Buzzy vibration above 60 mph

[jag69]

I am new to this Forum as well as to the GS500.  I have a 97 GS and love it.  The bike runs smooth and strong.  My question is this:  Is it normal for the GS to have a buzzy vibration above 60 mph in 6th gear?  Yesterday was my first time reaching this speed.  The only thing I have changed to the GS is new Tires (BT 45's) and a tank bag.  I purchased the bike from a dealer and it was serviced before delivery.  Thanks in advanced for your input.

[jag69]

Correction.  I did travel once at 60 mph with the old set of tires.  I don't recall any sort of vibration.  Could it be the new tires?  Balancing? Alignment?

[snapper]

depends on how much buzz you got.  I have a 91 and yes it vibrates at around 6000 RPMs.  If I am running at 5000 its pretty smooth.  From my understanding that is normal for our bikes.  
There was a thread on balancing carbs.  I think one of the gurus mentioned this in particular.  
Welcome aboard!
:mrgreen:

[rjsjr]

Its not unusual to feel a "buzzy spot" around 5500 rpm (mine does that a bit - not too noticeable).  With new tires one would tend to think of out of balance wheels, but that usually feels more like a thumping or pulling rather than as high frequency as buzz.  Check to see if you can reproduce it at the same engine speed in other gears or at the same speed at different rpm.  I don't think there is much you can do about it (blueprinting and balancing the engine would be extreme), but its nothing to worry about and usually not too noticable.

... rjs

[Pkaaso]

The_good_guys's bike had about the same problem.  We sync'd the carbs and this seems to make it better.  The bike is a two cylinder and it's normal for twins to vibrate.

We used the aquarium hose, yard stick, with a lite oil in it to syc the carbs.  It worked better than my expensive gauges.

If someone could find the thread it shows how to make one for a couple of bucks. I would but I'm lazy after 4 days of 10 hour graveyard shifts.

Paul

[jag69]

I road again last night and I tried to duplicate my rpm's in different gears.  You guys are correct.... same buzz.  It didn't bother me as much because I new what to expect.  The best remedy I could figure out was to sit further back in the seat about 1 inch so that I was not up against the tank.  This made the ride more comfortable.  I didn't feel like I was riding a weed eater anymore.  One question, How comfortable is it to ride distances with the buzz?  Thanks for the input.

[scratch]

The buzz hasn't bothered me on long rides over 200 miles (not continuous, maybe two 100 mile stints).

[glenn9171]

I don't know.  I'm not usually at 6000 RPM for more than a second.  Highway cruising for me has the tach about 9000RPM.  Quite smooth in that range.

[Kerry]

I don't know.  I'm not usually at 6000 RPM for more than a second.  Highway cruising for me has the tach about 9000RPM.  Quite smooth in that range.

Wow - 9000 RPM on the highway?  What size is your rear tire?  Do you have a 15-tooth front sprocket?

I ask because with my stock 16-tooth sprocket and a 130/80 BT45 on the rear, turning 9000 RPM in 6th gear would (theoretically) put me at 100+ mph.  I'm usually between 6K and 7K RPM on the freeway, which puts me at an indicated 75-85 mph in 6th gear.

Just curious....

[Cal Price]

Off topic, be very carefull on new tyres for at least 600 miles they are a bit too shiny to grip in the wet.

[glenn9171]

I don't know.  I'm not usually at 6000 RPM for more than a second.  Highway cruising for me has the tach about 9000RPM.  Quite smooth in that range.

Wow - 9000 RPM on the highway?  What size is your rear tire?  Do you have a 15-tooth front sprocket?

I ask because with my stock 16-tooth sprocket and a 130/80 BT45 on the rear, turning 9000 RPM in 6th gear would (theoretically) put me at 100+ mph.  I'm usually between 6K and 7K RPM on the freeway, which puts me at an indicated 75-85 mph in 6th gear.

Just curious....

Yes, 15 tooth front sprocket.  BT45's in stock sizes.  9000 RPM is about in "indicated" 95MPH.  Lower 80's actual speed.  That's just keeping up with the traffic around here on I-12 and I-10.

[brandiwine]

do you have engine guards installed.  i'm asking because i read last night the link off this site about racing a GS and there is a buzzing sound when the engine guard is broken at the lower mounting point and it goes unnoticed.  buzzing stops when he puts his foot on the guard.
here's the link:

http://gstwin.com/racers_corner.htm


the info i'm referring to is towards the very, very bottom of the page.  there are pictures that show the breakage.