Tire pressure for groms... looking to benchmark

That sounds great. I would say impart the wisdom and methods you’ve learned to him: go as low as you can until he’s pinging the rim. Add some air. Imagine being 90 pounds, EXO+ casings are probably like rally car tires to him!

for light riders, even a few psi too high is going to be super harsh and actually roll a lot slower so if you can get it nice and low it will make things a whole lot nicer for them. You're probably pretty close but if theres a safe-ish run you can try 2 psi lower and check for rolling/hitting the rim then it would be worth testing it.

dealing with similar question and always err towards the side of traction/grip at this point. like you're thinking, @sweaman22 tire roll on faster jump trails is always in the back of my mind.

here's a photo of a huck to flat and fake whoops section for fun - 26/24 EXO tires with my 70-pound son and 12psi front, 13psi rear. higher pressures had "it feels sketchy" responses on the trails. i guess it just shows kids will be putting down the forces just like adults will...even in crocs or running shoes 🤨

Pump up the tires to whatever pressure you think appropriate then have them push the tire into the corner of a board, sharp rock or root with their weight to see how much tire deflection they get. Do the same with your adult weight/pressure and compare notes. Similar to sspomer's last pic but static. 

around 20 regardless of kid weight and bike, more then 20 ~sucks, less then 20 requires meticulous  adjustments of not to low. 

I asked my buddy what he sets his kid's tire at.  He said:  1psi less than mine, so 18.5/21.5.  He runs EXO+, and just got back from a week+ trip to Whistler.  The boy is almost 10, and weighs about 90 lbs with gear.  I know that last summer they struggled with the kid flatting constantly at Northstar, switching to EXO+ from EXO and running higher pressure fixed it.  The kid races BMX too though, so even firm by MTB standards feels soft by comparison.

My 7 year old is 48” and weighs 53 lbs. he’s at 8 psi f&r on 20” DHF/ DHR2s. He could probably go 1 or 2 PSI lower and not have trouble. 

Their light weight is one consideration. Their aggression is the other. If they’re not strong enough to push into the tires/ ride high and light on the bike, they don’t need as much pressure. 

my 12 year old 110 pounds, runs 20 front and 22 rear for his trail bike with trail casing tires. Still destroys rims from time to time.


On his downhill bike, this is the result of 25psi , DHR2 , downhill casing and Tannus insert . Got 2 rides out of this rim. Last season at 100 pounds, only a couple minor dents , this year it’s getting expensive 

My 13 year old son weighs 105lbs. We run DH tires in the rear and lighter weight up front. 20psi rear and 18psi front seems to be the sweet spot for not blowing up wheels and having plenty of traction. Mostly ride in the Central Sierra, Central Coast of CA, and Mammoth. The only time I air them up higher is when he's riding after school with his buddies and bombing staircases at the high school

My 60lb 9yo is pretty aggressive, so he required 20psi front and 24psi rear in his 24” Maxxis EXO casings to keep from pinging on his park/dh race bike. On his XC race bike we were running 14/15psi. 

Now he’s on 27.5f/26r for DH racing and park, and we’ve been experimenting with 20psi front in an EXO+ and 22psi rear (albeit with a custom CushCore). No complaints of any over inflation symptoms.  Obviously, depending on the level of riding, the pressure demands will vary greatly. 

Online calculators should get you in the ballpark. Here's one:

https://axs.sram.com/guides/tire/pressure

I just played around with the Schwalbe tool, and that says my 13 year old son should be running 32psi in the back. Yikes.

I can't condone that - it's so bad I felt compelled to revoke the link.

The Wolf Tooth pressure calc is far more accurate than the SRAM or Schwalbe ones, especially if you use measured casing width and are honest about the trails you ride.