So I've got this old Miyata 610 that I'm starting to work on. Thanks to some of the other posts around here I got curious and went out and measured the frame spacing only to find that it's 120 mm. I'm thinking I'd like to re-space this to 126 and run with my old but still freehub equipped 105 hubs and 7 speed cassettes. Now I've also got some wheels with freewheels on them but they are all "no name". But with 6 speeds it would/should fit the current 120 mm. But from what I've seen the freehub setup is a little more stiff thanks to the wider bearing spacing and less axle to flex.

Thoughts on this?

rethink your thread title.

This is going to sound bad, but do whatever you like. If you like the 7 speed cassette, use them. If you like the six speed freewheel use that. By the way, you sure the 6 speed is a 120mm OLD? I know some were made that way, but a lot are 126mm.

If it was me, I would probably spread the stays to 130mm, but that is me.

I'm against spreading rear stays, period. There are enough old frames out there that you can certainly find one with the proper clearances to fit whatever wheels you plan on using.

Yeah, I'm also against removing brazed-on components, cutting off derailleur hangers, and - I guess - against any modifications to a frame except for paint. So I'm a curmudgeon. I'm proud of it.

I put a 9 spd 700c rear wheel on my 610. All I do is pull the chainstays apart slightly when inserting the wheel. Not difficult, nothing permanent. Seems to work great. Even the stock Suntour derailleur works fine with a 9 speed cassette and the stock friction shifter. Just buy a new 9 spd chain and set your limit screws and you're gold.

Az

I don't think you need to res-pace for 126 mm. I just finished rebuilding my '87 Schwinn. Before this I never had occasion to consider the frame spacing - I just rode it the way I bought it.

But this time around I checked and guess what? 120 mm chain stays and 126 mm 6 speed freewheel. Came that way new. I'd been spreading the chainstays with my hands as I installed the rear wheel and never considered that this wasn't normal. Thousands and thousands of miles and the hub is still fine.

According to Sheldon (pbuh), spreading is not needed when going up one step. He says something like the angle of the dropouts won't be too great to cause harm. One of my bikes, I haven't spread the stays yet and it is fine, but I will spread them. Even though no problems will most likely happen, I figure I'd get it spread so that the dropouts line up correctly. Why put extra strain on the axel when you don't need to?

Seems like apples and oranges to me. Removing braze-ons and derailleur hangers is permanent -- or at least complicated to undo. With a steel frame, you can go from 120 to 126 and back to 120 in a matter of minutes if you want. It's definitely less of a modification than a repaint.

I didn't hesitate to spread Capo #1 to 128mm, so that I could use a 7-speed freewheel. (I am currently running it at 126mm with a standard 6-speed.) I think I can avoid spreading Capo #2 by using a SunTour ultra 6-speed. I simply cannot get the range and tight ratio development I want with a traditional 10-speed transmission. I can barely do it with 12, and I can pretty easily get the gears I want with 14, 15, or 18 speeds.

Great info all. I had fogotten or missed that bit about just flexing it for a one size change. I'll give it a try first before painting and if it's pretty firm a pull to fit the wheel I'll probably spread it. If it's just a little pull and it centers nicely I'll just keep doing that.

Paulwwaters, I didn't think about any other meanings until I saw your post. You got me there...