Fork steering lower cup

[gizmo]

Any suggestions on who's are best fit at present. Last couple I've had have been borderline too tight. NOS ones are still available as an option

[gaz_powell]

Just bought a full kit from AF, not tried it yet..... Hoping all okay, be a while before it goes together.

Same kit on my last SIL frame and no problems on that... But that was a while ago

[bookertmgs1]

I bought a scootopia one last year & had to get it turned down by a local engineering place

Thankfully I'd kept the original so I had a reference to compare against once I'd discovered it didnt fit.

School boy error on my part not measuring before i attempted to fit it - should have know better that the chances of it being right were slim.

[gizmo]

I bought a scootopia one last year & had to get it turned down by a local engineering place

Thankfully I'd kept the original so I had a reference to compare against once I'd discovered it didnt fit.

School boy error on my part not measuring before i attempted to fit it - should have know better that the chances of it being right were slim.

I would be surprised if all frames are the exact same diameter so we are all on a loser to start with. I noticed allstyles do a re- machined one for a better fit. Might plump for a nos one

[Lord-Spanner]

I tried cheap and nasty first (big mistake), seemed to be way to tight to start with so canned them and bought a new old stock full race kit

[gizmo]

I tried cheap and nasty first (big mistake), seemed to be way to tight to start with so canned them and bought a new old stock full race kit

Just done same. Plus the bottom cup is the shallower depth not like most of the remade higher type

[Fast n Furious]

The nominal diameter of the bearing cup spiggot is 42mm.
There are minor differences in fork tube diameters depending on where and when the frame was made! There are also minor differences in the spiggot diameters of replacement bearing cups.
Almost always I find it necessary to skim the spiggot down in the lathe so that it fits easily using a lump hammer and a block of wood along with some loctite bearing fit. It's quite rare to find a replacement cup that fits "off the shelf" in my experience.
You don't need to use any heat. Freezing the cup before fitting does help, but not much.
If the fit is too tight, you risk splitting the fork tube by forcing it in and it also makes it a bastard to remove again.

[gizmo]

The nominal diameter of the bearing cup spiggot is 42mm.
There are minor differences in fork tube diameters depending on where and when the frame was made! There are also minor differences in the spiggot diameters of replacement bearing cups.
Almost always I find it necessary to skim the spiggot down in the lathe so that it fits easily using a lump hammer and a block of wood along with some loctite bearing fit. It's quite rare to find a replacement cup that fits "off the shelf" in my experience.
You don't need to use any heat. Freezing the cup before fitting does help, but not much.
If the fit is too tight, you risk splitting the fork tube by forcing it in and it also makes it a bastard to remove again.

Sound advice