Subject: Anti vibration bushes Sun Jan 02, 2022 4:41 pm
I don't run the bar ends on my GRiSO cause they hang out like dogs balls. Result, predictably, tingling vibration through the grips.
Looking at other solutions, packing the bar ends with leadshot encapsulated in silicon.OK up for trying that. But I'm thinking anti vibration bushes between the triple tree and bar supports with rubber washers above and below would be feasible. It is a solution found on some bikes as standard. This is the sort of thing I'm thinking of. Any experience or opinions ?
Subject: Re: Anti vibration bushes Mon Jan 03, 2022 12:27 am
get narrower bars and refit the weights?
evansnows Biondino
Posts : 202 Join date : 2019-06-05
Subject: Re: Anti vibration bushes Mon Jan 03, 2022 11:32 am
I'm reading up about the handlebar vibration issue with bikes. Not something I've ever delved into in 45 years of riding. It's an interesting topic, one article I read reckoned that the vibrations trigger the nerves in your hands which causes the tingling and fatigue.
The vibration is evidently due to resonance, altering the length and mass of the bars will change the frequency that the bars resonate at thus the revs that it occurs.
I'm not going to bolt the dogs balls back on but have threaded a length of heavy 10mm copper, rubber coated cable through the bars and compressed it with the end caps so that the rubber will touch the internal of the bars. Theoretically this will give some damping from the rubber and the copper will have changed the overall mass.
Online packing with lead shot, lead shot encapsulated in silicon, or sand are some of the suggestions. I was going to try lead shot but it's not easy to find and I had the cable on hand. I haven't been for a ride yet but I have no doubt that things will be changed. Whether better or worse remains to be seen. It appears that by fiddling with packing the bars and possibly altering the length will be all that's required to stop the vibration at cruising revs.
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Lazlokovacs Don Abbondio
Posts : 310 Join date : 2015-08-20
Subject: Re: Anti vibration bushes Mon Jan 03, 2022 3:46 pm
let us know how you get on, I've tried all kinds of things in the past... ball bearings or lead shot didn't ever work for me... but ping pong balls cut up and crammed into my clip ons did wonders on my lemans....!
I'll take the slight vibration of a well tuned guzzi over the high frequency buzz of an inline 4 any day!
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Lazlokovacs Don Abbondio
Posts : 310 Join date : 2015-08-20
Subject: Re: Anti vibration bushes Mon Jan 03, 2022 3:46 pm
papa - there's only so far you can cut down the handlebars before you start running out of space for the switch gear.....
lcjohnny GRiSO Capo
Posts : 1470 Join date : 2016-01-25 Age : 69
Subject: Re: Anti vibration bushes Mon Jan 03, 2022 3:50 pm
On mine the previous owner had fitted Norge bar end weights, ballbearings inside the bars and rubber strip between the bars and clamps!!!!
It still buzzed at the bars at 60-80mph.
When i started synchronising the throttles more carefully (see below) the vibration reduced a lot.
synchronising the throttles more carefully Back in the day if an owner of a multi cylinder bike kept coming back in complaining about poor pick up or midrange vibration we would suspect that the throttle balance was abnormally sensitive. After doing all the physical stuff (torque engine bolts correctly, undo exhaust and check it is not tensioned when mounted, set valve clearances equal, get timing correct, new plugs & leads) then we would stick the portable vacuum gauges on handlebar clamp with a bungee and ride it around adjusting to get perfect balance as all the throttles opened. - that always worked however sh1te the carbs/chokes etc were.
Paul Brice posted something on this site that reminded me of doing that in the 80s- so that is how i synch my throttles now = no vibration
I found the vibration was reduced more by removing the Norge weights not changed by taking all the ball bearings out and worsened by using the original mirrors on stalks (they may act like a tuning fork?)
Currently I use no weights in or on the bars & light bar-end mirrors and the bike is smoothish up to 100 and for 6 hr cross country 40-80mph.
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evansnows Biondino
Posts : 202 Join date : 2019-06-05
Subject: Re: Anti vibration bushes Mon Jan 03, 2022 4:11 pm
I'm inclined to think sand would be a good thing to try.
The point with the lead shot other than altering the weight is that is said to dampen the vibrations as a dead blow hammer does.
I would use the material that is used for sandblasting, it's dry, heavy and consistent grain size. I'd go for a quite fine grain. From when we used to bend pipes for the boats we'd pack with dry sand tapping the sides to get it to pack, seal the ends heat and bend.
