chiefgrooveguru, This is why my 29er Scandium frames are both lighter than the Linskey built ti 26er frame and are as flexy as the ti frame!

I forgot I had a scandium frame. It was damn light and rode very nicely.

Alex – have you become a metalurgist during your time off the bike! 😉

It’s all very well looking at tensile strength of the material, but how about how it changes at and around the welded, or in the case of some steel that is brazed, tube joint – some materials harden but does that make them more brittle (?) my 853 frame cracked through the welded joint of two tubes. Also the butting profile plays a huge part enabling the tube to be stronger (thicker wall) where it is needed most, and lighter in the centre for example. Some tubing is triple butted to make the most of this.

Here’s a question for you Alex, what is ”niobium dipped fine grain steel” as on the label of my tripple butted Columbus Life tubed my bike, and what characteristics does that have (?)more of a challenge than a question perhaps…… 🙂

They were meant to feel similar, just the ti was a lot lighter and perhaps a bit softer overall. a bit.

With that in mind James, you did a sterling job. Honestly, blindfolded I really don’t think I could notice the difference, except perhaps by holding one of the noticably larger main tubes on the Ti frame in hand.

But it can still be lighter, by almost a pound and a half in this case i think. I’d say it was a bit more flexible overall than the 853, but it’s subtle – compared to riding an older merlin or similar that can feel really whippy.

Basically, exactly what I was after, and I’m thankful for it to be honest. I was so worried I wouldn’t like the Ti version as much as the steel, I haven’t yet sold the steel frame! I vowed I’d keep it for at least 3 months in case the Ti version felt too flexy and I didn’t get on with it. As it is, they feel very similar just with considerably less weight, so I’d say you got it spot on. Having also ridden a number of older Ti hardtails from years gone by, even just briefly, they could be a horrid flexible mess, something I do not like.

Cheers again for the rigid forks by the way, they’ll be going on it soon now I’ve got a 2.4″ Rubber Queen to go up front too. Just got to build up a suitable front wheel for it…

We did do quite a bit of metallurgy in my degree, so it’s been lurking in my head for many years! 😉

The fine grain refers to the crystalline structure, presumably a result of the tube working process. Niobium dipped? The niobium would increase the corrosion resistance. Welding causes weakness due to crystalline structure changes, so the fancy steels contain alloying elements which discourage the formation of larger crystals and thus potential fault planes. If they get stronger then the action of welding must cause positive crystalline changing. I can’t see brittleness being caused by this because you’re tied into the Young’s modulus of the material. But if you get uneven cooling there’s the potential for micro-cracks which would cause stress concentrations and premature failure. I’d forgotten how much I liked this bit of mech eng but it’s all very rusty…

I’d forgotten how much I liked this bit of mech eng but it’s all very rusty…

I started off doing Mech Eng too, but I couldn’t cope with the Pure Maths so changed degree after the first year. Funnily enough though, the Metallurgy was the one bit of first year Mech Eng that interested me too! Though I’ve forgotten almost all of it for sure…

Ride an aluminium road bike next to a carbon road bike and you will find there is a hell of a difference.

Ride one alu road bike next to another alu road bike you’ll find there is a hell of a difference. Or at least a lot more difference than between an alu bike and a carbon one designed with similar levels of stiffness. Any other difference can only be ascribed to magic (and good old placebo effect).

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Ride an aluminium road bike next to a carbon road bike and you will find there is a hell of a difference.

My kinesis racelight is way more comfortable than the Trek Madone I was racing this season and there was nothing in the stiffness.The madone did handle better belting round the crits though.

Very impressive Alex!

For what it’s worth, close examination of the label reveals the tubes were niobium ‘doped’ assuming that isn’t going to make much difference over ”dipped”….

no probs mark, it’ll be a rigid 29er next if you like that set up, be warned )