Schwinn B9/B10’s

[dasberger]

I'll have to measure mine when I get a chance as it's in storage. As far as dating and the charts there is such a big gap in info for this era. People much more knowledgeable than me have spent a lot of time trying to nail these dates down and it seems there is still a lot of debate. The previous owner of my bike did a lot of digging and he found a few original examples that were dated by serial and crank. The closest serial to yours he sent me was 478513 which was dated to 1931.

 

[SKPC]

Yes, most likely the last of the Schwinn moto frames that used trumpet mouth joinery on the lower truss bar, the biggest clue.. Serial # also suggests this is a 1930 to 33 28" wheeled motobike.

 

[RustyHornet]

I'll have to measure mine when I get a chance as it's in storage. As far as dating and the charts there is such a big gap in info for this era. People much more knowledgeable than me have spent a lot of time trying to nail these dates down and it seems there is still a lot of debate. The previous owner of my bike did a lot of digging and he found a few original examples that were dated by serial and crank. The closest serial to yours he sent me was 478513 which was dated to 1931.

I agree that there is no absolute way to tell. I will have to dig and find the site I was looking at, I thought i saved it. My serial is 500727. I don’t know if there will be a way for me to nail down the date on mine. But I am very curious to the measurements when you get a chance on yours!

 

[RustyHornet]

Yes, most likely the last of the Schwinn moto frames that used trumpet mouth joinery on the lower truss bar. Serial # also suggests this.
28-er is most likely 30-33.

What say you to the measurements being exact same as my ‘39? I’m jot arguing, just trying to learn!

 

[RustyHornet]

I agree that there is no absolute way to tell. I will have to dig and find the site I was looking at, I thought i saved it. My serial is 500727. I don’t know if there will be a way for me to nail down the date on mine. But I am very curious to the measurements when you get a chance on yours!

I was also looking at that truss bar, came across several others claiming to be 1933-34 with same construction. I had a verified ‘28 a few years ago, I wish I had taken measurements of the frame...

 

[SKPC]

Some makers had different chain stay and fork lengths for 28" vs 26" during this transition period, but not all. Colson 100% did, but I am not so sure Schwinn/ others also did this. Your frame seems to be very added onto and pieced together, with the later badge stuck on with short badge hole distance.
@cyclingday , Marty may be able to chime in and add his thoughts.

 

[RustyHornet]

Some makers had different chain stay and fork lengths for 28" vs 26" during this transition period, but not all. Colson 100% did, but I am not so sure Schwinn and others also did so. @cyclingday , Marty may be able to add something.

Thank you, appreciate all the help I can get! I was actually looking for a 28” bike to play with again, but came across this. I traded for it thinking it was a 26er, I am ok with it being either! But would like to nail it down a bit more so I can either build it with 26 or 28!

 

[RustyHornet]

I may as well throw a picture of my old 1928 in here. This is all I have if it that would be useful. Visually it looks different to me, hard to tell though. And repost of the first pic in the thread of the bike in question to compare together. Again, the fork on the blue one is a WALD replacement so that won’t help at all looking at it.

 

[Freqman1]

I could be wrong but I thought the forks on a 28" were narrower and a tad longer. V/r Shawn

 

[RustyHornet]

I could be wrong but I thought the forks on a 28" were narrower and a tad longer. V/r Shawn

I’d have thought the same. Too bad I’ll never be able to tell with this one. I actually came across some information you posted last year about Schwinn still offering 28” wheel bikes as an option after the 26” came out. I was not aware of that and had never heard it! So the real question still remains, did Schwinn build one frame which then got outfitted with whatever wheels were ordered, or did they build 2 different frames at the same time? I could see the fork being different and changed for whatever wheel size.