Are factory bike really that much better?

What separates is the resources to change just about anything you want to find that "feeling". No, you won't be faster on some random rider's factory bike (well, not 5 sec a lap). You'd certainly get faster if you had a team pouring money into your own bike and making it fit YOU.

Suspension setup will make the biggest difference. Just going from improper springs to correct springs and sag could be a night and day difference for you. Then you start tinkering from there...

Edit: Also, you're arguably on the best platform known for being great "out of the box". Your gains would be minimal on a personal factory version.

Andrew Short, and a few recent guys were very competitive. That said a lot more than the bike contributes to the advantage of being factory.

It is the countless options and ability to get whatever you need. Spring rates fork rebound any bar bend you need little adjustments. Basically a no stone unturned approach to get the bike perfect for you. Which inspires confidence and faster lap times.

You've never ridden aftermarket suspension?  Aftermarket suspension makes a huge difference.  

A couple years ago when I think it was Pat Foster rode Cooper's Star bike. He said that the average guy wouldn't be able to hop on that bike and do better than a nicely set up stock bike. Reason being, is the Factory bikes are meant to go the pace of the Factory rider. And the Factory bikes aren't in their sweet spot of performing, if the rider can't push it there. So that always put things into perspective, for me. So basically if you choose whatever bike model suits you best and tweak it a bit (suspension, maybe a few minor mods here and there) it will likely work better for most average speed riders, better than a highly modded Factory version would (for that rider.)

To build off of AH387, One thing I will always remember my dad telling me about his days testing with Yamaha was him and Dubach got to break in a bike for Bradshaw before the San Jose SX and how great it handled when you charged and rode it as hard as you possibly could, but if you even backed off a hair the handling went completely south because it wasn’t built to be ridden like that. 

I wrenched for a few different privateers, and been up close with plenty of factory bikes, and as mechanics we looked hard at those factory bikes.  Here is my take:  Aftermarket suspension is a night and day difference, however factory teams dont run aftermarket suspension, they run factory suspension!  They have multiple sets of suspension all tweaked and built differently, and those components are never available on the market.  I have seen rear suspension, linkages, swing arms that were completely different on factory bikes.    

I sure as hell couldn’t ride one of those bikes to their full potential anyways 

Dude don't pay attention to that. You could have the most positive thread in the world and it will get downvotes. It's just trolling, it doesn't matter. 

Treat yourself if possible. It's so worth it

National pass time.

I remember way back in the 90's one of the Cali suspension shops sent me back my (by accident) forks/shocks but somehow messed up and i ended up with Larry Brooks SX suspension. I'm a big man and was a State level Pro - not elite obviously......it almost comical. Worked good if i over jumped everything to flat LOL. It was unridable. Their SX set ups are basically built so they don't die lol

Bikes today have so much power and with Vortex etc even an amateur can tweak the motor etc.......but i have always been curious to know what a factory gearbox felt like. I'm pretty sure that's the only part of a modern MX bike that might help me these days  

Here's a couple of good breakdowns on Kenny's bike from Racer X and Vital:

Can we get some clarification on aftermarket suspension? By that do you mean a simple revalve or do you mean whole units purchased aftermarket?

I’d call stock with a revalve “tuned” or “modified” suspension. If you’ve never had anything other than bone stock, you are really missing out. A good revalve wakes the bike right up. 

IMO, back in before 2007 yes they were.

Not in 2023.

Suspension and power delivery are the biggest thing today, not the durability of the motorcycles.  Some factory riders hate their factory bikes (last year's KTM'S?) and sometimes prefer stock components.

My 24 KTM 450 puts out 61 Horsepower STOCK. the was unheard of just a few years a go.

 I can move that immense amount of power around to where the rider wants it with a Vortex, and get the suspension dialed for rider preference, and it can work for the highest level rider at the professional level.

Look to Colt Nichols and Shane McElrath racing bone stock bikes with a bit of personal tuning onto top 10 finishes.

Look at Ty riding a KX 450 with a stock motor and his suspension. 

Didn't Masterpool's bike throw a crank after 15 mins at Redbud?

At those speeds and RPMs, having perfectly balanced cranks, perfect rods etc is a big deal

I watched most of the KR bike tests. That was really cool that Suzuki did that. Aside from maybe some weird chassis balance preferences, the motor seemed to make the bike very smooth and rideable, according to most of the testers. That bike seemed pretty friendly for a Factory bike. But I suppose it falls in line w/ Kenny's riding style.

Suspension and comfort is the biggest key. Had two buddy’s. Both had 2018 YZ450s. One stock and One had poured tons of money with factory connection into his suspension. Rode them back to back and It wasn’t even close. So I can only imagine factory level. I’ve always been against aftermarket suspension. Thought it was a waste till that day. I felt like I could push way past my comfort zone had I had better fitness on the factory connection bike. Note I suck at feeling a bike out but it was so much better. 

Alex Ray said it was a huge difference. He got a short stint on a factory Yamaha and went from barely scoring national points to finishing right outside the top ten (11th one moto at High Point). For the average guy it may be worse on a factory bike, but for a pro they could use it.

The ability to personalize the rider triangle so perfectly, the ability to change the characteristics of the bike and to dial it in very precisely. Plus you have better brakes, electronics, cooling systems, etc. 
 

 But the biggest advantage is the support. You can wear out endless bikes, you can properly train, you fly to the races, and you have a great support system at all the races. 

With regards to suspension revalves…most of my revalves I couldn’t even tell a bit of difference. So now unless the stock stuff is just way off…I just do correct springs, and adjust sag and ride on the stock stuff.  So many revalve shops (particularly small local shops) are snake oil salesmen…

Now, I rode some WP cone valves/trax shock (I think it was called) once…set up for a rider of my same build and riding ability…those were sweet!  I could tell a definite difference on those.  

Suspension is the most important part of the entire motorcycle. From C rider to factory racer it. It changes every characteristic of how a bike handles. I've had bikes that were setup correctly that made the bike feel like a completely different bike from stock in a good way and I've had the opposite. Some bikes require alot more setup changes from stock and some are pretty good stock depending on your weight and speed. I would rather ride a 10 year old stock bike with correct suspension than a brand new 450 with suspension that is not setup correctly. 

I did gold valves in my YZ KYB stuff with some internal parts and it is night and day and day and day and day better. It's not perfect but now I can ride my bike to my potential and that's huge. It also made the fat feeling YZ250 corner like no other. It's a sharp bike now. I think it's natural to think theres some secret unobtainium inside pro bikes but its the exact same stuff we use in different sizes, different coatings, and most importantly, thousands of hours and millions of dollars in R&D to make it what it is. You can spend all your money on trick bits but the "trick bits" installed in jett lawrences forks are actually just decades of research.

They will have secondary damping and spring perches, bottoming cups and cones, but you can buy some yourself too. I run SDi spring perches personally. 

I think this is one of those things where quality converges and the advantage is greatest for the best riders, with it making less difference as you go down the talent level. 

Even if they cannot put it well into words, the top riders at speeds most even sharing the gate don't have just seem to be more innately sensitive to the sort of refinements available.

I’m 100% confident that a stock 23’ YZF/KX/SXF is light years better than a factory 2007 KX250F

Yep, not even close