Jasper Janssen <
[email protected]> wrote:
> So, to sum up, the main thing keeping this [rear frame offset] back from being standard is
> non-standardness?
>
> If enough bike makers start doing it, it will of course eventually become standard..
Actually, I think the main thing keeping it out of the mass market is that it negates the subtle but
significant advantages of symmetrical construction. Comparative measurements between one side and
the other save both bike makers and bike mechanics from having to make a lot of painstaking absolute
measurements and keep a lot of references on hand.
Bicycle framebuilding is a lot more rudimentary a craft than many people think, with stretched
strings and meter sticks frequently used to check alignment. A maker who doesn't use industrial
inspection techniques or at least pretty elaborate purpose-built measuring tools would not be able
to yield as straight an offset frame for a similar amount of time and effort.
Likewise bike shop mechanics are able to do a lot of frame diagnostic work on a bike that's presumed
to be symmetrical. Not as much with an offset frame. In the worst case, an offset frame would get a
costly "straightening" by a thorough but ill-informed mechanic!
Similarly, offset built wheels pose a tiresome measurement chore to verify proper dish, a task
that's thus not likely to be repeated between successive wheel builds.
Something else to consider is that an offset frame (say a dishless 9sp
130mm) poses all the same clearance, chainline, Q-factor and related issues as does a 160mm dishless
rear, just all on one side. Meaning that the wider hub size possesses all the advantages of
both a dishless rear wheel and symmetrical frame construction, with no more complicating
issues than the offset rear already has.
Chalo Colina