UKC

We got our 4yo his second pedal bike for xmas (or Santa did, perhaps!). A "real" one with gears. I was really pleased he took to the gears almost immediately and I think he gets that you need a low gear to go up hill and can go in a high gear to go down hill and fast etc.

Then on the third day he went down a curb, somehow wrong, fell off forwards and split the inside of his top lip. Thankfully no other injuries anywhere, and he was wearing a helmet. His hands were sore but not grazed or cut. I've bought him some bike gloves now.

I was just wondering what I can do to help him avoid this again in future... he and his friends had been dropping off the curbs for ages so it did seem to be a one-off, but I also think he got off pretty lightly considering the way he fell and I would hate for the same, or worse, to happen again. I saw him come off and think he just came down at a bit of an angle and the front wheel was turned to the side too much, so it flipped him off.

There used to be a bike shop near us that did children's MTB courses but they have closed down. The only other courses I could find from a quick Google were aimed at kids who could only *just* ride a pedal bike, he's way beyond that as was riding his old non-geared pedal bike for 2 years already.

Is it just that he will get used to it over time, or is there something I could actively do to help him improve and be safer? Any thoughts welcome!

I think you might be overthinking this. It just sounds like an unfortunate crash to me. He will probably just get back on the bike and learn naturally. 

Could you teach him yourself ?

Maybe invent some drills, use some small cones to guide his movement? Jumping off curbs today; turning tightly around a maze of cones/chalk lines; zooming up onto pavement from the road - too shallow an angle and front wheel can be knocked aside, and down he goes again ?

I've been doing this with my daughter: one skill per session and at the start of each succeeding session she has to demonstrate mastery of the previous skill learned. I kitted her out with skaters' elbow pads in addition to her usual helmet/mitts combo. And so far, so good.

I learned by doing, mucking about with friends during summer holidays - pre-MTB. My daughter can't do that - she's the only child on our street with a bicycle.

Good luck with it - it's both scary as hell watching them try, but very heart warming when they get it right and become more autonomous.

Where are you based ? There will be a British Cycling GoRide club nearby I guess, which would be able to help with qualified coaches, and riding with other kids around the same age. Ours starts around age 5, but contact the club and see what they do. 
 

Meanwhile I would suggest working on ‘cone of movement’. Play some games where they ride round, and you shout “Giraffe” and they have to stand up tall, then “low branch” and they have to duck under an imaginary tree. 

Pedal MTB in North Wales do their mini shredders for ages 5-9, usually run at Coed Brenin on the skills loops close to the cafe. BPW have a similar offering but I think that starts at 6 years old rather than 5.

Possibly not what you’re looking for, but if you want to avoid him going over the bars again in the short term, a simple cue we often use in MTBing is “drop your heels”.

Assuming you’re stood up, dropping your heels on the pedals and keeping a slight bend in your arms positions you more to the back of the bike and allows you to resist any forward momentum more easily. When you’re going downhill, off a low obstacle (e.g a kerb) or braking sharply it makes it easier to push against the pedals to support your body. 
 

Like others have said, maybe set up a few basic drills and incorporate things like going off kerbs, steering between obstacles, and coming to a sudden stop.

Think British Cycling website has a load of tips for 2-8 y/o, but link seems to be broken at the moment: https://www.britishcycling.org.uk/coaching/article/20200415-Children-and-Sc...

Trying to teach my daughter(s) to stand up when going over bumps - she's a bit older, but was a late starter riding bikes (preferred her scooter).

Did he shout "watch this!" just before the crash? You must teach him to never use that expression as it precedes a large proportion of childhood crashes

Were you based? My lad goes to biking on the bmx track at platt fields in Manchester and loves it. Has just graduated to a pedal bike and can go round the track straight away. He’s 3 and I’m well proud of him haha. 

He’s a four year old boy.  Evolution as pretty much ensured the only way he really learns his limits is through pain.  Just make sure he can’t cause more damage than he can heal and he’ll figure it out.  Focus on him developing confidence on ways a crash is not going to cause to much hurt and he’ll get there.