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Old 07-06-21, 03:24 PM
  #34  
dddd
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Bikes: Cheltenham-Pedersen 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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One thing to know about the Helicomatic six-speed hubs (and perhaps all of the other versions as well?) is that the cog spacing is narrow, akin to "Ultra" or 7s spacing.

This is a factor in terms of what chains can be used, and how delicate that the shifting inputs from the rider need to be.

Unfortunately, the narrow cog spacing didn't seem to have been exploited in terms of improving wheel dish, as the cog stack sits rather far out from the spokes, and rather inward from the dropout (the latter is home-improvable but only to the tune of one washer's thickness or perhaps 1.5mm which I will take).

Also, the "forked" tips of the cog teeth give smooth chain pickup, but not under much load at all (as compared to period Uniglide or Suntour freewheels) without gross slippage of the "false neutral" or "skating" sort.

I have not found a better chain for use on a Helico freewheel than the Sedisport chain (have tried modern 7-8s and 9s chains).

I too wanted to keep my ~1984 (Trek 720 and Peugeot PH501) bikes original, but in both cases I finally replaced the rear hub.
I re-used the original spokes with no problems (using an HG-7 freehub and a Sunshine freewheel hub) in both cases.

It helps bearing life if the axle bearings are set up with pronounced freeplay that just goes away as the QR lever is fully secured.

Last edited by dddd; 07-06-21 at 03:58 PM.
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