Old 03-30-20, 02:15 PM
Ride, Wrench, Swap, Race
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Join Date: Jan 2010
Location: Northern California
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Bikes: Cheltenham-Pederson racer, Boulder F/S Paris-Roubaix, Varsity racer, '52 Christophe, '62 Continental, '92 Merckx, '75 Limongi, '76 Presto, '72 Gitane SC, '71 Schwinn SS, etc.

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For friction shifting, many of us have found that using modern freewheel and chain results in occasional or frequent "ghost" shifting.

The reason is that there is little-to-no noise-producing buffer between one gear's chain position "window" and the next.

So where the old-fashioned cogs would clatter if the chain position was anywhere near the onset of a shift to a larger cog, these new-style chains and sprockets can allow one to position the lever and thus chain such that a silent, sudden change of gear can occur. I've had this occur and it can disrupt one's control of the bicycle as the chain hunts between engagement with two different cogs.

One cure for the ghost-shifting problem is to use a less-modern chain. The ideal chain for this would be the early HG-compatible Sachs chains, as these do not grab the teeth of an adjacent cog very aggressively, yet still run quiet and smooth like modern chain. Even the older SRAM 7-8 and 9s chains, up until about 2002 or so, had flat outer plates so would usually tend not to ghost-shift without making continuous noise beforehand (following a previous shift).
The cheapest KMC chains still have flat plates and are compatible with 7s freewheels. These are low quality but actually work ok and tend not to break unless subjected to power-shifting under heavy loads. As such they are perhaps not truly HyperGlide-compatible like most chains are, but quite a few vintage-bike riders use these because of their very-lowest cost (well under $10).

One last thing that can make a modern freewheel more suitable for friction shifting would be to apply beveling to the drive side of the teeth, perhaps done quickly to an assembled freewheel using a bench-grinder(?). No, I haven't done that, I but have adjusted tooth bevels to make the shifting MORE aggressive, with beveling applied to the non-driveside of teeth or to the driveside of every third tooth so as to enhance shifting towards smaller cogs when using a "weak" vintage derailer that is being used with too wide of a freewheel (too many cogs). The beveling effects a lot of control over shifting behavior is what I'm saying.

Many riders use modern freewheels with modern chain and seem to have no complaints, so there's that.
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