first off the set up is...
C-record cranks with 52 / 39t rings newish rings.
zeus 6 speed freewheel 13 / 18t was new old stock
SRAM chain brand new
C-record 1st gen front and rear derailleurs
C-record friction shifting levers.
Ok my problem is the rear part of the drive train only will run in the 15t cog with out skipping, essentially in every other gear the chain will jump strait up and back down on the same cog over and over.
coincidently this is the cog in the strait chain line position, it works on both the large and smaller chain ring. and skipping on all other cogs happen on both chainrings as well.
i will add that while on the stand it shifts flawlessly but under load it skips.
chain tension is set to what I think is good, while chain is on the largest front ring and the largest rear cog I can pinch and turn the chain overlapping about one or so links..
and lastly I do realize there is a sweet spot in friction shifting, but it only seems to exsist on the one cog at the moment, I spent the day ridding up and down the street trying to figure if it was just that I haven't been hitting the right spot, but it doesn't seem to be the case.
any help would be fantastic, it is driving me mad... built up a sweet ride with gears and seems I am destine to be a single speed rider for life.