bearing size @ profile

hey unicyclists,

i’m searching for the measurings of the bearing’s which are used on the profile hub because of my selfmade frames. can someone give me the measures of the bearings ?


Profile uses a 99R12 bearing. it’s an american standard size, so if you’re in one of those evil metric unit possesed places finding one may be a bit troubling.

the bearings are 1 5/8" or 1.625" diameter

if your making bearing holders make them to these dimensions. any smaller will ruin the bearing any bigger will allow slop.

I can’t remember how wide the outer races are… if you can’t find it i’ll post again tomorrow.

i think this is near a 42mm metric bearing, not sure if they’re interchangeable though.

Felix -

The bearing used with Profile hubs is indeed an “inch series” with a generic designation of R12. For a double sealed bearing the dimensions are:

.750" inside diameter x 1.625" outside diameter x .4375" width

Be sure to post some pictures of your frame!

Steve Howard

While this is true for standard Profile hubs, it is possible to use 40mm OD bearings with them. For example, the KH20 and KH24 pro-series bearing housings have been made with both sizes; most recently with 40mm size.


hey thanks to you for the informations. now it is easier to build the frames :slight_smile: if they’re ready for selling, i’ll post some pictures of the frames…