New to Pneumatics: PSI and Balancing Questions

So I just got my pneumatics set up on some 3D printed hubs (PETG printed hot, no cooling fan, many walls, they are basically solid PETG). They feel great! I tried searching around a few times over the past few weeks and haven’t found any true direct/clear answers about this… I am a urethane skater born and raised and never even really delt with pumping bike tires so please don’t crucify me if these questions have obvious answers, cause it’s not obvious to me… lol.

Although I love the ride… I want to mess around with different PSI, and I am curious what is the most common recommended PSI? Also, what is a safe range for the 6x2in pneumatics? They say 70psi max on them, but this seems really high, as even 42psi feels pretty hard… I expected pneumatics to be even softer than this. Additionally, at 42psi the 6x2s take on a fairly rounded shape compared to their airless square-like contour. Is it safe to run these things maybe at like 20, or 30 psi instead? Besides some decreased fuel efficiency, are there any other dangers/downsides to doing this?

Finally, how about balancing? I know this is a thing, but is it usually necessary to balance your wheels? I notice mine wobble a bit, and I can play around with them a bit to get them to run more true, which helps a bit… But even if I just pop the tires on the hubs, air them up, let them be quite wobbly, the ride even up to 30mph feels smooth and without vibration… So, if the tires don’t exactly spin true unweighted but rode great otherwise, is this even an issue? Or should I shoot for having my tires spin perfectly true without vibration even when I’m just holding it off the ground?

Thanks for the help guys…

Welcome to Pneumatic s,

I will try to answer a few questions based on my 200x50mm experience. You can run different PSI based on what type of ride you want to experience… I have run between 35-70, obviously the lower is a softer more compliant ride great for off road conditions but if you want top speed and low tryre rollover the higher PSI is the way to go. the nice thing about pneumatic is you can play around with the PSI and tune to your preferred performance.

In my pesective is you can balance the tire by tighting and loosening bolts on rim to get it pretty good never had a problem once I got them running stright. I have not used wigths but someothers do opposite stem.

There are a few options considerations in tyre selection should be around: tread, PSI, compound and ply. You can find very good tyre and some very poor ones at the same time. My recommendation is to buy from a good brand car/motorcyclist company.

Good luck and let me know how things work out for you,



You can run with lowerpreasure no problem, but you trade it for a bit of speed and range for sure. I would advise to not go below 20 psi, at some point they will become unstable and have a higher risk for puncture. 30 psi is a very soft feel nice for extra grip.

Just mess around a bit and find the right values for your ride.

Balancing can be a thing, most of the time the valve is causing the major imbalance but it can also be the tyre or the hub which isn’t perfect. Over all it is more likely that your tyre isn’t all the way centered on the rim if you can not really feel the imbalance, this can happen very easily but you can also fix it really quick. Just reduce the preasure to a low level then try to adjust it while it’s on the axle, give it a little spin to check if you fixed it and pumb up to your disired preasure again.

In a perfect world they should spin basicly vibration free when they hit their max speed but 100% perfect balance whith at least 4 diffrent parts (tyre, tube, hub and pulley +bearings) that spin on one axle is not easy. If it botheres you cou can follow one of the dozen YT guides how to balance wheels you just need to figure out how to hold your small weights on the hub.

Just inflate it if you want it harder and deflate if you want it softer, theres nothing like a minimum limit or something, around 2.5 -3 bar is really nice for me but a bigger dude 90kg :smiley:

I would definitely balance your wheels, im yet to do mine but i have researched the weight of the valve its 9.1g without cap or added rubber, i intend on using around 30g of bike balancing weights and black tack/balancing putty in combined 10g amounts placed at 3 6 9 o’clock.

I’m a big ol heavy guy so I run 70 on street set up and 50 when I go off-road it’s perfectly safe for the tires and tubes now if a 3D printed hub can handle the pressure is another thing.

I used 7gram stick on wheel weights that are used on cars at the dealer I work at.

Yeah, been running 42 for a bit now and just started to notice the PETG I used is cracking a tad bit in a couple spots. Gonna have to give Nylon rims a try, and save the PETG for the core.

I don’t know about 3D printed but superstar rims can take 100 PSI, I’ve been running like that for 2 months with no sign of them being stressed.

I have a question about balancing beads. They’re essentially micro ball weights right? what’s the recommended weight to put in a 6 or 7 inch air tube? I bought a jar of micro glass balls (0.3 mm) to make transparent grip and I’ve got a lot left. Would that work as balancing beads or is it a bad idea?