I have a 18 inch rear wheel that is 4 inch wide. I can't find what bearings fit as the bearings I've ordered only fit in the 3.5 inch rim I have. I want the 4 inch rim as Ive just had it resprayed 

 

Any help on what bearings is much appreciated 

 

Regards 

Dan

Most bearings have the size inscribed on the outer race face edge, you should be able to read the size from there..! Are these non standard wheels then? Or are they an up-grade from the original bike? If they are an up-grade what bike did they belong to originally?

your looking for a code something like 6220rs measure the outer race and the spindle for a size and cross reference that way.

 

don't forget there's usually a mushroom spacer that fits inside the sprocket carrier bearing (on the inside) and peeps throw that away with the bearing. and yes you need it as one bike I serviced for a friend had it missing and the bearing was about to fail

Thanks alot. I got the new bearings. 

It was originally fitted with a 3.5 inch 3he rear wheel but has had a 4.0 inch 3he rear wheel.

Thanks again