I currently have a Centurion Ironman which (still) needs a tune up. The wheels aren't true. I was thinking the cables must be replaced because of the color of the cable (oxidized?) and some fraying at the ends. Then, that got me thinking of the chain wear. I don't have a chain tool, but I was wondering if I would need a new chain (not sure on what kind, but I'm aware that there are plenty of types). I figure since if I do need to replace those two, I might as well replace the rear threaded freewheel and possibly my chainset and rear derailleur. I pretty much might as well upgrade my whole groupset. Any suggestions? I don't have a brick load of change laying around, but if the upgrade is worth it, I'm sure I can sacrifice some lunches and evenings.

Off topic, but here's what's happening so far regarding my Ironman. My Shimano PD-1050 pedals had old plastic toe clips, and both of them cracked today. I'm lucky to have MKS-GR9's on my fixed gear. I swapped them out. I'll be receiving Shimano PD-m540's as a birthday gift. I received a pair of Pearl Izumi cycling shoes that are barely used (and happen to fit me) from my cousin J, and will be receiving some cycling clothes for my birthday. I'm just really excited to work on my first real road bike.

What about picking up an "old" lol shimano 105 6500 or Ultegra 6600 used from eBay or sim?

Measure the chain and see if it is stretched. Use a tape and from one pin to another should be 12". If it isn't stretched too much the FW should be fine. I would maybe replace the brake pads they are likely to be worn and dried out.

Unless something is broken I see no reason to start upgrading.

Not sure... I kind of feel like I don't want to buy older parts when I can put modern parts on my Ironman. When I bought the bike, the owner gave me another freewheel- a Dura-Ace MF-7400. I like the fact of having the bigger gears for those steep hills, but I don't think I'm approaching hills correctly (if I'm in the lowest gear, it's easy to lose momentum). I currently have a MF-6208 (600EX) installed.

The brake pads seem fine. I don't see any cracking. I took a ruler and placed it so that one pin lines up at 0 inches. At the 12" side, it is ~1mm before the pin.

On my Ironman, I've got mostly stock parts, but switched out the wheelset for one with a 9-speed cassette (and naturally a new chain), just switched to Suntour Barcons, plus new tires, saddle and bar tape. It all works great together. Replacing some parts doesn't necessarily mean you have to replace everything else, especially if you go with friction shifting.

I'm uncertain if I'm happy with 6 speeds or if I'm not. My tires are new Bontragers, and the bar tape appeared to be recently installed. I haven't experienced much saddles, so I can't really say about my Schwin saddle. That said, I go prefer the SIS shifting. I'm not saying I will replace everything all at once, but I would like to know my options and upgrade at my own pace.

On another note, my gear and brake cables are oxidized and seem old and slightly frayed at the ends, but are operational. When would I really need to replace them?