I'm no genius, but solid stock is more likely to break instead of bend. So if you were in trouble the tube would bend instead of bread, still giving you something to hold on to. But like I said I'm no genius, so someone correct me!

 

These bars were vintage race bars and used in pretty severe enviornments. With the solid aluminum being stronger than the tubular steel, there would be a point where the steel would bend and the alumiunum wouldn't. And whatever force that would snap the aluminum bar would snap the steel bar as well. Aluminum has very good ductility.

 

Saying aluminum has very good ductility is WAY too broad a statement! It completely depends on the alloy and it's processed condition!

Hit the books and do your homework.............. Pay attention to the -T"x" in the 6061 family and beware of vibe fatigue in aluminum structures!

 

Saying aluminum has very good ductility is WAY too broad a statement! It completely depends on the alloy and it's processed condition!

Hit the books and do your homework.............. Pay attention to the -T"x" in the 6061 family and beware of vibe fatigue in aluminum structures!

Thanks for the input. I have a pretty good handle on the grades and tempers of aluminum. 6061-T6 has just as much or more elongation as DOM steel. ERW steel has more elongation that both DOM and the 6061-T6. Steel handlebars are made from both DOM and ERW all the time. I don't believe ductility is an issue, but I would agree fatigue could be. But if the steel bars are designed for infinite life and the aluminum will last you only 50 years, do you really care? It would take an awful lot of force to snap 1" solid aluminum bar.

 

Aluminum has very different fatigue qualities than steel. Most steel parts are designed to have an infinite fatique life. But because of aluminums inherant properties, there is no way of designing a part that has infinite fatique life, this is why most aluminum assemblies are designed with a huge factor of saftey on sizing, this way their number of fatigue cycles untill failure is increased enough to survive what the manufacture thinks is the parts lifespan.
This is one of the reasons you only see aluminum connecting rods in race motors. Their fatigue life is too short to withstand the nimber of cycles of a regular motor.

 

This is one of the reasons you only see aluminum connecting rods in race motors. Their fatigue life is too short to withstand the nimber of cycles of a regular motor.

Hmmm...someone forgot to tell Triumph that.

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This is an interesting and well thought out discussion.

...but, what are you guys doing on your bikes that you're concerned about 7/8 solid stock handlebars failing?!

 

Risk vs reward. I'd rather spend a few extra ounces on something that has better fatigue characteristics than spend another night in the "Tim Taylor Suite" of the hospital "again".

 

What? You've NEVER seen a TRIBSA twin with a hole in the case?

BSA and Triumph motors will shell their alloy rods with very little provocation if the timing or drive side bearings get sloppy. The side loading stresses the rods outside of the normal rotation plane. BSA twins are especially susceptible to this because of that crap plain timing side bearing. A little slop = little oil pressure too.

They put those rod dims in the book for a reason. Show me a tri rod wit 100k on it and it'll be longer than a new one. Just the nature of the metal.

 

BSA and Triumph motors will shell their alloy rods with very little provocation......blahblahblah.......for a reason.

Far cry from the statement

....you only see aluminum connecting rods in race motors.

Their fatigue life is too short to withstand the nimber of cycles of a regular motor.

Nitfuckingpick away.

(besides, the thread topic is handlebars)

.

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Whatever...... You gonna add something technical to the discussion or just throw rocks?

 

Hoping to pick the collective brain here. Seen some 7/8" solid aluminum dirt-track bars on ebay. Ran some numbers for 1" solid aluminum (6061) and turns out on paper the aluminum would be stronger in bending and torsion as well as lighter than the 1" x .120 steel. Is there any reason why you don't see more of these?

Besides not being able to run internal controls

To attempt to answer your question; I think one of the reasons you don't see them is because it is harder ($$$) to make aluminum handlebars with bends in them than steel. And at least one factory I know of, and the related aftermarket is not concerned with weight. Alot of sportbikes have alum. clip ons, but they are straight. I think the 7/8 solid bars would be far stronger than you will ever need and would be cool. They were designed to be dropped at speed and maybe get run over and still survive.

 

I don't buy the $$$$ to make. I don't know why it is. Downhill mountain bike handlebars are bent aluminum and are dirt cheap compared to motorcycle bars and they take a fucking beating. I know quite a few down hill racer's and one pro and I can't ever think of a single bar failure. Bent from falls and shit ..... yes.

 

Sorry...thats why aluminum rods arent recommended in a daily driven motor...

 

Well, this is my first post. I have been browsing the site off and on for some time now getting ideas for my build that will undoubtedly happen and be ridden the the socal Chop Meet in July. I feel that I need to put in my $.02 since I make aluminum handlebars for dirtbikes. It is true that aluminum has a fatigue life and is quite different than that of steel but there is nothing you are doing on your streetbikes that compares to what a motocrosser puts their bars through and you wont find steel bars in this industry (well you can, but...). Yes, they will bend in a crash... yes they can break in a crash... but if the vibration on your bagbobchopwhatever is bad enough to cause any concern with fatigue on a set of aluminum bars then it would be unrideable... or maybe your girl would fire it up when you arent around to have a sit.

Bottom line is you will be fine... I think just a plain set of 7/8" bars without a crossbar would look goofy but a set of oversize would look kickass. Thats just my opinion, or ask Halwade... he has good taste.

oh, btw to touch on the solid bars... if you truly mean solid aluminum, dont do it. Hollow is stronger and lighter at the same time.

 

Rule of thumb in life....
"Steel over Aluminum in all things possible....except wheels."

 

...and maybe F16's.

 

i have a set of solid aluminum bars floating around my garage. they seem just as heavy if not heavier than tubular steel bars.

 

Yeah, the only way you're going to save weight with aluminum bars is run a tube with slightly more wall thickness than you'd use if they were steel...

As a VERY broad rule of thumb, aluminum is 1/3 the weight (please don't nitpick, this is the broadest of approximations) of a common steel alloy like 1018. Solid aluminum bar is going to weigh a good bit more than correctly sized steel tube. Not to mention, as another poster said, tube technically has more bending resistance.

 

I have a set on my KZ . . . I"ll post if they kill me .

 

haha what a nice guy

 

The main reason I stick with steel tube handlebars on my race bikes is that they will bend and absorb alot of energy if the bike gets tumbling. The aluminum bars they sell now are hugely stiff. I'd rather wreck the bars than the triple clamps or frame.

 

Thanks for the feedback guys. The only technical reason I can see to not run the solid aluminum would be fatigue. I found some fatigue data on aluminum on www.matweb.com and if you compare the soild cross section with the tubular cross-section and factor in the fatigue effects over time, the alumiunum soild would be approx 30% weaker than the steel tube after 500 million cycles. To put that in perspective, you would have to cycle your handlebars every second of the day for almost 16 years to get to that point. I know that the amount of force matters, but I think it reasonable to think that you wouldn't really approach that. 1" soild aluminum bar weighs less than 1 x .120 steel tube. Check out www.speedymetals.com they have the weight/ft calcuated out on their site.

Thanks again for the banter, I think I'm going to bend me up some 1" aluminum.

 

Guys, I have two questions on this handlebar issue. My risers are made to accept 1" steel bars, how would the clamping capability be affected if one used the 7/8" bars? How many guys here would choose an aluminium hollow bar over steel, price not being a factor?

 

If the risers are for 1 inch bars and your bars are 7/8ths , then they wont clamp at all .

You would need bar shims to make those work . . . or the right size risers or different size bars .

 

go get some triumph shims. the p clamps are set up for 1 inchers from the very early days.