Hello, it seems like someone on here will know how to answer this!
I have GT Series 4 road bike; it has a 50/34 crank and the stock cassette was an HG-50 12-25. I do lots of hill climbing, so I upgraded my wheels (Mavic Ksyrium Equipe) and put an HG-50 13-26 cassette on, for a little better climbing range.
Here are the sprockets on each:
12-25: 12,13,15,17,19,21,23,25
13-26: 13,14,15,17,19,21,23,26
Since I changed, I've definitely liked the step from 25 to 26 for my bailout gear. However, I'm finding that I don't have a good high gear for really fun down hills (where you really want to fly). More specifically, I'm finding that I never use the "14" and the "13" isn't high enough ... I feel like I need an "11" or "12". I was thinking something like this:
12,13,15,17,19,21,23,26 (a combination of the two cassettes)
or like this...
11,13,15,17,19,21,23,26
I'm really leaning more toward the custom "11-26" if possible. But, I dont' know how build it, where to get the appropriate 8-speed cogs, etc.
Thanks, Scott