How easy would it be for frame designers to allow for stands when building bikes ?
Very easy!
What is usually involved is simply brazing or TiG-welding a plate across the forward end of the chainstays, with or without a chainstay bridge being present (if the bridge is absent, the lower end of the rear mudguard attaches to the 'stand plate). The plate usually has cupped edges to prevent the kickstand from rotating. The beauty of it is, one can tighten the kickstand mounting bolt as securely as desired with no risk of crushing the 'stays -- because the kickstand mounts to the plate...which is brazed to the 'stays.
Alternatively, a CNC-milled or investment-cast mounting plate can be used, as on Steve's R&E tandem.
Adding a bracket at time of manufacture solves "most" of the potential problems of a BB-mount kickstand, but not all.
If the kickstand mounting bracket is in the usual place, it can still be fouled by the left crankarm if the stand is down when the bike is wheeled backward. Even this would not usually be a problem unless the bike has been left in low gear. It is astonishing how much force can be generated due to the mechanical advantage afforded by low gearing. On the examples I repaired, both the alu crankarm and the stand were deeply embossed by contact with each other, and the mounting plates has been torqued off the stays.
Also, if the plate has been essentially tack-brazed to the stays, it can tear off the stays when required to support a heavy touring load or a seated rider (
Why?!? do people sit on bikes supported by kickstands? well, they just...do). I have seen it happen, and I know of at least one manufacturer who has advised their factory mounting plate not be used if required to support a touring load; they instead suggest mounting a kickstand to the rear stays, where it has a better bracing angle due to a slightly higher mount. People really shouldn't sit on bikes with 'stands near the dropout, and they almost never do, 'cos the stand is too far rearward to be actuated while on the bike. It is a human-factors issue.
Here's Rivendell's take on the matter:
http://www.rivbike.com/category-s/335.htmHere's a photo of what a good,
plate-type kickstand mount with anti-rotation flanges looks like:
For reasonable use, the brazed-on kickstand plate solves a number of problems presented by clamp-on stands in the BB location. A kickstand mounted near the left dropout between the seat- and chainstays is far less problematic, as well.
Best,
Dan.