Handlebar vibration

I would like to reduce the handlebar vibration on my '94 R100RT. I heard of an item called the bar snake, but two riders who tried it (on other makes, not BMWs) said it did not work as expected. Also, once you put that thing in, it looks impossible to get it out.

One recommendation I got was to fill the bars with small lead shot. If that does not work, at least the shot can be removed.

Can anyone tell me what you have tried? I am not trying to eliminate the vibration, just make it more tolerable. My fingers tingle after about 20 minutes at speeds of 60-65. At 70, the vibration is gone, but it is hard to go that fast on the freeways here due to numerous speed traps.

Before you get into these kinds of "fixes", be sure that your carbs are balanced. Do you feel buzzing in the footpegs and in your butt as well? If so, then you really should look into the carbs. Also, use a timing light and shine it into the timing hole on the left side of the bike. If you see double images of the marks at idle and also full advance, then you have ignition problems that are also contributing. This means that the firing pulses for the left and right side are not at their ideal points...this is harder to fix.

And I'm sure you've already done this, but be sure that all the fasteners holding the handlebar on the triple tree are tight...

Kurt in S.A.

The carbs are balanced. The carb stix show both columns nearly equal height all the way up to 4,000 rpm. Very little footpeg vibration at any speed and rpm. No seat vibration.

I had an '88 airhead some years ago. It also vibrated at the same speed and rpm as the '94. Once you get to 4,000 rpm, vibration is minimal.

Bike pulls hard during acceleration, no misfires, etc. Cruise at 70 mph or above in top gear is very smooth.

Must be the system harmonics. These bikes just get in a vibration zone at 60-70 mph.

Well, I guess you've got the important issues covered. I've never ridden an airhead other than my /7 and I don't notice any annoying vibrations. The mirrors are not crystal clear, but the level of vibration isn't enough to make me notice it in my hands.

You could try the lead shot, but you really want the material out near the ends. How would you keep the lead shot from moving around...unless you completely filled it but that would result in quite a bit of weight in the bars.

I seem to recall that some of the crotch rockets have small metal extensions just outside the grips. I'm sure these are designed to keep vibrations down. I think they're weighted and out at the ends where they do the most good.

Good luck...

Kurt in S.A.

my bike vibrates too more then I would have liked, everything is tuned and balance using an electronic balancer and a timing light
I put on a set of grip puppies, and thta took care of my vibration "feel"
but to me, this bike is still smooooth, my last bike was a 900 kawzaki, and talk about vibration

Most who ride my bike would say that the vibration is not that bad, but I am very sensitive to vibration. My fingers will start to tingle in short order and that limits my riding time.

I thought about trying the bar end weights. I have seen them on other bikes. Sometimes a bit of mass in the right spot is all it takes. Most of these bar end weights thread into the end of the bar. No way to do that on the tubular bar without making some sort of threaded adapter to attach to the end of the tube.

I am not too keen on the lead shot idea. It would have to be packed in and secured somehow, maybe with RTV forced into the end of the tube. The added weight may be a problem.

Funny thing is that the left grip vibrates worse than the right. Go figure. Maybe the mass of the brake reservoir and plumbing is enough to make a difference? No reservoir on the left grip (cable clutch) so I have no other explanation for the difference in vibration between grips.

What about taping some lead weights, etal, to the bars as a short term experiment? If that worked, then you could replicate the weight and/or location with lead shot or part of a bar snake. That would allow you to try different things before you committed some money and "real" effort.

Kurt in S.A.

Kurt:

You and I are thinking alike. It would be no problem to cobble up something and temporarily attach it to the end of the grips. It would not look pretty but it would provide some good data to run with.

Another idea I had was to attach a brace between the riser portion of the bars. I have seen this on some handlebars, usually on dirt bikes. This might reduce the tuning fork characteristics of the tubular bar. This would not be my first choice as a fix. That brace just might get in the way of other things.

Try switching the grips to a foam style. They may soak up the vibration just fine for you and they can be had cheap.

the grip puppies are foam, and they did soak up lots of vibration

Isamemon said:

the grip puppies are foam, and they did soak up lots of vibration

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But now you have to squeeze through extra layers of foam to get the same level of feel on the grip. I've got some aftermarket kind of foamy things on my R69S and don't really like how I have to squeeze ever so much more...

