What’s your opinion of foldable bicycles?

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I have a Downtube folding bike and it is a hoot to ride! Unfortunately, the components are crap so you better be ready to either suffer or replace most of them. I have replaced the front wheel and added a disc brake. Brake/shift levers, grips, saddle, and seat post have been changed too. You won’t get the same range of gearing in my case, despite the 11-34 cassette. Blame the small tires and the single chain ring in the front. I wouldn’t tour on it unless I knew I wasn’t going to do any serious climbing. If you insist on touring with it, make sure you can get a double crankset in the front or be prepared to upgrade your rear wheel with a SRAM DualDrive hub.

It’s not very stable at high speeds. The tall steerer tube vibrates a bit. Since you are also sitting so upright, your center of gravity is higher. Just be sure to take it easy on those machines. They are not road bikes.

People do give you the oddest looks when they see you on it.
I had one, they are ok, but not that nice to look at
I have a very old green one. It works fine, not the best bike in the world, but it rides and folds up.