A magnesium bike!? Plus a tiny backpack and super cheap GPS are just some of the five cool things coming soon from Vaast, Rapha, Dhb, Van Rysel and Birzman

Rapha jumped the shark pricewise some years back, but even for them to make a backpack so overpriced it probably couldn't carry its own price in pound coins is pretty spectacular.

Pure magnesium in thin strip form burns at the slightest provocation, as those of us who did school chemistry in the days before H&S well know. Presumbly they're only allowed to see virtual magnesium burning virtually now.

We aleady have essentially 4 excellent cycle frame materials: steel, aluminium, titanium and composite. You wonder at the point of another material.

wtjs wrote:

... those of us who did school chemistry in the days before H&S well know. Presumbly they're only allowed to see virtual magnesium burning virtually now.

 

I remember burning magnesium in hydrochloric acid (for some reason) in school in the mid-2000s.

wtjs wrote:

We aleady have essentially 4 excellent cycle frame materials: steel, aluminium, titanium and composite. You wonder at the point of another material.

I watched a GCN advert video on one of Vaast's previous Magnesium models. Apparently, the point is that it's much easier and less energy/resource intensive to recycle than any of the other mainstream materials.  

Also, magnesium is way lighter than Aluminium. I work as a programmer in the extrusion die industry. 99% of the profiles my company works with are for aluminium, but occasionally we'll get samples back of the magnesium profiles too. It always takes you by surprise how light they are compared to the aluminium ones, you nearly throw them through the ceiling when you go to pick them up.

BalladOfStruth wrote:

Also, magnesium is way lighter than Aluminium. I work as a programmer in the extrusion die industry. 99% of the profiles my company works with are for aluminium, but occasionally we'll get samples back of the magnesium profiles too. It always takes you by surprise how light they are compared to the aluminium ones, you nearly throw them through the ceiling when you go to pick them up.

And yet it is in fact heavier than certain aluminium bikes (e.g. CAAD13 claimed frame weight of 1.182kg). 

Could be less dense than aluminum (and therefore your sample profiles are much lighter for a given volume) but also lower strength to weight, and therefore need much thicker tube walls for the bike frame? 

Very possibly. I have no idea what it's like to work with in different forms, but magnesium is very difficult to extrude, at least. Magnesium hollow dies look crazy compared to aluminium ones - if an alu die needs a 50mm pad thickness and a larges bearing of 3mm, the magnesium equivalent would have a 120mm pad and a 35mm bearing. They also go through way more revisions until they run properly - it could be that some of the old weight-saving tricks, sch as triple-butting, are harder to do with magesium?

wtjs wrote:

We aleady have essentially 4 excellent cycle frame materials: steel, aluminium, titanium and composite. You wonder at the point of another material.

Bamboo.

Fond memories of mid-80s chemistry lessons. Our teacher grew up during the blitz in London and had what today would probably be seen as a dangerous obsession with exothermic reactions. We spent around 18 months exploring ever more reactive reactions (aka blowing stuff up). All the usual fun, sodium in water, hydrogen manufacture, even made a thermic lance (a lot of lads had relatives who worked on the railways). Oh and "played" with phosphorous. Completely insane and remarkable that we escaped with all extremities intact.

Very similar memories from exactly the same period; our chemistry teacher was a former Royal Marine, he wasn't all that as a teacher but by golly he liked blowing things up. Sadly his activities were curtailed somewhat after police and three fire engines called by neighbouring houses turned up after as an end of term treat he took us out onto the playing fields and threw a lump of sodium the size of a cricket ball into a pail of water.

wtjs wrote:

Presumbly they're only allowed to see virtual magnesium burning virtually now.

Happy to conclude that we still burn actual magnesium in our school, at least when resources allow or for classes that are sensible enough to watch (or not watch, in this instance).

My magnesium pedals on my racing BMXs have lasted really well. I presume they're magnesium alloy.

Too bad it's actually made of Unobtanium.

Those are some very nice welds I wish my Tig skills were like that