That's a good point, but the outside of the inner cog is also clearly closer to the inside face of the DO, which is not a function of outer cog size. And, most conclusively, I laid the two FW's side-by-side and the Shimano stacks higher by nearly one cog. So I'm convinced that either the Shimano cogs were thicker at their base, or they used thicker spacers, or both.
Now that I think about, it, I believe I've observed in the past that Shimano FW's give significantly less clearance between the outside cog and the stays than any other brand, even with the same number of teeth on the small cog. Until now I didn't think a lot about it as it was usually just a matter of more difficultly in changing the wheel, rather than the chain actually rubbing the stay.
Regards,
Jerry Moos Big Spring, Texas, USA
Thomas Adams <thomasthomasa@yahoo.com> wrote: Dear Jerry:
The Shimano may be wider than the Atom, but don't forget using a 16 instead of a 14 tooth small cog lifts the chain up higher, and therefore closer to the seatstay which is slanting in as it moves from drop out to seatlug.
The only fix I can think of is to respace the rear hub to 122mm or so by adding a washer or two, so as to splay the seatstay out a tad more away from the new chainline. Good luck.
Tom Adams
Manahttan, KS, USA
From: Jerome & Elizabeth Moos <jerrymoos@sbcglobal.net> Subject: [CR]Freewheel Spacing?? To: "Classic Rendezvous" <classicrendezvous@bikelist.org> Date: Saturday, August 23, 2008, 9:39 AM
Recently ordered a custom 16-34 Shimano 5 speed FW from Loose Screws for my 1972 Follis 172, as I intended to commute on it with a fairly heavy large laptop in the pannier, and one short but steep hill on the way to work. The FW arrived yesterday. But when installed the Shimano FW in place of the 14-28 Atom, the chain rubbed the seatstay when on the small cog. This is a newer Chinese made FW body, with a mix of new and NOS cogs. It appears the Shimano is simply wider than the Atom. The lip behind the inner cog that butts against the hub shell doesn't seem much different, so I think ether the cogs are thicker, or the spacers thicker, or both. Probably more the spacers, as the cogs cannot be too much thicker and still accept 3/32 chain. Both the Atom and Shimano are supposedly "normal" 5 speed spacing, but the Shimano is quite obviously wider. Has anyone else observed significant variation in the actual spacing of FW's of different brands?
There were of course the SunTour Ultras and narrow spaced FW's from other manufacturers, but it appears even "normal" spaced FW's varied a lot. Was Shimano notorious for having wider spacing than others? Did most manufacturers use the same spacers for "normal" 5-speed as for "normal" 6 speed, or was even the "normal" 6 speed spacing a bit narrower than 5 speed? Are there thinner spacers that will fit a Shimano 5 speed FW? Regards, Jerry Moos Big Spring, Texas, USA --- StripMime Report -- processed MIME parts --- multipart/alternative text/plain (text body -- kept) text/html --- _______________________________________________ Classicrendezvous mailing list Classicrendezvous@bikelist.org http://www.bikelist.org/