My 3 y/o was having trouble keeping up with her sisters. She could only spin so fast in the flats and was also struggling up the hills while her sisters were spinning, so I finally ended up building her a 3-speed. I thought you all might be interested in some pictures.
The Specialized Hotrock has 28h wheels, so I got a Sturmey Archer AW 28h 3-speed hub on ebay for $30. I unlaced the original original rear wheel, sorting the spokes into bins (drive and nondrive, leading and trailing), and rebuilt it around the 3-speed hub. Once true and destressed, the spokes ended up sticking about 1.5mm - 2.0mm past the nipples, and it was easy enough to trim them with a Dremel tool.
I stripped the shifter and linkages from a Huffy Sportsman in rough shape that I picked up from Craigslist for $15. A couple zipties and a hose clamp later, I had them installed on the Hotrock. I also fitted it with a pair of hand brakes.
Maggie's really benefited from the gearing. She doesn't get bogged down on hills nearly as easily, though I often have to coach her to downshift. She's also keeping up better on the flats; we were all cruising along at 12 mph for a while this past weekend.
Btw, this was my first wheel build. I've done some minor truing before, but nothing to this extent. Still, after some reading and care, the wheel came out really wheel, better than it had been before. Took about 2 hours on Labor Day Monday.
I think it would be great if kids bikes came with 3-speed hubs. They're hard to kill and really extend the possibilities.
I'm happy to answer any questions.
Results 1 to 1 of 1
Thread: 3-speed build on 16" Hotrock