So I've been googling and forum-surfing all day, and while there are lots of answers to the "I'm a big guy..." questions, none I've found remotely approach what I'm looking for. I'm hoping someone will see this and think, "I know a guy exactly like that [or that's me], and I know what works for him[/me]"!

First and most importantly is this fact: I raced motocross throughout childhood and teens. I was a little guy then and started on a (relatively huge!) 125, then 250. Only after 18 was I "grown into" the bikes I rode. So I feel most comfortable on a relatively large, heavy machine - with my body spread out, back NOT bent over (but still sprung), and arms relatively high and wide. (I could not tolerate BMX bikes [all the rage then]...WAY too tiny!)

Now, I'm in my 40s, 6'3", 210 lbs (fit). I've sworn off motorcycles, but ride MTBs pretty aggressively. When I first bought a MTB, I got the biggest one I could find. But it's still so damn tiny it kills me. It feels like I'm riding on a miniature greyhound rather than a horse. It's not a downhill variety, although that is what I prefer (and should have bought). The rake is so steep, the wheelbase so short, and the bike is so cramped and tiny and light--that it shakes and wobbles like crazy!

(It's all relative I know...I'm used to 400 lbs of combined kinetic mass pummeling through and over obstacles like a hot knife through butter, with huge knobbies thudding and pounding the dirt like ultra-low frequency sledgehammers, while the chassis barely budges as it floats in graceful curves through space. But, my MTB experience seems no "worse" in absolute terms than anyone else on an MTBs. It's just an issue of mass and geometry.)

After 10 years of "more than casual" mountain-bike riding, and surrounded by a wide assortment of excellent single-track mountain/hill trails, I have STILL not gotten used to the cramped layout, steep fork rake, short wheelbase, twitchy handling, and lack of mass-induced momentum. It drives me crazy, that to stand up on the pedals (knees bent of course), requires me to be SO bent over, due to the basic MTB geometry. (I could care less whether or not it's optimal breathing posture - it's just damn uncomfortable for long stretches especially long downhills. I've tried all the posture tips, my bike is set up as well as it can possibly be for my body, and my core is very strong - but it's still murder on my back.)

Let me put it this way: a recurring dream I often have, is racing on downhill mountain bike course...on a dirt-bike with the engine removed. Ahh, to be able to stretch out, arms higher and wider, back straighter yet still well-sprung, neck not craned upwards just to see where I'm going... It's heaven. Until I wake up and get on my actual mountain bike.

So, with that in mind, any recommendations? I'm looking for a serious downhill variety, with as long a wheelbase as possible, long travel, as slack of a fork rake as possible, and handlebars as high and wide as possible (and by "possible" obviously I don't mean "physically possible", but within reasonable and practical constraints).

I ride more than just downhill (xc and freeride), and fully understand the drawbacks of using a downhill-specific bike for these other purposes. Those drawbacks don't concern me. (I really only like to blitz downhill anyway and the others are just ways of getting there.)

I also understand that a longer, heavier, more stable bike will be slower to toss around in the tight stuff, and to generally change velocity and vector. A trade-off I'm quite eager to make!

I don't currently race downhill though I would like to (assuming I get the bike part right), and even then I'm not so concerned with hyper-competitiveness to the point I'm willing to sacrifice bigger size and stability for faster times.

(At this point you might be asking: why not just get back into motocross? A good question. The answer is multifaceted; involving much higher investment in time and money, a different set of friends advised that don't actually exist in my sphere, and severely limited [to non-existent] options for practicing, casual riding, and racing in my area. Not to mention much higher physical injury risk involved with "casual riding", even if racing itself is quite safe. Plus, I do like the considerably closer connection to nature with mountain biking.)

Cost is not a factor. Well, not the most significant factor. A $2k bike will of course be much preferable to an $8k bike. But honestly, if I have to spend $10k to not be stuck on a circus monkey bicycle for another 10 years, I will.

So...that's alot of info but if you made it this far, I'm hoping it's because you know exactly how I feel...AND have cracked that nut yourself (or seen it cracked)!

Thoughts? I'm assuming the solution will in part include starting with one of the new 29-inchers?

Thanks!
-Jim