AMC steering head question

[antoni]

My G3LS had 'self centring steering syndrome'.

The ball bearings look OK - not oval but I've got new ones anyway. The races themselves look like Friday afternoon jobs, turning marks evident even on some of the bearing surfaces. The races have slight indentations on the most stressed areas where the balls were while driving straight-ahead.  I'm too tight to buy new ones which might turn out to be made of Chinese chocolate anyway.

So swapping top and bottom and rotating through 180 degrees seems in order. Just disturbing their positions would have helped as that unsynchronises the indentations top and bottom of the same race.

Can't see how to get the bottom yoke race off, I haven't tried the top yoke one yet but how does that one come out?

Now let's see who can beat Wetdog to an answer....

[wetdog]

bin em and change to tappers , I would not like to think im riding a bike with a steering race problem (even with a dampner)

[JFerg]

Changing to tapered rollers is a good engineering solution, but a huge job.  Tapered roller bearings are much bigger, so you need carriers top and bottom, which means you need a longer stem etc and so forth.

As you have discovered, the original races aren't supreme of quality.  However, being what they are, they are hard right through, and this is good.  It means that you can re-grind them to clean up the bearing track fairly easily.  The four races will all be slightly different ID.  Measure them, then make a tap-fit arbour to suit the largest.  Using a die grinder or a Dremel with a 3/16" mounted stone, while running the race in the lathe in back gear, it's  a matter of a few minutes to produce a lovely new surface.  Knock that race off, take a whisker off the arbor to suit the next largest ID race, and repeat.

Getting the races off and out is gorilla work.  To get it off the bottom yoke, start with a small cold chisel, working gently one side and then the other until it is far enough off the yoke to get a better drift behind it, although it won't have to come far to be onto the clearance diameter and free.  Knock them out of the steering head with a long bit of rod held against the opposite side of the other end to keep it on target.  Again, work it from either side and it will come.

cheers,

JFerg

[rogerwilko]

They are fully floating type bearing races. No way can you convert to tapered type. Just buy them off ebay tightarse. You're lucky they even make them. 10 years ago you couldn't buy them anywhere.

[33d6]

I wouldn't worry too much if I were you. The AJSMOC has one of the best club spares schemes around and have been incredibly active in ensuring quality spares are available. If your new head bearings came from any source with Club associations I'd be dumbstruck if they were made of Chinese chocolate. Remember, your bike shares these parts with all the other big bikes in both the Matchless and AJS range so they are around in their thousands. If there was any concern it would have cropped up long ago and the whole world would know.
Of course the originals would have turning marks on them. How do you think they were made? These are adjustable bearings that that have extremely limited movement at very low speed. They are not ball races required to revolve at speed. The requirements are very different. Head bearings take pressure, not revs, so don't worry about turning marks.
I wouldn't worry about taper bearings either as they can't be fitted. You have the pleasant economy/touring/commuter model of the range. The standard bearings are way, way, more than adequate for what your bike can do.
Usually wear marks in head bearings occur after extremely high mileage or overtightening. Overtightening by an enthusiastic owner happens more often than you think. It will wear the bearings out very quickly. Make sure you adjust the bearings exactly as the factory instructs. A fraction too tight is much worse than a fraction too loose.
Have fun,

[wetdog]

you can convert to taper bearing , I have done to ajs , velo, panther , bsa (now off the shelf from srm no frame work req) there is frame work involved , it does not incress the head stock  length from standard (would be pointless) its not cheap so maybe not a option for your self , and I don't know if your in the uk , anyone else who needs this ateration contact mcsalvage@tiscali.co.uk

[Rex]

Yep, just spring for a new set, they're not expensive.
Don't bother with taper rollers either. No real benefit, especially in a 60mph 350 heavyweight single, and you'll likely find the fork shrouds don't fit properly any more if you fitted them as the yokes end up further apart.
{Unless you buy those thinner taper roller races designated for light use only, and that's just false economy}

[wetdog]

ye light use like your lightweight A10 , , gives positive steering and improved handling, taper bearings are superior to other types of bearings for the steering head. i started to fit when the ball races became harder to find for some british bikes , all distances remain the same this , is very important on girder fork machines to maintain link angles as standard (unless sprinting or trials )

[antoni]

All good info thanks.

and congrats JFerg.