General Cycling Discussion - Ti

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It seems that awhile back there was a weight weanie thread, and dirtgrinder and myself for starters, came away thinking poorly of Ti. However, I did a little research, and also someone posted a link that contained info about Ti(I'm sorry, I don't remeber who, I think it was thbirks). Anyway, the reason Ti seems a little "less" durable than aluminum or steele, is because Ti is actually much more durable, and lighter. Soo, what happens is bike manufactuers use Ti almost exclusivley for weight savings. Very few manufacturers who work with Ti, try to build just a "regular" bike. Litespeed did for a few years by building the Kitsuma, which they called a "freeride" bike. They built it up nice and sturdy, and the complete bike came out at about 27 pounds. In the reveiw I read in Mountain bike, the Kitsuma could take drops that would snap an aluminum frame.
So, the moral of the thread, Ti IS durable, and Ti DOES last, but most manufacturers use it in a way that gives it a bad rep. But!! manufactureres wouldn't be able to do that if Ti wasn't durable.
Thank you for your time, fubar5 :D
That's interesting and thought-provoking, fubar5. Thanks...
It reminds me of computers and software: manufacturers and writers latch onto the most powerful features and by over-exploiting them make them into weaknesses. Then the consumer has to pay.
Hey JonR! Hope you had a good Christmas!
Ti is actually much more durable, and lighter
Thanks Fubar.
That's exactly why I bought (or rather my wife made me buy :D) a Litespeed last spring. :thumbup:
Originally posted by RonH
Thanks Fubar.
That's exactly why I bought (or rather my wife made me buy :D) a Litespeed last spring. :thumbup:
LOL!
I typed all that up just for you RonH!
There are no bad commonly-used frame materials, but there are good and bad frame designers and builders.
Bobsled
12-28-01, 01:43 PM
Anyway, the reason Ti seems a little "less" durable than aluminum or steele, is because Ti is actually much more durable, and lighter.
Fubar, that doesn't make sense. Anyway I've always heard/read that aluminum is stiffer than my (censored). That's why aluminum frames have a short life expectancy. But I may be biased since I ride Ti.
Originally posted by Bobsled
Fubar, that doesn't make sense. Anyway I've always heard/read that aluminum is stiffer than my (censored). That's why aluminum frames have a short life expectancy. But I may be biased since I ride Ti.
Ummm, I'm not sure I understand your post...I for one, always thought Aluminum, even though it was stiff, and the stiffness cut its life expectancy, was more durable than Ti. But I only had that impression because manufacturers who build with Ti are usually trying to cut the weight of the bike, which causes the Ti to break, because how do you cut weight? You make the tubes thinner and use less material on the welds right? There may be a few things I am missing, but those are the biggies. Well, if they(the manufacturers) didn't take weight savings to such an extreme level, Ti breaking would be pretty much an oxymoron.
LittleBigMan
12-29-01, 01:04 AM
Titanium is light, strong, and very, very expensive.
:eek:
Originally posted by fubar5
Well, if they(the manufacturers) didn't take weight savings to such an extreme level, Ti breaking would be pretty much an oxymoron.
I strongly suspect you're exactly right. Why? Because what you're describing is exactly what manufacturers tend to do: "refine" a concept till it's useless, the product breaks, the consumer is left with the bill, and the manufacturers go on to the next "great" thing, leaving perfectly good technology in the dust.
A few years ago, I saw ads for an automobile that bragged, "We've completely redesigned the xxx!" OK, I thought, how is it that the xxx was so great last year, and this year you had to completely re-design it? :confused:
As a mechanical engineer, one aquainted with the strength properties of various metals, I can safely say that Titanium is, for a similar cross-section of metal, about as strong as any of the common steel frame alloys, but weighs roughly half as much, while costing a lot more.
Aluminum, on the other hand, has roughly 1/3 the strength of steel, but also weighs roughly 1/3 as much. As a result, Aluminum often is used in wide tubes. It is also more easily shaped than steel, so you see many odd-shaped tubes with aluminum. Titanium is likewise more malleable than steel.
