For many reasons our favourite bicycle frame material is steel, that’s another whole story, but not all steels are created equal.
It’s a bit like saying you like wooden tables, but as we all know there’s a big difference between a solid, handmade, hardwood table with dovetail joints and a cheaply made laminated chipboard table - even though they are both made of wood.
Similarly, you get steel frames and you get steel frames, they can vary greatly in quality - from the cheap department store kids bike to the high end hand made custom frame built for the most discerning of bicycle connoisseurs.
So how do you tell a good steel frame from an average one?
It’s not that easy. they all look skinny and similar. Because of the incredible stiffness-to-volume ratio of steel (about twice that of Titanium and three times that of Aluminium), it allows steel tubes to be really skinny, this in my opinion makes for really pretty bicycles. It also makes it hard for a good modern steel bike to look different from a cheap heavy one. Other frame building materials fatigue if they flex too much, so they need bigger diameters to prevent them flexing (btw stiff frames aren’t faster).
You can tell quite a bit by the quality of the joints: Lugged, TIG welded, MIG welded, fillet brazed etc, however the technique often just comes down to personal preference, but good workmanship should be obvious. Also try learn a bit about the bike brand and who builds the frames, if they’re hand made or machine welded etc. Thankfully there has been a bit of a steel revival recently and there are some really talented craftspeople out there building beautiful steel frames. Check out Cycle EXIF every now and then to grow an appreciation for the craft.
I find the best way is to look for a recognised tubing manufacturers sticker on the frame. Because any frame builder who spends money on high end, name brand, steel tubing is going to let you know about it by placing the tubing specification sticker on the frame. Also if you’re using expensive tubing you tend to work a bit more carefully.
There are a handful of highly respected steel tube manufactures in the world, the most famous are: Columbus tubing (Italy), Tange tubing (Japan), Reynolds tubing (England) and True Temper (US). All of these companies make a wide range of specialised tubing, including some very sophisticated exotic tube sets. These technologies include: special alloys, cold-working, heat-treating, air-hardening, butting (thin wall thickness in the middle and thicker at the ends for the welds), to mention but a few. These technologies were often developed for the aeronautical and space industries and for the motor industry (for things like lightweight side-impact bars). A high-end steel tube set has so much advanced technology and is chalk and cheese from the basic (similar looking) steel tubing found on cheap bikes. It’s well worth getting to know the hierarchy of the manufactures range of tubing, there is a bit on it here.
So if you have the budget, there are plenty material choice options available for a high end bicycle frame, but the durability, beauty and ride quality of a high-tech steel frame is very, very hard to beat. Just make sure you’ve checked the label and know what you’re paying for.