I think we're making this harder than it is. Remember, were talking about only 6 mm here, and some "120" hubs are more like 122, so it can be as little as 4 mm. That means the axle is only 2 or 3 threads shorter on each side. If you have thick pro quality DOs, a 120 axle can often still get enough support in a 126 frame. It all depends on the frame and the hub, but sometimes all you need is a couple of axle spacers. Add 2 mm or 3 mm of spacers to each side of the hub. If you add the same amount to each side, the wheel stays centered and there is no need to redish. This may not give enough extra clearance for a 6 speed FW, but you can fix that by using a 5 speed FW. Even if you have to add say 4 mm to the drive side and 2 mm to the off side, the shift in the centerline of the wheel is barely perceptible, and can often be addressed just by recentering the brakes. You may have to have a longer rear skewer, but some 5 speed skewers are long enough to handle a 126 hub.
I've used 5 speed wheels more than once in a 126 frame just by adding spacers to each side of the hub. No sense making a simple adjustment into a major project unless you really have to.
Regards,
Jerry Moos Houston, TX
Jay Sexton <jvs@sonic.net> wrote: John, Care to elaborate on the "subtle machined ring identifiers as to thread type but no numerals"? Thanks. Jay Sexton Sebastopol, CA
George Allen wrote (reduced): regarding going from 120 to 126mm
3) Buy 120mm hubs, change the axles to 126mm and then have the wheels built up. But then I'll need longer a QR. I assume you can switch out to a straight lever from a curved lever QR.
Test don't guess, with the curved skewers that read open & locked, the mechanical dimensions are slightly different, old levers in later skewer end cases are a no go, the axles may be the same, measure first.
The period correct officials will notice if the hub bodies are matched to the skewers by looking for the stamped thread spec. on the body, earlier hubs did not have this. There were subtle machined ring identifiers as to thread type but no numerals.
Regarding lock nut & cone stamps, only the mechanic will know for sure and or the next owner.
John Jorgensen
Torrance Ca