What kind of bike is this?
What type of seat did it have?
I only found a number stamped under the crank: 1620
What kind of bike is this?
What type of seat did it have?
I only found a number stamped under the crank: 1620
This era of bicycle is especially hard to pin, it could be a Elgin, Hawthorne/Wards, Phillips, an Iver Johnson or many others that were making similar bikes. Do the pedals have any words on them embossed in the plastic?
If i had to guess i would agree that it is a Pre-WWII as other have said probably around mid to late 30's. Many frames back then had the dual top tubes however many had a bend in the upper one and a "gas tank" in between them. I assume there is not head badge or any other kind of markings? If original the hub and components may lend some information but it is difficult to say from this era.
The saddle was likely a dual rear spring leather "brooks" style saddle that looked something like the one seen on this Iver Johnson:
The double top-tube frame looks very much like this bicycle, reportedly a BSA Gent’s Heavy Roadster from the 1930s. BSA was making bicycles like that at least as early as 1917 and well into WWII.
Follow the links for a bunch more pictures, including a closer look at the top of the seat stays, which seem to match yours. Your bike would be the smallest one that I've seen, but BSA definitely had different sizes, including some that were extremely tall.
Hat tip to sixtyfootersdude for adding the BSA picture to another question where I first saw it.
Perhaps the original drive train failed and was replaced by a skip tooth from Hawthorn? The ninja star chainring from the picture in your question reportedly first appears in Hawthorn's "spring-summer 1940 catalog." Such a replacement may also be why your bicycle has no handlebar brakes.
This is an old bike! This bike was probably made pre or during WWII when the chain for bikes was being modified/advanced. The Skip link chains were thought to be stronger and were used on many bikes in that time period. They were used for power, not for speed. The Cogs have a "tooth", or one chainring spike every other space.