Steel, Titanium or Carbon frame?

Discuss light weight issues concerning mountain bikes & parts.

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Cheers!
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by Cheers!

I think any high end frame from any of the big brands is a good bet. Trek, Giant, Rocky Mountain, Cannondale, etc etc... It all depends on your opinion towards each of these brands and how well the marketing has got you hooked.

However, I don't endorse any of the cheap carbon frames on ebay or other companies *****force... etc... I've ridden many and they all ride poorly. Stiffness not optimized correctly is my biggest complaint with them. Or some just are way to too stiff in all dimensions and makes for a bad ride.

by Weenie


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Dilbert
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by Dilbert

Carbon is the best material on paper, in terms of strength, stiffness, mass, fatigue life etc. The exception is impact damage - but can be repaired better than aluminium can.

Aluminium is fantastic too, imo, and on a mtb with fat tyres and suspension, how much will you notice the frame material properties, anyway? Down side is more mass compared to carbon.

Im not a fan of steel, although I have had steel road and mountain bikes - just does not work for me. Also, On a mtb the frame sees a lot more water, which is not always great for steel, unless you get a stainless steel frame, but that costs a lot.

Ti is not worth the cost imo, but it has the expensive, exclusive retro thing going for it.

ticou wrote:
Some figures; the top steels ( reynolds 953, columbus XCR) have a tensile strength of over 2000 MpA. My frame, a zero replica from Dedacaia ( sic) has 1400 MpA. The most you will get out of Ti is around 1000MpA. Carbon is far below this, (Alu is around 700 MpA) and is used mainly for Cat 3 and above racers. Lightweight non racers generally use them for weekend blasts, never or seldom as a daily beater, unless they live in a part of the world with baby smooth roads.

Strong carbon/epoxy has a tensile strength of 3000 MPa, plus the density is low, so you can use as much as is needed and still have a light frame. Black magic? :twisted:

HillRPete
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by HillRPete

My goal is to have one bike of each material. Including Bamboo.

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Cheers!
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by Cheers!

Stephen: Can you explain how this is possible? Is it somehow reinforced inside? Because I'm just if I did that to my Cervelo it would just crumble.

http://www.youtube.com/watch?v=Y_O9PLorYPA" onclick="window.open(this.href);return false;

<iframe width="420" height="315" src="http://www.youtube.com/embed/Y_O9PLorYPA" frameborder="0" allowfullscreen></iframe>

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stephen@fibre-lyte
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by stephen@fibre-lyte

I'm skeptical that it's even a legitimate video. I'd like to see it done in person. If you notice, there is not even any paintwork damage at the area where he's hitting the fork with the hammer. Also bear in mind that the fork is effectively floating in air with him holding it. Carbon will basically bounce away from the hammer reducing the effect of the impact. If it was fixed solid, there would be a lot more damage. Watch the way that the fork moves away from the impact each time it is hit.

Dilbert, tensile strength doesn't tell the whole story. What about compressive or torsional strength? Carbon makes by far the stiffest frame but the stiffer something gets, the more brittle it gets.

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yourdaguy
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by yourdaguy

I have a Niner CArbon fork and it has bounced of rocks and everything else for 3 years and still looks great.
For certain parts stiffer is more important than lighter.

thisisatest
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by thisisatest

I believe if the fork was on a workbench and he hammered it, the story might be different. That said, I have swung a hammer through many frames (warranty replaced, have to destroy the old one) and I can tell you that besides some specific bikes that thankfully aren't around anymore, carbon frames are pretty tough. Especially most mountain frames. I'd whack them a few times, barely make a scratch, then have to really wail on it. A pedal wrench has an easier time, though, due to the much smaller, sharper edge.
Many moons ago, trek did this one example using a steel top tube from their 520 touring frame and an OCLV top tube. They would start hitting the carbon tube with the steel tube. The steel tube would start denting, there would be no signs of damage on the carbon tube.

ticou
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by ticou

Dilbert wrote:Carbon is the best material on paper, in terms of strength, stiffness, mass, fatigue life etc. The exception is impact damage - but can be repaired better than aluminium can.

