Yo press-fit BB question

gradeAfailure

New member
I'm just about to send my Yo away for repaint but need some advice/info on the press-fit BB - I'll be getting some new bearings for it (probably from Rody), and was just wondering whether it would be better to mask off the BB shell, or to do as I'm doing with the head tube which is leave it unmasked and then have it reamed to the correct dimension? If the latter, what would be the dimension to have it reamed to?

Thanks!
 

mainlyfats

New member
I'm just about to send my Yo away for repaint but need some advice/info on the press-fit BB - I'll be getting some new bearings for it (probably from Rody), and was just wondering whether it would be better to mask off the BB shell, or to do as I'm doing with the head tube which is leave it unmasked and then have it reamed to the correct dimension? If the latter, what would be the dimension to have it reamed to?

Thanks!

You risk taking a chip of paint off the face of the BB if you mask, but it's what I've done in the past. I bet you could use the same facing tool on the headset and bb shell; never tried that though.

If you make the painter aware of the issue, he/she will find a solution that works.
 

jh4rt

New member
You risk taking a chip of paint off the face of the BB if you mask, but it's what I've done in the past. I bet you could use the same facing tool on the headset and bb shell; never tried that though.

If you make the painter aware of the issue, he/she will find a solution that works.

Just pressed my new bearings into my Yo this morning. There is a recess machined into the bottom bracket for the bearings, so you don't likely want to use a ream. On the other side of that, my original bearings had a groove machined into them, and a snap ring to keep the bearings from moving inward. Seems unnecessary to me. In any case, if you use the snap ring, it rides on the face of the BB. I ordered new bearings directly from Phil. They didn't have the machined groove and I pressed them in flush and installed the new spindle. No issues.

Fwiw.
 

rthomer

New member
Just pressed my new bearings into my Yo this morning. There is a recess machined into the bottom bracket for the bearings, so you don't likely want to use a ream. On the other side of that, my original bearings had a groove machined into them, and a snap ring to keep the bearings from moving inward. Seems unnecessary to me. In any case, if you use the snap ring, it rides on the face of the BB. I ordered new bearings directly from Phil. They didn't have the machined groove and I pressed them in flush and installed the new spindle. No issues.

Fwiw.

I just removed BB bearings from my Monster, they didn't have a snap ring, just pressed in. Curious as to which bearings you purchased from Phil, were they the new outboard bearings? If so what keeps the spindle from moving, my Monster had a collar, I don't see room for that on an outboard BB setup....or maybe I'm missing something here.
Thanks...Robert
 

mainlyfats

New member
Just pressed my new bearings into my Yo this morning. There is a recess machined into the bottom bracket for the bearings, so you don't likely want to use a ream. On the other side of that, my original bearings had a groove machined into them, and a snap ring to keep the bearings from moving inward. Seems unnecessary to me. In any case, if you use the snap ring, it rides on the face of the BB. I ordered new bearings directly from Phil. They didn't have the machined groove and I pressed them in flush and installed the new spindle. No issues.

Fwiw.

You are so right! I totally forgot about that little lip. What to do then? A wire brush on the end of a drill to get rid of excess paint?
 

jh4rt

New member
You are so right! I totally forgot about that little lip. What to do then? A wire brush on the end of a drill to get rid of excess paint?
i think I would mask it. Otherwise, yes, a wire brush, or light sanding, and then press them in...
 

jh4rt

New member
I just removed BB bearings from my Monster, they didn't have a snap ring, just pressed in. Curious as to which bearings you purchased from Phil, were they the new outboard bearings? If so what keeps the spindle from moving, my Monster had a collar, I don't see room for that on an outboard BB setup....or maybe I'm missing something here.
Thanks...Robert
The outboard bottom bracket is for use with a modern two piece crank.

I called them and told them exactly what I had, and they sent me the bearings, as if they knew exactly what they were doing. ;-) These same bearings were spec'd in merlins and Kleins for a while as well. They are standard industrial sealed bearings, btw. If you knew the number you can probably get them directly from King or other bearing house. But the spindle, well that's a different story.

I had to get a 123, even though my original was a 121. Going to put it all together in mock today and make sure I can get a good chainline. If not, I guess I can clean up and use the original spindle. Phil has the spindles as well..
 

gradeAfailure

New member
Cheers for the input guys - it's not going to be Rody painting it (wrong side of the pond!) but I'll most likely be getting the new bearings from him as I believe he supplies the correct ones with the snap-rings to prevent them being press-fitted too far into the frame. Looks like I'll just be masking off the BB shell where the bearings sit.

Thanks!
 
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