I've been away from this thread for a few days, so I've missed some interesting discussion on what ribbon might be suitable. I thought I had better throw in my own thoughts, for what they are worth. I had a Contax II partly stripped awaiting ribbons for a couple of years, while I tried, and failed, to find suitable ribbons. I was, and still am, determined not to modify the friction clutches. In the end I tried some polyester Berisfords 'Double-sided satin'. The dimensions are spot-on, but it seemed to have too much friction. I changed to the Aki-Asahi, but without adjusting the friction, and the camera functions at all speeds, but the speeds are not good. In the very near future I'm planning to do a full shutter strip-down, clean and lube, and perhaps try experimenting with altering the tension of the 2nd curtain relative to the 1st.
Someone suggested the curtain strap material from Micro-tools.
Measurements are slightly off though. 3.17mm wide and 0.25mm thick.
http://www.micro-tools.com/product.htm?pid=147157&cat=14013
That looks just the job, according to the dimensions, but judging from the picture, I don't think the weave would be suitable.
Milo is sending me some different strap materials to play with.
He dids say it's best not to mess with the clutches at all.
Agree about the clutches. I'm sure the factory must have set the clutches on the production-line according to whatever ribbon happened to be on the roll that day, but I'd still prefer to leave them where they are.
Brett also suggested (via Facebook) shimming the clutches instead of crimping them, by folding thin sheet metal or other material around them.
Was contemplating the shim idea with the Contax II. I don't think shimming the bridge part of the clutch could work. For one thing, the 'bridge' is not straight, which would make it impossible to fit the shim material closely. Also, the A-A ribbon is rather wide and fits the friction slots close to the sides, and I think the end of the shim insert would tend to cause fraying. I thought it might be possible to fit a shim behind the ribbon, between the ribbon and the 'yoke', but in the end, abandoned this idea as well.
It is rather hard to believe there is not a ribbon out there that is more suitable than the A-A. It definitely should be a 'grosgrain' weave. Contax ribbons, Kiev ribbons, and the Aki Asahi, are all grosgrain, which has a distinctive lateral ribbing. Most of the 'grosgrain' ribbon available on eBay is all of the same Chinese variety, which is too thick, and much too coarse. There is also another slightly rarer variety sold as "3mm", that looks quite suitable in weave and thickness, but unfortunately it is 3.7mm wide.
Steve.
