Advice on groupset swap needed....
 

I've got a chance to swap out my complete Suntour GPX 7-speed Accushift package (brakes and all) for a Dura Ace 8-speed package, but I'll have to come up w/hubs and crankset. Is it worth my time and cost of used other stuff.

If you have the money and time to burn, then go for it. But what will the extra cog do for you? Anything wrong with the Suntour that would prompt the change?

I have the GPX group on a bike and the only downside is the Suntour spaced rear freewheel - when it finally wears out I might try a Shimano freewheel but I'm not sure if it will shift well - the Suntour has a slightly different cog spacing. The GPX brakes are excellent.

Are you going to keep the GPX parts, or trade them for the DA parts? If it's an even trade go for it - the DA is for sure an upgrade, and you can use any Shimano hub with 8 speed cassette that you want. Any crank will work as well. One thing is you'll have to respace the rear to fit the wider 8 speed axle.

If you're paying good money, well then it depends on how much. You'll gain one gear and it might be a little bit lighter (or heavier too...hard to say). I do think the polished DA does look better than the grey painted GPX. Good luck with it!

Nothing wrong with the Suntour GPX, one scratch on the rear 'rail. I have Shim 600 8-speed w/STI on another bike, and I like the narrow range cassette I have on it (few hills here). Not so w/the blue/gray GPX, which shifts smoother, but is hard to find a cassette w/narrow range cogs. No money would change hands, but I'd have to find front and rear hubs and a crankset on my dime. I've already found the crankset, and hubs are out there. Not sure I want to spend the $$ to move an Ironman Expert to "Master" components if the Suntour stuff can do the job. Thanks for the advice, all, and it's definitely appreciated.

I do not think the conversion is worth the added expense.

I've decided to keep the Suntour GPX, which was OEM on that '89 Ironman Expert. I'll try to find a narrow range rear cassette, and if I don't, I'll deal with it. I didn't need the downtime or the expense, and thank everyone for their feedback.