Older bikes and upgrading

I've been hunting around for a beater/commuter bike. The only real options out there in my area seem to be older rigid mountain bikes, and there aren't many of those in my size out there. However, if it survives grad school, I'd like to keep riding it, if lifestyle allows. I came across a 1992 Giant Iguana and am talking to the seller about taking a look at it. In the meantime, I have a few questions for the mechanically-inclined.

It looks like the parts are all original. This thing has Sun Tour components and 21 speeds. (Kind of dates it, doesn't it?) Do I have anything in the way of options when it comes time to replace anything--chain and cassette especially? Or does it make more sense to turn it into a single-speed at that point, given that I'd have to replace EVERYTHING (cassette, possibly the wheel, chain, shifters)? I'm also sort of concerned about the shifters, because I know nothing about Sun Tour or anything about bikes that old. (Sounds funny to say that.)

I will be chatting with the mechanics at work too.

SunTour was great stuff, although very costly to upgrade because you basically need to replace a lot... I've done tons of these bikes. If the front shifter is working, you might be able to leave that for a bit, but reality says that SunTour is not compatible with anything outthere. So it means that if the drivetrain is worn out now or if you wear it out later, you'll be looking to replace shifters, derailleurs,chain, cassette, rear wheel as the cassette is made for SunTour cassettes and does NOT fit anything else. On the other hand, maybe you'll be lucky that someone didn't ride it all that much and you won't need to do anything for a bit. The Giant Iguana frame was pretty decent quality, so if that's in good shape you might be lucky there... but in the long run this will be a very expensive bike to keep. Another thing to keep in mind is that it is a 90's frame, so that the top tube will be fairly long and may not fit you very well... and you may need to spend money there in order to try and shorten the reach a bit.In the 90's many bikes were freewheel rear wheels, which often times would mean that the freewheel would simply break off the hub.... so something else to think about as well.It sounds as though you work at a shop, so perhaps you'll save some money there.

In the long run, I wouldn't recommend you buying a bike that far back simply because at some point it's going to cost you quite a bit... if you're working in a shop get something that is more up to date whether new or used and you'll be able to maintain over the next few years much easier.... and you will have many more options for fit.

Just a quick comment because I've got to go to work.
About 22 years ago I bought a Trek hybrid. It was one of the first, I think, steel frame, no suspension. It was my everything bike. About 10 years ago I got something new, and the hybrid ended up on the trainer. I never maintained it much when it was on the road, and then after living on the trainer for several years, I decided this winter to get it road worthy again. It, too, had the 21-speed Suntour components (I think). So the LBS replaced the brake levers, cassette, derailleur and some cables. He didn't use high quality stuff and it came out to about $200, just to give you an idea. I should replace the wheels, but for now it's fine. I felt like a little kid when I got back on it.

But I've also been perusing Craigslist. Lots of big old steel road bikes, and I just love how anything really old (and rusty) is being described as "vintage".

I, too, got a free mixte Raleigh bike of the 1980's vintage. took it to a shop and had "the works" done to it; including handlebars, brakes, fenders, paid about 300 dollars. It's worth it IMHO, and it gives a LBS some cash.
I can't tell if you're going to do the work yourself or not.

Thanks, all.

It's a 16" bike, 21" TT, per the seller, which puts it at a hair longer than my CX bike. (Yes, I'm taking a tape measure with me if I go look at the bike.) According to the seller, it spend the last 15+ years sitting in a garage, poor thing. If it's in good shape, it's a possibility, because I don't want to put a whole ton of money into it just yet, though it'll need new grips, pedals, and tires (slicks), possibly new brake pads, and almost certainly a new saddle. The worrying thing, of course, is when the chain/cassette/derailleurs/shifters go. Even without the discount, I could probably manage to put low-end Shimano or SRAM on it for not too much money. If it's not so good (or it doesn't fit), not worth bothering with, even if the frame's in good shape. A little sad, because I've seen some pretty cool touring-type set-ups on Iguanas...but they were largely newer Iguanas with Shimano parts that were more easily interchangeable, by the looks of it.

I have an old multi-use bike (1990 vintage Klein Pinnacle) that has a 7-speed drive train. Out of necessity, the drive train is now a mixture of parts - Suntour indexed shifters, Shimano derailleurs, Sachs freewheel, and SRAM chain. Somehow it all works perfectly. So I wouldn't worry about replacing parts on a used bike. (Check out Amazon for parts availability.)

If the bike you are looking at has been without routine maintenance for 15+ years, the grease in the hubs, headset, pedals, and bottom bracket needs to be cleaned out and replaced. And I'd go ahead and replace the chain too.

I must admit that part of me wants this bike to work out, largely for the ability to say "I ride a giant iguana to school every day." (Yes, I might still be ten to twelve years old.) Part of me hopes that it definitely doesn't fit so I'm not tempted to get it as a project bike, because I think we all know that a project bike (esp. that old) is not exactly a money-saver. Hasn't stopped me from looking for parts, though.:rolleyes:

Edit: It isn't totally ridiculous to upgrade, with the exception of wheels. Probably in the $300 range. But at that point, I may as well find a nicer bike now.