Originally Posted by rp macpherson
I bought a 1983 Roberts touring bike that I am still in the process of upgrading for my first loaded tour this fall. I posted about it once before but I cant find the old thread. The bike is a little quirky and my approach to it has been a constant struggle between maintaining the original character of the bike and making it a practical machine. Since the rear dropout spacing is unconventional (126 mm i believe) i was initally torn between cold-setting the frame to accomodate a new wheelset or having the wheels rebuilt, replacing the tubular Mavic GP4 rims with clinchers, and maintaining the 6-speed freewheel. After much debate, I decided that the 32-13 freewheel was wide enough and I had the original wheels rebuilt with Mavic a719s.
So now, having decided to keep the freewheel, my focus is shifting to the original crankset. It is a double-chainring half-step (40-36) Sugino that leaves me in the dust when I ride with my roadie friends and I imagine would slaughter my legs on steep climbs when loaded. I eventually want to replace the crankset with a touring triple but I am wondering about compatibility. If I get a triple, will I have to get a new front derailer as well? What about the rear derailer? I'm trying to get this done as cheaply and efficiently as possible, but this project has proven to be a lot more work and money than I'd anticipated. Will replacing the crankset be another expensive upgrade? Any answers and advice would be much appreciated.
You can find inexpensive cranks all over the place.
Bikeman has an Impel for $25 but it will probably have steel rings that would be difficult to find. Nashbar sells some for cheap and you can always go with a Shimano Tiagra or 105 which will probably be a 52/40/30. The 30 tooth cog can be replaced with something lower if you need it like a 28 or even a 24. Since you probably have an old bottom bracket you may need to replace it. I'd say, depending on the quality and whether or not you can find a deal, you are looking at $80 to $120 if you stay cheap. If you want better stuff...well the sky's the limit
