Originally Posted by jonwvara
I have an old Raleigh Sports from 1966--it used to be my dad's bike--that I'd like to keep as an occasional rider. It's in decent shape. From what I've read, the old Raleighs usually came with 46/18 gearing, but for some reason this one has a 48 chainring to go with the 18-tooth cog. That's ridiculously high, it seems to me. I'm planning to switch the cog to something bigger, but can't decide between a 22 or a 24 tooth. The 22 would give a middle gear of about 52 or so, the larger cog would be maybe a 57. Any thoughts? I live in the steep hills of Vermont. Also, if I went with the 22-tooth cog, is it possible that I might be able to get by without a longer chain? Looking at it, it seems possible, but never having tried it I don't know. I'm pretty sure that going to a 24-tooth cog would require a new chain.
JV
We sell a lot of the 24 tooth sprockets
http://harriscyclery.com/saparts
For each tooth you add, the axle will need to move forward by 1/8", so going from 18 to 22 would be 1/2", 18 to 24 would be 5/8".
48/24 would not be nearly a low enough gear to cause damage to the hub, especially one of the old ones like you have. (Later English-made models were not as good steel as the older ones.)
I've gone very low with AW hubs, probably the lowest is 28 front 36 rear on my 54-speed tandem. I generally avoided using anything but the lowest hub gear when riding in the lower chain gears, so there is less strain on the driver prongs.
I am also quite careful about securing the axle against rotation, using two nuts on the left side for extra oomph. Threads well greased.
Sheldon "Sturdley-Armchair" Brown
Code:
+---------------------------------------------------------------+
| There are 10 kinds of people in this world: |
| Those who understand the binary system, and those who don't |
+---------------------------------------------------------------+