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!craig
smk@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?