Bicycle Built for 1: Part 3 Materials

Frame Materials are pretty important to the feel of the bike so I thought I’d include this in my rambling thoughts about my bicycle of the future.

There is a good synopsis of materials on wikipedia so I won’t summarise it here but will make a few comments about what the metals mean to me in terms of frame material.

Aluminum
Aluminium is light, strong and relatively corrosion resistant, but fatigues over time. When fracturing etc appears it is not an easy repair job. For me its defining quality is stiffness – If I were to go with aluminum I would consider a suspension seat post. I am trying to think long term with the bicycle frame, and give it’s propensity for fatigue fractures, I think aluminium probably isn’t what I am after.

Steel
Steel as far as I know is heavier, less corrosion resistant and relatively hard. It is strong, but has a subtle flexibility to it. High quality frames are usually alloys and widely used in many cycling applications. There is some debate about frame materials as you might expect and some believe that a lugged steel frame offers a great deal in terms of ‘feel’, durability, ease of repair, cost and aesthetics. It has a lot to offer someone looking to design a bicycle that will last many kms. Steel can and does rust and so stripping the frame and repainting may be required over the longer term.

Titanium
High strength, light, highly corrosion resistant, more flexible than steel, but difficult to weld and repair and high cost. I can’t be sure whether I am afflicted with a lust for titanium beyond the good properties of the metal, but a Ti frame would be very nice indeed. It’s defining feature for me is high corrosion resistance, feather weight and a supple ride…Hmmmm

Carbon Fibre
Super light, Stiff or supple depending on the design, corrosion free, but strong only for the forces it is designed for. Crash or crush the frame and it’s good night! Too risky considering it’s price, and my potential application. This material is for well sponsored athletes, not me.

Very quickly in summary I reckon that Steel and Titanium are the likely candidates here. The decision will be about price and how long I intend to have the bicycle. Something that lasts a long time is good value if you get enough use out of it. My only apprehension about Ti is that it may be hard to repair, but would I repair a damaged frame – or get a new one? In the case of steel a new frame would be affordable, however a new Ti frame may not, so steel is probably my first choice.

I haven’t forgotten bamboo and plastic as materials, but I’m not seriously considering them for a long term, reliable bicycle. Making a bike out of Bamboo would be fun – but it’s not at the top of my list of things to do right now. If I had the time, it might be an interesting way to get acquainted with frame geometry and strength.

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