Originally Posted by jolly_codger

As I was working on my winter project (`85 or `86 Schwinn Peloton modern build) I got to wondering why horizontal dropouts continued to be used so long. I can understand bikes before the widespread use of the modern rear derailleur needing the ability to adjust chain tension. I can't believe the purpose is to be able to vary wheelbase because i bet 99% of riders wouldn't be able to discern a difference of about an inch. Was it for frame builders to have room for error for slight mis-alignment? And don't get me started on the whole adjusting bolt & spring that end up seized since no one regularly fiddles with them. When you do get them out, the cursed little spring disappears to the black hole underneath the toolchest and you get to pay for an overpriced replacement set. There a lot of smart people who are regulars on this forum and I am counting on them to school me on the lowly horizontal dropout and the reason(s) for their reign lasting so long.
Cordially,
John