Bicycle Mechanics - U-brake replacement for 1988 MTB

Hi, I’m building a winter bike out of an old lugged Japanese MTB frame that is made with Tange MTB tubing. The problem I am having is with the rear brake. It uses a U-brake which mounts on the bottom of the chain stays and from what I learned it this was used for about one year 1988, and was discontinued due to a few problems. Since I do not have the original U-brake what can I use as a replacement? Any help will be appreciated.
Regards,
Gordon P

I have an '87 mtnbike with the under the chainstays U-brake also. I too would like something else, maybe some cantilevers on the seatstays, but alas, that would involve welding posts to the seatstays and cable stops to the top tube. Rollercams (I don't think they're made anymore) may be an option, or they may not fit (someone else here may have an answer to that). The U-brake was/is notorious for getting clogged up with mud. I try and stay out of mud if possible, if not, then I clean mud out. I switched to some Koolstop pads from the original pads (they were ~ 18 yrs old) and braking significantly improved. This particular mtnbike was my first and I rode it in all conditions. I'm currently building a newer bike with modern stuff so the old one has been relegated to pulling the Trail-A-Bike but can still go offroad if needed with a switch of wheels. You're probably stuck with the U-brake:( .

I believe that the BMX style bikes still use U-brakes. So you should be able to find them relatively easy.

rock the roller cams. they are as strong as good cantis, and you can land them on ebay with ease.