Problem with flanders dog bones risers

[CryptoKnight]

The bike is nearly done, and I have issues with the flanders dog bones risers on the custom springer. It has 4 pivot points, and even though the pinch bolts are SEVERELY torque'd down, it still moves and pivots on those axis when going over bump/pothole or when kick starting. I kick started it tonight and the bars were 5 degrees twisted. I'll bet if I wrenched the bars I could get them 30 degrees pivot in either direction. Not good!!!

So, it's operating kind of like a differential (at least, that's how my brain sees it). A force on the bars causes the dog bones to flex and one bone move forward and the other back, so the handlebars are no longer parallel with the top tree. It doesn't help that the ears on the top tree and the handlebars are slick, neither is knurled.

I'm scratching my head on this. The only thing I can think of is to [1] knurl the ears and handlebars, carefully, with application of channel locks or pipe wrench to dimple and knurl the chromed surface (but, that means future rusting), or [2] carefully drill and tap holes on top and bottom of each dog bone, and install set screws. However, that means that the bars really can't adjust.

Pulling my hair out on this, any ideas? Has anyone run into this? Picture below...

 

[TwoManyXS1Bs]

Yep, clamping chrome-on-chrome is a problem. Two things you can try.
Rosin.
If that doesn't work, red loctite...

 

[angus67]

How bout a shim cut from beer can? The different metals will grab

 

[fredintoon]

Hi KryptoKnight,
Gawd! after I dunno how many times Mr. Stupid has wondered about your signature I've finally recognized the Superman connection.
Back to dog-bones.
Are the 'bones eyes fully closed; with their halves touching each other on both sides when they are tightened down?
If so, try filing a few thousandths of an inch off their faces so that the fastener torque can make the 'bones grip the bar instead of trying to stretch the bolts.

 

[Iowa Mark]

A trick I've used is cutting some rings out of long skinny balloons and using them as shims between the bars and the bones. Once things are in place and tight, razor blade the extra off.

 

[CryptoKnight]

Hi KryptoKnight,
Gawd! after I dunno how many times Mr. Stupid has wondered about your signature I've finally recognized the Superman connection.
Back to dog-bones.
Are the 'bones eyes fully closed; with their halves touching each other on both sides when they are tightened down?
If so, try filing a few thousandths of an inch off their faces so that the fastener torque can make the 'bones grip the bar instead of trying to stretch the bolts.

It's actually a double joke - my biker road name is CryptoKnight, because I do information security & CRYPTOgraphy, and I protect organizations, so I'm a Knight, one of the good guys... with an obvious nod to Superman. But, CryptoKnight was taken on the XS650 forum, so had to settle for misspell.

The bones have a near 1mm gap, so that's not the cause of the problem. It's just that nothing is knurled.

 

[fredintoon]

- - - The bones have a near 1mm gap, so that's not the cause of the problem. It's just that nothing is knurled.

Hi Kryptoknight,
OK then, Angus' beercan shims may work although I'm doubtful about the effectiveness of Iowa Mark's used rubber trick.
But first I'd try sandblasting the gripping surfaces after carefully masking off everything else.

 

[TwoManyXS1Bs]

More ideas:

http://xjbikes.com/forums/threads/clamp-on-highway-pegs-slipping-problem-solved.14034/

 

[mrtwowheel]

I like the aluminum shim idea, but a ring of dried enamel paint may do the same thing.

Scott

 

[Iowa Mark]

With 1 mm, .040" gap, my balloon idea has no chance of working. I was working on the idea of inherent slipping between smooth chromed surfaces. You need to fill that crater with something besides knurling. Or machine the caps down for some crush.

 

[DrewMartin]

With 1 mm, .040" gap, my balloon idea has no chance of working. I was working on the idea of inherent slipping between smooth chromed surfaces. You need to fill that crater with something besides knurling. Or machine the caps down for some crush.

If I understand OP the 1mm/.040" is under the flats and should have adequate crush. But it's on two pretty hard surfaces that are fairly low friction. I'd try some red loctite or loctite 680 retaining compound before I personally took some vice grips to my bars. I use 680 all the time at work and its honestly shocking how well it works. I'll slip fit bearings onto shafts to save machine time and use an adequate amount of 680 and it won't come apart without a press or BFH.

http://www.henkel.com.au/aue/content_data/327273_UPGRADE680EN.pdf

 

[CryptoKnight]

Well, we tapped and inserted set screws in the bottom of the dog bones, and that seems to have done the trick, but I'm going to also add 680 Lock Tite to the bars.