Trouble indexing with Sachs Huret DT shifters
 

So, I've got this bike...

http://img713.imageshack.us/img713/3412/pic26.jpg

I'm having trouble indexing the shifters with the cassette (Sachs-Huret 5000 ARIS 8 speed + SRAM PG 850). Is there a way to get this to work? I'm hoping I won't need to search around for a Sachs freewheel (and thus, lacing up an older threaded hub), but it looks like it might be the case. I'm hoping you can prove me wrong :(

What rear derailleur are you using? Is it a Sachs from the same era as the shifters? So far as I know Sachs rear derailleurs from that era had their own cable pull ratios and were not compatible with either Shimano or Campy derailleurs.

I am not sure what the spacing was on 8 speed Sachs freewheels but considering 8 speed freewheel hubs propensity to bend axles I would only want to build a 8 speed freewheel wheel using a Phil Wood freewheel hub.