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Steering Head Bearing Cup and Cone

A_HRD

Well Known and Active Website User
VOC Member
Hopefully this is a problem associated with my trying to use spares which I bought new years back - some from VOCSC and some from Terry Prince. But I was frustrated to note that of 3 different unused sets of steering head bearing races on the shelf, all of them were unusable due to radial slackness in the races with new balls fitted. Quite by coincidence, I have a copy of a very old VOCSC drawing giving the internal ground radius as 9/64 - I wonder who stipulated that and why?!

Has anyone else noted this problem in the past, and are new sets free from this problem?

I know, I know! Go the taper-roller route and stop fretting..... But my question still stands.

Regards,

Peter B
Bristol, UK.
 

nkt267

Well Known and Active Website User
VOC Member
I had the same problems about 8 years ago when I rebuilt a Comet for a relative.I kept tightening the races to no avail,then thought the races were slack in the headstock.I finally put a set of secondhand original ones in and they are still there.John
 

John Appleton

Well Known and Active Website User
VOC Member
A_HRD;116 Has anyone else noted this problem in the past said:
I am interested in this 9/64 dimension. Some years ago I fitted a set of spares company bearings and was never able to eliminate the side play. on checking the componants I found that I had been supplied with 6mm balls, which did not seem to fit in the tracks as they should. 1/4 balls made a big difference, but there was still noticeable play. Could it be that these replacement bearings should be fitted with 9/32 balls, or even 7mm balls?
This is all of passing interest as I am going for taper rollers over the winter, but I am sure there are others out there who would like to know what is going on.
John
 

Prosper Keating

Well Known and Active Website User
Non-VOC Member
The correct ball bearings are 1/4" or 6.35 mm. If there is still play in the new head races when correctly adjusted - in the vertical plane - and the balls are of the right dimensions, the head races themselves would seem to be wrongly sized. 9/32" equals about 7.15 mm. If these fit in the races you have, then use them but you should probably fit nineteen balls in each instead of the recommended twenty 1/4" ball bearings.

PK
 

Prosper Keating

Well Known and Active Website User
Non-VOC Member
An afterthought: check that the steering races are evenly machined and concentric in relation to one another. Assemble them in the headstock with a length of threaded bar, wide washers and nuts - the same 'tool' we use to pull 'female' races into place - nipping them up to nil clearance as they would be when adjusted for use, and turn them with a straight edge across each washer to make sure that they're machined straight. On the road at 80 mph or more is not the place to find out that your steering races are machined out-of-true. That could be really nasty.

My opinion: smash them to pieces with a 30lb hammer so nobody else can use them and buy properly made items or the taper rollers.

LOL!

P
 

A_HRD

Well Known and Active Website User
VOC Member
Partial Success

An update, for what its worth. I managed to get some high quality steel balls from my bearing supplier which were of 17/64th diameter. (They weren't cheap mind at 25p each). They fitted perfectly into 2 sets of my old-stock steering-head races - eliminating all sideplay without increasing the overall height of the assembly. But they were too big for the other pair which have been machined differently.

Also, worth a mention, I bought a cup and cone from Vinparts the other day (while they had their 10% discount :) ) and the quality of finish and the fit of the standard 1/4 balls was pure perfection, absolutely mint. Thanks Russell and Debbie.

Peter B
Bristol, UK.
 

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