Steering Tapered Roller Bearings

[JParty]

Hello,

I bought a set of tapered roller bearings from DSS. They look like they use QMP SSH 750 from the packaging. They didn’t come with instructions but after calling they issued a short document to me. The main thing I was unclear on was where the spacer (washer) went. From the instructions it is meant to go over the stem first before the lower bearing. The ID of the spacer was too small for the stem so I have to file down the centre.

Having ensure the cups were properly seated and the washer and lower bearing were hard up against the stem I’ve now tried to assembly the stem into the frame. Only 1-2 turns of thread is available at the top when trying to get the top cap (the nut that is torqued with a C Spanner). Because of the ridges on the bottom side of the top cap, it is only possible to start this thread with the nut upside down. With this torqued there still isn’t enough thread to see it come up the other side of the nut. I can’t get the thread started with the top cap on the right side up. Even if I can get a machinist to machine off those ridges on the top cap it doesn’t get my many turns of thread.

After triple checking that the bearing cups are seated in the frame, I’m running out of ideas. As far as I know, the steering stem and frame headset are all original for the 1976 CB400F. I’m reluctant to remove the spacer as it looks like the lower yoke will start to get plenty snug on the bottom of the frame.

Lastly, I was surprised to see an absence of any dust/dirt caps to protect the bearings...

Any help would be mega - thank you!!

[K2-K6]

They're all like that sir, unfortunately not a joke.

Your experience is the same as many other on here and can't easily be resolved.  Basic problem of dimensions in the bearings not being equivalent to the original specification that's difficult to resolve. Also results in the headlight ears no longer fitting correctly between top and bottom location.

Contemporary taper roller sets had the bearing track ground to bring a match to the bike components as they made up the sets, but std bearings are now sent out without that adaption.

[Laverda Dave]

This thread may offer some help

http://www.sohc.co.uk/index.php/topic,14529.0.html

[JParty]

Do you know if I completely remove the lower spacer whether I should expect binding between the bottom triple clamp and the frame? It’s difficult to measure without actually pressing that bearing on (I don’t like my hopes of getting the bearing off if I have the inner race hard up pressed against the lower triple clamp without spacer)!

[McCabe-Thiele (Ted)]

I decided to just use a combination set up Taper Roller above spacer in the bottom with plain bearing at the top - it was best of the  limited choices for me.

[allankelly1]

I fitted a All Balls set and they fit fine with plenty of thread

Also looking at the spacer it looks too thick

(The all balls set come with different thickness spacers)

Hopefully you can see that with mine the lower face of the lower yoke is flush with the top of the bearing cup and the top yoke has plenty of thread

Also they come with seals and the top bearing cover covers the top bearing ok






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[ka-ja]

I had no trouble fitting with the All-Balls set on my 400/4, plenty of thread forthe top nut

[allankelly1]

Yes

I think the All Ball kits used a more shallow taper roller hence no build height issue once fitted

Just they cost a bit more


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[Seabeowner]

Recently took apart the forks and head on my 73 CB500. I was surprised that it already had tapered bearings and just re-greased and re-assembled. I should have remembered as I put the bike together in 2003 and it must have had them before that as I didn't replace. Plenty of thread left at the top. I had already bought an All Balls set a little while back and will use them on another bike.
And they were less than this and cheaper than DS.
https://www.ebay.co.uk/itm/263739039912?fits=UKM_Make%3AHonda&hash=item3d681260a8:g:-2gAAOSwvmNbFrrz

[McCabe-Thiele (Ted)]

Yes

I think the All Ball kits used a more shallow taper roller hence no build height issue once fitted

Just they cost a bit more


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I've never hear of this All Balls Kit no one mentioned it when I was wrestling with my headset - are they still available and where from do you have the bearing heights by any chance or part numbers ?

[allankelly1]

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[Seabeowner]

I posted it in reply 8 but maybe you need it again. All Balls:
https://www.ebay.co.uk/itm/263739039912?fits=UKM_Make%3AHonda&hash=item3d681260a8:g:-2gAAOSwvmNbFrrz
And save £6.39.
But no guarantees that they fit perfect.

[McCabe-Thiele (Ted)]

I posted it in reply 8 but maybe you need it again. All Balls:
https://www.ebay.co.uk/itm/263739039912?fits=UKM_Make%3AHonda&hash=item3d681260a8:g:-2gAAOSwvmNbFrrz
And save £6.39.
But no guarantees that they fit perfect.

Thanks for the last two replies yourself & Allan I might re-think my planned headset arrangementwhen I get to assembly.

[JParty]

Thanks for the replies. For anyone coming to this thread - do not buy the tapered bearing kit from DSS, the upper bearing is too big to get the whole lot to close up when trying to fit the dust cap/nut. Pretty disappointing that they choose to stock from this supplier - I would have bought the all balls kit if I had known about it. 

[JParty]

Update: DSS is going to refund for the steering head bearings which is good support, even though this has been a bit of a faff!