On 9/16/2018 6:11 PM, wrote:
I am trying to change the gearing on a beloved seventies 6/7 speed. I would like to use a 50-34 compact crankset but stick with a 6 or 7 speed freewheel in back so I don't have to change wheels and spread the frame. I need rear derailleur ideas that could handle a 30T capacity and a 28T rear cog. Do you have any suggestions? A website suggested the Campagnolo Veloce 10 speed derailleur, but when I tried this model, it doesn't work, even with substituting longer adjustment screws there was too much travel toward the spokes. Thanks.


With friction shifters a Veloce long cage should shift well.
You do need a longer low gear screw (m4x0.7) but you can
buy one for pennies at any hardware store.

Ensure derailleur is vertical (cage parallel to chainrings),
ensure chain length is adequate and then shift firmly with
your thumb like this:
http://www.yellowjersey.org/photosfr...t/gearchek.jpg
so you know absolutely that the chain will not shift off the
back of your low gear sprocket.

The low gear limit is the one on the left. You can see its
function by looking up from under the changer. Once the
shifter is adjusted properly, connect the gear wire. Have
another go, you just missed something.


--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971