Steering head/bearing cup inquiry

[tobydmv]

I'm never sure what to call these. In bicycle terms they are headset bearing cups. The morini parts manual calls them cap and cone. They hold the loose ball bearings around the triple tree stem. Mine are pitted after cleaning lots of rust off. They look to be hardened steel that was chrome plated. What do you guys recommend I do with these? Is there a tapered roller conversion out there? I really hate loose ball bearings in this application. Send the cups off for chrome plating? Plating has become insanely expensive in the states. I'm waiting to hear back from Herdan about NOS.

Thanks,
Toby

[Steve Brown]

Hi Toby, cup and cone is the English description, as you said. They aren't chromed but a hardened bearing surface like in other regular bearings. The good news is they may be recoverable. EV Guru did a few videos about recommissioning the club Strada, and one has a few pics of the steering head races/cups/cones showing the bearing surfaces. They can look pitted but in fact are only lightly marked and simply replacing them in a different position with fresh grease and new balls can be all that is needed. If they are a bit too 'notchy' then they can be cleaned up by a little (accurate and very skilled) grinding. The hardness is only on the outer skin of the material and a very light grind can sometimes be enough to repair the races.

This is all a bit unnecessary if you can find new parts, but last time I tried in UK nobody owned up to having them in stock.

Taper roller conversions have been available but I don't know who does them now. NLM would be the first to call. Mine are taper rollers but as soon as I can find a good set of original cups/cones I will go back to them. With taper rollers the yokes end up spaced further apart and while it seems to work fine I don't like the look of the old clamp marks on the stanchions I am getting very fussy in my old age. If you ditch your old cups/cones send them to me please!

[tobydmv]

Well I dont want them to rust again. Should I sand lightly with some 600 and then clear coat? Or maybe just paint them black....

[EVguru]

Quite a few modern bikes have gone back to cup and cone. Taper rollers are just too rigid and create too much drag on the steering. My Gilera CX125 has taper bearings and the steering is almost impossible to get perfect, you either get a slight chatter, or a slight low speed weave.

When looking at a conversion, you have to consider if the bearing housing is suitable. Verlicchi would have taken a machined tube and then welded it into the frame, which inevitably causes some distortion. Taper bearings need to be aligned much more accurately.

If the bearing surfaces are OK, then I'd highly recommend keeping them and fitting a new set of 1/4" balls. Mild damage can be cleaned up and there's a trick used by the vintage, vetteran and pioneer motorcycle rebuilders. Mount the cup or cone in a lathe, round over the end of a wooden dowel of suitable diameter and load it up with valve grinding paste. Spin the dowel in the bearing track whilst revolving the cup or cone. A power drill is ideal for the job.

The original setup was good for 30-40 years and in good condition will serve for 30-40 more. Most owners would be dead before seeing any benefit from a 'longer lasting' taper conversion.

If stuck without a usable set of cup and cone, I'd go for sealed deep groove or angular contact bearings rather than taper.

For the cosmetic outer surfaces, just paint or powdercoat.