2008 FXSTC Vibration under load
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Joined: Jun 2009
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From: Alexandria, VA
2008 FXSTC Vibration under load
I've got a 2008 FXSTC Softail Custom with 11,000 miles on it...New rubber at 8300 miles, w/balancing. Well cared for at all maintenance intervals, etc.
I went to a run in West Virginia last weekend and began noticing a pretty serious vibration under load when pulling up long grades. It seemed to be most pronounced in 6th gear, running at 65-70 MPH, and rolling in some throttle to maintain speed or pass while pulling up a grade. I'd feel the vibration in the foot pegs, handlebars, and in my butt.....basically everywhere. As soon as I rolled out of the throttle, it stopped instantly. No vibration whatever unless the bike is under load....acceleration or up a grade. It was almost like a chatter, like maybe something was loose.
I had a similar feeling in a bike a long time ago, on a old panhead chopper. When the tranny mounting bolts loosened up (and it happened all the f'n time), I'd know immediately because I'd feel a vibration or chatter under load. While this an entirely different machine, the darned feeling was almost identical.
Could this be a belt? Primary chain? Anything else? Is it normal and I'm just getting around to noticing it?
Thanks
I went to a run in West Virginia last weekend and began noticing a pretty serious vibration under load when pulling up long grades. It seemed to be most pronounced in 6th gear, running at 65-70 MPH, and rolling in some throttle to maintain speed or pass while pulling up a grade. I'd feel the vibration in the foot pegs, handlebars, and in my butt.....basically everywhere. As soon as I rolled out of the throttle, it stopped instantly. No vibration whatever unless the bike is under load....acceleration or up a grade. It was almost like a chatter, like maybe something was loose.
I had a similar feeling in a bike a long time ago, on a old panhead chopper. When the tranny mounting bolts loosened up (and it happened all the f'n time), I'd know immediately because I'd feel a vibration or chatter under load. While this an entirely different machine, the darned feeling was almost identical.
Could this be a belt? Primary chain? Anything else? Is it normal and I'm just getting around to noticing it?
Thanks
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From: Rochester, NY
That speed/rpm range is not one the engine/drivetrain combination is very happy in, especially under load.
I have found that you can cruise just fine in sixth down to as low as maybe 45mph, but if you are not going down a steep grade you better be ready to drop it into fifth, fourth or even third if you expect to put the engine under load.
Cause that nice big 96incher and sixth gear do not like one another below about 60mph and it can get really ugly if you try to crank on the throttle too fast.
Scared the crap out of me the first time it happened. I thought the engine was going to jump out of the frame and bite my *** for being stupid or something.
I have found that you can cruise just fine in sixth down to as low as maybe 45mph, but if you are not going down a steep grade you better be ready to drop it into fifth, fourth or even third if you expect to put the engine under load.
Cause that nice big 96incher and sixth gear do not like one another below about 60mph and it can get really ugly if you try to crank on the throttle too fast.
Scared the crap out of me the first time it happened. I thought the engine was going to jump out of the frame and bite my *** for being stupid or something.
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From: Alexandria, VA
#705 of 2600...I think that's the number. Will double-check when I get home.
The feedback helps a lot. I'm going back up in the mountains for East Coast Sturgis, with about the same load of stuff, and I'll screw around with gears. I never run in 6th below 60 MPH...the bike hates it.....but I never really noticed this damn vibration above 60 under load. Maybe it was the long uphill grades that made it more pronounced and noticeable. Hell, I just rode the thing 3,140 miles the first two weeks of July, but not a lot of mountains. Went from Alexandria, VA to Nashville, to Vicksburg, to New Orleans to Jacksonville, and back to Alexandria.
I'll add that this is the best damn motorcycle I've ever owned, and I've had a few. Never let me down once on that trip. In context, the vibration is small stuff, and just one of those things that I was wondering about.
Thanks, all....Ride safe
Ken
The feedback helps a lot. I'm going back up in the mountains for East Coast Sturgis, with about the same load of stuff, and I'll screw around with gears. I never run in 6th below 60 MPH...the bike hates it.....but I never really noticed this damn vibration above 60 under load. Maybe it was the long uphill grades that made it more pronounced and noticeable. Hell, I just rode the thing 3,140 miles the first two weeks of July, but not a lot of mountains. Went from Alexandria, VA to Nashville, to Vicksburg, to New Orleans to Jacksonville, and back to Alexandria.
I'll add that this is the best damn motorcycle I've ever owned, and I've had a few. Never let me down once on that trip. In context, the vibration is small stuff, and just one of those things that I was wondering about.
Thanks, all....Ride safe
Ken
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Joined: May 2008
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From: Houston, Texas
Question?
do you get the same feeling if you are in a lower gear, same speed/situation?
does it happen if you are in a different gear (5) but about the same RPM's?
I very rarely use 6th...below 70...even on the flat roads I ride...
CC
do you get the same feeling if you are in a lower gear, same speed/situation?
does it happen if you are in a different gear (5) but about the same RPM's?
I very rarely use 6th...below 70...even on the flat roads I ride...
CC
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From: Alexandria, VA
Going to experiment a little with gears, etc and see if I can re-create the condition...Will update the thread.
I've got a friend with a Heritage Softail who runs in 6th all damn day, and she swears by it. Fast, slow, whatever. I figure hers is somehow geared different. My bike just won't run right in 6th below 60. I gotta get into 5th.
I've got a friend with a Heritage Softail who runs in 6th all damn day, and she swears by it. Fast, slow, whatever. I figure hers is somehow geared different. My bike just won't run right in 6th below 60. I gotta get into 5th.
Tourer
Joined: Feb 2010
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From: MCAS SC
Check your motor mounts, including the big allens in the cyl heads. First thing I would look at assuming you haven't thrown a weight off a rim, is the mounts, all of them, torqued to spec. It might be lugging, not arguing that, especially if it is bone stock, but I would want to get that bike on a lift and take look if it persists.
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6th Gear
Joined: Aug 2008
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I got an 08 Crossbones with Short Shots, high flow air cleaner and a Power Commander. It's had two dyno's (another story) and dyno's great. I have the same issue. Anything under 65/70 and it's like sitting on a jackhammer. Really started noticing it when I went to a frame mounted seat but I could tell it wasn't quite right with the stock seat. Very slight improvement with the windshield removed. Talked to two different dealers and the both said it's common and normal. I use 5th most of the time and don't worry about it.
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From: Alexandria, VA
Great info, everyone. Thanks. This thing is about due for service, so I'll have them check mounts, etc when it's in. That description of the Crossbones just about tells the tale!
It's just about stock. Had them put on side-slash pipes when I bought it, which required a Screaming Eagle ignition kit, a SE inner air filter kit, and remapping. But that's about it.
It's just about stock. Had them put on side-slash pipes when I bought it, which required a Screaming Eagle ignition kit, a SE inner air filter kit, and remapping. But that's about it.