MTB to motocross

I've ridden mtbs since I was ~12, started racing at 14, am 37 now. 

I picked up a YZ250 when I was 32 and started racing the next year. However, I was fully committed to the trail/woods/GNCC/WEBE/Hard enduro side of things, not the track. Every now and then I'd have to ride a track as part of a race, but its certainly not a focal point for me. 

Besides snowmobiling, which I also picked up as an adult, I had no moto experience prior to the yz250.

I'd say go for it, be careful, learn a lot, and know that its going to feel whacky as hell for the first 20 hours of engine time. If you can get to 40 hours on the bike, you'll start to really dig it, but then you need to keep site of what you don't know. Things happen fast on a moto!

 

I biked and dirtbiked as a kid till about 13. Then just mtb till 30 when I got a dirt bike again. Are you really interested in racing motocross on a track only or do you want a dirt bike for trail and maybe a little track riding? If you're thinking of trail riding much get a trail/enduro motorcycle not a moto race bike. I made that mistake. For example get a crf250x for trails not a crf250r. The hardest thing to adjust to a motorcycle coming from mtb is throttle control, clutch control as well. A trail/enduro motorcycle will have a broader more useable power band on the lower end and be a lot easier to learn on even on a track, a race bike has has no low rpm power and goes from no power to all the power within a seemingly narrow range of throttle input. So for slow tight trails and low traction situations this makes everything way more difficult. 

Any time is a good time to start riding motocross.  Sounds like you are on the right track with planning to get a lesson asap.  Technique is everything.  Whether you decide to stick with motocross or get into woods riding, I would highly recommend starting on a track.  The benefits of repeating obstacles and corners lap after lap is hard to beat.  You don’t have to send any jumps, just ride and focus on yourself.  It is a hell of a lot of fun, enjoy it!  Also check out AJ Catanzaro’s Moto Academy: 

https://club.themotoacademy.com/

I definitely wouldn’t classify myself as someone who motos.  Just a guy who occasionally hops on a friends bike whether it’s a pit bike or a 450.

biggest thing is safety and acknowledging your skill level.  There is a lot more to pay attention to than simply staying on your bike.  
 

also fitness is a real challenge.  Mtb will prepare you some especially if you are gym training for it.  But for me riding moto is way more taxing and I’m way more apt to make a mistake with throttle or clutch when I’m tired.

I have been riding MTB for 35 years with being most of the time focused on DH racing.  I only started to ride moto in my 40's few years ago. I'm riding trails, desert, and motocross track and even raced the baja1000. 
It's as much the same than it is different. Cornering, climbing technique, and throttle control are way different but line selection, jumping, and braking point (somewhat) are similar. It's also a similar headspace: riding the track feels like riding DH.
Riding trails (especially technical downhill) are exactly the same than MTB.  You'll quickly be comfortable.
I would definitely advise learning some techniques but then you'll be surprised at how fast you progress and how moto can also give you a new perspective on your mtb technique.
Riding a motocross track lap after laps can be really beneficial for your mtb technique just by the volume of hitting the same features over and over.
You might also realize how weak your upper body has been so far ;-)

Welcome to the dark side! I started in MX, so I can't give you the advice you're looking for. Just learn all you can and practice proper form. The rest will come in time. 
 

Honestly dude, if you are new to riding, a class won't help. Half of the stuff they will tell you won't really make sense until you get better. Just spin laps and have fun. I agree that the crossover from moto to downhill is a lot easier (which is what I've done). Have fun riding!

& I only say this because I have several friends who race pro moto and they've done classes with kids that have just started riding, and the things they tell them don't really stick, like form, positioning, etc. I feel that it's better just to spin laps and learn to get around the track consistently

Seat time. All about seat time.

I Rode an electric dirt bike the other day... IT WAS AWESOME - Ive done alot of cool things but that was sick as...Ive now just preorderd a Basic electric dirt bike.
Its been many many years since i rode a moto but man electric stuff is just so cool now.

I started riding MX a few years back, after years of MTB (mostly DH). The skills won't really transfer over, but it will be a lot of fun. Coming from mostly park riding the ratio of actual riding to time invested for the day is wayy better. Just learn the basics of bike handling in an appropriate area, don't hit a track straight away. After you have mastered stuff like clutch use, brakes use, throttle control, standing, you can begin progressing a bit. It will be very hard at the beginning but you'll pick it up quickly. After you feel comfortable riding off road for sure hire a trainer to teach you basic technique ( if you have the money). Remember speed come from proper technique, don't try to just go fast. other than that it's just seat time and having fun. One more advice: get your bike setup properly (sag and springs) for your weight, and other than regular maintenance do not skimp on brakes and tires. Use high quality brake pads and good tires (especially for the front, for the rear you can run an intermediate/longer lasting tire). Have fun!

