ANYWAYS.....

I am dealing with a similar knee issue. I toured Texas-NY State with 22/34 as a granny, worked fine most of the way until New York State. I now have two 20 tooth chainrings on hand from the guy who makes 'em in California (be aware they arrive in an envelope regular mail so there will be no tracking numbers or parcel delivery). I'm gonna have to machine down the heads of the mounting bolts (as instructions suggest) before they will not hit the chain on this tiny chainring.

My plain ol' friction levers on the downtube should allow me to transition to 9 speed (no problems with the original derailleurs going from a 7 speed freewheel on a 27" wheel to an 8 speed cassette on a 700c) so I also have an 11-36 tooth 9 speed cassette inbound as we speak. Should lower my gear inches from my present 17" to around 15". I'm pretty I'd need a new derailleur also to clear a 42 tooth cog.

I was spinniing at 4.5-5 mph with the 22/34 set up, I'll keep folk informed on how the 20/36 works.

Mike