What is the next step in engine/chassis development?

I see smaller CC engines for both classes, just like the 500cc, the 450 will become a relec.

I could write a novel on this stuff, but in the interest of time, here are some high level points to answer your questions:

Is triple clamps flex a major part of a bikes handling? 

It can be significant. We make clamps as stiff as possible in all directions except front to back. That makes them handle precisely and keeps the fork tubes better aligned for less binding, which ironically makes it more comfortable despite the clamps being stiffer. The stiffness front to back is tuned for comfort and can make a big difference in feel on the track.  

Some people have been complaining about a bikes suspension and handling being bad. Can adding more triple clamp flex give them what magic cure they are looking for? 

There's no magic cure for anything; it won't fix all your problems, but the right flex can certainly make things a lot better for comfort and handling. Clamps are perhaps the largest change you can make in terms of stiffness changes on the bike. That change will vary significantly by who made the clamps you're using, though, and won't necessarily be a good thing... 

Another part is Fork tube flex could be a major part of this too.

Everything flexes to some extent. Fork tubes are a big part of that, but there aren't many options for swapping those out for tuning. Here's an old blog post about that: https://www.luxonmx.com/blog-luxon-fork-tube-stiffness-flex.html 

Frames also use the motors for part of the frames bracing and strength and I see some are completely removing motor mounts so the frame actually flexes more. Is this transferring a load in one area of the frame that is now a place that will eventually fail and crack?

Possibly. That depends on a lot of factors, and will vary bike by bike, so I can't give a blanket answer for all situations. I wouldn't recommend removing any engine mounts entirely, and it likely wouldn't be a good result for handling anyways. Aftermarket mounts with a hole in them have more of a mental effect than a physical one. They flex more, but not much more at all. Doubling the flex of something that hardly flexed to begin with doesn't do much! We have rubber isolated engine mounts coming out that are a different story. There's enough give to actually feel a difference and remove some vibration, but it still provides the structural support the frame needs and maintains precision in handling. 

I believe Yamaha has been developing an active rear suspension system, it actually changes damping when the rear brakes are applied. This allows the rear of the bike to settle instead of hopping in braking bumps. Really quite ingenius!

That doesn't sell new bikes though. All these OEMs are pretty much always going to be NEWER, FASTER, BETTER! 

Yamaha has already done that for a short period on production bikes with a cable going to the shock from the rear brake pedal along with Z spokes 

Yes - BASS - that was my obscure sarcastic joke, sorry! 

I feel like we are getting to a point where we're trying to get the engine and chassis work in unison where I gotta wonder if they're trying to optimally align crankshaft vs output shaft to have a certain affect on the chassis under load etc etc. With todays technology can we drastically alter bore / stroke and make power in a different way to reduce rotating mass and affect the chassis in a particular manner? Puff puff, pass...

Since Suzuki dropped the first cartridge forks and FI, I'll be keeping an eye on those upcoming releases from the yellow squad.

On a serious note, Honda does sell the high end version of the Africa Twin with active suspension. I can't imagine their engineers not wanting to try it on the smaller CRF's.

Whatever there doing to the 450,s it’s not working , except for the Hondas in the nationals. I see backends constantly swamping & kicking left & rt but not real quick.  Watch a 91 500 national even Bradshaw,s yz490 didn’t kick & swamp . And he ride that bike hard & was the fastest at some tracks. 

More like an impossible wish but:serious weight loss without breakage and costs going wild.Like I said,wishful thinking but would be so great.

Yep, I've been saying for years that a destroked 450 (400cc) would make it a touch slower but would lap quicker & safer.

The ZX Moto has a slipper clutch as well.

We have electronic suspension already (for the fork at least) through Dal Soggio's NXTRAX kit. I got to see it first hand on Clayton Gerstners beta at the Scot Harden Idaho ride, I cant believe people aren't talking about it more! 

The thing I want to see chassis development wise are reach and angle adjustable headsets/headtubes like the mtb industry. This is the single biggest change I think mfg's can make to have their bikes fit a wider range of people comfortably and I know I would personally benefit from like another degree and a half of angle on my ktm and its the only thing I hate about the bike and there's not really anything I can do about it. But on my mtb I can spend a hundo and an hour of my time and totally change the handling of it. Mind blowing stuff. On that note every bike should be coming with adjustable peg mounts like the Kawi or perhaps an even better system and a better more adjustable handlebar mount interface stock. 

The headset thing has been done in pre-pro testing by ktm so there's no reason we cant have it on a production bike:

On the topic of slipper clutches; I ran a recluse auto clutch on my Yamaha 450fx to help specifically with off-throttle front end dive and it totally helped transform the way that bike worked. If the Honda clutch works to combat that in its own way it'll be a big asset on a 450

I think Honda had the cartridge fork back in 86, did you mean production twin chamber fork? 

Slipper clutches have been used on road motorcycles for over 30 years, so not exactly cutting edge technology. I wonder why OEMs would suddenly be interested in using it for their dirt bikes?

The immediate future is variable valve timing, which is what Ducati is doing.  Theirs is similar to VVTI system in the Toyota where the gear on the end of each cam has 15-20 degrees of rotation so it can advance and retard valve timing dependent on RPM and engine load.  The Japanese are probably working on it already. When Ducati signs a serious top flight guy, the rest of the competition will notice the performance advantage.  

