To Cold Set or Not To Cold Set? I have a Trek 620 (Reynolds 531 lugged steel frame) from the mid-80s the rear dropouts are spaced at 126 mm. I'd like to be able to run an 8- or 9-speed cassette and I was wondering about the issues involved with running a modern road hub with 130 mm spacing without adjusting the frame spacing.

It seems to me that the rear triangle would have the ability to flex 4 mm without needing to be cold set – at the expense of a small misalignment of the dropouts.

Are there problems with doing this? Other than the slight hassle when installing the rear wheel?

Would it impact the value of the frame – the bike is a rider, probably not a candidate for a restoration (frame could use repainting and I'm not sure the components are original, the wheels definitely are not)?
No need to cold-set.

I have a BSO with the same problem. The rear dropouts are about 6mm too close for the hub. I can just flex them apart and let the hub in.

The misalignment of the dropouts would be virtually nonexistent at 4mm flex.

If you remove your wheels often, and putting the wheel on is a pain, it might be worth cold-setting your frame. Other than that, don't bother.