uncomfortable wobble at 90 to 100

[jay760]

Don't suppose you were wearing a loose jacket, with the wind causing it, I think you should donate the engine to me and buy a standard 650 engine, you wouldn't have the problem then.
Sitting farther back shouldn't cause it, my 760 has a Tracy body and I'm sat vertually on the back wheel, though I have dropped the forks through the triple tree as far as they will go.

 

[gggGary]

Yes sag, sack same thing. Uneven chain stretch, Bike on center stand, rotate rear wheel, watch to see if the slack(belly) in the chain changes as it revolves over the sprockets. Pictures, we need to see pictures of your bike! Sounds like a nice set up.

 

[xsjohn]

Could try snugging the bearings down just a bit ...if no one has mentioned that before.......

xsjohn

 

[urbandork]

Yes sag, sack same thing. Uneven chain stretch, Bike on center stand, rotate rear wheel, watch to see if the slack(belly) in the chain changes as it revolves over the sprockets. Pictures, we need to see pictures of your bike! Sounds like a nice set up.

Could try snugging the bearings down just a bit ...if no one has mentioned that before.......

xsjohn

which bearings? the steering head ones? or the wheel bearings?

 

[xsjohn]

Steering head......

 

[Manolo]

Any of these bikes in good condition, no matter what the year, should be steady all out in a straight line. I have had many bikes over the years, including a 75 xs which i bought used in 77. On the highway, in a slight down hill it would go close to 130 miles per hour (gauge speed) and was steady as a rail. A few years earlier while still living in France, a friend of mine had a 1970 xs with front drum brake and we could ride all day long at speeds in excess of 160 kph (100mph) with no problem. I had a CB750 at the time with a 950 Japauto big bore kit on an otherwise stock bike and i remember travelling from Paris to the South of france cruising at 180, 190kph. The higway in the south of France, Autoroute de L'Esterel has long curves which can be taken at very high speeds. I remember my Kawasaki 500 MachIII starting to wooble on these long curves, you could feel the frame flexing right by the swing arm pivot but even with that bike, which was a pig as far as handling, never did i have any tank slapping wooble. That was reserved to early Triumph Bonnevilles with frames bolted together. In other word, any Japanese bike of the 70s' and up that is in good shape, can be ridden all out safely.

 

[grizld1]

Right, Manolo--assuming everything's in good condition and set up properly. Urbandork, I'd stopped following this thread before you posted your photo, but one source of your stability problem (and it ain't always just one thing!) is glaringly obvious, and we should have asked enough to catch it. The OEM fender provides bracing for the front forks, and you have removed it. If you're going to run that way you need a fork brace. I use an old Daytona alloy tweak bar. My favorite among current items is the TKat brace--nice-looking, light, and effective.

 

[Punkskalar]

I agree with Griz... You need a fork brace for sure...

On my bobber chopper thing, I don't run a brace, but I have the forks lowered 3.25" so there is more upper tube into the lowers and that helps. I rode another XS that was stock height and had no front fork brace/fender and it was a bit scary at speed as well.

 

[xjwmx]

Mine has stock height and the front fender is from a different bike, attached using a fabricated adapter on either side. Pretty flexible arrangement. No stability problems, but then I'm not going 90-100 either, and never will.

 

[Punkskalar]

PS, I have been told by Pete to slow down as well.... He's a wise man, there is no need for triple digit speeds on public roadways... Stay safe, and hit the track if you need that kinda speed thrill....

 

[xjwmx]

The fastest I've ever gone is about 75. The first time was because I took a wrong turn and found myself on the interstate. Night time, dense fog, rain. Bumper to bumper traffic. And the worst entrance ramp I know of, leading right to a 1/4 mile long river bridge about 1000 feet in the air. But no stability problems there. Not with the bike I mean And I was under dressed and freezing.

 

[Punkskalar]

Any bike should be able to run 75MPH just fine, as long as it is maintained and up to snuff...

Pete got onto me for 120+ Speeds on a rigid with 1.7" front travel. Bike was stable as can be.

 

[xjwmx]

I wouldn't do that and I've been known to jump out of perfectly good airplanes. Sounds like you've got a good friend in Pete.

 

[grizld1]

Who gives a shit what you'd do or how you ride? This thread isn't about you. It's about a man's handling issues. Shut up and crawl back under your bridge, troll.

 

[xjwmx]

LOL somebody has mental problems. That's not really funny but since it's aimed a me I can laugh.

 

[Manolo]

I am in the process of restoring a 75 xs which i bought on Ebay in the fall. The guy advertised it as showroom condition. When i go it, the pipes were dented, the engine cases were corroded and the battery boot had melted and coated the swing arm and the frame. I think the guy had a battery failure or even fire. So, i powder coated frame swingarm, and bought a used battery box on ebay. The bike is on the way back together, needle bearings on the swing arm and steering as well as a tx750 swing arm to get a bit more rigidity at the rear. Completely stealth, unless you look closely, you can't see its there. I just bent the rear break cam lever outward an eight of an inch, easy. Since the bike needed a front brake rebuild, i bought another disk and caliper and will install a second disk. Handling should be even better this way.

Emmanuel

 

[donkeytool]

If you get yourself a 70 through 73 model you will cure your problem. They will scare you so much at that speed that you will never run that fast! I know. I have current 'sperience!!!

Amen to that. I,ve got a 71, ratted out cafe style. You do not want to be behind me @ 75MPH ...because I,m sh!tting my pants.

 

[Manolo]

Donkeytool, what would you do if you had a Vincent, early fifties vintage with no brakes and very primitive suspension system. Yet these bike easily passed 120mph. It's all in the riding!

E