Vibration at highway speed

[Apyle]

I usually avoid the freeway because you miss a lot of countryside and that is what my riding is all about. I went on a ride yesterday which just happened to go right up the freeway. At about 65 mph, 3000 rpms in 5th gear on my 1987 FXRS, there is a vibration that comes and goes. It seems to start in the seat and work its way through the entire bike. It doesn't occur at 55 mph but I would like some ideas on what to check. I'm planning on checking the drive belt and the primary chain. Any other ideas on what could be occurring or what else to check would be much appreciated.

 

[TQuentin1]

I usually avoid the freeway because you miss a lot of countryside and that is what my riding is all about. I went on a ride yesterday which just happened to go right up the freeway. At about 65 mph, 3000 rpms in 5th gear on my 1987 FXRS, there is a vibration that comes and goes. It seems to start in the seat and work its way through the entire bike. It doesn't occur at 55 mph but I would like some ideas on what to check. I'm planning on checking the drive belt and the primary chain. Any other ideas on what could be occurring or what else to check would be much appreciated.

Double check the torque on your neck bearing (fall away). When was the last time you changed tires/had the wheels balanced? Finally, have you adjusted your primary chain tension recently? Those are the quickies that come to mind. Given all that OK, look carefully at your drive belt to make sure it looks OK all the way around. Easiest to put the bike on a lift, or at least raise the rear tire off the ground and with the tranny in neutral, slowly rotate the rear tire while you inspect the belt. When you are done, check/adjust the tension on the belt.

Let us know what you find.

Check out Glider's self help forum for pointers and tips:

Self Help Information and Tips - Harley Davidson Community

 

[Technologist]

What tires are you running? I just got new Metzelers.... and they were AWESOME at low speed (below 50 mph)...

But when I went Highway (65, 75, etc...) I got a bad vibe.

after I scuffed 'em up some they felt better, but still not like the original dunlops....

But the Metzelers are sweet....

 

[Fisher]

What exhaust are you running?
I'm thinking drag pipes.

 

[Apyle]

Ok the tires are a set of brand new HD dunlops. I adjusted the primary chain tension last year when I got it running, about 5,000 miles ago. Yes I am running a set of straight drag pipes. I just looked into getting a set of baffles for them because I get a dead spot in the throttle. I'll check the upper engine mount and all that other stuff, thanks.

 

[wildspirit97]

What tires are you running? I just got new Metzelers.... and they were AWESOME at low speed (below 50 mph)...

But when I went Highway (65, 75, etc...) I got a bad vibe.

after I scuffed 'em up some they felt better, but still not like the original dunlops....

But the Metzelers are sweet....

I would say if you got that problem with a Metzler, or any other quality tire for that matter, that it was a mounting a balancing problem not a problem with the tire itself. If your tires or one tire "is" out of balance your gonna have handling issues and premature tire wear. Might be worth looking into and getting them checked, some places will do it for free if you bring the tire and wheel in.

 

[Fisher]

Ok the tires are a set of brand new HD dunlops. I adjusted the primary chain tension last year when I got it running, about 5,000 miles ago. Yes I am running a set of straight drag pipes. I just looked into getting a set of baffles for them because I get a dead spot in the throttle. I'll check the upper engine mount and all that other stuff, thanks.

Many drag pipe brackets on FXR's are the cause of unusual vibration.It's the way they're mounted.Do yours still have the rear pipe attached to the trans?And then the rubber mount is used to join the two pipes with a bracket?

 

[Technologist]

Thanks, will do, if todays inspection show anything weird. I need to give the bike a "q-tip" clean (a good detailing)... and just got a new jack, so I will lift the bike and check everything out good.

If the vibe continues, I'll just take it back to the shop that put the new tires on...:s