Below are two guides/links that will help to explain how to convert wheels to sealed bearings.
If you have a rear Puch flake then you need 16101ZZ (12x30×8) they are $$$ and can be found at firstname.lastname@example.org.
As an alternative you can use 6201 2RS and 16101 2RS bearings. These are bearings with a double rubber seal instead of metal shields. Compared to the ZZ, the 2RS bearings have an increase internal friction and a limited RPM range of 15.000 instead of 26.000. On the otherhand, 2RS bearings have a much greater ability to exclude water and retain grease. So, for low friction performance, go with the ZZ. For high durabilty and weather resistance, go with the 2RS. For more information: SKF
Remember that on front wheel conversions , you will have to drill the brake backing plate and the speedometer drive washer . Also note that on stock forks you will have to shave some metal from the edges of the inside of each fork. The 12mm axle will not fit between the fork tips. I have not tried this on aftermarket forks.
The length of the spacer required for the Puch snowflake rear is 75mm
Puch Grimeca 5 Star Wheel Conversion
Puch Leleu Spoked Wheel Conversion
Converting spoked wheels to sealed bearing.
Parts needed for converting spoked wheels:
- 180mm M12 bolt x1 + washer and lock nut
- 150mm M12 bolt x1 + washer and lock nut
- 6001zz sealed bearing x4 and .5mm shim stock
- Loctite 262
- .5" Nom. Aluminum Pipe
Tips for Installing Bearings and Shim Material
- Using the tip of a razor blade or a small file, put a chamfer on the edge where the bearing is going to go into.
- Wrap the shim around something about 1" in diameter, then put it on the bearing, making sure it fits tight all around and the ends don't overlap.
- Slide the shim about half way off the bearing, then gently start the shim into the wheel. You may need to use a small flathead screwdriver or two.
- Once the shim is started, apply a thin coat of loctite around the bearing and the shim. Tap the bearing down, only hitting the outer race. The shim should slowly tap down as well, until they're both flush with the surface of the hub.
- Once the first side is done, measure and cut the spacer (.5" ID) for between the two bearings, then install the 2nd bearing.
If you have Italian / Grimeca flakes you need : Bearings JAF 361201 (1235×10) and can be bought from email@example.com or here.
Please See Pictures to side titled Italian Mag Part 1,2,3.
The newer Tomos mags will already have the sealed bearings, however if you wanted to change over to the old super fly 5 star style mag which use the old loose bearing, you can actually use the stock size bearings from the new mags 6201z (1232×10) and can be found here or at treats.
I have found it best to use 12mm axles when possible on doing any sealed bearing conversion for the purpose of added strength. Tomos axles seem to work well for this and are easy to find.
Be sure to make the brake plate properly spaced out to avoid any rubbing of plate metal on rim metal, this will create dust /debris and will make your brakes work very poorly.