Eliminate Handlebar Vibration, Kill It DEAD with a Fake Snake!

T

Tomterrific

XS650 Junkie
Messages
810
Reaction score
129
Points
43
Location
Columbus, Ohio
I used a thick vinyl tube about 5/8" in diameter. Cut the tube to the length of my flattrack bars and plugged one end. The tube was filled with #12 lead shot which I had on hand, then the tube was plugged on the fill end. The tube is heavy but only about a quarter of the weight if I filled the entire bar with shot. I greased the tube and forced it into the bars through the throttle end. Note that the length was cut slightly less than the bar so the end would not interfere with the throttle. This trick virtually eliminated the vibration below 60 mph (stock gearing) and the bike feels good to a 75 mph cruise. I notice the footpegs really vibrate and that is the bothersome area now.

Soon after I talked about my 'fake snake' another long distance XS650 rider did the same and reported the same great results. Many have since done variations, all helping with vibration but I can only vouch for my method. The weight of the lead, the small individual shot vibrating together, the semi flexible thick vinyl tube jamed tight through the bars, plus the tube being a smaller diameter than the inner diameter of the bars allowing it to move, all this I calculated would help in some way at some rpm.

Tom Graham
 
There was another recent post about vibration and oldbiker mentioned that someone he knew put solid bushings in place of the rubbers ones and it cured the vibration problem. This would be an easy lathe project but I wonder what the result would be. I know Hugh sells a kit for $75 on his site but have never heard of anyone using them or the result. You can buy a 12" piece of 1 3/4" 6061 alum for around $13, might be worth a shot.
 
Last edited:
I have the original rubber bushings on teh handle bar risers. Like so many others, I used washers that fit over the shaft of teh risers and inside the top fork clamp so the rubber is forced into compression and becomes very tight. I did this for assured handling not vibration control. Neat if I got a little vibration control out of this mod/fix for the loose bar mount rubbers but the bars still vibrated until I used the Fake Snake.

Tom
 
I think I siliconed an old bolt forced into the end but I really don't remember. Friends have used lead shot in the bars of a daily rider and the shot turned to dust from teh vibration. I was worried about the lead dust so I sealed the ends quite well and securely.

Tom
 
What do you suppose the result would be if you used soild bar stock for a set of bars? The 7/8" material isn't that expensive for steel, aluminum or even stainless. The trick would be getting it bent to shape.
 
Hi Kbetoy 79 xs.Question has anyone installed a steering damper on a 79 xs ? I am looking to get rid of vib at hwy speed. Any help would be great. Thanks kbtoy
 
If your bars vibrate that much maybe it's time for a carb synch'ing session, maybe tune up in general since timing being off can also generate more vibrations.

My bike vibrates through the pegs and seat a bit at certain RPMs, but the bars are not an issue when it's tuned.

If you need a steering damper something is fishy IMO...
 
Hi kbtoy The vibs In my bars are just bad enough tobe annoying I want to install the aftermarket damper because the bike will see alot of hwy miles Thanks
 
^Probably. When put cb750 bars on my xs I noticed the ends had some kind of big heavy slug made into them. It eliminated some vibration, but there never was a lot to start with.
 
A damper that fits between the frame and forks won't help the handle bar vibrations. They help control steering head shake.
I have a set of bars that came on my 75 and a set of bars off my 82 XJ650. Both are bent the same. Superbike bars I think is what they are called in the catalogs, Any way both had steel inserts in the bar ends. The ones in the bars off the 75 came out. They are a slip fit in the bars with grooves about a 1/2 inch from the ends. Maybe for O-rings to hold them in place. The 82 bars the weights don't come out. They may help a bit.
I agree that proper engine tuning helps as much as anything. A well tuned engine with properly synced carbs reduces vibes a tremendous amount.
I thought that pushing a plug down in the bars and pouring melted lead to fill the bar ends full.
I think this will work better than lead shot.
It will weigh more and not turn to powder as shot can.
Leo
 
XSLeo said:
...I thought that pushing a plug down in the bars and pouring melted lead to fill the bar ends full.
I think this will work better than lead shot.
It will weigh more and not turn to powder as shot can.
Leo
Click to expand...

I've thought about that. Have plenty of lead (for makin' musket balls). If/when I can get a handlebar similar to my stocker, maybe 1"-2" narrower, I can give it a try. Current stock bars have steel slugs in 'em.
 
I don't know for sure just how those end weights are installed. They might be a lot like the ones of my 75 and are held in place by O-rings. Can they be pushed in? If so you might try drilling and tapping a hole in the weight and using a bolt in the hole and pull them out.
I cast boolits for my handguns and rifles. So I have plenty of lead around to try. As it is now the vibes with properly tuned engine are minimal. The 750 kit in the 75 cuts the higher rpm vibes back to be about the same as the low rpm vibes. So I haven't felt the need to, except just to see the effect.
Leo
 
A lot of you guys are missing the mark on vibration damping. It's not sheer mass that you should be after, but TUNED mass. Tom has it right, as do the bike manufacturers that put weights in only the end of the bar.

The goal is to provide a mass capable of vibrating at the same frequency as the bars, but in the opposite phase. Tom's idea is one of the better ones. The vinyl tubing does not fit tightly in the bars, and allows some movement. The lead shot adds mass. The tubing is then free to vibrate by itself, somewhat independent of the bars. If the mass is even close, it will tend to move with a delay, meaning; 1/the bar will push up on the tubing, 2/the tubing and shot will absorb that momentum, 3/the bar will reach its apex of movement and stop, 4/the tubing will use the absorbed momentum to begin moving up, 5/the bar will move down, and encounter the tubing and shot moving up against it. This cycle repeats. This is tuned mass damping.

Simply increasing the mass of the bars (solid steel stock, lead-cast inside bars, etc.) will not counteract the vibration of the bars. What it will do is move the resonant frequency of the bars outside of the range of vibrations present in engine. While it will help a good bit, its not as effective as a properly tuned mass damper.

Please don't take this as criticism of anyone's ideas or efforts. Just offering my limited insight. :)

oh, and the mass is most effective at the point in the bars that react the most, i.e., the ends of the bars. Mass near the center doesn't do much.
 

Similar threads

Bushyeyed1
How-To add Brembo caliper and a 18" spoked rim
2
Replies
39
Views
7K
Bushyeyed1
Bushyeyed1
Royboy
Bar Snake
Replies
7
Views
1K
fredintoon
fredintoon
G
Handlebar vibrations
Replies
9
Views
3K
ReycleBill
ReycleBill
QWERTYMage
Another 75 brat.
Replies
19
Views
3K
QWERTYMage
QWERTYMage
gggGary
Wrist savers?
Replies
3
Views
1K
CDNTX650
C
Back
Top