I'm looking at getting a new bike for commuting and winter riding. I'm thinking of a steel bike. What are the differences in quality of the diffent type of steel? Most of the bikes I'm looking at are entry level bikes with frame materials of 4130, Reynolds 520, Tange, and some seem to be house brands such as Masi. I'm looking in the $900 - $1200 for a complete bike or about $400-$500 for a frame.

I looked through some old post comparing Columbus to Tange but that was for bikes from the 1980s

For what it's worth I have a 1988 Giant Sedona CroMoly Quad Butted frame that I'm using now.

Thanks

The metalurgy for most any butted steel frame <$500 is going to be 4130 CrMo (Renyolds 520 and most tange tubes ARE 4130 CrMo) but differences such as seamed/seamless tubing, diameter, thickness, butting profile and cold-working the steel can result in significant differences even between CrMo tubes that all conform to the 4130 metalurgy spec. Additionally, further strength can be added by heat-treating steel (such as True Temper VS-HT, Tange Prestige, Reynolds 725). Even more advanced steel metalurgy (such as a stainless steel, columbus niobium or nivacrom, truetemper P3, reynolds 853, dedaccaia 18MCDV6) can be made into thinner tubes but will be above your pricepoint and is overkill for a commuter.

Thanks for the reply.
So, Reynolds 520 Butted Chromoly Tubing vs Seamless Butted Chromoly, would imply the seamless is the better quality frame? The example comes from the Raliegh site comparing the Clubman to the Furley.
How can I tell from a companys web description the quality of the frame?

seamed tubing is generally thicker and heavier than seamless, unless it's not. Some of the best tubing made is seamed. If the same company has a less expensive line that is seamed, you can assume it's not as good as that same company's seamless. Comparing across brands is fairly difficult. This whole subject is fairly complicated nowadays, there was a time when it was easy to make generalizations.

Thanks for the responses. I was hoping this would be easy but...

"Quality", as in the general roundness, straightness and detail of the tube manufacturing is generally going to be similar. If you mean "ride quality" then don't worry about the alloy. In your price range they are all going to be made out of similar steels- it's what they do with the steel that matters. Frame design, fit and features are going to have a much bigger impact on the bikes appropriateness for you then what pipes are in it. Go test ride some bikes and take home the one that meets your needs and its your body. Don't get to hung up on (or even rally worry about) what the little frame material sticker on the seat tube claims.

And why do you want to replace it? What do you expect to gain?

I'm looking to change some of the features on the bike. It's used it for commuting and would like to add disk brakes, drop bars and go with 700 cc tires. I would keep this bike as a back up commuter. I like it and it rides well but I feel the need for a change.

Thanks.