In theory the sand having much more surface area in contact with the handlebar walls should act better as a vibration damper. Dry sand would be essential to prevent corrosion and for the sand to flow and settle. If my current experiment doesn't work sand will be my next trial. I'd drive in a cork in one end fill with sand and another cork in the other end, probably with a little epoxy poured on the ends to keep everything in place.
From what I've read so far you can dampen and change the frequency at which the bars resonate rather than stop it, which should be all that is required as it won't be a problem unless it vibrates at the bikes cruising revs.
All this is an issue that I'm tackling because I built the GRiSO as a long distance tourer so being able to ride all day comfortably is necessary.
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evansnows Biondino
Posts : 202 Join date : 2019-06-05
Subject: Re: Anti vibration bushes Tue Jan 04, 2022 5:32 pm
Just went for a ride. The heavy cable did what was predicted, changed the frequency of the bars and subsequent vibration. Now it is between 2,250 - 2750 rpm. No problems at cruising revs. It looks like with a bit of experimentation with the packing media that anyone with a problem could sort it this way.
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Papa Lazarou GRiSO Capo
Posts : 826 Join date : 2014-10-07 Age : 70
Subject: Re: Anti vibration bushes Wed Jan 05, 2022 3:10 am
Lazlokovacs wrote:
papa - there's only so far you can cut down the handlebars before you start running out of space for the switch gear.....
Which is why I fitted Rizoma Fatbars
Pete Roper GRiSO Capo
Posts : 10711 Join date : 2013-05-29 Age : 67
Subject: Re: Anti vibration bushes Wed Jan 05, 2022 3:20 am
I've got Rizoma bars and Stelvio weights on the Yellow Peril. It buzzes a (Tiny.) bit at 100kph in top, enough to numb the fingers of my right hand after an hour or so, but since an indicated 110 is *Safe* around here I can travel above that point most of the time. Or use fifth gear instead. The bike's real 'Sweet Spot' though is 130-140. At that point it's butter-smooth and eerily quiet. Sadly the wallopers take a dim view of such speeds.......
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Holger Grignapoco
Posts : 153 Join date : 2020-08-22 Age : 72
Subject: Re: Anti vibration bushes Wed Jan 05, 2022 4:33 am
Hello, with your many changes...hardly anything remains of the beautiful GRiSO ...
you have no other tasks?
( I hope you can take a joke )
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SMTCapeCod Tiradritto
Posts : 324 Join date : 2020-12-17
Subject: Re: Anti vibration bushes Wed Jan 05, 2022 6:54 am
evansnows wrote:
I don't run the bar ends on my GRiSO cause they hang out like dogs balls. Result, predictably, tingling vibration through the grips.
Looking at other solutions, packing the bar ends with leadshot encapsulated in silicon.OK up for trying that. But I'm thinking anti vibration bushes between the triple tree and bar supports with rubber washers above and below would be feasible. It is a solution found on some bikes as standard. This is the sort of thing I'm thinking of. Any experience or opinions ?
This is the stock arrangement on my Victory. Early models had bars bolted through a rubber bushing, but that had a lot of excess movement and would wear over time. The next generation used a press fit captured insulator/isolator like the one pictured. I changed from earlier to later, it tightened up the mounting without introducing additional vibration.
PJPR01 GRiSO Capo
Posts : 213 Join date : 2018-04-24
Subject: Re: Anti vibration bushes Wed Jan 05, 2022 10:49 am
Papa Lazarou wrote:
Lazlokovacs wrote:
papa - there's only so far you can cut down the handlebars before you start running out of space for the switch gear.....
Which is why I fitted Rizoma Fatbars
Curious to know which model you fitted? Are they less wide than the originals and do they have a different sweep or geometry for the wrist position? Thanks!
evansnows Biondino
Posts : 202 Join date : 2019-06-05
Subject: Re: Anti vibration bushes Wed Jan 05, 2022 11:06 am
Yes my GRiSO is a different animal to what I started with.
From when I first spotted the Grisos I thought carbon wrapping that exposed frame rail would look good, so that was a given before I even started.
The first cosmetic change when I got my GRiSO was to satin black heat resistant paint and step inboard 19mm the original muffler.
From then the black kind of grew until most of the bike was infected. I chose the red colour because the original black tank and covers didn't contrast with the carbon wrapped frame rail.
The bent coat hanger bolted on to the side stand had to go.
