Steve - what I find most helpful is to plot these things on a gear chart, with the chainwheels as the columns and the freewheel cogs as the rows. the intersection cells get the gear, which I usually do as gear inches (=27*cw/fw). The 13-26 you have selected is a close as possible to geometrically equal steps (constant ratios). I think you will find that the 42/53 or 42/52 puts one chainwheel shift just larger than one freewheel shift.
Us half-step guys would aim for a 4-tooth difference with that freewheel, so each chainring change splits the gap between two freewheels. (with your set-up, 8 on the chainring should be about the same as the step between two freewheel cogs). I haven't checked out the numbers, leaving that as an exercize for the reader, but pretty confident that's what you'll find.
FWIW, I generally ride with a "half-step" as described above with 5- and 6-speed setups. For a 5-speed, here's the guide:
3 cw teeth splits a 14 - 24 4 cw teeth splits a 14 -28
and so on.
harvey sachs mclean va
At 21:15 4/2/2001 -0400, Steve Freides wrote:
>I would like to know if, during the 6-speed freewheel era, 13-26 was a
>popular choice for a freewheel. Whether it was that or just close to that,
>I'd like to know the specific cogs usually used.
>
>All my asking about chain for my Raleigh has reminded me that I have
>mixed-breed Shimano freewheel on there now because that's how I could piece
>together the combination I wanted, which is 13-15-17-20-23-26. I recall
>hearing that using a 22 in the next to the last position was more common but
>that seems like too big a jump to me. I'm pretty sure the freewheel body
>I'm now using originally was configured as 13-14-16-19-22-26.
>
>If it matters, and I believe it does, I'm riding with a 42/53 in the front,
>and I think 42/52 and 42/53 were both popular then.
>
>I confess that my inspiration for both cog and chainring choices comes from
>my working out my preferences with modern 2x9 drivetrains, where I also ride
>42/53 and 13-26, the latter as 13-17,19,21,23,26. I'll also note that 13-26
>is neither a racer's nor a tourist's choice, but since I'm neither a racer
>nor a tourist, I think that's OK.
>
>--
>Steve Freides in ever more sunny Ridgewood, NJ.