The next thing after that will be ride by wire. The throttle will still have a cable. The cable will run down to the front of the frame somewhere, and terminate in a hall sensor contained in a housing. Then 3 wires will run from that hall sensor housing into the ECU which will actuate a servo attached to the side of the throttlebody. So, the throttle housing on your handlebars won't look much  different.  Your throttle cable will just be a shorty to reach the sensor, wherever they decide to mount the sensor.

Combine those two technologies and what you'll find on a dyno chart is a torque curve that jumps straight up around 2000rpms, flattens out and stays flat to red line. 

Yeah it's interesting. I have a 3rd-Gen R6 which has a slipper but no electronics. You still have to rev-match on downshifts to keep the rear from hopping. The slipper, alone wont prevent that. I might keep it from locking up but that's about it. I feel like on some of the newest bikes with the full electronics, a quickshifter with an autoblip for downshifts, does a lot more in that area than a slipper would. I'm not sure if that would transfer over to dirt very well though. There is so much difference between the 2 disciplines and riding techniques, that sometimes a feature being really good at 1, doesn't mean it will work on the other. But I'm just a regular guy that rides, not an engineer.

This is what they wheelie boys will want powered by Ai. 

KTM had slipper clutches 10y ago with Dungey on the factory bikes. Could buy Hinson aftermarket also. They went away from it.

You can already control engine braking with electronics, as on the KTM App. So I'm not sure if this is something Honda just puts on as gimmick. Why add more complexity to the engine, and weight if you can handle some of it using ECU tuning?

Companies - aftermarket - started coming out with Slipper Clutches very early in the  4 stroke take over years.

And, there's been a few models come with them. Mainly Supermoto models, but, as written earlier , there's been usage of them with ' Special Models '

And, of course, they were in use far earlier in Road Racing.

I think with the ever growing sophistication with EFI, a Lot can be done with that to ease engine breaking - I've had a go on mates bikes that have had settings to reduce engine breaking, and, have been impressed with it. Well, the whole 'multi setting' thing of modern EFI impresses me.

VVT - I Really expected - ages ago - the first VVT on a Dirt Bike would be on the "New RMZ Suzukis" . You know, what so many have wanted / fought for / fought against for (how many?) years now.

As their VVT on GSXRs was specifically developed to be purely mechanical - as Superbike Rules banned Electric modes of it, though, I have no idea if that rule still applies. It is pretty simple, and compact, as is the Ducati set up on some engines.

 I spend a few days a week surrounded by Ducatis, but have to say, I really haven't paid much attention to their VVT , shame on me, I guess. I tend to be playing with 2 valve AC engines, and Sport Sedan Chassis when I'm in that workshop. I do ogle my mates various  WSBK  spec Desmoquattros, Testastrettas,  Panigales, (both Twins and 4s) though - but, they are Well , WELL Past My Pay grade. 

I too believe that VVT is the future and is coming in some form, but you will get smashed on here due to "supercross whoops". Those teams can choose to use it or not but, Suzuki's design is genius and could really help smooth out power (if reliable). On a side note, the race tuned Panigale is the angriest, most pissed off motorcycle I have ever ridden.

Yamaha has got a few 150 cc(?) Watercooled, EFI'd, VVT Models.

Have had them for a fair few years. I've got to ride a few of them in Asia - and, in whatever 'style' of bike, they were an Absolute Hoot!

And these are entirely affordable little bikes. 

We have the YZF-R15Ms here in OZ with the VVT engines - it's great to see the youngsters in the Race Series set up for them going at it 'hammer and tongs'. 

Lucky little Blighters!

As for 'full house' Ducati V4S's and Rs (etc) :

First time I encountered them at a track day, a few years ago, while riding one of my mates fairly rapid 1198s, pinned down Eastern Creeks main straight ( about the Only time this Old Man 'pins' anything ) , A couple of V4s went past me like I was standing still.

My mate had warned me about them, thankfully, as, I think I would have had a bloody 'hearty' at how Violent it all was....... 🥵😁

I'm surprised that the Ride By Wire setup, in the way Goat of Lurkers has suggested, has not yet been put to use on some of the 'Special' 450s, at least.

electronic adjust on the fly suspension.  just like fox does for the raptors and side by sides.  factory bikes and eventually consumer bike will have suspension that gets soft in the bumps and goes to fmx stiffness over jumps.  its wild how good the big vehicles handle with shocks like that

I could see a hybrid electric/combustion engine working out well. Electric for torque, ICE for horsepower and powerband.

Does polishing intake ports (not adjusting their size, just polish) on a two-stroke really make that much more power? 

AFAIK Kawasaki are the only ones who have tried the hybrid route for their road bikes and so far the've failed to sell more than a handful of them, even though they've now cut the price in half.

Besides cost and maintenance, I can't see any benefits for a race bike: more complex systems, heavier and cumbersome (need to fit gas tank, battery, engine and motor in a 250-ish lbs package).

Electrics are already pretty competitive as is in SX, MX and Enduro. Hybrid might help them compete in long race format like Baja, Dakar and so on but then in this context I'm not sure what advantage hybrids would have over gas bikes ?

Electronic suspensions indeed could be a game changer and not just porting an innovation developed decades ago for road bikes. Might need a change of technical rules to be allowed in competition but could still be of great benefit for all kinds of riders.