I've been through this a couple of times; it's a real nuisance. Here are a few possibilities:
1. What size is the smallest sprocket? Some bikes were just not intended for use with small sprockets that aren't very small.
2. Is the derailleur claw preventing the hub from sliding back far enough? If so, some filing may be in order. Or another claw.
3. The hub hardware may be wrong. For a 5-speed, there should be a minimum of 29 mm from the outer locknut to the surface where the freewheel rests (i.e., that little ridge just toward the inside, next to the threaded part.) If this is too small, you might need to add washers or use other hardware.
4. Finally, there is a lot of variability in the thickness (for lack of a better term) of freewheels. If the hub dimensions are OK, but there is only a mm or so of locknut protruding beyond the freewheel, obviously there will be fit problems. I keep a whole box of freewheels around, and often I have to go through a lot of them to find one that has a good fit. Then, cannibalize another to get appropriate-size sprockets for the one whose body fits the hub.
Steve Maas (97 F in) Long Beach, California (but at least the power is on, and the AC works!)
Atrikerider@aol.com wrote:
> I just tried to put a 120 mm rear wheel with a 5 speed freewheel into an
> early 50's frame that measures 118 mm (?). The teeth on the 14t cog hit the
> chainstay and therefore it doesn't turn. I can't move the wheel further back
> because it is already against the gear hanger for the derailleur. Should I
> start looking for a 4 speed freewheel? The frame did originally have a derailleur
> because the brazed on fittings are there for the shift lever and the cable
> guides.
>
> Paul Patzkowsky Longmont, Colorado
>
>
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