[meilaushi]

I know thumpers vibrate, but mine seems to do so more than otherwise I'd expect.  It's nice at around 40mph (where the cars around here run up your rear fender) but at 50 its a bear, and I can just imagine what it'll be around 60, though I see fellows who say they run their Bullets at that speed rather nicely.  Are some of these engines so out of balance that they vibrate that much?  Will it tone down as I get more miles on it (right now it's just over 800 on the odo)?  It's fun at 50 but feels like it's going to vibrate itself apart.  Is this normal? 

[Thumper]

I know thumpers vibrate, but mine seems to do so more than otherwise I'd expect.  It's nice at around 40mph (where the cars around here run up your rear fender) but at 50 its a bear, and I can just imagine what it'll be around 60, though I see fellows who say they run their Bullets at that speed rather nicely.  Are some of these engines so out of balance that they vibrate that much?  Will it tone down as I get more miles on it (right now it's just over 800 on the odo)?  It's fun at 50 but feels like it's going to vibrate itself apart.  Is this normal? 

Thumpers vibrate a lot. Do you have a basis of comparison? If you really feel it is excessive, there are common-sense things to check:
- You're at 800 miles. Have you done the critical 300-500 mile initial break-in maintenance? This includes re-torquing the cylinder head - which is important and could add to vibration.

- Ensure that all engine mounts are fastened securely
- Ditto your remaining frame/chassis components (including handlebars), brackets, nuts, bolts etc.
- Related to the first item: ensure that the bike is in a good state of tune - especially the ignition timing and valve tappet adjustment.

Matt

[Foggy_Auggie]

Mine came up on 2600 miles yesterday.  Have to say I don't really think about vibration much.  It's subjective by mood, speed and road conditions.

Some days I notice it more than others.  Mine increases a bit over 60 MPH indicated and it's through the bars more than the seat.

I just reshift it to make sure I'm in 5TH gear and keep on truck'in!

[bob bezin]

vertical twins viabrate just as much , both pistons going up and down at the same time some newer bikes have counterbalanced cranks which smooth out the vibes quite a bit.i has a 400cc suzuki that was very smooth  did  two really long road tripe two up on it on the interstates but that was about 20 years ago

[Leonard]

Check the head steady.

[cyrusb]

You might want to take out the quill bolt and observe the end of the crankshaft in motion in addition to what is mentioned above. Just to be sure.There should be little to no observable runout.

[Bankerdanny]

At 50-60 mph I get more of a high speed buzz than a shake.

[DonK]

at that speed, maybe front wheel out of balance?

[Foggy_Auggie]

A spoked front wheel that has a rim slightly out of true will cause a slight oscillation in the handlebars at speed.  Also a tire slightly molded out of true.

Usually it's so minor that as long as all the spokes ring tight it's left alone.

Prop the front of the bike up with a block under the front down tube bracket at the crankcase.  Spin the front wheel and eyeball it.  Tap the spokes with a wrench and make sure they have the same tone.  Tighten any loose ones and keep spinning to make sure it's still true.

If it's out of true and the spokes are tight, it's best to take it to a bike shop - unless one has the patience of Jobe!

[meilaushi]

I suspect it's probably the engine... sometimes it seems smoother than other times.  Maybe it's a bit like Beemers... mine smoothed out after about 5000 and really got better after 15000.  Seems the Bullet's a bit less inclined to vibrate now at 800 miles than when first brought home.

I'm hoping it's normal as I strongly suspect.

[deejay]

I put on an 18T sprocket and it makes for a much more comfortable ride. I recommend it.

[PaulF]

Deejay, how do find it effects your low-end torque?

I thought about this but I'm afraid of losing that low-end grunt that the RE is (relatively) good at.

[Bankerdanny]

I have the 18-tooth on my 2002 4-speed. I didn't notice any decrease in low end power (but then it wasn't very quick off the line to begin with) but my mid range seems to be much better and the overall flexibility is much improved.

At 60-65 mph revs are down just enough so that it doesn't feel like the engine is pushed to the limit.

[PaulF]

How about the chain? Did you have to remove a linik or was there enough adjustment?

[Bankerdanny]

There is enough adjustment to use the stock chain as is.

[Foggy_Auggie]

Ticked over 2700 miles today.  Made a point to notice vibration.  No buzz through the handlebars nor through the footpegs.  Nothing to note at all.  But didn't go over 55 MPH and it is 90 F and humid.  The forks just did the shimmy shake while stopped at idle - this was stopped by applying the front brake.

