I am trying to solve a very puzzling problem - and need a little advice. The problem is that the chain brushes against the inside of the large chainring when it is riding on the small one - not much but enough so that when I have the bike in a stand and I spin the wheels slowly I can both hear it and watch it happen. This occurs when the chain is on smallest two of the freewheel cogs. It is the rivet heads that are contacting the inside surface of the large chainring.
Here is the setup for my bike:
1972 Peugeot PX10e
* Stronglight cranks 52/40
* Regina freewheel 14-17-20-24-28
* Regina chain 3/32"
* Shimano Deore XT RDR
* Shimano Deore XT FDR
* Normandy HF hubs
I have ridden and maintained this bike since it was new, so I know its history. For all of that I don't recall when, but sometime ago I crashed it and badly. The dropout flange to mount the RDR was bent as was the RDR cage. I have straightened both out fairly well. The axle is fine and I can spin the wheel in my hands and there is no wobble, bearing grinding or slop, nor any noticeable alignment issues.
I have just replaced several spokes that were kinked in the crash and trued and dished the wheel fairly well. the HF hub on the RH side has a distinct "out of true" spin to it, but it has no impact at all on the wheel spin, nor on the freewheel spin - mostly it is from having been pushed in slightly when I crashed. The chainline looks reasonably good to me.
I have tried to puzzle my way out of this and for the life of me cannot see why this is occuring. I ordered a new SRAM PC951 chain hoping that the smaller chain would solve this, and while it is on the way I am open to any and all insights here.
BTW - every part of this bike has just been torn down, cleaned, all bearings and races checked and repacked with new grease. This includes the BB, the hubs, the pedals and the head tube. The RDR has new pulleys as well. The axles were checked for straightness by rolling them on a bench stone and they are as new. So what is going on and what do I do?