Stickers for Detels often say they were made in Green Bay.
Budget Bicycle Center often has high prices, they seem to have a vast amount of bikes. Here is a Detel Marathon there.
https://budgetbicyclectr.com/1985-de...d-bicycle.html
1985 Detel Marathon Road Bicycle Ishiwata 022 tubing. Suntour Superbe brakes, levers, rear derailleur. Suntour AR front derailleur. Modolo carbon shift levers with a Campagnolo clamp. Campagnolo hubs Sekae aluminum handle bars. EDCO headset, bottom bracket. EDCO cranks are cracked from over-tightening on to the BB spindle. Detel Bikes were made in the USA for less than a year in 1985 in Green Bay, Wisconsin. They went out of business about seven months after production began when they did not have the cash promised to start up, or as some say, an investor backed out. Once the company went out of business the bikes were mostly given away as bonuses by companies selling autos or appliances, although quite a few were sold in real bicycle stores. I've found them with Ohio bicycle store labels on them. Only two models were made, the higher-end Marathon (Ishiwata 022) and the more standard Legend (Ishiwata 024). There was also a numeric designation (either 6000 or 4000) added to the model name to indicate the grade of the componentry. REF# 134713
One was on our CL lately but too small. Another one was on about a year ago, I believe one of those silver or gray Marathons. I'm sure they are good bikes.
I'd look at one in good condition to sell say from $150-$200 in the Midwest area, Wisconsin etc. If one is on the West coast, maybe the cost changes some.
Here is a Detel Legend 4000, I think there actually 2 different Legends, 4000 and 6000 as the ad says.
https://madison.craigslist.org/bik/6123009435.html
DETEL Legend 4000 built in Green Bay Wi! - $200

The Detel Legend 4000 is in Very Good Shape, Everything moves as it should. These bikes are hard to come by as they where only built for a Very Short Time! So if interested let me know. Serious Buyers Only Please. I am Asking $200 for the bike.
You will need to email or text to set up a time to look at the bike. Please Include the name of the bike Detel in ANY Text show contact info so I know which bike your interested in.
Details: Detel Bikes were made in the USA for less than a year in 1985 in Green Bay, Wisconsin. They went out of business about seven months after production began when they did not have the cash promised to start up, or as some say, an investor backed out. Once the company went out of business the bikes were mostly given away as bonuses by companies selling autos or appliances, although quite a few were sold in real bicycle stores. They have been found with Ohio bicycle store labels on them. Only two models were made, the higher-end Marathon (Ishiwata 022) and the more standard Legend (Ishiwata 024). There was also a numeric designation (either 6000 or 4000) added to the model name to indicate the grade of the componentry.