Raleigh Technium
 

I see Raleigh Technium bikes for sale on CL now and then. I'm interested in learning more and maybe buying one. My understanding is that they are aluminum tubes bonded into lugs or something like that. Is this true? Are there any unique issues with this type of frame construction? Debonding, etc.? Derailleur hanger issues? If I were to look at a Technium-framed bike, what should I look for?

There's a Technium frame in my size for $30 on the local CL....

Most of them are aluminum tubes bonded to steel lugs. A few of them are steel tubes (753, 531...) bonded to aluminum lugs. I had a Competition with 531 OS tubes bonded to aluminum lugs. Unfortunately the down tube separated from the head lug. I was told that's common because of the galvanized effect between two dissimilar metals.