Triumphrat

RICHO

My 71 OIF Bonneville has developed quite a heavy shuddering vibration going through the rev range at around 3000. If I were in a car I would suspect a wheel had become out of balance. Nothing up to 3k, and stops after about 3.5k and seems more pronounced when she's warmed up (as well as quite "tappetty" pulling low gear low revs. This is a recent thing (last half dozen rides) and seems to be getting worse.

Any clues as to where to start looking?

My thanks as always!

jimmy bush

Check all your frame/engine mount bolts for tightness, including the head stay. Look for cracked engine mounts while you're at it. Check that the chain hasn't tightened up or developed a tight spot. If you have twin carbs, check for balance. Check your timing.

30942

That's just the motor doing it's thing. I can tell when I hit 3K and when I pass 3.5K, just like you..... I checked my wheel weights the first couple of times also.... Thought I threw one off. (don't use weights anymore, but that's a different story).

Now, with that said, if it's real bad, you might have a problem. But real bad has to be determined in person. I'm saying mine does it and its cause is the engine design....

pookybear

Richo,

Listen to Jimmy's advice. And it depends on the riding you do
where to look first. Just doing light crusing say under 50mph.
Check the carburator balance and sync first. If you find yourself
blasting down the highway all the time. Look for lose bolts and
engine mounts.

Pookybear

RICHO

I have a wheel weight on the front, but not the back! Is this to offset the valve,etc and balance the wheel? Should I have one on the back? Could it have fallen off? Could that be shuddering at certain revolutions? Why is the sky blue?

30942

I'd definitely replace that first to see what happens. Myself, personnally, I'd not go through the entire process of removing the wheel and balancing tho.. Just get some of the motorcycle stick on weights, stick one on opposite of the valve and give her a test ride.... then try two weights.... see if the vibration changes.

How bad is the vibration? Is it a teeth rattling, arm shaking kind of deal? If you relaxed your head/neck, would your vision jiggle? Have you had the bike a while and you are familiar with the ride and now it's different?

RICHO

I'll try that - seems like a pain to whip off the back wheel. This vibration is new, and its a teeth rattler!

30942

That sounds like it.... There probably should be something there to balance the wheel and it probably fell off.....

Now, to my other story that I mentioned in the earlier post (why I don't have wheel weights...) -- There is a product called Dyna Beads -- little itty bitty ceramic beads that you put in the tire (tubeless and really simple) or in the tube through the valve stem -- a royal PITA. Takes a bout 20 minutes to get them in the tube this way. But once they are in, you are good to go. Ever since I've started using them, smooth ride and no wheel weights at all....

If you want to know more, look at this.... http://www.innovativebalancing.com/motorcycle.htm --- poke around on the site and you'll get the whole theory as to why they work. Other forums (BMW and ADVRiders) seem to almost swear by 'em.

72TIGER-X

out of balanced wheels shake at a speed not a rev range, go with what jimmy said

pookybear

Richo,

I have no weights on my wheels and no viberation from them,
you can also use a liquid blanancer in your tubes. But really if
it has just started you are looking for loose parts, unbalanced
carburators or ignition problems.

And the second part of your question Why is the sky blue?

Easy the atmoshere is full of small dust particles. These particles
act like a small filter. As we all know white light is composed of
different wave lenghts of light. Each producing a visible color to
our eyes. Now each wave lenght will travel so far through a dust
filter before it gets filter out and is no longer a major componet
of white light. Some of the componet will make it through but most
will not.

As it works out the distance of atmoshere with the normal amount
of dust with it, filters out the blue wave lenght most of the time.
As the sun sets it goes through more atmoshere and thus more
dust, so purples and reds come to be filtered more.

This also is the reason why grass and most plants are green, as the
is the color wave lenght that reaches the ground the most. Thus
chlorophyll is amided at that wave lenght of light as it is not filtered
out.

Easy eh?

Pookybear