nice story but the ads are awfully annoying, and b4 u suggest an adblocker, I’m on a phone.
I suggest an adblocker for your phone
MIT Aluminum Bicycle Project 1974 (2016)
61–70 of 152 posts
Re: MIT Aluminum Bicycle Project 1974 (2016)
#62> He ruled out magnesium, which is best per unit weight in compressive buckling but is brittle and difficult to extrude. There's a fascinating, and very new, class of nano-laminate magnesium alloys called Long Period Stacking-Ordered (LPSO) alloys. These are very lean -- the standard version is 97% Mg + 1% Zn + 2% Y -- and they have outstanding mechanical properties. At an equal weight, they're much stronger and stif…
I thought stiff was a problem with aluminum - stronger is better but is stiffer better?
That said, I wonder if there is a way to make frames more comfortable without having the flex absorb pedaling energy.
Re: MIT Aluminum Bicycle Project 1974 (2016)
#63> He ruled out magnesium, which is best per unit weight in compressive buckling but is brittle and difficult to extrude. There's a fascinating, and very new, class of nano-laminate magnesium alloys called Long Period Stacking-Ordered (LPSO) alloys. These are very lean -- the standard version is 97% Mg + 1% Zn + 2% Y -- and they have outstanding mechanical properties. At an equal weight, they're much stronger and stif…
Interesting. I haven’t heard of them. Joining would still be a problem for a bike frame. Any idea on how well they work with other severe plastic deformation processes?
They appear to benefit from ECAP, if that's what you mean. For e.g.: https://www.sciencedirect.com/science/article/abs/pii/S09215...
Presumably they'd also benefit from SMAT and other forms of surface modification.
That said, they're really good as extruded, and they don't appear to benefit as much from SPD as some steel and aluminum alloys do.
Re: MIT Aluminum Bicycle Project 1974 (2016)
#64I'm convinced titanium is a pretty optimal bike material. I hate aluminum frames, too stiff, some amount of flex makes a bike so much nicer. Hate carbon, too. Steel is nice. I've have a lite ghisallo frame which I think was under 2lbs. The whole bike is under 15lbs and still manages to carry my 200lbs of weight.
Titanium frames have a devoted fan base. Personally, I tried to notice the difference back when I did road racing but didn't. Maybe I didn't want to: Ti ain't cheap.
Custom ti frames are cheaper than the high end carbon frames nowadays.
Re: MIT Aluminum Bicycle Project 1974 (2016)
#65> He ruled out magnesium, which is best per unit weight in compressive buckling but is brittle and difficult to extrude. There's a fascinating, and very new, class of nano-laminate magnesium alloys called Long Period Stacking-Ordered (LPSO) alloys. These are very lean -- the standard version is 97% Mg + 1% Zn + 2% Y -- and they have outstanding mechanical properties. At an equal weight, they're much stronger and stif…
I thought stiff was a problem with aluminum - stronger is better but is stiffer better? That said, I wonder if there is a way to make frames more comfortable without having the flex absorb pedaling energy.
I don't believe that the frame material makes much difference to comfort. The part that can deflect/absorb bumps and vibration the best is the tyre. So the answer to your question is bigger tyres at lower pressures.
Re: MIT Aluminum Bicycle Project 1974 (2016)
#66aluminum is nice, yet once in a blue moon you get something like this year an aluminum hiking pole broke when i lost my balance on a slippery slope and put a lot of weight on the pole and falling i almost got skewered by it's broken off jagged lower piece. I really want steel poles now, yet can't find them to the point of pondering DYI-ing from some Home Depot steel tubing.
Re: MIT Aluminum Bicycle Project 1974 (2016)
#67Just an anecdote thats been horrifying me for the last week since Klein is mentioned.
I learned last week that my colleague bought a commuting bike from an old friend. A true once in a lifetime barn find. Mid 90s Klein Attitude, only used for a few weeks before being stored in the barn until 2023. My colleague is currently putting it through its second winter on salted, snowy roads.
Re: MIT Aluminum Bicycle Project 1974 (2016)
#68Favorite road bike I’ve ever owned was the aluminum Klein Quantum Race designed by Greg Klein.
Klein bikes of that era had the best paint jobs I have ever seen. I was way too young to even know about these bikes back then, which is a shame, as they are pretty much at the very top of what constitutes bike porn for me.
Yeah they were good
Don’t need a bike manufacturer to do that for you though
Re: MIT Aluminum Bicycle Project 1974 (2016)
#69R.I.P. Sheldon Brown. I'm glad his pages still exist both as useful resource and as a time capsule of what the best of the old web looked like: useful, content rich, no ads, fast loading, stable urls.
There is an aliexpress ad on top of the page.
Re: MIT Aluminum Bicycle Project 1974 (2016)
#70aluminum is nice, yet once in a blue moon you get something like this year an aluminum hiking pole broke when i lost my balance on a slippery slope and put a lot of weight on the pole and falling i almost got skewered by it's broken off jagged lower piece. I really want steel poles now, yet can't find them to the point of pondering DYI-ing from some Home Depot steel tubing.
That's a problem with aluminium - no fatigue limit. This means that cyclic loads on an aluminium frame (or pole) will eventually cause it to fail. Steel does have a fatigue limit such that cyclic loads below that threshold won't cause eventual failure.
There's some good info on bike frame materials here: https://bike.bikegremlin.com/11144/bicycle-frame-materials-e...