A quick reminder of the ever widening array of materials your MTB can now come in...
Steel Demand for high quality bike steel is increasing, with 'harder when welded' alloys like 853 leading the renaissance. Its resilience and repairability are also finding it new friends in the hardcore jump/DH arenas. Future development centres around further refinement of alloys and tubesets. Buy steel if: You like that classic 'spring heeled hardtail'. XC response. You regularly slam your aerial adventures.
Aluminium
The joy of aluminium is its low weight and that it's so easy to play with. Stretch it, squeeze it, cast it, forge it, or just sculpt it - it's the Plasticine of metals. Just don't leave it too thin or it'll snap without warning. Buy aluminium for: Sharp, crisp feel. High value and low weight. High price and ultra low weight. Awkward shaped suspension bikes, fat tubes, big box monocoques and novelty machined sections.
Carbon
Done right, carbon fibre is the lightest, strongest and most shock absorbent frame material. Early breaks marred its reputation, but three major brands are restoring faith at the moment. Easton with its handlebars and seatposts, Trek with their OCLV HC (HoneyComb) sandwich, and Scott's long, thick fibre HMF technology on their Strike bikes. Buy carbon if: You want ultra low weight. You don't mind the damped, slightly dull feel. You like that black, hand knitted look... and metal makes your hands cold
Titanium
The hardest metal to work with, Ti rewards with reliable long term strength, light weight and corrosion resistance but at five times the price of an alu frame. Litespeed, Serotta, Merlin and Seven are slowly pushing the boundaries. Buy titanium for: Reliable 'sprung' feel. Low weight and high strength. No paint or rust worries. A bike for life
Other materials
Magnesium: Potential for incredibly light weight and shock absorbing qualities. Initially came up short on guaranteed durability. We've got some test frames that are still going strong, though... Thermoplastic: While carbon fibre is essentially super tough fabric set in a resin glue, thermoplastics are formed by melting nylon around the fibres. More tricky to build and use than carbon fibre, it's as yet largely unadopted
Canondale Super Raven Thermoplastic Mountainbike 1999