The original speedo / rev counter just didn't cut it for me, whereas the Acewell unit in the custom carbon screen and console I made works and looks great. After coming off and damaging the bike I developed protection for vulnerable areas in case it happens again.
We all know that the original headlight is woeful and the carbon black Stedi unit works really well and suits the bike.
So yes over a period of two years lots of changes. To my mind I've ended up with what is still obviously a GRiSO but tidier and smarter. She certainly gets noticed when out and about.
Mechanically / electrically I installed the essential roller conversion. replaced two bent inlet valves, the left hand switch to have a more conventional control of the lights (off, parkers only, headlights ) and with the indicator switch above the horn button. Beefed up wiring to the starter solenoid and earth and a relay triggering the solenoid to overcome the starting issues and other bits and pieces that seemed like a good idea at the time. Predictably as has been suggested I'll be fitting the black tank badges
Subject: Re: Anti vibration bushes Wed Jan 05, 2022 11:15 am
Yeah, I ordered your tank badges a couple of days ago. They are coming in an order for a Stelvio fork leg which is on back order but it shouldn't be too long.
lcjohnny GRiSO Capo
Posts : 1470 Join date : 2016-01-25 Age : 69
Subject: Re: Anti vibration bushes Wed Jan 05, 2022 11:23 am
evansnows wrote:
.....the left hand switch to have a more conventional control of the lights (off, parkers only, headlights ) and with the indicator switch above the horn button.
Evansnows - did you find a particulafly good left switch option?
Buellbloke Nibbio
Posts : 713 Join date : 2021-07-30 Age : 61
Subject: Re: Anti vibration bushes Wed Jan 05, 2022 12:56 pm
evansnows wrote:
Yes my GRiSO is a different animal to what I started with.
Predictably as has been suggested I'll be fitting the black tank badges
Subject: Re: Anti vibration bushes Wed Jan 05, 2022 1:16 pm
Yes this worked really well and it has a tiny led that shows that I'm running with either the parkers or headlights on. Really turning all the lights off is only if the battery is getting flat and all the power is needed to try and get started. The original switch set up only turned on the parkers when the ignition switch was set to lock or park can't remember which but a total bullshit idea. Of course I had to fiddle with the wiring in the new switch to get everything doing what I wanted when I wanted but with a multimeter to test what came on with which setting that was easy.
Subject: Re: Anti vibration bushes Wed Jan 05, 2022 5:47 pm
I had the fat bars on my streetfighter and liked them a lot. Stock GRiSO bars work fine for me. Pete is right on with the 130, 80mph, that's where mine is happy!
beetle GRiSO Capo
Posts : 10200 Join date : 2013-09-30
Subject: Re: Anti vibration bushes Wed Jan 05, 2022 5:59 pm
. [You must be registered and logged in to see this image.] . In GRiSO we trust! .
Papa Lazarou GRiSO Capo
Posts : 826 Join date : 2014-10-07 Age : 70
Subject: Re: Anti vibration bushes Thu Jan 06, 2022 12:15 am
PJPR01 wrote:
Papa Lazarou wrote:
Lazlokovacs wrote:
papa - there's only so far you can cut down the handlebars before you start running out of space for the switch gear.....
Which is why I fitted Rizoma Fatbars
Curious to know which model you fitted? Are they less wide than the originals and do they have a different sweep or geometry for the wrist position? Thanks!
No worries. Rizoma Fatbars MA009B 50mm height. Narrower than stock with more pullback, so a lot easier (for me, at least) to sit more upright without the outstretched orang-utan riding position of the stock bars.
Subject: Re: Anti vibration bushes Thu Jan 06, 2022 1:59 pm
Papa Lazarou wrote:
PJPR01 wrote:
Papa Lazarou wrote:
Lazlokovacs wrote:
papa - there's only so far you can cut down the handlebars before you start running out of space for the switch gear.....
Which is why I fitted Rizoma Fatbars
Curious to know which model you fitted? Are they less wide than the originals and do they have a different sweep or geometry for the wrist position? Thanks!
No worries. Rizoma Fatbars MA009B 50mm height. Narrower than stock with more pullback, so a lot easier (for me, at least) to sit more upright without the outstretched orang-utan riding position of the stock bars.
Excellent...thank you! That sounds like a good option, I've been contemplating slightly narrower bars, and having them a bit more upright wouldn't hurt at all. Risers and Good Grips are already on, so it sounds like the final touches would be a replacement bar! Much appreciated!