Here is what I have on Lotus in the Used Bike Buyers Guide. Unfortunately, the early models I have listed with Tange don't specify the model of tubing. Lou Deeter, Orlando FL
LOTUS: Lotus/Tsunoda company. Early distributor was Alpha Cycle Supply, P.O. Box 3, Syosset, NY. Japan/Taiwan. Founded by Sid Start. Now name owned by Sears.
Models:
Supreme SL
Classique 82 Tange
VS-1 Grand Prix 82 Steel
VS-3 Unique 82 Tange
VS-4 Eclair 82 Tange
Excelle 80-89 Tange Triple Butted
Triomphe 83-86 SL or SP
Legend Comp 84 Columbus
Prestige 84 Tange #2
Supreme 85-86 SLX
Elan 75 87 Prestige
Prestige 87 Prestige
Elite 600 87 Tange #2