Originally Posted by
Sir_Name
Plus converting 26" to 27.5, if realistically possible, you'd most likely end up with less rubber/air volume at approximately the same outside diameter, a losing proposition.
...for MTB use at least.
Actually, I've gone this route four times, with good results. That said, the bikes I've converted were old-school 'limousine' frame MTBs with really long chainstays, and I converted them as city bikes & tourers:
The first was a '93 Trek 820, which I used as a test bed, mostly to see if I liked the result... (Sold in 2011)
The second was a larger size '91 Trek 820, which I still use as a touring bike (the frame is very similar to a Surly LHT)...
The third was my Univega 'FrankenRover' (Posted somewhere here in C&V), which I built up strictly as a townie (& to clear out spare parts from the previous two builds)... (Sold in 2015)
... And fourth- my Panasonic CB-620- wasn't so much a conversion as a restoration/ reversion, as the original Japanese (non-export) version, the Viatore CT, was actually a 650b rando. This frame was modernized at TiCycles here in Portland.