Wonky steering at high speed

[motoman]

Glad to hear the bike is acting normal for you. Bolt that fairing back on(if that's your preference), bout 5psi in front forks along with 42psi in the tires and it should handle the same way.......

[scoot]

Hey, motoman- I'll try the higher tire pressures and see if it fits. Running some new Continentals, a Milestone in front, a Tour in back. The front sez 42psi max like you called it, but for some reason the rear sez 40psi. Front, load range B, rear load range C. Anyway, I'm liking the swirly tread pattern as a change from the old Dunlop 491's.. Not even a hint of trailing the rain grooves on the freeway.

scoot

[3Phase]

Scoot, do you still have the hard bags on the bike? It might be the aerodynamics are messing you up. If so, take them off and see if it helps.

My '80G with just the full Yamaha fairing rode straight and true all day long like it was on rails. I added a set of hard saddlebags and they turned my bike into a Weeble at speed. I remove the bags and no more problem, except not having saddlebags.

[scoot]

Well, 3Phase, I'm very glad to report that today's test run without the fairing was very positive. In fact, I'm positive the fairing is the culprit since the wobble was gone. Totally. If I had to do without the hard bags, it would change the way I roll. Man, those things are loaded: tools, multimeter, air compressor, jumper cables, maps, food, water, glasses, hat, gloves, hood, cable w/ lock, other people's stuff... and that's just the right side.

Maybe your suspension needs a review or adjustment using some of the earlier ideas in this thread. Seems like there's a lot of variables all around our bikes.

[3Phase]

Scoot, I know what you mean about needing the saddlebags, mine are similar and I have a chrome surfboard rack on the right-side lid in case I need to lash something to it without scratching the delicate factory paint. I need to find one for the left side but they're like hens' teeth.

Before I got the saddlebags I had stuff stashed and wedged in crevices all over the bike (I still do, actually! ), in the fairing, with the rest loaded in my A.L.I.C.E. pack, strapped to the luggage rack and the seat. I don't need to do that any more except for long trips now -- it's great!

See, the thing is, my bike is fine, too, with the bags but without the fairing. It's also fine with the fairing and without the bags.

Fairing + bags = Weeble.

Adding the fairing lowers make my bike slightly more stable and I know for a stone cold fact it's not a bent or broken frame; steering stem, wheel bearings, tires, swingarm and suspension are fine, although you would be well advised to check yours for yourself anyway just to be sure! It's aerodynamics.

I use the wobble as a better warning system than that insane Rube Goldberg system they're proposing in the UK: a vibrator stuck under the seat (might be fun for the pillion) with flashing lights and an assortment of warning tones to tell me that I'm riding too freakin' fast and I that need to pay attention to what's going on around me and slow down.

[GARTHXS]

an easy way to check the rear is to put it up on the center stand and give the old side to side and see if you have any play , also check the rear tire by ataching a marker to the swing arm and put it real close to the tire and give it a spin, see if it rubs at any point. my 78 with a pacifico was stable up to 110 but my yellow streak kicks in and I realize I am pushing the limits of a 32 year old hunk of metal

[3Phase]

Scoot, check everything that's been suggested to be sure there's nothing mechanically wrong with your XS but don't be surprised if you don't find anything. Try not to break the good parts while you're looking for the bad parts.

I realize I am pushing the limits of a 32 year old hunk of metal

You know it, Garth, there is that, too.

I've noticed that when my XS starts to get Weeblish out on the highway it's running pretty close to the lower edge of instant arrest right on the spot anyway: all of the carefully stashed stuff yanked out and spread along the side of road to be searched, much to the amusement of everyone on the road but me; XS and whatever is left of my stuff impounded for some, usually usurious, initial fee plus daily, sometimes hourly, storage charges; loss of my license and insurance until the judge's unborn grandchildren graduate from college.

[scoot]

Stop! Stop! 3Phase - you're harshing my mellow with this visual.! I'll be good! I'm slowing down right now! Don't need my stuff spread all on the ground by the Man...
Seriously, I hear you, throttle discipline is a good thing.
Anyhow, tonight I checked the tire run out with a Harbor Fright dial indicator like it shows in Clymer's and like Garthxs was saying to do with a pen. Rear tire is in spec, 4 thousandths out of round, but the front wheel is 17 thosandths out. Fails the spec test and I now have to check the wheel bearngs and maybe need a new rim. Good to know. So this is probably influencing the front wobbble along with the fairing. Hmmm.

scoot

[3Phase]

Didn't mean to harsh you out there, Scoot, ride your own ride! It's been a while since I've seen a good motorcycle chase on the 11 o'clock news.

