These are what I have and they are the hardest steel that is corrosion resistant and sealed, my machinists buddy picked them out for me because I don’t know metallurgy.
He warned me against the ceramic ones as the ceramic are not intended to be longer lasting or smoother rolling or even corrosion resistant as the races are often steel that isn’t corrosion resistant… but are meant to prevent electrical damage to the race in specific special cases where transient currents and high static can arc across all metal bearings and are only sold outside of this as a sort of idiot tax. Not my words but it made sense ymmv.
Some bearings just don’t like to be cracked on either. Just make sure there isn’t any movement on the axel and it should be okay as long as you have full contact between everything.
I forgot about the seismic options. They have been around for some time but I have never once actually seen the 10mm built-ins in stock anywhere. The website does have a spring 2023 availability date tho. I don’t trust ceramics as I think they are over priced and not worth the safety risk but the steel version cost $40 still. A bit steep for my blood, especially since I’d have to clean and grease out the box for better performance.
Take this advice, i had a bunch of 10.16mm spacers cut for me because i kept killing bearings and the problem evaporated, i had gotten some 10mm spacers from Amazon (bike axle parts i think) and the little bit of side load from being too short was making them blow out quick. Good luck
Boardnamics, doh, this will make a huge difference. I couldn’t find a good source of what the spacer should be and wrongly assumed a spacer sold for skateboards by a skateboard website would be correct. Do you have any spacers you could sell?
If not I guess I could use a 1.5mm and 0.1mm shim off McMaster to add to my incorrect 10mm long shim.
If the spacer is too large the bearing can slide in and out of the wheel on both sides as the bearing is not up against the stops in the wheel (one side will go in while the other pushes out). This could over time bore out the wheel and put weird loading on the bearing. I don’t know if 10.5mm is too big though?
I believe the bearing to bearing distance isn’t very precise on the Hollow Wheels due to the two piece core. When I’ve used them on 8mm axles, 0.400” spacers did not allow me to crank down the axle nut without affecting freespin.
I think 10.5mm will be fine for these wheels in particular, and I’m sure someone from Hoyt can chime in about the effects on other wheels. You make a good point that if the spacer is too large, it also puts stress on the bearings and the bores.
Okay digging into this some more. Another issue I found is the tolerance stackup becomes a real problem on a two part wheel (Momentum Hollow Wheels). Here are my two front wheels, they have a ~0.2mm difference which is not much but enough that I probably need to build a custom shim set for each wheel. To make things worse the bearing seat on the wheel is tapered so the gap is larger than what is measured. I will need to put a 22mm OD washer in to get an accurate measurement then minus out the thickness of the washer.
Hey, im the guy that ordered the BN M1’s for savage1 TKP’s recently, can i have a set of those 10.2mm spacers added into the order lol? Those would definitely be helpful.
A proper shim set between the bearings I think fixed it! Now when I tighten down the axle nut it does not affect the spin of the wheel. I had to build a custom shim set for each wheel as the tolerances were between 10.2mm and 10.5mm.
1) I used a bolt and some washers to create a bearing press that would put the force on the outer race of the bearing so I could really crank on the bearing to make sure it was fully seated before taking measurements. The inner bearings hollow wheels are tight
3dp spacers take a couple of minutes to design/print and have sorted me out every time.
