We build asymmetrical frames in 135 to improve wheel strength and also build symmetrical single frames with 145 spacing and 165 spacing to allow for 0 dish wheels and allow for other drive options. I built up my custom folder with a small offset to improve wheel strength and this also allowed for an improvement in chain line.

Biggest issue is when that bicycle finds itself in another shop and the mechanic decides that the frame needs to be "aligned"... we make it very clear to customers that they should never allow anyone to make frame adjustments and we should really have a warning label.

One customer was so concerned with this he opted to have his long tail touring bike built symmetrically and went with a wider hub and spacing... as we also build the hubs this is not an issue.

The Pugsley is a pretty obvious case of frame offset and it has this front and rear... the wheels are also dished to the non drive side with drive side tensions being lower.