Steering stem bearing issues

[mik_str]

So, after putting up with a knocking in front end (this, despite tightening having "new" tapered roller bearings in and tightening them up no less than 5 times!), I dropped the bike off at a local dealership (am not set up to do it myself) to have the issue fixed (asked for new bearings). When I picked the bike up yesterday, I was told the bearings were pristine, that the knocking came from the lower bearing's outer race moving around inside the steering stem cavity. WTF????? The mechanic laughingly told me to cut down on the wheelies (told him I never wheelie the bike, don't want to risk bending the magnesium rim). Very, very odd (though it must be said our roads here are essentially paved over cowtrails). Anyhow, the tech used a punch to pinch the race in place and green Loctite (sleeve retainer) to hold it there. Hopefully that will fix it for good, otherwise, I guess I'll be looking at a new frame (should it come to that, I will be it braced up nicely before swapping)......

anyhow...... weird stuff....... hope it's the end of it.....

[mattycoops43]

That's not great. Usually caused by an accident stretching the hole.

[mik_str]

no accident here... have owned the bike since it had 15,000 km, is now well over 200,000... our roads, however, are f***in' atrocious, so the front end gets constantly beat into submission.......

[lloydie]

Describe the knocking you had as I'm getting knocking and I can't find where it's coming from

[VTRDark]

It's a pair of knockers

That's a very unusual diagnosis Mik. The only thing I can think off is that the tolerance is a bit small on the aftermarket bearing.

(:-})

[mik_str]

the knock (sounds like two pieces of metal colliding, a dull thudding sound) would occur when running over bumps in the pavement, or when using the brakes semi-aggressively. Earlier on, I had a look at the steering stem (yoke nut if you will) when braking decently hard and saw it moving to and fro.

I really hope this fixes it but I suspect it will creep up again, give our shitty roads......

[nt1980]

I had the same issue with my mine last year since i have changed the bearings and put the cbr900 yolk in it doesnt do it any more but i have not tried it out properly yet

[mik_str]

starting to look ahead here as I am not convinced the "fix" used on the lower bearing race (inside steering tube) will hold so I am trying to figure out what will come next. So, to all resident machinists, a couple questions for you:

- can the neck be rebored with the engine,... still in the frame or would everything have to be stripped off the frame? (If everything needs to be stripped, may as well just replace the frame.... get a newer one with bracing welded in place)

- assuming it (re-bore) can be done with bike still assembled, would a steel sleeve (pressed in and held in place with sleeve retaining compound) be a good option?

I still can't believe I am even having to think about this crap........

thanks in advance

[VTRDark]

Are you sure it not juts down to incorrectly sized bearings/bad batch.

(:-})

[darkember]

Before going down the new frame route. Buy yourself a replacement steering stem off the bay or somebody on here should have one and give that a go.

[mik_str]

it's not the stem that's the problem, it's the frame (neck cavity)......

was also thinking about perhaps using some industrial acrylic glue to hold the lower race in place (know of it as Polaris uses it, structural bonding, on the frames of its new snowmobiles, allows them to mate dissimilar materials together, tests show it to be stronger than welding). As most of the perimeter (ie, frame neck which holds the outer race) is good, it would have a good hold on the race.... need a bit of heat when time comes to break the bond and replace......

[Steve6088]

Have you thought about using JB weld?

http://www.ebay.co.uk/itm/JB-WELD-WORLD ... 3a676a9763

The mechanic I use has used this stuff for repairing crank cases and even velocity porting engines! Seems real strong the times I have used it for bonding metals togeather.

[fabiostar]

worse comes to worse id get the bottom seat of the frame opened up and get a shim made up for it and sweat the outer bearing into it.

[tony.mon]

I'm not sure that there's enough metal on the lower section of the neck to bore it out much without weakening it.

Any machining will cost, but spare frames are cheap enough- you take a chance that it's straight, of course.

I'd try JB weld or the adhesive you mentioned and see how it goes, but buy a spare frame just in case and have the bracing done.
While you're there you can have the "ears" welded on so that you can use SA outrigger supports, and you might as well have rearset mounting positions welded on while the welder's playing around.
I'll be doing that at some stage when I can get some time, using mounting points for 929/954 Blade rearsets, or R1, as they come up all the time on the Bay of Bargains and they're always cheap, as there's loads available.