Let me start in the beginning. I had a single speed bike as a gift (SE DRAFT Bike). Later I bought 1977 miyata Americans 10 gears(off from offer up apps for $100). I never enjoyed that stem shifts. It wasnt my type shifting. So I brought the miyata to a LBS and told them I wanted that bike to a single speed. They did everything I asked them to do. When I rode that bike on the way home, I noticed this bike wasn't at the same speed like the se drafts. With this se draft, riding on single feels single speed. But with this 1977, it FEELS like I'm riding on a gear that you put it for going uphill. When I pedal, I'm pedaling faster than my draft bike. But moved kinda behind than the regular speed I did with draft bike. Its not the same as my draft bike. Do I modify the 1977 sprocket to speed up on a single gear it is it something else ? I counted 40 teeth on the 1977. And 42 on the draft bike. If I buy a new set of sprocket, with more teeth, will it make any different? I'm kinda new in this. When it comes to numbers, I'm trying to understand if it a big thing to pay attention to.