Since it appears that there are some real issues with the core quality on these wheels, please make an informed decision on whether or not you decide to buy/ride them. More information can be found here at the tail end of this thread:
The riders affected have reached out to iWonder with good results, so we may see an actual solution from them. Hopefully it’s a switch to a Kegel core or a big leap in core design of some kind.
Looks to me like a cheap core.
Brittle plastic in a spongey wheel. If you have a very soft outer wheel then the core needs to also have some flex. When the wheel can move laterally around the core on corners then the bearing seats need to be able to deal with that movement.
Kegels for the win.
Only reason i have never even considered a set of foamies.
Could also be bad tolerance. The foamies are the tightest fitting bearing I’ve ever seen. On every set of 608 bearings I’ve tried that fits in other wheels with medium pressure, I’ve had to put all my weight on one bearing to pop it out. That’s a lot of expansion pressure the core is dealing with before it even gets weight on it.
The bearing and spacer set is the only solid in a wheel set up. Its absolutely fixed if correctly installed. The core being a softer material will move around this fixed point and i am talking laterally as in hard corners etc. The weaker the core and the softer and usually grippier thane will cause higher stress on said core. Lets not beat around the bush because these are cheap wheels and they use cheap materials so they can be cheap.
Hopefully they get it sorted though because its a really cool idea.