greatwhite Posted February 11, 2017 Posted February 11, 2017 Having pissed on the batteries of the 'steel is real' crowd - see https://community.bikehub.co.za/topic/166107-is-steel-real/page-1 (BTW, apologies to them if I offended, but I believe art and science should acknowledged for what they are and these days, steel is art, not science IMO), I got to thinking what other custom bike options there are out there? A bit of googling revealed: 1. Steel seems to be the most prevalent (no surprise)2. Titanium next (again no surprise)3. Aluminium custom frames now seem to be a growing thing4. Carbon can be custom built, but is nowhere near as sophisticated as a mass produced carbon frame - depending on the manufacturer they seem to be made in similar fashion the the trek5500 frame Lance 'won' his 1st TDF on many years back or even more primitive like the old Alan and Vitus frames of 30 years ago5. Magnesium frames - vary rare, but a material that has potential to made extremely light frames, due to its low denstiy (about 2/3 of aluminium or 1/4 of steel) I also discovered that the 2006 TDF was won on a magnesium main triangle/carbon rear triangle Pinarello AK61 Dogma frame. - this was after Lance had 'won' the TDF 7 times on a carbon frame - suggesting Mg frames could go toe to toe with carbon at that time. There was also the Kirk Precision frame +/-30 years ago (see http://www.kirk-bicycles.co.uk/Kirk.htm ) So my questions are:1. Who here has ever ridden a magnesium frame? And what did you think? What I'v read suggests is have good vibration damping, but that could be marketing BS (nearest I've come is Mg rail in the seat)2. Who thinks there is a future for this material in cycle applications?
bikebloke Posted February 11, 2017 Posted February 11, 2017 magnesium is light and fairly expensive and it can be cast in a one piece mould thats all good,but its also weaker and less rigid than steel even when alloyed. the stronger magnesium frames become the heavier they get . by the time they compare in strength and rigidity with steel they weigh the same as a steel frame and they cost more .hence they dont happen its just math.
Omumborombonga Posted February 11, 2017 Posted February 11, 2017 Works wonders for my cramps...That made me laugh!
Malpiet Posted February 11, 2017 Posted February 11, 2017 That made me laugh!No matter in what dosage they dont help my cramps!!
Audible Anarchy Posted February 11, 2017 Posted February 11, 2017 In the hacks and bodges section of this weeks GCN show there is a guy who built up one of those old kirk precisions. The show presenters have some interesting chirps on how "durable" those frames were ... Gotta agree with bikebloke here ... Steel would still be better value and easier to work with. Personally I would love a Titanium bike one day - In the unlikely event I would ever want to stop riding my Cotic Steel frame
Meezo Posted February 11, 2017 Posted February 11, 2017 These penis sizing contests showing up all over the show
EmptyB Posted February 11, 2017 Posted February 11, 2017 Magnesium apparently reduces fatigue...good for longer rides
Christie Posted February 11, 2017 Posted February 11, 2017 If magnesium could be built lighter and as stiff as carbon, more would have been around. The key indicators of a frame material would be specific stiffness (stiffness/density) and specific strength (strength/density). Cabon is just so vasly superior as an engineering material that it makes no sense to develop alternatives that will not be as good. Laminate properties for top end carbon is hard to believe - if I remember correctly : 2000 GPa Young's modulus and 4000 MPa ultimate tensile stress - black magic ingeed. Back to magnesium; Mg needs special care to work with. While it is a misconception that a mg component would burn at the slightest exposure to fire, this is true of shavings from machining and filing etc. It also corrodes when exposed to chlorides - salt water & sweat.In general I think the development effort outweighs potential benefits. I do not agree wrt the OP's statement about custom carbon being simplistic. Some companies like Parlee, Cyfac and Sarto make carbon frames that is cuatomized in all regards - custom geometry, custom layup, custom tube thickness. The top companies effectively offer custom ride quality.I cannot for the life of me understand why anybody would spend R100k or more on a frame that is mass produced in China and lots of very near copies could be bought for R5000 a pop, if a bespoke frame could be had for the same money. In that lies one of the attraction for metal frames imo - there are no cheap chinese copies. The metal frame may be heavier than carbon, but would 500g more make a difference to 95% plus of riders at an event? I dont think so - most ride to finish, not to podium.
BaGearA Posted February 11, 2017 Posted February 11, 2017 In the hacks and bodges section of this weeks GCN show there is a guy who built up one of those old kirk precisions. The show presenters have some interesting chirps on how "durable" those frames were ... Gotta agree with bikebloke here ... Steel would still be better value and easier to work with. Personally I would love a Titanium bike one day - In the unlikely event I would ever want to stop riding my Cotic Steel frame Cotic for the win
BaGearA Posted February 11, 2017 Posted February 11, 2017 If magnesium could be built lighter and as stiff as carbon, more would have been around. The key indicators of a frame material would be specific stiffness (stiffness/density) and specific strength (strength/density). Cabon is just so vasly superior as an engineering material that it makes no sense to develop alternatives that will not be as good. Laminate properties for top end carbon is hard to believe - if I remember correctly : 2000 GPa Young's modulus and 4000 MPa ultimate tensile stress - black magic ingeed. Back to magnesium; Mg needs special care to work with. While it is a misconception that a mg component would burn at the slightest exposure to fire, this is true of shavings from machining and filing etc.It also corrodes when exposed to chlorides - salt water & sweat.In general I think the development effort outweighs potential benefits. I do not agree wrt the OP's statement about custom carbon being simplistic. Some companies like Parlee, Cyfac and Sarto make carbon frames that is cuatomized in all regards - custom geometry, custom layup, custom tube thickness. The top companies effectively offer custom ride quality.I cannot for the life of me understand why anybody would spend R100k or more on a frame that is mass produced in China and lots of very near copies could be bought for R5000 a pop, if a bespoke frame could be had for the same money. In that lies one of the attraction for metal frames imo - there are no cheap chinese copies. The metal frame may be heavier than carbon, but would 500g more make a difference to 95% plus of riders at an event? I dont think so - most ride to finish, not to podium.This man has got A excellent point ^
V12man Posted February 11, 2017 Posted February 11, 2017 1 - total bitch to weld2 - corrodes in air...badly Never going to be a great bike material - ever. Porsche built some 917 frames out of mg- put valves in them to pressure test them to ensure structural soundness mid race... so a frame cracking would leak pressure and it would show on a gauge. They did this for a reason...
V12man Posted February 11, 2017 Posted February 11, 2017 [quote name="Christie" post="3063615" In that lies one of the attraction for metal frames imo - there are no cheap chinese copies. The metal frame may be heavier than carbon, but would 500g more make a difference to 95% plus of riders at an event? I dont think so - most ride to finish, not to podium. Never underestimate the Chinese- big mistake... they do custom frames if you like - you won't tell them apart from a Lynskey. http://www.waltlytitanium.com/
Christie Posted February 11, 2017 Posted February 11, 2017 Its just that the potential money to be made from a chonese copy of a metal frame is less, making a copy less likely.
BeegMig Posted February 11, 2017 Posted February 11, 2017 Like the 7 Tours before it, magnesium wasn't quite the main ingredient for success.But still, I'm always on the lookout for a magnesium Dogma on the interwebs in my size.Beeg ones hardly ever pop up
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