I hit the brakes when I get in the 30mph range, speed is not a priority. If I can hit 27-28 down hill I'm fine, if gravity takes me faster then I can brake to stay within my comfort zone. I don't want to run out of gears very easy going up hills. General riding now I bottom out at 29.4 gear inches. For the "portable riding" I would think this would be a good target bottom, but lower would be good too.

My target use for the bike is airline travel. I want to carry luggage, also, for some touring so racks are going to be a necessity, as well as fenders. I won't be using it as sole transportation, but I'd like to be able to do an over-night to 2 night trip. Weight-wise since I started riding I am back to well under 140lbs, so a 200lb limit would give me roughly 60lb of gear capacity = more than enough. I know there are more options in a 20" wheel bike, but I need to get a more compact package so that's why I decided on the 16".

The internal gear hubs look interesting. I was talking with a fellow biker at work today and his buddy has a bike shop. He's looking in to the folding bikes right now too - the commuter train doesn't allow bikes until non-peak hours but the folding ones that tuck away in a bag would work any time. In any event, the internal gear hubs came up because he was saying there is no rear derailleur to worry about. I guess I am not looking at that as too big of a drawback, but maybe it is a big over-look in a travel bike (especially one that will be out of my hands a lot in the luggage compartment, conveyors, and the hands of careless baggage handlers at the airports).