There are times though when having one gear simply is not enough and having the versatility and efficiency of a multi geared drivetrain comes in handy. What generally happens for me is that I end up riding in 2-3 gears even if I have 18-20 gears available. Having the ability to have 18 different gear ratios and only using 2 of them seems like a very complex and costly way to achieve what is essentially a 2 speed bicycle.
I've installed a Paul Components Melvin tensioner which allows the use of two front chanrings for a simple but effective two speed drivetrain. I simply change gears with the front derailleur.
Two Speed Conversion
Lots of chain tension and wrap with the Paul Components Melvin tensioner.
The 18 Tooth Cog - 46 Tooth Chainring Combo
The 18 Tooth Cog - 36 Tooth Chainring Combo
Simple Cable Routing, Bar End Friction Shifter.
Riding this bike as a two speed has made the experience much more enjoyable for me. Making it simple and still enjoying the benefits of a multi geared bike. The bike is just as versatile as it was with 18 gears. It does make the engine work harder, which is a good thing.
It rides and feels lighter without the large rear gear cluster.
Sometimes two is enough.