I only ride 9 on off-road. While @scrubski is on 8inch.
It’s like I am rolling on 40" tires and he is on 33" lol
I personally don’t ride 9 inch on the road, super heavy… And I have street board for that.
If someone is trying to only goes offroading, I’d recommend go for 9inch, otherwise, not worth it for road use.
Thanks so much for writing your review and starting this thread! It is a great resource and should help out many people in the future 
9" for the win!
if your hitting trails that is.
my local trails are full of tree roots and stones and i smash straight over them, my mate following on 8’s not so much and i’m always waiting for him. So much so that we’re changing his ride over to 9" tomorrow.
Also you get a much smoother ride on the dirt tracks and pavement.
I have found some in the past, but don’t remember where I posted them
I had this ones saved on AliExpress, but no one similar to the MBS ones unfortunately
US $6.17 5％ Off | High Quality Electric Gasoline Scooter with 11-inch Road Tyre 300-4 Tube Tyre 3.00-4 Tyre Inner Tube
US $28.40 39％ Off | Mini Moto Quad Tyre Tire 3.00-4 Tyre 9x3.5-4 4" 4 Inch Inner Tube Mobility TA
US $6.67 18％ Off | 2.80/2.50-4Tire with Inner Tube 2.80/2.50-4 fits Gas / Electric Scooter ATV Elderly Mobility Scooter Motorcycles bikecle
US $14.24 5％ Off | High quality the front 4.10-6 inch tire of Bull Beach Car Parts Thickened Vacuum tyre
In general my favourite setup is 9" on the rear and 8" on the front. keeping the 8" on the front makes the board more nimble than when you slam 9" all around. This setup is a great compromise for all type of riding.
8" or even 7" on all wheels definitely is better for pure on road use, but they greatly limits what you can actually do off the road.
Overall though i have to say that the 10" tyres all around really ruined both 9 an 8" for me. Those fookers just go over stuff like it aint there. They sure make the board heavy and clumpsy but shit is it hilarious to surf over whatever the heck you want! I tried to put the smaller tyres back on the board but when out riding i found myself constantly wanting to hit those gnarly forest paths that only them BIG boys can handle. Always in the back of my head "why did i change back to theese peasant rubber infants.
I really need to get that 1:6,25 ratio instead of my current 1:5 while using the 10" though. it currently tops out at 75kph which obviously takes a huge crap on my low RPM torque.
All the big Aliexpress tires are very expensive IMO.
MBS T2 tires are made for MTB and the price is reasonable.
I can imagine but if you think 10" is enough then you have to try 11" 
This is definitely by far the most wicked board I’ve ever ridden, the 4wd heavy duty offroad monster of @Duffman 
It’s like a tractor, unstoppable! I scratched both shims from riding through bushes, that was fun!
Haha yeah mate for sure, i tried this board down in Paris last year aswell. It’s a off-roading machine out of this world!
What’s your current motor and battery amp settings and which motors?
I guess that you can always just keep on going bigger with the wheels, at some point though you have to compensate for those fat wheels by changing gearing. My board like most of our mountainboards is really built for 8" tyres in mind. With 180KV motors and 1:5 gearing in my case. never thought i would be doing real off-roading, not trail riding but actuall real off-roading. I am able to do this quite well with my 2wd board and 10" tyres. Not like Peter’s insanity tractor but still 
usually got the system set at 120 motor amps and 80 battery amps.
sometimes i do turn it up to 140 motor amps and 90 battery amps but that makes the motors run quite hot so i try to avoid it.
Ok 
then higher gearing as you said
Indeed. the hazzle of gear drives is to change gearing though. so basicly a 1:6,25 gearing would make my 8" tyres useless getting a top speed of 40kph. that means i’d have to change the motor gears every time i change wheel size 
My opinion is very close to that of Seabjorn
My setup is as follows (so you can judge it):
PRO: Comfort in off-road even on more difficult routes, with superficial roots and holes. Less rolling resistance. Less torque, but easier to manage.
CONS: Just say that each tyre weighs about 800gr. So you can forget about agile driving with fast jumps and accelerations.
Damn you slam 110 amps in those motors without overheating them? In that case, why in the hell do I use 80100 motors 
Maybe because the sk3 has lower 149kv than 80100?
I don’t know!
Shipping kills it for me, it’s like double the price of 4 tires last time I talked to them
Nah that’s not it, generally a higher KV motor of the same size can handle some.more amps.
Very impressed that your sk3’s can handle that. I tried 100A on my old 6384 130kv APS motors, they didn’t like it to much.
Anyways sorry for derailing, topic was about rubber and not motors
@ixf Did you ever get an answer to this, or does anyone else know? I want to pick up a set of MBS 9" tires, but if I can save some $$ and use 8" tubes, that would be super.
I rode with 8 inch tubes in my 9 inch tires for a few days and didn’t have any issues… Who knows long term though. I didn’t put them through rough use during that time, and I feel much more comfortable about using 9 inch tubes long term.
I ponied up for 9inch tubes. I eyeballed them and i think the inner diameter was different. Since i use 3ds hubs that wont work for me. I can see them working for trampa or 5star though but again, you’ll be stretching the tube pretty thin as you inflat them, probably not the best
FYI, for those looking for 9" tubes but not wanting to pay $13+shipping from MBS.
These shipped via DHL and got to me in like 10 days or less (don’t exactly remember, but was surprised by their promptness).
