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What is the stiffest ti frame? Just curious.(11 posts)

What is the stiffest ti frame? Just curious.aet
Jan 28, 2002 8:57 AM
I ride a Klein Q race and i love it. i hear that it is a really stiff bike, to the point of being uncomfortable for some but i like it. so if i ever get a ti bike, what is a really stiff model.
re: What is the stiffest ti frame? Just curious.TJeanloz
Jan 28, 2002 9:27 AM
I'd have to vote for the Litespeed Ultimate. A number of people have complained that it was too stiff.
Tried a 2002?pmf1
Jan 28, 2002 10:55 AM
I was wondering if the carbon stays have made the bike less stiff. I have a 1999 model and like it quite a bit. I don't find it uncomfortable.
Jan 28, 2002 11:39 AM
The Ultimate is a butted 6/4 ti with an oversized down tube, short chain stay (you practically sit over the rear wheel) race worthy aggressive bike. I can't imagine any ti bike being stiffer, and I don't think the CF rear would change that.

The Colnago Ovalmaster is also oversized 6/4 ti, but see other threads bashing Colnago Ti... I just can't speak to that.
Jan 28, 2002 12:01 PM
Only the down tube is 6/4 ti on the LS Ultimate. The rest of the bike is 3/2.5. I think the over-all stiffness comes from the huge amount of material that meets up at the botom bracket. The stays are only one cm shorter than a conventional bike. Its not noticable.
Jan 28, 2002 12:36 PM
Well, in my size (55 cm) the stays are 2 cm shorter, the BB a little higher and the wheelbase about 2 cm shorter too. Compared to my Catalyst I found it exceedingly stiff and quick steering.

I know the whole bike isn't 6/4, but isn't it head tube, seat tube, and BB? Then the other parts are 3/2.5 for vertical compliance. Maybe I'm wrong, but I thought that's how they got the stiffness so good.

In any event, my vote still goes to the Ultimate.
Jan 28, 2002 12:44 PM
I also think 1cm on the c-stays can make a difference (although of course there are many other factors and it's hard to isolate any one thing). I have one road bike with a 40.5 c-stay, my Merckx has a 41.5 and my cross bike has a 42.5 (with a higher bb). All feel pretty different both in terms of stability/handling and comfort over rough surfaces, and I think the c-stay lengths have a lot to do with that. Short c-stays combined with beefy downtube = stiff.
In this case, does aggressive mean twitchy handling?(nm)aet
Jan 28, 2002 1:03 PM
6/4 Ti vs. 3/2.5Nessism
Jan 28, 2002 1:36 PM
The stiffness of a material is dependant on the materials Modulus of Elasticity (E). For Ti, both 3/2.5 and 6/4 have the same E. Because of this, if two frame tubes were made to the exact same dimensions (thickness and diameter) they would flex exactly the same.

6/4 Ti is stronger than 3/2.5 by approximately 30%. Because of this, 6/4 Ti can be made into tubes that are thinner without risk of breakage. The thinner tubes are lighter but more flexable. To get the stiffness back up, the 6/4 tubes need to be made larger in diamater. Unfortunately, up to this point, there does not seem to be any frame manufactuers that have done this to any great degree.

Aero down tubes, made from sheet 6/4 wraped around a mandrel and welded, are not very stiff torsionally and do not lend all that much to the bottom bracket stiffness than many crave. They do look cool however.

If one is looking for a stiff Ti frame, it's necessary to look at the tube diamaters (particularly the downtube and chainstays) and the overall frame weight. The weight will indicate how thick the tubes are.

So which Ti frame is the heaviest? Good guess that this is the stiffest. If it has a 1-1/2" downtube, you can lay money on it.
stiff? titanium?ColnagoFE
Jan 28, 2002 9:48 AM
TI isn't all that known for being stiff. That said a LS Ultimate is supposed to be pretty stiff. Also the Serottas I've tried are also pretty stiff. People say the Colnago TI bikes are stiff as well, but I haven't tried them--plus if I was going TI, I'd stick with an American make.
stiff? titanium?tempeteKerouak
Jan 28, 2002 11:41 AM
True, Ti is not known as a "stiff" material.

However, it has been shaped into pretty stiff frames... There has been examples of olympic track champions on titanium frames (did I mention oversized as in BIG tubes!)

Ti 6al 4 va is reknown to be stiffer. What's in an alloy...

I'm 5'10 and some, 175 pounds (pretty strong, I am!!) and I think I flex wheels, handlebars, cranks and BB spindle before the frame itself... So what's with the flex thing? Gimme a diamond frame that don't collapse when you squeeze the rear with one hand...