You can make a frame more 'durable' by designing it with more mass in the critical areas, such as at the joins between tubes, or by filleting and gusseting the corners. Material alone does not provide durability. Both Steel and Titanium have "endurance limits", meaning that they will have an infinite life, provided they are not over-stressed (I believe that the limit for TI is lower than for steel, though), whereas Aluminum will always have a finite life.
I'm shocked that Litespeed would build a bike weighing 27 lbs! Most of their road bikes weigh somewhere around 16 lbs.
The 27 lb bike they were selling was marketed as a "bighit" or freeride bike. So had to build it pretty beefy. But 27 lbs, for a complete freeride bike, is a wowzer. Freeride bikes tend to be in the 30 to 40 pound range.
Bobsled
12-29-01, 12:14 PM
Both Steel and Titanium have "endurance limits", meaning that they will have an infinite life, provided they are not over-stressed (I believe that the limit for TI is lower than for steel, though)
Usually it's rust that will be the ulimate demise of a steel frame (as long as you don't crash) and of course Ti frames don't have that problem. Good to see a metal's properties brought up as that is what makes a metal attractive to frame builders.
As a side note: several years back I had read that most Ti was being mined in the former USSR. Is that accurate?
The Ural mountains of the former USSR are rich in valuable mineral deposits, including Ti.
Buddy Hayden
12-29-01, 02:56 PM
I have heard that in new exhaust systems on cars , it is wise to coat the lining with "fish oil" to avoid rusting out , could the same technique be used on steel bicycle frames ?
Buddy, there is a product dalled: "Frame Saver" that is sprayed into the frames tubing. The Mfgr claims it will prevent rust from forming on the inside. Any LBS can order it for you, if they don't stock it.
Bobsled
12-29-01, 08:08 PM
I have heard that in new exhaust systems on cars , it is wise to coat the lining with "fish oil" to avoid rusting out
God, can you imagine driving behind that car? "What the HELL is that smell?"
BWAHAHAHAHA!!!!!
oh, that's a good one!
To quote Colin Chapmin, the man responsible for transforming Formula One racecar design into the Modern Era, "If it doesn't break, it's too heavy"
His theory was to design critical suspension components so light that they'd collapse as they crossed the finish line.
Great for his racing legacy but not great for a drivers confidence!
pat5319
12-30-01, 04:21 PM
Buddy,
Yes, it is a very good idea to put a protective coat inside your steel frame, especially if you live in an areas with salty air/high humidity or if your bike is stored where the temperature varies. I haven't heard about using fish oil myself, but it does sound very plausible, I've heard Linseed Oil works too, as it spreads well and thickens as it drys. There are automotive products that can serve the purpose, I can't recall any brands, that are designed to spray on and set as a light liquid that spreads and permeates and then drys and sets into a thick/hard film that stays in place. There is an outfit named Weigle(?) that makes a spray specifically designed to coat the inside of frame tubes as well, you'lll see it advertised and in catalogs occasionally.
Ride Non Rusty
Pat
Colin Chapman's Lotus racing cars took lightness to the extreme. One of his cars ended up with a buckled floorpan by simply spinning around! At least one of his drivers was killed because a critical part failed at speed, without being hit.
MichaelW
12-31-01, 11:14 AM
Ive ridden plenty of steel frames, some of them very old, but none have ever broken due to rust. Most get crash-damaged or their wheel size becomes obscelete long before they get eaten by rust.
In independent frame testing, frames were fatigued to the point of breakage. Surprisingly, the Al frames proved more durable than steel or Ti, but the samples used were not really valid. Most fatigue failures are caused by heat damage or stress raisers formed during manufacture, and has little to do with the lab-measured properties of the material.
Try taking your Ti or Al frame to a frame-builder and ask for some "braze-ons" (weld-ons) to be added , removed or moved. Ive done this with steel bikes.
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