According to this guy it's all advantages and no downside. So why isn't it used more?
Probably because all the previous attempts have been notable (and often catastrophic) failures.
And now that carbon has matured as a technology it'd be an even more difficult sell.
The new C-line Pinion gearboxes use magnesium casing to save a load of weight over the P-line alu ones, so it obviously works for that almost-structural use
I don't think I've ever seen a magnesium frame
I don’t think I’ve ever seen a magnesium frame
I give you Kirk Magnesium!...
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...I had long term use of the road bike back in the day. A mate bought one (he had a matching MTB version too) then went abroad for a year, so I rode it. I wasn't sad to hand it back - the deadest feeling bike I've swung my leg over.
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I don’t think I’ve ever seen a magnesium frame
I give you Kirk Magnesium!…
Yep, friend had one in bright pink back in 92...
Have to say I'm not sure it's aged that well - looked very cool at the time IIRC....
TBH the GoCycle is magnesium, I had one and did love a lot of the design - the wheel hubs were lovely.
Just didn't like the sticky up handlebar.
I give you Kirk Magnesium!…
A guy in my cycle club had one.
Well to be more accurate, he had 5, they all broke and for a while Kirk replaced them before telling him that he couldn't have any more.
Managed the quite unique characteristics of being utterly dead to ride while also being so flexy that you could change gear just by sprinting and the flex in the back end would randomly shift the chain around.
It did look cool though.
The problem is that the only thing anyone remembers about magnesium frames is Kirk and how bad they were so it's already a hard sell. RockShox Mag 21's had magnesium lowers though - they seemed structurally sound but then the material didn't really have to do a whole lot at the bottom of fork legs.
I’m just thinking of frame names now.
Magnacarver.
Magnesium PI.
I give you Kirk Magnesium!…
Would look fabulous if it wasn't for the dropouts
I think
Aren’t almost all suspension fork lowers made of magnesium alloy?
Carerra sold at least one in the early 2000s - the Zelos, IIRC. This was during a period when Carerra were attempting move beyond their bargain basement reputation so it was maybe pushing a grand and had some fairly decent bits on it. Except for a fairly aggressive metallic lime green finish it looked pretty much like any other hardtail of the era so Magnesium doesn't have to mean something like the Kirk Precision.
IIRC the few reviews there were of it might have said it was a bit too stiff and harsh.
eBay handily has a photo of one:
I’ve just ordered some magnesium flat pedals. £60, 270g, they’ll be going on the gravel bike.
https://www.bike24.com/p2134534.html
I’m just thinking of frame names now.
Magnacarver.
Magnesium PI.
Papa's Got a Brand New Mag
Carerra sold at least one in the early 2000s – the Zelos, IIRC. This was during a period when Carerra were attempting move beyond their bargain basement reputation so it was maybe pushing a grand and had some fairly decent bits on it. Except for a fairly aggressive metallic lime green finish it looked pretty much like any other hardtail of the era so Magnesium doesn’t have to mean something like the Kirk Precision.
I worked there at the time, they were crazily light compared to other Carrera's, let alone the Saracen Raw we sold at the same time. They came with a Rockshox July fork, Hope Mono Mini brakes, Hope hubs with XC 319 rims, IRC Mythos XC Semi slick tyres, XT drivetrain and a Richey finishing kit. All for £699.99!
That also snapped easily at the headtube weld. Which was a pity as I had one set aside for myself while I paid it off and swapped it to a Kraken instead, an upgrade to a Marzocchi Mx Comp fork, the same wheels as the Zelos had (warranty ones that were never collected!) and a Hope Mono Mini brakes on the front meant I had 90% of the Zelos for a lot less money.
Magnacarver.
Magnesium PI.Papa’s Got a Brand New Mag
Oxide
Salt of the Earth
Ne3s
Above Strontium
Am I also right in thinking many fork lowers are magnesium still?
As reductantjumper said a lot of the carreras came back broken to the Halfords I worked in. We never managed to get one to catch fire like magnesium strip did in chemistry though. I don't remember them being any different to an aluminium framed bike.
Am I also right in thinking many fork lowers are magnesium still?
Yeah some are. Managed to crack some old Fox one's next to the arch/bridge. When I took them off, to replace them, they fell apart like wet chipboard, crumbled in an almost granular way!
Doesn't magnesium oxidise like an absolute pig?
Magnesium fork lowers and Taiwan being about the only place that can cast them, is why there are not more small/custom fork manufacturers.
Doesn’t magnesium oxidise like an absolute pig?
If not coated the moisture in the air will react (but not quickly).
I once made some magnesium valve spring retainers and the first set got scrapped because moisture built up in the bag they were stored in, after that they were covered in duck oil.
I thought magnesium was very prone to fatigue? that's why magnesium car wheels have a service life.
We had students who worked at a foundry that cast and machined magnesium car parts, apparently casting fires were weekly (not including the furnace fires obvs)
Oxide
Salt of the Earth
Ne3s
Above Strontium
No magg_outandabout?
We had students who worked at a foundry that cast and machined magnesium car parts, apparently casting fires were weekly (not including the furnace fires obvs)
That sounds… exciting?
https://singletrackworld.com/forum/topic/who-owns-a-non-popular-bikeshow-and-tell/page/2/
We did this 13 years ago.
My uncle has a Kirk in his garage that he keeps talking about selling. A white road bike version.
My 90’s DMR V12s died pretty quickly after sitting unused for 12 years. Pin threads just crumbled from normal use and couldn’t be re tapped.
That said they are still using it for their new SL pedals. Quoted benefits according to DMR
Six benefits of the magnesium casting process:
1. Most of the magnesium used is extracted from seawater.
2. Magnesium uses less energy to process the material than aluminium (bauxite).
3. Casting magnesium uses less energy to make the finished product (than CNC aluminium).
4. The casting process wastes very little material.
5. Any waste material is recycled on site (zero waste).
6. Magnesium is non-toxic and is very safe for manufacture and use.
From my limited understanding, it’s a decent material for lightweight solid cast parts. Bikes made out of solid parts aren’t great, and magnesium is not a good material for making into tubes.
Ne3s?
Physics is not working anymore.
Got caught out by bulk Mg once - demonstrating reaction rates - powder, ribbon, car wheel - kidding, pencil sharpener in hydrochloric acid. The pencil sharpener went off much faster, must have been a catalytic effect from other metals in the alloy or the steel blade. On my feet, asked the class to explain what had gone wrong.
Anyway that sharpener was my goto hydrogen generator for a while.
I'd be 'interested ' to see how well they fatigue.
Or take impacts. It's a bit rich that bloke hitting it a little bit with a spanner or whatever and saying I wouldn't dare do that to a carbon frame. I would, and on top I'd be more twitchy of fatally denting an Al frame like that, esp. as olde skole Crack'n'fail, and I have a nasty suspicion Mg alloyss would take us back to those times.
Those Xpedo pedals in Tom's link are available in colours too, looks like an interesting brand with some weird pedals in their range, those dual colour faceoff ones caught my eye, but just make sure you don't rub the X off the logo 😀
From memory it was a manufacturing defect that made the Kirks go wobbly, the magnesium was contaminated so some batches were perfectly fine. Even the properly made ones felt dead though.