new to mtb

[rudis_dad]

they do tend to be less serious bikes for girls

I disagree. Have a look at what Cannondale, Specialised, Trek and Orange have to offer.

Cannondale
Orange

 

[BikeLiker]

Sorry, but that simply isn't true. A smaller frame is going to to be stiffer than a larger frame all day long, simply because of the reduction in leverage.

It's clear that you don't know much about engineering, frame design and triangulation or material properties.

Well, sorry I can't reciprocate with sweeping generalisations on your abilities or lack of them after reading two sentences you have written, I must lack your sagacious insight into these matters. Either that or your vitriol stems from feeling slightly embarrassed because you have bought / recommended a woman's frame

Back on topic, an equilateral triangle provides the most rigid form for three tubes joined together. The more you deviate from this form the less rigid the result which is why there are 3 tubes instead of 2 on any serious bike The woman's frame has more assymetry in the length of seatpost v toptube so is less rigid for a comparable size.
Setting aside engineering theory, me and my wife have owned the 2 bikes above and I maintain from that experience that women designed frames are inferior.

 

[rudis_dad]

Oh right, okay. So engineering "theory" (or "facts" as I prefer to call them) must have been wrong for centuries then...

I agree that the old "step-through" women's frames were very much inferior in their structural properties than the equivalent man's frame because the front "triangle" was actually more of a parallelogram; but to state that a smaller diamond frame will be inherently more flexible than a larger version is just utter nonsense.

By this argument, a BMX frame would be like a modelling balloon compared to the biggest road frame available, which clearly isn't the case!!

Any frame designer, fabrication design engineer (that'll be me then, although 25 years in the trade can't be called any sort of experience, can it?), structural engineer or even architect will tell you the smaller the triangulation, the stiffer the structure.

I would hazard a guess that with the two bikes given as an example, at that price point you will experience an incredible amount of flex from poor-quality machine-built wheels and spindly mass-produced suspension forks. And to be quite honest, unless your good lady is, erm, shall we say, very "big boned" (which I am sure she isn't), there's no way on this earth that you're going to be able to induce a noticable degree of flex in either frame short of putting it in a flexure test jig. A 5-foot, 7 - 9 stone woman is never going to put as much stress on a frame as a 6-foot, 14 stone bloke, whichever way you look at it.

Having said that, I don't know why I bother because you can't argue with idiots...

 

[Cubist]

Well rounded argument and a particlularly impressive last line. Gets a 7/10 from me as it's not quite sweary enough

 

[BikeLiker]

Having said that, I don't know why I bother because you can't argue with idiots...

We're discussing bikes. I've had a nice day in Llandegla doing this.

Try it or, alternatively, one of these and lie down in a dark room for a year.

 

[Tango]

And besides which, you don't see many lady MTBers wearing skirts these days...

I am sure I detect a note of disappointment there

 

[Tango]

There are some great women specific mountain bikes as mentioned earlier

MrsT has a WSD Trek ex5 and loves it, specialized myka, orange diva, etc are also worth a look.

If possible try before you buy is a good idea