Originally Posted by
dundas
Thanks for the replies. The wheels are 700c, so that's not a problem. A couple more questions: Will my existing shifters still work as indexed if I jump up to a 7 or 8 speed? Would a new crank for a 9/10 be necessary because of the tooth spacing? Could a new chain ring do the same thing?
Since I didn't pay much for the bike, I'm trying to do the math on upgrades that would cost less than a new bike of comparable quality. Plus I love the look of the frame. Thanks again.
The indexing will only work just-right with 6 speed. Shimano did market shifters as being 6-or7-speed indexed compatible, but the spacing between cogs is slightly different between the 6- and 7-speed by a few tenths of a mm, so adjustment is infuriating in my experience. As I'd mentioned above, you won't really need a new crank, as the chainline among road groups didn't change much, even as the rear hubs grew wider, as well as the freehub bodies once we jumped to 8+ speeds. You will probably want new chainrings, because one you get to 9+ speeds, the chain is significantly narrower, and you might find the chain "skating" atop the teeth of the rings immediately following shifts. If you can live with this, you won't need new rings. My OCD doesn't allow it, though.
Originally Posted by
Zaphod Beeblebrox
The 710 was a nice bike in its day and is as good as any reasonably priced production steel frame you could get today.
I'm curious as well. Why can't you use old chainrings with a 9/10 speed rear wheel?
Your existing shifters will only do 6 speed indexing. You can use them as friction shifters but for indexing those shifters are strictly 6 speed.
You might be able to adjust the derailleur just right and shift past the 6th gear and get it to work with 7 speed, but you're really better off with the correct shifter
The chainrings get narrower as the speeds go up, as does the chain. You can run 9speed chainrings with wider chains and <9speed cassettes, but things get crunchy if you try to rock it vice-versa. B/c cassettes got only very slightly wider between 7 and 8, and stayed the same between 6 and 7 (and 8 and 9,as well), and actually got
narrower between 9 and 10, most old rear derailers will swing enough to accommodate cassettes with more speeds, given the proper shifter. Most shifters being run on friction will pull enough cable to jump up a few speeds, but you may run into some trouble, and should budget accordingly. Dialing the limit screws on the R.Derailer properly goes a long way with this.
Dundas, i personally feel that you might be better off just getting your existing components tuned up as best as you possibly can, rather than replacing them. Some things will be worn out, and these should absolutely be replaced. (Chain, rings, freewheel/cassette, brake pads.)
If the wheels are in very bad shape, and/or you're worried about bending axles, it might pay to replace the wheelset with something that has cassette hubs. A 126mm, 7speed-spaced rear hub would be preferable. Wrk101 is a very skilled cheepskate (that is fully and truly intended to be a compliment), and his advice is probably the best on this thread. Get yourself a used 7-speed freehub wheelset. ride it as long as you can, and when it gives up the ghost, rebuild the hubs, and rebuild the wheels around the freshly rebuilt hubs. One caveat: if the wheelset you get has a uniglide freehub body, replace it with a 7speed hyperglide body (these are still available, and quite cheap.) Replace it when it is already a fully-built wheel; you'll have lots of trouble removing a freehub body without being able to use the rim for leverage. (7 speed hyperglide cassettes are still available; uniglide cassettes are available only as NOS/used, and aren't exactly plentiful.)
Seriously, especially if you're being budget-conscious, you're probably better off keeping as much componentry as you can, and replacing only what needs replacement. This isn't about "blasphemy" or anything like that, it'll just help you conserve money, and prevent any wasting of decent components. Save money, save your cool vintage stuff, and enjoy the ride.
-rob