Trek 41X vs 61x frame
I acquired an early Trek frame 80/81 and by serial # it could be a 41X or 61x frame. There is no frame material ID sticker left. Any way to tell what frame it is. Thanks
You might find some indication of both model and tubing on the steerer tube. Mine has REYNOLDS 531 stamped on that, apparently by the Reynolds factory, and 720 apparently cut by hand with a Dremel or similar, apparently at Trek. And yes, it's a Trek 720.
DRF aka Thrifty Bill
Unfortunately, 61x and 41x both had Ishiwata high ten steel forks and stays. The only part Reynolds are the main tubes.
In my experience, 95% of what I find from that era is the 41x variety. Finding a 61x model would be pretty unusual.
How do you know the year? If you have the full SN then you should know the frame size, model and year.