Aluminium is fantastic too, imo, and on a mtb with fat tyres and suspension, how much will you notice the frame material properties, anyway? Down side is more mass compared to carbon.

Im not a fan of steel, although I have had steel road and mountain bikes - just does not work for me. Also, On a mtb the frame sees a lot more water, which is not always great for steel, unless you get a stainless steel frame, but that costs a lot.

Ti is not worth the cost imo, but it has the expensive, exclusive retro thing going for it.

ticou wrote:
Some figures; the top steels ( reynolds 953, columbus XCR) have a tensile strength of over 2000 MpA. My frame, a zero replica from Dedacaia ( sic) has 1400 MpA. The most you will get out of Ti is around 1000MpA. Carbon is far below this, (Alu is around 700 MpA) and is used mainly for Cat 3 and above racers. Lightweight non racers generally use them for weekend blasts, never or seldom as a daily beater, unless they live in a part of the world with baby smooth roads.

Strong carbon/epoxy has a tensile strength of 3000 MPa, plus the density is low, so you can use as much as is needed and still have a light frame. Black magic? :twisted:

ticou
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by ticou

What a load of nonsense. There ain't no carbon DD's in my town, no couriers use em either, this website is chock full of carbon crack ups as well.


TheRookie
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by TheRookie

Trek offer one of the best frame warranties available, they could bankrupt themselves if they produced shoddy frames, clearly a hand made frame can be good or really bad, I didn't say the trek frame would be Better though if you read what I put.....

The Treks and others use prepreg and an expensive mould, you could never have that with a one-off frame as the moulds are circa £5k each, plus going mass produced you have time and budget to do development builds and testing......
Impoverished weight weenie wanna-be!
Budget 26" HT build viewtopic.php?f=10&t=110956

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Dilbert
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by Dilbert

ticou wrote:What a load of nonsense. There ain't no carbon DD's in my town, no couriers use em either, this website is chock full of carbon crack ups as well.

I can only talk from my perspective, thats how we roll in this corner of Africa. Carbon damage can be fixed, cracked aluminium frame is toast, Ti usually also toast if it cant go back to the manufacturer (it is extremely difficult to weld properly), steel can be repaired.

Here is my bike: It is an Ellsworth Truth, I had a Scott Scale hardtail, but I ride a lot of rock gardens and the ht beat me up too much. I wanted a classic suspension design, and I love the colour of the frame - its not painted, but anodized, which looks nice for longer. I dont mind the extra mass of alu over carbon, but carbon would be stronger. Cant get this finish in carbon, though. This frame is perfect for what I wanted. Somebody else will have completely different priorites.
Image

ticou
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by ticou

And ride 'em with my blessing, they just ain't for me.

digit3
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by digit3

Like several others I have had bikes made from those three materials. Currently I have two carbon and one titanium. I have also had perhaps four aluminum frames.

IMHO, carbon gives you a really stiff ride that transfers power the best to the drivetrain. As you know it is also very light and if well built can be quite durable.

Steel and titanium have the most similar ride qualities I think. A bit softer, certainly less harsh than carbon. I have had two ti bikes and loved them both. A lot depends on the builder and choice of tube sets for both materials. For me, steel isn't what I have stayed with due to weight and potential longevity. I recently sold my Merlin XLM frame after getting fifteen seasons out of it. Scotch brite the tubes and it looks brand new. The ti frame that I kept is near and dear to my heart as it was made for me and is only eight seasons old. I love the snap from the rear triangle yet how supple it rides at the same time.

I have the lightest Scott carbon frame made (going into the classifieds today) and it has been a great ride. I am getting rid of it only because I just poured more $$ into a full suspension carbon bike. However, if I were to choose just one frame to stay with it would be the titanium one. The stuff lasts forever and if you can get past the initial sticker shock it won't seem so bad when you are riding that same bike a decade from now.

My opinion is solely based upon hardtail frames.

TheRookie
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by TheRookie

But there is no reason for a carbon frame to be stiff, it can be made just as supple as any steel if that is what the maker wants, also as it has the highest internal hysteresis it's the best damped.....
Impoverished weight weenie wanna-be!
Budget 26" HT build viewtopic.php?f=10&t=110956

by Weenie


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