Originally Posted by
ThermionicScott
If it were my project, I'd consider flipping which cog was the freewheel and which was fixed. A fixed cog is just fine in flat or gently rolling terrain. If you climbed a steep hill with a 30T fixed cog, it would get VERY spinny very fast once you got to a flat area, let alone a downhill. If you used a freewheel for your low gear, descending the other side of that steep hill would be no big deal, so you could save your gear changes for when you're moving between flattish and hilly regions.
BTW, the biggest fixed cog I've seen was 24T. My brother bought it for a weird project, and I think it was made in India or eastern Europe.
Thanks for the post.
I would ONLY use the large rear hub sprocket for CLIMBING HILLS. when I got to the top I would dismount and flip it back to the free wheel. That is why it makes sense to me and my bike mechanic friend to go fixed with the large rear wheel sprocket and free wheel with the small sprocket ad one that I would use 95 percent of the time, that means flats, down hills and smaller hills. The large sprocket is just for STEEP climbing. That is all. The only time I need it is when I would use it. When I do not need it, I do not use it so I am not spinning like crazy fixed going down hill ever.