Broken left handlebar

[Conrad]

There I was, braking hard from 130, entering a hard left hander, next thing I knew was there was no pressure coming from the left bar

This was something that had entered my mind often, hence my desire to get the rather spendy LSLs, which I got from www.murphskits.com ,    If I never pushed this hard, i would feel quite safe with what the factory provided.  I wonder if Rossi or Spies use cast bars?  Or any of the riders who frequent the track?  Hey Steve, ever consider getting cast put on yer track bike?

At least you could still use the clutch eh?

[Mister Tee]

I tend to agree that these bars seem to be strong enough for their purpose. There have been so few cases that it certainly cannot be any kind of built- in design problem.

For what it is worth, I think the bars are die cast aluminum. It would be a tremendously difficult shape to make from powered metal if it was possible at all. And powered metal parts have <relatively> low tensile or torsional strength, and a poor choice for handlebars. But no matter the material or manufacturing method, it does not seem to be a common problem. My bike even survived being tied down with Canyon Dancers (not my choice, the only thing available on the flatbed); I watched the handlebar stanchions flex as the C.D.'s were loaded but nothing broke.

Brian

Yes, I agree they are definately die cast.

[Shoe]

I think the bars are strong enough for normal use. The use of Canyon Dancers or other means of tie down in my opinion over stresses the bars. Adding blocks with normal usage I believe over stresses the bars. If an engineering reader has access to a stress analysis program I would be curious to find out if it does.

I believe Kawasaki should have designed in more safety for the use of tie downs.

That's my 2 cents.

[stevewfl]

There I was, braking hard from 130, entering a hard left hander, next thing I knew was there was no pressure coming from the left bar

This was something that had entered my mind often, hence my desire to get the rather spendy LSLs, which I got from www.murphskits.com ,    If I never pushed this hard, i would feel quite safe with what the factory provided.  I wonder if Rossi or Spies use cast bars?  Or any of the riders who frequent the track?  Hey Steve, ever consider getting cast put on yer track bike?

LMAO!

No sir, I use Graves or VORTEX clip-ons and such

[B.D.F.]

It would be virtually impossible to reverse engineer those handlebar stanchions well enough to do a decent stress analysis on them. The first problem is the guessing what material they are made from (aluminum certainly but <which> alloy). Then there is the material treatment they were given (T2, T4, T6, etc.). Finally modeling them accurately given all the intricate shapes and tapers involved.

By blocks I assume you mean risers? If so, then no, adding bar risers will not change the way the bars are stressed. The risers themselves cannot add stress, only because the angle of the user added stress to be applied differently.

The easiest way to review the bars' performance is in actual use; there just are not many broken sets of bars around on these bikes. The time most likely to break handlebars is when they are heavily loaded by a large rider and the bike being braked very hard and then striking something (obviously talking about a vehicle accident now). At that point breaking one or both handlebars isn't really an issue and a case could even be made that it would be safer to break the bar(s) out of the way for the inevitable forward motion of the rider. Unless of course the stanchion breaks in the middle and leaves a ragged post for the rider to be impaled on....

Brian

I think the bars are strong enough for normal use. The use of Canyon Dancers or other means of tie down in my opinion over stresses the bars. Adding blocks with normal usage I believe over stresses the bars. If an engineering reader has access to a stress analysis program I would be curious to find out if it does.

I believe Kawasaki should have designed in more safety for the use of tie downs.

That's my 2 cents.