craig@hp-pcd.UUCP (05/09/84)
5 speed spacing is 120 millimeters inside dropout to dropout
6 speed is 125mm.
If you want to convert to 6 speeds in 5 speed spacing, you'll need
a narrow ("ultra 6") freewheel and a narrow chain (Sedisport works well).
If you want 6 speeds and don't want to get a new chain (or want
seven speeds and a new chain) you have to spread the rear dropouts.
No big deal but you may want to have a shop do it so they can make
sure the dropouts are aligned and the rear triangle straight after spreading.
According to something I read somewhere (you might check The Bicycle
Wheel by Brant) wheels built to 5 speed spacing are 40% stronger than
6 spacing (because of the increased dish). This appears to be academic
(immensilly powerful racers ride 6 speeds with no problam) through
loaded tourers may want to think about it.
If you race, most of the spares in the follow car are 6 speed spacing.
Shimano makes some hubs which fit 6 speeds into 5 spacing by doing
some juggling of the hub spacing.
Craig Durland
...!hp-pcd!craigsmk@wxlvax.UUCP (Simon Kao) (05/23/84)
() What's the wisdom out there on putting a regular 6-sp rear hub into a rear triangle spacing for a 5-sp? I've been told everything from "it's only a few millimeters" to "use an Ultra-6" What's the real answer?