can be had for under 30 bucks.

Originally Posted by ryansu

My understanding for going to a sealed unit is the following measure your current spindle length for reference but more importantly note the crank you are going to use and check the crank manufacturers recommendations for bb. lets say you were going to use a VO triple they recommend a JIS 124 mm bb.