My 0.02...Kurt in S.A.

thats ok
my bike ahd the original rock hard grips, and with my old age, after a few hours, the arthrhitis etc began to kick in
so I tiried the foam, and at first I did not like the way they felt, and moved, but after a weekend, they stuck to the old grips good enough to feel part of the bike, and the extra diameter, and less vibrataion was a real help for me
but it could have been my old grips
as my brother has a newer rt, and his grips have a lot more "factory sponge"
Im riding an old stock 78 r-80/7
and at $7 it was worth the experiment
those interested, look under gear forum for the thread "larger handgrips", thats what got me to the puppies

fracture said:

The carbs are balanced. The carb stix ...

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If you're using carb sticks, you'll never know whether your carbs are balanced by observing this tool.

More importantly, R100 Airheads DO NOT vibrate substantially when carbs are balanced except for a few apparently built with unbalanced parts.

I'd recommend treating disease rather than symptom.

lkchris said:

If you're using carb sticks, you'll never know whether your carbs are balanced by observing this tool.

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Please explain.

fracture said:

Please explain.

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No serious BMW mechanic uses carb sticks. They're not a precision tool.

Most these days use Twinmax, but the point is to use a dial type vacuum gauge with centering based on opposing inputs.

I do not see how a column of mercury can be considered inaccurate. If two columns are the same height, what is the problem? How is a vacuum gauge any more accurate? Never used a Twinmax, so no experience there.

Of course, no instrument is 100% accurate. Variations exist. But if the carb stix are no good, then I should have a very lumpy idle (it is smooth), and at 70 mph in top gear the bike should shake (it is smooth).

If the stix columns are uneven, the idle is lumpy and I feel more vibration everywhere. I see no reason why the stix are not good enough. I can try vacuum gauges and see if there is a difference.

This bike, like the one I had before it, simply has certain zones where the harmonics of the system create more vibration. I have been on other makes that have the same characteristics. There may be no easy cure.

being an old fart who worked on old english cars, I have the balancing "sticks" ( old unisyns) and another nice old tool called a color tune.
I thought I had the carbs pretty darn good, but still had a rough spot and thought the bike ieled a little rough
used my brothe rin laws vacum balance, and I saw an amaing difference
dont think his was called a twinmax, sure there is others out there, but , made a real difference, and fast and easy, and did not have to remove the airhorns
Im sold

Isamemon said:

being an old fart who worked on old english cars, I have the balancing "sticks" ( old unisyns) and another nice old tool called a color tune.

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Hi,
Unsyn and Color Tune. Are you bringing back memories or what? I never had a Color Tune, but I've seen them, and I used the Unisyn to balance carbs on my 3.8 MkII Jaguar, TR6, and BMW Bavaria (with an adapter). The most recent of those I sold 30 years ago! I suppose the Unisyn might be able to be made to work on an airhead. Now that I'm a convert to the Dark Side, airheads are also distant memories.

wow another old fart like me
someone that has even heard of a color tune
sorry about that
yes I used them on old jags, tr's, mg's whatever
and with a unisyn and a color tune, I could zero in a old british car better then the factroy trained dealers/mechanics
thats how I made my "chings"
but you talk about being a convert, and airheads are........old
for me...........simple..........old.........I can work on them without a bazillion dollars in tools and computers
give me an airhead, or a TR-3 or 4
something, in the middle of nowhere, I can limp home
yes , strange person I am

luke
dont look to the darkside

so why couldnt you get a unisyn to work
just got to pull off the air horns
I had no problems
except for instead of swithching carbs an inch from each other, I had to reach around 6 gallons of gas ( the gas tank)
the dual vacum boxes are fast, and a fuzz more accurate, but read FAST
and color tunes
wowie zowie, ill take a pair over a computer ( $120 over 2k)
a computer gets it at the tail pipe,( we all do) both carbs can be way off, one ugly rich , one vlave burnig lean, and in the tailpipe balance each other. color tunes tell you what a carb is doing , right there at the head, sometimes millimeters from the carb, EACH CARB
I actually own 3 from the old jag days
6 cylinders and 3 carbs
colortunes and a unisyn
ill sell you some , as an old friend, a old jag mechanic ( trully from the old country, who taught me, adn went home) can get them at a good price
but for me, in my olden days, when rocks were soft and rear shocks had chrome covers......................
............. if the dealer couldnt tune it with the computers and exsaust analysers they brought it to me.............chings
jags, tr's, mg's. maserattis, ferraris, multi carb hot rods, and now out of retirement,,,,BMW scooters


luke
dont look to the darkside
come back to the airheads
memories are good thing( I know your name is not luke, just trying to play on the darkside thing of star wars)

folks, im in the retirement, not drumming up work, no brownie points needed, just trying to help some of you out