Out of curiosity, which sport do you reckon is more expensive in terms of running costs, assuming you spend the same amount of time at the trails/track?

I know nothing about MX, so can only assume there is a constant fuel and track entry fee for most rides. That said my MTB running costs are pretty high lately with tyres and constant breaking/replacing components.

To the OP, any time is a good time to get into moto. I only started in my mid-30s; I'm 41 now. I only wish I had started younger. I ride trails/enduro since the only tracks around me are a long ass drive away. In general, the fitness and line choice skills from MTB helped a lot when I first got on the moto. Like others said, take your time, ride within your abilities and seat time, seat time, seat time! Now that I have a few years under my belt, I have found that the skills from each reinforce each other. I feel physically stronger after riding the moto a lot, it changes the sensation of speed, and when I go back to my 30 lb trail it feels incredibly light.

@Mugen I think the running costs are about the same once you get set up, assuming you are doing most of your own maintenance. That said, the barrier to entry for moto is even higher than MTB. I bought a well used but in good running shape KTM 250 XCW for about $3,000. But you need boots, a full face helmet, clothing, chest guard, knee guards, a stand, a ramp or rack to transport, tie downs, oil, air filters, tires, specialty tools, various lubes and cleaners... The list goes on. I tried to cheap out on some of that kind of stuff and it usually bit me in the ass. 

Riding techy trails you're inevitably going to drop the bike and break stuff and of course there are plenty of wear items. I probably spend $1,000-$2,000 per year on parts and maintenance depending on how much I'm riding.

I race moto and MTB. Moto is more expensive especially as you get faster. Don’t forget track fees, oil, gas, tires, chains sprockets, generally more gear, unless you live near a track there is the truck van etc transportation. When you are learning some things like brake pads will last you a long time, MTB tires are “almost” the same cost as moto tires but everything else is more on a moto bike.
Good thing is you really can’t ride moto everyday like you can a MTB, so the cost do get spread out depending on how often you ride. Not trying to discourage you in any way, moto is awesome “if” you have good riding opportunities near by. It is a lot more work tho, loading unloading, washing, maintaining the bike is a lot more work. I live in a moto rich area and ride my Moto once or twice a week, but I get burned out on the effort it takes, I love how easy the MTB is for sure. 
Let us know what bike you buy.

I would have to disagree with this. If you are an experienced MTB rider, you will have some habits that are not necessarily in line with the same technique you will want to have on a moto. Yes seat time is absolutely vital. But if you start getting comfortable on the bike but are doing it incorrectly, you are teaching yourself bad habits. Just my $0.02. I took a class after a few years and wish I had taken them sooner. 

No time is too late to get into the sport. I race off road moto and got into it in my early 30s. I had essentially no experience with motorcycles prior to it. It is super addictive. 

Advice: buy good gear! If you are gonna run knee braces, get em early so you are used to them. Buy good boots and a good helmet. 

These are really good points! Coming home from a long day of moto, the last thing I want to do is unload. Especially since I don't have a garage. I have to roll my bike and gear through 3 separate gates to get to my backyard where I keep everything. It probably takes 15-20 minutes to unload and that's if I'm just dumping everything in a pile to deal with the next day. 

I considered getting a 350 or 500 so I can ride to the trails and cut down on the loading/unloading time but that presents other issues like having to ride in sketchy Atlanta traffic. The dream would be to live out in the sticks somewhere with a barn and easy access to trails. 

On a tangent about moto cost: I can't remember where I heard this (might have been race broadcast) but I thought it was interesting. Some motorcross privateers on a tight budget, run in the 450 class even tho by ranking they could/should be in the 250. They do this because the lap times in 450 are only slightly faster than 250, but a 450 will be able to do that at lower rpm and less strain on the engine and thus less frequent valve adjustments and rebuilds. Less time and money in short. Might be more of a factor for heavier riders too. 

This reminded me: 5 or 6 years ago, when my wife and I first moved to the town we live now, we had a little apartment till we could find a house to buy or a better place to rent. I stored the moto just inside the backdoor in the laundry room, it blocked the back door and made getting into the washer and dryer a real pain. And it was two story building with the lower a half basement and our apartment was on the top. Stairs on the outside, so I had to lift/push it up ~10 stairs then lift around a sharp corner into the door. Stairs were wood and kinda weak, I didn't trust my throttle control enough to ride up without damage to them and/or me. so it was engine off and heave it up. Wasn't too bad if my wife was there to help. We were there for 6 months. I really appreciate how tolerant my wife is, and that that the landlord had a resilient sense of humor! 

That is totally true. It’s very expensive to build and maintain a fast modified 250f, and then only get 10 hours of run time out of it. But that’s only in elite level 250 pro stuff. Lots of professional 450 privateer bikes have stock motors. Modern four stroke moto bikes are very reliable with basic maintenance (air filters and oil)