First Ride - First Question(s) - Vibration

[Troll]

Thanks for the reply.

The date code (if I have this right) is 4316.  Not sure how to decipher (I think I USED to know how).  I'm now thinking maybe its engine speed (below), and somewhat encouraged.

So I rode in this morning, paying even closer attention to what was happening.  It SEEMED a little better after addressing the mount bolts, but realistically, probably just wishful thinking on my part.

Bike seems to smooth out a bit over 40, very nice at 50, particularly for such a large twin.  Below 40, particularly below 35 in third, the washboard resonance throughout the bike is pretty strong.  If I am accelerating say, in second, not so noticeable, letting off or shifting up into third brings the vibration.  I pulled in the clutch a few times and held the revs, still there.

This may be a big clue.  When I got to the office here, I revved it in neutral, a lot.  The resonance can be felt as the rpm drops lower, just as it is returning to idle.

Harmonic balancer?  Fueling?  It seems like we're getting somewhere.  And I can't tell you how much any insight is appreciated.

Pic at work - still a very proud papa.  Love this thing.

You must have a number for the code wrong, according to that, they will be made in the 43 week of 2016....

[JagLite]

Tired of tires? 

When I bought my 99 1500 the seller told me the tires were ok but had been on the bike when he bought it 3 years before.
I ordered new tubes and tires for it because I would be riding it from California home to Alaska and wanted good tires.

When I removed the rear tire I found this:

A piece of the tread had broken out down to the cords.
Not what you want on a heavy bike!
A blowout on a highway can be deadly.

The general view is that kind of tread damage is caused by riding with very low air pressure in the tire which can cause cracks as the tire flexes.

My thinking is that (if you haven't noticed yet) checking the tire pressure in the rear wheel is a real pain so it gets ignored.
The front wheel is much easier to get to the valve stem but the rear is a challenge at the best of times.

I have 90 degree angle valve stems as I think most use and that helps a tiny bit.
I also installed the Ride-On Smart Caps that have LED's that light up to let me know if the tire pressure has dropped.
But, as you will discover, you have to roll the bike around and keep checking until the valve stem is visible below the fender.
http://www.ride-on.com/smartcap.html

I still check my tire pressure with a gauge if I haven't ridden in a while but so far I haven't lost any air.
I'm a belt and suspenders guy so as long as a rider checks the pressure regularly the Smart Caps probably aren't necessary.
I like them because I can just roll the bike to see the Smart Cap on the valve and if the light isn't on, I'm good to go.

Valve stem, are you down there?

Anyway, I don't know why you have the vibration, and it shouldn't be tire related if it goes away as the speed increases, but tires are the only connection to the ground and are critical so I would start there.

[Old Drifter]

Robert, on my '99 I had a similar vibration/washboard type feeling when leaning even slightly. I was also thinking the driveshaft/bevel gears, however with only 5500-6000 miles I thought this would be rare. I'm glad I didn't open that up because It wound up being the rear tire. It was worn in the center and the edges were kind of squared off, thus causing the washboard effect. The tire rubber was also old and hard, 17+ years old.

[rwantin]

Thanks for the reply.

The date code (if I have this right) is 4316.  Not sure how to decipher (I think I USED to know how).  I'm now thinking maybe its engine speed (below), and somewhat encouraged.

So I rode in this morning, paying even closer attention to what was happening.  It SEEMED a little better after addressing the mount bolts, but realistically, probably just wishful thinking on my part.

Bike seems to smooth out a bit over 40, very nice at 50, particularly for such a large twin.  Below 40, particularly below 35 in third, the washboard resonance throughout the bike is pretty strong.  If I am accelerating say, in second, not so noticeable, letting off or shifting up into third brings the vibration.  I pulled in the clutch a few times and held the revs, still there.

This may be a big clue.  When I got to the office here, I revved it in neutral, a lot.  The resonance can be felt as the rpm drops lower, just as it is returning to idle.

Harmonic balancer?  Fueling?  It seems like we're getting somewhere.  And I can't tell you how much any insight is appreciated.

Pic at work - still a very proud papa.  Love this thing.

[greenbarn]

Is the vibration related to wheel speed, or engine speed?  Could just be crappy tires -- Can you find the date codes on the tires?

[rwantin]

Thanks Troll!  Yours was one of the threads I looked at while researching.  Thanks for chiming in.

Just returned from the garage (was out there before I saw this).  The frame through bolts were at maybe 15 lb-ft - adjusted them to 33 per the manual.  I will check the rubber grommets on the exhaust.  I did a cursory grab of the muffler - there's a little movement, not rixed overly rigid, which I'm guessing is appropriate.

It's definitely at lower speeds, seems to smooth out above 40.

I think I'll ride it to work tomorrow to get another read, maybe the frame bolts helped.  It's only a 7 mile surface street ride.

So maybe there's hope.  Thanks again.

[Troll]

The propshaft joint vibration usually come in at a bit higher speed, like from 50 up...Incorrect motor mount torque will do it. Start by loosening both front and read mounts and let the engine run at idle for a while. here's a list of correct torque values: http://www.vulcangadgets.com/files/torquesettings.html
Retorque the mounts with the engine off. Make sure that the rubber grommets are in place for the exhaust, especially the 2 BIG ones that support the goat bladder. Try to determine if not only speed, but on/off throttle makes a difference, Get the bike up to speed and pull in the clutch and let it coast down to the problem area...There is a resonance point where the vibe will be, always...mine is about 50 in high gear. Not really bad, but if you're looking for it, you'll find it.

[rwantin]

Thanks guys.  Tires are new, I'm seeing weights, but of course, it may not have been done well.

I'm actually hoping it's not the joint, will see if I can have a look when I get home.  Will also check the torque on the motor mount through bolt.

Again, love this bike!  Most I have owned have required some sorting out, maybe this one needs a bit more than usual.  In any event, it'll be worth it.

[DC]

Great looking ride.

The vibration might be something as simple as wheel balancing.  Before you tear into the shaft gearbox, wait until others weigh in on the other potential vibration causes.

[CDNRatMan]

 Very sweet ride and you will get a lot of expert help shortly, these guys love a challenge.........

[rwantin]

The bike finally arrived Thursday.  Friday, went to the Secretary of State, transferred the title, got plates, and spent all day Saturday going through things.  I've still got some things to go through (fluid flushes, etc.)  One thing is for certain, I am madly in love with this bike.

Father's Day was a good excuse to go for the first ride to Dad's.  The bike starts, runs and sounds beautiful.  And as it was a 90+ degree day, was glad to see the cooling system up to the task.  All good.

Except for one thing, and given the bike's reputation for smoothness, a little disconcerting.  There is a vibration, best described as going over a washboard, at lower speeds (under 40) and light loads.  Seems to smooth out under power and at speed.

I did a little homework here - the ujoint seems to be a potential culprit?  Can something like this go in only 6600 miles?  Granted, that doesn't take into account abuse or an inexperienced clutch hand.  That, and the bike is a 1999, so there were perhaps extended periods where it didn't move much.

Admittedly, I have not inspected yet, is this something that can be done without a lift?  I've never needed one before but obviously I do now.  I have had a few shafties in my sordid past but never had to go into them other than gear oil changes.

Any other areas I should consider?  Stock muffler and mounting appears sound.

Sorry, new baby and temporary Vehicular Hypochondriac, hence stupid questions.  I do nearly all my own work, just not familiar with this bike (yet).  That will indeed change.

Thanks!

Robert