My Honda Nighthawk would have left me with hand tingles - I ride it faster...

[clamp]

At 800 miles you should still have some call on the dealer. It should not be that bad that you notice it or feel you  have to write in about it.

     They are not well built and Im sure that sometimes a bad one gets past inspection . If it is that bad it needs looking at. Take it to any dealers and get a ride on another to base a comparison.

       I am at a total loss as to how a untorqued cylinder head could cause vibration.

   Check to see if  the cylinder head brace has been removed or is loose.

[Foggy_Auggie]

Also check to see if the front and rear gas tank mounting bolts are snugged up.  If they are loose a vibration and a noise resonance is telegraphed through it.

[Thumper]

       I am at a total loss as to how a untorqued cylinder head could cause vibration.

Go out into your shop and grab any mechanical device that is assembled with nuts and bolts. Shake it. Notice that it moves as if it were a single, solid object. Now, loosen all the nuts and bolts and shake it again. Note that it now feels like what it is: a loose collection of parts that move and shake and rattle.

Matt

[clamp]

An untorqued cylinder head means the bolts or nuts are not sufficiently torqued ,--it does'nt mean it is falling off or rattling about!!!!

   We are also talking of two different things here,- vibration--the consiquences of vibration and the amplification of vibration.

    I think we need to determine if it is vibrating or not,-as in something out of balance.

[Thumper]

An untorqued cylinder head means the bolts or nuts are not sufficiently torqued ,--it does'nt mean it is falling off or rattling about!!!!

   We are also talking of two different things here,- vibration--the consiquences of vibration and the amplification of vibration.

    I think we need to determine if it is vibrating or not,-as in something out of balance.

The example I gave was exaggerated to make the illustration. The principle still applies. The extreme stresses involved in combustion will result in vibration when the head, cylinder and crankcase are not sufficiently fastened together (torqued).

Upon breaking in these engines (like so many engines of older design), it is critical to retorque the heads after several hundred miles - and the manufacturers recommend what that mileage is. All of the motorcycle I've owned which required that I retorque the head during break-in - from Urals, to SR500s,  to my Bullet, to even an Evo Sporster - has needed to be retorqued significantly. It is my experience that many, many things can contribute to vibration. I've offered up one possible cause that can be checked, and possibly eliminated - based upon my own experience.

Whether you understand how it can contribute to vibration or not, why in the world would you recommend against checking the torque of the cylinder? That just doesn't make sense. Do you think that checking the torque of the head to the cylinder to the crankcase is harmful? If not, what is the point of your reply? Why would you advise someone to not check a possible cause - especially when it's something that should be regularly checked anyway?

Maybe we should all refrain from offering suggestions and just let you provide the answers.

Matt

[clamp]

 The cause of the vibration is  what we need to determine.

     That does not include an untorqued cylinder head. But hey check it if you want.

     As far as I know the head does'nt move making me feel that it probably isnt the source.

    More likely to be a poorly balanced crank shaft,-- would'nt you say.

   However before we get there,- we should determine if the owner understands how much vibration is normal.

[meilaushi]

Yeah, that's the problem.  I'm not sure how much vibration is normal.  I have a new ('07) Bonneville, and it's smooth--well counterbalanced.  But the RE, which I actually prefer, vibrates like a beast betimes... as if something isn't quite balanced, but it could just be the fact that it's a thumper, though I've also ridden a BMW F-Bike, and while it is noticeable that it's a single, even though it's a 650cc there's no vibration anywhere near the amount the RE treats me with.  But of course, comparing a Beemer to an RE is comparing apples and oranges.  Foo.

[cyrusb]

Have you taken out your quill bolt and  observed the crank end runout yet? It takes all of 2 minutes and is a good start at solving this problem.

[PhilJ]

[quote author=meilaushi link=topic=1897.msg19491#msg19491 date=1216754059
.....I've also ridden a BMW F-Bike, and while it is noticeable that it's a single, even though it's a 650cc there's no vibration anywhere near the amount the RE treats me with.  But of course, comparing a Beemer to an RE is comparing apples and oranges.  Foo.
[/quote]

The F650 is way counter balanced. and with the rpms that thing turns shouldn't even be compared to a real thumper.. First hand info...that was the last beemer I owned. And this is the first RE I've owned and wonder what took me so long...