STBO Mamachari

This will be a step thru frame bike built on a gravel bike theme, but not with drop bars, it'll be along the lines of a klunker but with skinnier tires. So a mix of gravel and klunker.
I originally though this was a cheap frame the wife bought, but as I cleaned it up found it was decent Japanese quality.

I found a registration decal on it that I thought was in Japanese.

The Japanese only keep their city bikes for a few years then trade up. The old ones get shipped to other countries, and the Philippines gets a lot of them. There's a big market because of their quality and utility. I went to a translation webpage and found out this bike was registered in the Niigata Prefecture in Japan.

I built it up as the Leopard Lady, using 26" wheels as it came with new. Maybe 26 x 1 3/8ths.

It didn't see much use, so it was fair game for this build. I painted it like a leopard but it will get something completely different for this build.
I have a wheeleset I built recently, 700C using gold spokes and a Sturmey Archer kickback hub with coaster brake. They fit this frame and forks. Tires are 38mm, the widest I found at the time.
With the 2 speed, it has a direct and high gear, so a smaller chain wheel will give me a good low gear for offroad and high gear will be good for normal cruising on the road. I have 39 tooth and 36 tooth chain wheels to choose from and can swapout the cog on the kickback hub if needed. I'll start with 39/22 and see how that works out. I have 2 leather seats to pick from also.

No handlebars yet. I would like klunker bars. If I'm lucky enough to find a good American step thru frame this all could change.

I threw the parts together using BMX bars for the time being. They might work ok. I may swap out the standard fork for a chrome newer style. I'll get in a test ride soon and see how the gear ratio is. Not today or tomorrow even though it just needs a chain. We have flood warnings with a tropical system ready to dump a lot of rain.

I checked the chain line and it's way off.

The old bb extends out too far for any of my cranksets. I have a new sealed bb that is just right, but the old bb won't loosen up.

I'll take it by the bike shop and let them get it loose.

I tried the chrome fork, just barely enough room at the top for the tire. I like it better than the originals.

I tried it. The spindle wasn't hollow so I had to find a bolt long enough with the right threads. There were none with the right threads so I used a
standard bolt and it threaded into the spindle about 5 turns, which was enough to secure the bb adapter thing.


I should have put the wrench on before the bolt, the washer kept the box end of the wrench from sliding over, so I used the open end and laid it on the floor. I should have worn my good slippers for pics.


That damaged the bb tool as the wrench rounded off the edges, so I redid it and used the box end up on the workbench and used the hammer to tap it. Success!



First video of the build off?


The new bb went in with some grease on the threads and the chain line looks good.


Now it's a rider and ready to test. I think a plain matte black paint job would work on this.

Thanks to twojs.bike for the tip!

I found a brake that fit, even with the oversize wheel.


The frame has a lot of scrapes and pock marks, so I gave it a quick sanding and paint job to see if it's worth all the trouble of making it pristine. I'll have it powdercoated later if it grows on me. I also tried a lighter pair of handlebars. And again ready for a test ride but three or four more heavy rain days ahead.

I did some more research on this bike. They are numerous in Japan and used for shopping and transport and are called Mamachari, Mom's bike. So the name change. I still have to go for a ride.

Big change up, but using the same frame. The wheels got snagged by my other build and I had planned on returning this to the original size 26" wheels. I tried the 27" wheelset from another bike and they fit but only with a 27" fork added. They are a tiny bit larger than 700c. The other build got the previous fork so that worked out ok.


Since that changes the whole theme, I think this bike will be done up in a stempunk kind of theme. I have a cottered crankset with a fake skiptooth chainwheel and other parts that look old. I may paint the frame copper like the wheels and add some other things for a stempunk look. The pedals have copper pieces added and a leather seat with old style handlebars and stem will also add to the look. Some kind of frame insert will top it off. I'm open to suggestions too.

The coaster hub came with an 18 tooth cog. With the 52 chain wheel (26 by skiptooth) the gear index was 80, way too high. I went online with no luck, no bigger cogs for a coaster hub here in the Philippines. So I swapped with the SA kickback hub which had a 22 tooth cog. That brought my gear ratio back into normal range at 65 GI. Wheels are ready!


I dismantled everything and the frame will get sanded until smooth before getting a copper paint job. I just received notice that my paint will show up today.


I ordered a pair of handlegrips in brown, same style as the black ones. And the brown seat looks more to the style of this bike. I may paint the rivets copper.

The first coat of copper paint is on. I want it to look like it's made of copper tubing.

Watching paint dry, in between coats of clear.

Going back together. I didn't trim the fork tube thats too long. I plan on a set of truss rods or something similar and left room for a bracket. The crankset looks good here.


However there's a problem. The threads on the non drive side were rusted so badly that the bearing cup won't stay put, so the cottered crankset can't be used afterall. I have to use the 3 piece sealed bearing set that works in this frame. The insert on the non drive side doesn't hold any weight, the drive side holds everything in. I just need to find a chain wheel that fits the bill like this one did.


I painted the rivets gold on the seat. The previous bb will go back in.

I mocked up what I have so far. With the 47 tooth chain wheel, I'll have to revert back to the 18 tooth cog.

I may add a basket up front for shopping, as this bike was intended for when new. This basket arrived with no bottom supports so I went through my pile of junk to find something that might work. One of the chrome rear racks is just the right size to make into a support for the basket.



From the junkpile I pulled out a dropstand for a 26" bike. It cleared the tire by a little over half an inch and was made for this type of frame so on it went.

I picked up a rivet set not knowing the first thing about how to use it. I'm going to do a frame insert and want to add some rivets, so I'll study up and see what happens. I don't even know what kind of rivets to use or if I need a special hammer or anything.


This will be an "Old Dogs and New Tricks" type of thing. I think this will be more of an aviation hot rod versus a steampunk theme.

I used an old insert and trimmed it to fit this frame. It has a vinyl woodgrain but I'm going to rivet on some crocodile skin that will match up better to the color.