How does amateur racing in Europe work ?

Depends on the country.

But one thing is common for all countries, we have no such thing as a supermini class. 85cc 2-stroke/150cc 4-stroke is the top mini bike class. Once you age out or are too good you'll jump up to a 125 (a tiny minority straight to a 250F).

In Italy we have the following classes (ages may vary slightly):

65 Debuttanti/Junior (8-9)

65 Cadetti/Senior (9-11)

85 Junior (10-12)

85 Senior (12-14)

Superminis are not a thing here.

125 Junior (13-17)

When it comes to the Junior Italian championships there are area qualifiers (2/3 rounds) and then finals (4 rounds). Two motos for each class and moto duration ranges from 10 to 20 minutes + 2 laps.

We have also regional championships: same classes, motos are just a little shorter.

Super mini is not a thing in europe, we ride small or big wheel 85’s and instead of super minis that just cost a shit ton of money to build the kids jump up on 125’s instead.

we don’t have stock and mod classes like you have, we allow tuning.

65cc 7-11

85cc 12-16

125 youth 14-17 

Here in Sweden.

the race length is often two 15 or 20min +2 lap heats.

Our national championships is often a series with 4-6 races and not one weekend like Lorrettas in the US.

Auto 6-8

65 8-10

85SW 11-13

85 BW 13-15

125 / 250 F 15 + 

There are some organisations that are slightly different, but that is it.

No stock classes, loads less classes in general, and nobody races 2 classes. 

So many championships now that nobody knows who the fast guys really are, bar for a few stand outs. 

Here is what we have for France 

2/4 temps is 2/4 strokes then you can see cc numbers.

You can start racing Minivert (50, 65, 85 cc, 6 to 13 years old in various categories, 8 min + 1 lap for 50cc, 15 min + 1 lap for 65 and 85cc), then jump to Espoirs (66-85 cc, 20 min + 2 laps) and finally Junior (125 cc, 25 min + 2 laps).

Then amateurs can go National 125 (2 strokes), National 250 (125 2 strokes from 13 years old and 250 4 strokes from 15 years old), National 450 (up to 500 2 strokes, 650 4 strokes).

National races are 25 min + 1 lap, regional is usually shorter.

Plus a ton of other championships like sidecar cross, old bikes (MX à l'ancienne), old dudes (Veteran), hill climb (montée impossible), Supermoto...

We have trial, enduro, sand races...

In France Minivert, 50cc is stock, 10" or 12" front, 10" rear, 65 and 85cc can be modified without changing capacity, 12" rear for 65cc, 14" or 16" rear for 85cc, do what you want with the rest.

2 days schedule is tight, 6-7 rounds a year, AFAIK race time is respected.

Here in sweden the motos never gets shortened. 

The kids on stock bikes do okay, it's always about the rider, and people that belive otherwise should check out Carson Browns video where he race a ktm super mini against one of your best super mini riders and beat him on the lap time. The power to weight ratio that Carson had compared to that kid should be like Brown riding a stock bike.

I belive that free tuning in youth classes cause more bad than good. Parents buy expensive parts and don't know how to set the bike up just makes it harder to ride and more prone to brakedown.

When i rode 85's in the early 2000's the only tuning that was allowed on the youth bikes in sweden was a exhaust and cdi change. But many parets cheated and instead of DQ the riders SVEMO (our AMA) let tuning free in the classes since they could not handle to prevent it.

Kids dont need tuned engines and this sport is expensive enough as it is.

I wish we would have legit GNCC racing here on a local level. Or local races on club level coming back for people as a starting point for racing. Lowest level is still a whole day at a track with about 40 minutes of riding for 50s.

We can get more bike time within a three hour practice period.

i think it is important to explain that in Europe there is no distinction of amature or pro races, all races are like open sport, there are levels of races that go from local league, to national championship, to internationals.....in most countries in europe the youth  classes (50,65,85), usually race the same day and track as the open classes (125jr,mx2,mx1), in the big countries 125jr has its own race, but in the smaller ones it races the open mx2 class..

a normal kid will start racing his local league races in his age group class, then stepping up to his national championship races, mostly racing in the same day and track as local open classes, or national open classes. Then if he is good enough and well backed, he can go internacional, and there are a few inter races and inter series around europe to race, with the big goals being the worldjunior race in the end of the year and the emx series. This allows the good kids from 65s up, to race for national and world titles every year, giving them a lot of high tension moments and big track experience since very young 

because all classes are open, for rider and for bike, and there is no superminis, a kid at 14 years old can race the mx2 open class of its country national championship, if he qualifies for it, which in some countries it is very high level racing....

all this combined, and the under23 rule in mx2, makes for a constant search for new talent from the main mx2 teams, their youth programes are getting bigger, ending up in a constant flow  of a bunch of kids, not only fast but well prepared and experienced, that get a chance to prove themselves at highest level .......

In Aragon, Spain. Amateur, all classes in one day, 11 races this season
sorry for putting it in spanish