My thinking on gearing. I have bad riding technique. I don't pedal if I have a 15 to 20 mph descent speed so I don't worry about spinning my top gear out. I have never had a bike with a gear so low that I could spin it out going up a hill.

I have a 12 28 on the rear and a 38 42 on the front. So far these gears are working well for my riding style. I could probably just ditch the 42 tooth gear but it is there to prevent cross chaining.

I have one bike with a 28 28 and I still don't spin it out going up the hills that I ride. It would be interesting if there is a gear that I would spin out. I might spin out a 20 up front and a 34 in the rear.

My hill riding is limited to maybe a max of 10% grade and that grade would only be for a few feet along the total climb.

The hill that I spend almost all of my time on is .4 mile long with a total rise of 60 feet. My down hill coasting speed is around 28 mph and my normal climb speed is around 5 mph. On a day when I am felling good I can push over the top maintaining around 7 mph and I can also crest the hill at 10 mph spinning like a maniac. So this old engine is not very powerful, overheats and blows oil but it is all fun. But like I said if I tried spinning at 10 mph all the way up the hill I would blow up and not come close to maintaining that speed.