Which material damps vibration best - steel or aluminium?

[JackyJoll]

Ally vs. Steel is gonna be basically the same when you're comparing steel vs. CF for example. Wood is way more damped than CF though, which is why CF piano boards are really good, but CF bells are shite, IYSWIM.

Yes there is wood on my bike.

[porter_jamie]

Not got me glasses sorry about typos

[mangocrazy]

Experiment with various weights on the end of the bars and also with one side heavier than the other.

At the moment that's precisely what I've got. The RH bar with the eBay rubber bushed bar end weight vibrates a small but noticeable amount, the LH bar with no bar end weight (it vibrated out) vibrates significantly more...

But it's instructive that in over 11,000 miles of ownership I've never felt the need to complain about vibes through the bars and in all that time I've had the standard Aprilia mass damper insert and bar end weights fitted.

The problem has only reared its head when those have been removed.

[mangocrazy]

Honestly I'd use steel for a way more fundamental reason.

You can get away with a lot using steel Tough as old boots, doesn't mind being dinked a bit, much easier to weld....

I suspect Aprilia used ally for cost more than anything. Or cost/weight/stiffness optimisation.

Yeah, steel is way more forgiving. After thinking about it and reading the stuff on here, I'll be re-fitting the OE Aprilia bar end tackle to my steel Ace bar copies:

viewtopic.php?p=253377#p253377

In the meantime (and seeing as I'm in France and all the OE Aprilia bits are in Sheffield) I'll just have to live with slightly tingly digits.

[KungFooBob]

Smash.

[Le_Fromage_Grande]

Experiment with various weights on the end of the bars and also with one side heavier than the other.

At the moment that's precisely what I've got. The RH bar with the eBay rubber bushed bar end weight vibrates a small but noticeable amount, the LH bar with no bar end weight (it vibrated out) vibrates significantly more...

But it's instructive that in over 11,000 miles of ownership I've never felt the need to complain about vibes through the bars and in all that time I've had the standard Aprilia mass damper insert and bar end weights fitted.

The problem has only reared its head when those have been removed.

Put them back in then

[mangocrazy]

Experiment with various weights on the end of the bars and also with one side heavier than the other.

At the moment that's precisely what I've got. The RH bar with the eBay rubber bushed bar end weight vibrates a small but noticeable amount, the LH bar with no bar end weight (it vibrated out) vibrates significantly more...

But it's instructive that in over 11,000 miles of ownership I've never felt the need to complain about vibes through the bars and in all that time I've had the standard Aprilia mass damper insert and bar end weights fitted.

The problem has only reared its head when those have been removed.

Put them back in then

That's what happens when you only read the last couple of posts in a thread.

[Horse]

Wasn't there a product call 'Bar Snake', a flexible weighted ... thing ... that was pushed along the length of the 'bars?

Edit: there still is: https://www.barsnake.com/index.php/about-barsnake

[mangocrazy]

They say it 'dampens' rather than 'damps'.

Oh the horror...

There are so many fails in just the first sentence on their home page that it really isn't funny:

The Barsnake eliminates harmonic resonate frequencies that eminate from cylic engine vibrations that are transmitted through the vehicle frame to the handlebars. The Barsnake dampens out these resonate vibrations because the polymer of the Barsnake has a low hysterisis factor, which means that the polymer doesn't transmit vibrations.

[Horse]

They're Americans. English is a foreign language

[Dodgy69]

What happened when they put a strip of rubber at your clamps.

[JackyJoll]

What happened when they put a strip of rubber at your clamps.

Bad stuff. I saw it in Casino Royale.

[mangocrazy]

What happened when they put a strip of rubber at your clamps.

I didn't know they had...

Not entirely sure what you mean, old bean. The OE Falco bars have a nifty little arrangemnt that's not easy to explain in words, so here's a parts diagram.

Falco_bars.JPG (35.43 KiB) Viewed 413 times

My problem is that I needed different bars to work with the risers and I never adapted those bars to accept the OE Falco anti-vibration system. And the bike (and me) are in France and all the bits are in Sheffield.

[Mr. Dazzle]

If the OE system uses a kind of tuned mass system...well, stating the obvious but it's unlikely to be tuned to the new setup!

Can't work out if that's what's going on here. Is that what number 4 is?

[Count Steer]

If the OE system uses a kind of tuned mass system...well, stating the obvious but it's unlikely to be tuned to the new setup!

Can't work out if that's what's going on here. Is that what number 4 is?

1,4,5,6,9,10,11.

Like I say, wind it in, wind it out. I know some have gone a bit about resonant frequencies but the bar vibration that bothers the rider is all about when the engine vibes resonate through the bars. If they vibrate uncomfortably throughout the rev range, I'm wrong.

[Mr. Dazzle]

Ah yeah...if its adjustable, retune it

[mangocrazy]

The parts diagram gives an idea, but it's not entirely obvious. The long rod (4) has a rubber sleeve (5, I think) at the end that goes furthest into the bars and the rod protrudes through the part (6) that screws into the bar end. The long rod also has a hole drilled in it, through which a pin (9) is inserted, with an o-ring (10) behind it. The actual bar end weight (1) has a groove machined in it to locate the pin (9). A small allen bolt (11) fixes the bar end weight to the end of the long rod (4).

I'm sure that explanation makes it all much clearer...

[Screwdriver]

Following on from my 'ramblings' post, I was wondering what difference a choice of material (i.e. steel instead of aluminium) would make to the vibration absorption (or rejection) properties of handlebars made of differing materials. Would there be any noticeable difference between a set of steel bars compared to a set of ali bars?

Yes there would be a noticeable difference. No you won't know what difference it will make until you try it.

Chances are, the manufacturer will have dialled out vibration for whatever OEM fitting they decided to use so there is a higher probability that changing anything will make it worse. That might even be true for bar end weights. If the mfr could make the handlebars vibrate less, they would have tuned the end weights already.

If you change the bars (or the entire handlebar mounting!) you're starting from scratch so you might as well suck it and see. Steel or aluminium makes "no difference". You can't say one is "better" than the other until you try them. It may be that the particular mounting happens to work best for steel, it might work best for ally but there are too many fantastically complex parameters to even think about calculating a response.

I would hazard a guess that changing the length and shape of the bars would have just as much effect as swapping steel for aluminium.

[Horse]

Can't work out if that's what's going on here. Is that what number 4 is?

Looks to be almost like a 'pendulum' mounted to swing from the bar end weight. Perhaps giving some sort of 'longer bar' effect. Or it works almost like a balancer shaft in an engine?

[demographic]

An aid to lessening vibration on KX500s was something called a Bar Snake which although I've never tried or even seen one up close didn't seem a kick in the arse off a bit of flexible pipe filled with builders silicone.

Not tried it but its cheap enough to have a go.