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Re: New shaped titanium bike frame [tri_yoda] [ In reply to ]
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tri_yoda wrote:
Any frame can be made lighter (no matter what the material) to an extent, its just a matter of trade offs. I said "claimed" benefit (in the sense that you can't really substantiate such a claim

Good proven aluminum frame designs come in at <1100g. And they are cheap. Bossi are claiming 1500-1550g for this Ti frame.
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Re: New shaped titanium bike frame [Shambolic] [ In reply to ]
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Shambolic wrote:
Well spotted but at least it's an Australian company. Hard to buy anything made in Australia now days but I will always be somewhat patriotic.

Apparently these are knocked out of a factory in China. Not that this necessarily means the quality is bad, just that it is not Australian made.
https://www.facebook.com/hangluntitaniumbicycle/
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Re: New shaped titanium bike frame [Rocky M] [ In reply to ]
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Rocky M wrote:
Zissou wrote:
gorgeous bike, but I will say that my heart sank when I saw the 14.5k AUD ( >10kUSD) price tag for the complete bike.



Geezus, that's crazy $$. I have a Made in the USA Quintana Roo Tiphoon Ti 54 cm (I think that is the size), I'll sell someone dirt cheap with Sram Red/Force, wheels (ya rim) for dirt cheap if you want Ti that bad. Heck I'll even add in a rear Corima tubular race wheel for a wee bit more plus about 5 tubulars on top of that. (of course I haven't figured what *dirt* cheap would be..

Is the executive summary of this, "Slowman suckered me in during the 90's and I even got suckered in by Chris Boardman on the parachute Corima speed decelaration wheels..." (yes, we all went all in back then LOL). I had a 1996 Litespeed Saber that I really regret selling because it would have been the ultimate travel bike with a 50 cm frame, 650 wheels, and bomb proof on airline travel !!!! It got "retired" in 1997 after Ironman Canada and I sold all my gear thinking I was done with that Ironman shit....and then in 1999, I went all in and did 25 more IM's on top of the 6 from my 1997 retirement day LOL
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Re: New shaped titanium bike frame [BergHugi] [ In reply to ]
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Old article but I was told it was still 100% relevant by my LBS and they are big enough to see a lot of bikes: https://www.sheldonbrown.com/...ame_fatigue_test.htm.

In short all types of frames fail but for different reasons. Carbon fails because it was damaged during transport or crashed. Steel fails at the weld joints where stress is localized due to tubes flexing in different direction. Alloy fails due to stress localization around point of damage i.e. your alloy frame may have survived the crash today but that crash damage will cause a failure down the line. Titanium fails because its a PIA to work with resulting in critical flaws during production.

My LBS told me that their experience with Ti frames is that they either last forever or fail early on. Depending on usage case thus can make Ti an ideal frame material but it also accounts for the range of stories you hear about how durable the frames are.
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Re: New shaped titanium bike frame [rruff] [ In reply to ]
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rruff wrote:
tri_yoda wrote:
Any frame can be made lighter (no matter what the material) to an extent, its just a matter of trade offs. I said "claimed" benefit (in the sense that you can't really substantiate such a claim


Good proven aluminum frame designs come in at <1100g. And they are cheap. Bossi are claiming 1500-1550g for this Ti frame.

Not really clear what your point is? Are you claiming no one could ever build a Ti frame that weighs less than an Al one? I agree with you that in general, you can build lighter frames with Aluminum, but that's not an absolute, depends on what your overall design objective is. For example, Al has a fatigue life, for most bicycle applications Ti is above the endurance limit; if you were trying to build a 50,000 mile touring frame I am not sure the aluminum would be lighter than Titanium.

Good proven carbon are coming in at 800g these days. You also need to be really careful about claimed weight, what size frames (are they comparable?), is it frame only, frame and fork. People play all kinds of games when quoting weight.
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Re: New shaped titanium bike frame [hercules] [ In reply to ]
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As far as tube shapes go, I'll never understand why frame builders can't just use round tubes and then add a shaped plastic strip along the trailing edges to complete the NACA airfoil. It would cost pennies on the dollar instead of using structural material for a job that doesn't need it.
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Re: New shaped titanium bike frame [ZenTriBrett] [ In reply to ]
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Because it wouldn't look goo and probably not be as aero as tube only. They would also need to open tooling for those plastic pieces if they want it to have a reasonable rigidity to it.
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Re: New shaped titanium bike frame [gmh39] [ In reply to ]
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After a couple of tries, it would look just fine. Possibly better. Cars have plastic parts all over them that are color matched. And then it could possibly be even more aero since it's easier to make weird shapes. And you don't need any special rigidity.

Frame shapes going aero is an expensive solution looking for a problem. People got all caught up in it and forgot you can just add some trim pieces and make it look cool and be done with it. We are all paying for the insanity.
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Re: New shaped titanium bike frame [ZenTriBrett] [ In reply to ]
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Is that against UCI rules? I just always assumed it was, because it seems like such an obvious choice.
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Re: New shaped titanium bike frame [tri_yoda] [ In reply to ]
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tri_yoda wrote:
rosshm wrote:
What are the benefits of titanium as a frame material?


expensive, allows you to brag to your friends.

capable of having a brushed/polish finish which looks cool.

"superior" corrosion resistance. Which isn't really really much of an advantage, because corrosion isn't really a problem (even for steel bikes) if they are properly coated/painted and cared for.

the claimed benefit is "lighter" and more compliant than other metallic materials. The reality is that titanium is pretty "squishy" and a well designed steel bike built with a high quality, butted, alloy tube set (like Reynolds 753) is going to be a superior performing bike, same or lighter weight, stiffer where you need, compliant to the extent you need it.

Titanium is a "cool" material, but best left to applications of high temperature service, where corrosion or oxidation is a serious problem. For bikes, it really is a boutique material and if you did an objective comparison across a range of material properties against the functional performance requirements for a bicycle frame there is almost no way it would ever come out on top unless you just had some kind of emotional love for the material.

Savage
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Re: New shaped titanium bike frame [cujo] [ In reply to ]
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cujo wrote:
Is that against UCI rules? I just always assumed it was, because it seems like such an obvious choice.
yes, yes it is. Functional things can be aero, but you can't just add on aero parts that have no other function.

If you were allowed plastic fairings then it would be much smarter to put a big bubble visor in front of the rider, not just on the tubes.

Of course, there's nothing beyond fashion that says we the common people have to follow UCI or other competition rules.
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Re: New shaped titanium bike frame [jimatbeyond] [ In reply to ]
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Sexy....
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Re: New shaped titanium bike frame [law321] [ In reply to ]
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Titanium frame advantage #7: you can melt it down and make a spaceship out of it.

"Aquabike is a swim then sleep session on aerobars ...."
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