Originally Posted by gleearch

I'm new to this forum but have been lurking for a few years. I came here initially to find a folding bike for my son who was a small 9 year old in 2017. After reading all the threads about folders for kids, I reached out to a few folding bike builders like Yan about his Downtubes. I received a lot of helpful advice.

What I ended up doing was buying a used ThorUSA customized Dahon Curve on craigslist. It had a Tern stem with Andros stem version1. Automatix SRAM two speed with coaster brake. Caradice snap on bag with Tern stem carrier rack. No kickstand and no fenders.

I made a few changes:
Removed the rack and water bottle cage.
Flipped the Andros stem to face inwards for better reach. Replaced the Ergon GP2 grips with regular grips for small hands.
Installed crank shorteners to allow for growth. The holes allow you to go from 170mm to 135mm. Uses the same pedals.
Replaced the pedals with MKS FD-7
Replaced the seat post with a Tern Telescopic seat post - ironically it is meant for taller riders but when fully retracted is much shorter than a regular seat post which allows you to have the seat real low and not scrape the ground. I did not want to cut the original seat post because I figured it's still a very viable adult commuter bike when he's older.
Replaced the seat with a kids gel padded seat
Added a kick stand and black fenders.

The changes to the bike allowed my son to gain confidence with the bike. His first ride on the bike was 11.6 miles. He had been riding since he was 4 or 5 but the folder was bigger than anything he's ridden before. I just got tired of buying bigger bikes each time.

Then over a few months, I kept moving the pedals down till it was back to full 170mm.
The bike seat kept getting raised too.
It's two years later and I figure I saved by not having to keep buying a new bike.

I would post photos but I don't have sufficient posts count here but I figured this information might be helpful to anyone thinking of a folder for their kids.
It can be done and it's affordable if you happen to find the right used folder.

We are a folding bike family.