Hey I'm just getting into working on bikes and so I put an add on the local trading post here looking for old bikes that people were going to throw away or just wanted to get rid of so that I could dissect them and learn from them. Well this lady calls me up she has a whole pickup truck full of them so I get her to come over and dump them off in my yard lol. Well one of them is a fuji folding frame from marlboro ironically. I guess they had something to where if you smoke enough cigarettes, they give you a bike to ride lol. The sticker on it says "chromoly" 4130 tubing. I was wondering if this is high quaility tubing, because I read in the bicycle magazine book that "chrome moly" tubing is approaching the finest of steel alloys, is this bike i have the same or is "chrome moly" different than "chromoly"? I would think not but just wonedering because the spelling is different, if it is high quality then I might invest some money in it to build it back up because the frame is still in good shape.
Listen to me
I have a Marlboro Fuji fold-up and love to ride it. I recently fitted it with a set of fenders from an older 3-speed. The frame material is as nice as any cro-mo frame but the extra tubing required to make the frame a folder negates any weight reduction possibility. I plan to upgrade the Shimano SIS components and low end handlebars/stem.
The correct name is chromium-molybdenum, also known by it chemical symbols CrMo, or its AISI designation number 4130. Actually, any steel begining with 41 is CrMo, but 4130 is typically what is used in the bicycle industry.
The proper name has been morphed by our lazy-society and marketing spin doctors into various contactions, with the most common being chrome-moly. Since your sticker indicates it is a 4130 composition, the chromoly designation is just another spin.
The cheapest and heaviest materials for bicycle frames are hi-tensile steels, which are generally found on entry level bicycles. The next step up is to go to a lighter and more expensive CrMo steel. Beyond that, are butted CrMo steels which have thinner sections in the middle of the tubes for lightness, while providing thicker ends for strength where the tubes are joined together. When a tube is not butted, it is called plain or straight gauge and that is probably what you have, as the marketing guys would not miss the opportunity to flaunt butted tubes.
CrMo is a good steel for bicycle frames. The other steel of choice is manganese-molybdenum, with Reynolds 531 being the most recognizable tubeset. However, in recent years, steel has lost favour to other materials, notably aluminum, carbon fibre and titanium. Whether it is actually better than these materials is the subject of much debate.
4130 is where decent bike frames start and go up from there. Hi ten and plumbers pipe are lower. Consider it above bottom of the barrel if it's double butted.
Originally Posted by bikenutt
so thats cool then it's a good find