Originally Posted by
Phil_gretz
So, I'm going to disagree with not using a gear calculator. If your goal is to tighten your gear range to suit your riding style and local geography, then the gearing calculator is the very first step. Your 12-19 freewheel has steps from 8% to 11% or so. What if you had 4% step between your chainrings? Then you would achieve very tight gearing on the half-step. The original 613 might've had 52-42 or 53-42T front. What if you went 44-42T, then the steps would be grand, as evidenced by the following:
I lived in the mountains in western Virginia for about 10 years and I made extensive use of Sheldon Brown's gear calculator to figure out the best configurations for dealing with some fairly steep climbs in the Shenandoah. Now I live near the coast. The only time I use the crank small ring is to relax the chain when I hang my bike and to loosen up for 5 to 10 minutes before I start my ride. Where I currently live is rather flat with some moderate hills and hardly anything that is very steep. I rarely if ever use anything other than the large crank ring and the 3 smallest cogs on the back. If I am climbing a hill and I need to shift down, the next largest cog is always comfortable after not being able to sustain the higher cog. To me that is the definition of a properly geared bike. In addition, the gear inches on my smallest ring (12 teeth) with a 52 ring up front is 117.0. Using your example of a 44-42, I would not even reach your highest gear inches of 96.6 until I have shifted down to the 4th cog (15 teeth) on my Sachs 12-19 while on the 52 ring up front. That would be totally unusable for me. Hope this helps. Thank you for posting.