I'm mounting a fairly clean Eco Duopar on a bike and running into a problem. The nut that goes on the back of the attachment bolt behind the drop out won't clear the chain on the small cog. I've used the nut before on a five speed set up, but this is a 7 speed ultra freewheel and things are pretty tight. On the other hand, the main bolt is holding the whole derailleur pretty tight to the drop out and the derailleur seems unmoving as I shift up and down the cluster.
Is this nut essential? Maybe it's only for simplex style drop outs without the stop/shoulder? Anyone else seen this problem?
Tom (Ten Thumbs) Adams, Shrewsbury NJ