Tapered Contact Bearing - 3CL

J

Jod

Full member
Was in the bearing shop today inquiring what other type of bearing they have 25/52/15 and they said a bloke called Will Stein gets these Tapered Contact bearings.

Anyway put a standard tapered on the lower side and a sealed Tapered Contact on the top of the triple tree.

After some bearing adjustments, 40mm of conduit in the Cerianis to give me an inch of preload the bike was perfect! Never been better!
 
Will is the Treasurer of the NSW club and funnily enough was talking about just these bearing at last Wed nights club meet.Bet that was Silverwater CBC
 
Is there any advantage having tapered bearings top and bottom?
 
Is there any advantage having tapered bearings top and bottom?
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The SFC750 and Rg series have this as standard - I prefer to use this setup as the sealed ball bearing could make the steering "tension" tighter than I like - Regards - Phil
 
Conical roller bearings top and bottom is the ideal setup. However, nearly all the axial load is on the bottom bearing because the weight of the bike sits on it. The top one doesn't carry much axial load at all, so you can use a ball bearing there if you want to. One good reason to do this is that the top bearing should be sealed against water ingress and it's easier to find sealed ball bearings than sealed conical bearings.

Ball bearings can carry a reasonable axial load. Indeed, I think the bikes left the factory with ball bearings top and bottom. This arrangement is reasonably idiot-proof as far as tightening up the steering head nut goes (provided it's not over-tightened). The steering stem will stay pretty well aligned even if the top nut is allowed to get loose.

Tapered roller bearings (whether you have one or two) need to be adjusted accurately to keep everything centred and not have any clunking in the steering.
 
Cam, that is basically what my line of thought was. Especially as the bottom taper does take all the weight you would need to get the top taper pretty well spot on in adjustment or the potential for slop in the steering would be fairly great - just my thinking of course and I am certainly not a mechanic.
 
The factory fitted tapered bearings to the bottom of the steering stem only, top bearing was always a sealed ball bearing.  Exceptions were the RGS series and the 750SFC, as Phil stated.

I find the tapered bearing in the top is difficult to seal adequately against the elements amd rarely wears as well as the ball bearing.  But most wear occurs at the bottom bearing anyway, so no big deal, if the top bearing is shot, the bottom one surely is as well.  The tapered bearings are slightly wider when fitted and thus throw out all fitting dimensions for the stock headlamp bracket tubes.  Some sort of packing will be required to take up the extra resulting 1-1.5mm so that the brackets don't rattle around.

A few modern bikes use ball bearings top and bottom, with a distance tube fitted between them, much like a wheel-bearing set-up.  Was also originally fitted to Norton Commandos, so not really very "new"!

I prefer the tapered/ball combo, the friction of the top sealed bearing is so low(at least with good quality bearings) it makes no difference.  Also seriously considering reverting to taper/ball on the RGS as well, the tapereds are well and truely knackered and require replacing before the season starts.  If it weren't for the strengthening ribs within the headstock for the steering lock, I'd be comtemplating the double ball set-up.

piet
 
sfcpiet said:
The factory fitted tapered bearings to the bottom of the steering stem only, top bearing was always a sealed ball bearing.  Exceptions were the RGS series and the 750SFC, as Phil stated.
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I'm wondering if perhaps the factory used ball bearings in the bottom if there were no tapered rollers to hand.

When I replaced the steering bearings in my brother's 3C, the cruddy and rusty old un-sealed bearings I took out were deep groove ball bearings top and bottom. He's had the bike since new and the bearings hadn't been changed before, so they were factory originals. There was no internal distance tube (nor any need for one in my view).

I replaced them with tapered roller bottom and sealed ball bearing at the top. And yes, now that you mention it, I do have a vague recollection of the headlight bracket tubes going all floppy and needing spacers.

Cam
 
sfcpiet said:
I prefer the tapered/ball combo, the friction of the top sealed bearing is so low(at least with good quality bearings) it makes no difference.  Also seriously considering reverting to taper/ball on the RGS as well, the tapereds are well and truely knackered and require replacing before the season starts.  If it weren't for the strengthening ribs within the headstock for the steering lock, I'd be comtemplating the double ball set-up.

piet
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Agree with that. And also because the dual tapers need frequent adjustments while the tapered/ball combo is almost a fit and forget option (if good quality fitted correctly bearings).

JLO
 
"the top bearing should be sealed against water ingress and it's easier to find sealed ball bearings than sealed conical bearings."

I was fitting unsealed tapered bearings to my 3cl the other day and was concerned about the lack of protection. I looked at my MKII Lemans and it had this lovely little chrome cover over the top tapered roller. It fits spot on, same shaft diameter, about 0.6mm thick, covers the bearing with about 0.1mm gap between the headstock and the inside of the cover, but doesn't touch or rub. Looks good too..

Now I've just got to find another one for the Lemans....

Regards

Greg
 
Sorry guys but I should have explained the Tapered Contact bearing more. It is a sealed and bound together bearing just like the sealed ball bearing which was originally  on the yoke top.

So the old school tapered bearing (like on your old car) in put at the base of the headset and the Tapered
Contact (sealed and bound together bearing) at the top.

It is easier to get it set up correctly and water will not get into the top bearing.

By the way for $6 Wolfgang has nice covers which keep the water out of the top bearing.

Thanks again Wolfgang!
 
I always use the "Rondella Bombata"  part No 33 270 004 as fitted to the lower bearing, over the top taper roller. The 500 uses this type of arrangement too. Never had a problem with dirt or water - not a high mileage man these days but can't remember when I had to reset the steering tension.
 
Hi Jod

I think perhaps you are confusing terms. What you call a tapered contact bearing sounds from your description like an angular contact ball bearing. Not a tapered roller at all.

Cheers,
Cam
 
Hi jod, is that you john z?  Give me a ring, as discussed on sunday, will fitted these to my 120 jota, brilliant.  I can put you in touch with will to discuss.

Cheers

Marty
 
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