k series wheel bearings

[GS1168]

ive got a k8 5.5" wheel for my 92 7/11.  just wondering what wheel bearings u guys have used for this to get down to 20mm.  the only ones ive found are open style.  the factory k8 bearings are sealed and the slingy bearings are shielded.  running open bearings ok?  worried about possibility of grease sling onto tire.  or should i just make a sleeve/spacer and use the k8 bearings

[Joseph]

Only bearings i found with 20 ID are slightly slimmer and non sealed.

Sprocket side is not really a problem, since it is shielded by the sprocket carrier.

Disc side you just need to use an appropriate sized seal.

Done this on two bikes, i found that the bearings don't last as long but it's hardly an expense and if no sealed options are available it's the best that can be done

 

[clivegto]

I found some 20mm sealed ones but there 3mm thicker which isn't a problem really just need to make a new spacer for inside the sprocket carrier and an appropriate wheel spacer for the disc side not forgetting a new spacor for the outside of the sprocket carrier. It's in my 10/4 Si project. 

Edited April 28, 2022 by clivegto

[wraith]

You could keep the standard bearings in, make a sleeve to go through the standard wheel bearings to reduce the size down to 20mm.

[bluedog59]

A perfect opportunity to make up some captive spacers and make wheel changing a whole lot easier, or measure the o/d of the bearing and I'll look in my bearing catalogue and tell you what sizes are available.

[GS1168]

they would be 20x52x12.  i found a pair of correct size bearings but they are open style.  i would prefer the bearing swap but may end up doing the spacer/sleeve.  i just cant find any sealed bearings in that size

(factory k8 is 28x52x12)

[clivegto]

Could have a go at making some seals for the bearings. 

[bluedog59]

According to my SKF bearing book ( which is a few years old ) you can get

25x52x15 ( bearing number 6205 )

20x52x15 ( bearing number 6304 )

There is nothing listed for 28x52x12. ?

The 4 digit number denotes the bearing size. If there is a Z after the number it means it has a metal seal, 2Z or ZZ means 2 metal seals. RS means rubber seal, 2RS means 2 rubber seals and nothing after the number means an open bearing. A quick Google search does bring up a 20 X 52 X 12 but they are silly expensive. Given all this, I would stick with the stock bearings and make some captive spacers. Wheel now fits the spindle and the spacers don't fall out and roll out of reach when you're trying to get the wheel back in.

[GS1168]

thanks, appreciate the info.  looks like i have more lathe work to do

[clivegto]

16 hours ago, bluedog59 said:

 

20x52x15 ( bearing number 6304 )

 

These are the ones I used.