But seriously, if your rim and tire turns out okay then check the weight distribution front to rear and left to right. At least temporarily move the bowling ball, barbells, and the gallon of moonshine over to the other saddlebag and tell your friends they'll have to carry their own fishing weights and deer slugs until you get it straightened out.

[scoot]

3Phase, I'll try a run without the bags and with the windshield when I get into the swing arm bearings. I may remove that swing arm to repack those bearings, . Those bearings are probably wearing the original grease, so if they aren't needing replacement, they at least need new grease. I may also include swapping the final drive with this 850 drive I've been hanging on to.
Today I ran the bike in first gear up on the center stand and got behind it to watch the wheel spin true. Odd how visible the 4 thousandths of an inch was. It looked like an eighth inch or more. But the dial indicator says it's .004". Whatever. Weekend's here. Time to ride.

Funny you mention the weight and balance, reminds me of flight school calculations for small airplanes. I reckon getting up over 100, the bike starts acquiring flight handling caracteristics.

scoot

[3Phase]

Funny you mention the weight and balance, reminds me of flight school calculations for small airplanes. I reckon getting up over 100, the bike starts acquiring flight handling caracteristics.

Scoot, if you can see the tire moving, double-check the tire at the rim. There is a small raised line on that should be just above the edge of the rim all the way around the tire. If it looks like it goes higher or lower, the tire is not mounted correctly. That will give you all kinds of joy and happyness when you're trying to ride and it's easer to fix than a bent rim.

At speed, if the mechanical side is good then it is mostly about aereodynamics: lift, balance, drag and weight. 100% drag would be finding out exactly how much six cops weigh when they lift and unbalance you right off your bike then tackle you.

[oldnortonrider]

at speed~~weave wobble ("Pan weave&quot

Folks on here might be interested to read the bottom of this Wikipedia link http://en.wikipedia.org/wiki/Honda_ST1300
re what is being said about "weeble"; calling it "pan weave". My regular daily ride machine that I've had for 18 years started exhibiting this about 2-3 months back, at speeds above 60-70 mph, for the FIRST time. AND, furthermore; I've never had a motorcycle to do this with me, before, throughout 58 years of aggressive and steady and dedicated riding. I've had 'em "headshake", and I've experienced "speed wobble"; but not this "weaving wobble" = "weeble". What particularly got my attention in the ST article, re the part addressing the wobble weaving~~was mention of the rider following the rider piloting the machine known to have the "weave" problem~~observing the rear wheel having an alarming back and forth sideways movement, when at speed the weave starts up.

[XS1100_OEM4ME]

Just read

I just read your post so my input is too late, but, when you talk about 100mph + riding with a big air foil mounted on the front of a 30 year old bike, well, it sounds like you got it figured out

Well, I just ran the freeway with the fairing removed. Tires were a little low, so I set them to 38psi front and rear. Ran like it was on a rail, and more nimble, all the way up to 115, 117mph with more speed available if I wanted it. I didn't want it. Jeez, I had to pretty much lay on the gas tank to keep my head on my shoulders.

I'll play around with the fairing position to get it as balanced and smooth as I can and call it good. Maybe look for a smaller unit that still blocks the wind pressure. I do enjoy a windshield for all day riding. And my maintenance schedule now includes checking and packing the swing arm bearings.

Thank you all for your input, I very much appreciate it.

scoot

[T99Ford]

+1. If you are trying to run at those speeds with a fairing and bags, you kinda deserve what you get (meaning wobbles & such). I would run WOT with my cafe 11, even in corners and such, and the handling was marginal at best--although most of the wobbles were caused as much by rider input as the bike itself. Even with low bars and everything in good trim, it had its issues, until I learned to handle it really smoothly in those situations. I would say if you're going to ride a bike dressed for an old man, ride it like an old man

*disclaimer* No disrespect meant to "old men" for their experience and wisdom in riding out of the wind and rain, with lots of wise contingencies loaded for emergencies. The flip is that none of that stuff has any place at high speed!

[cywelchjr]

I've not passed 100 with the fairing and bags, and I'm not sure how much above that I could get to with that stuff of the bike, but the bike is nice and smooth at that speed. Key is proper mounting of the fairing and bags, AND if not pretty much empty, proper loading/packing of the bags and trunk to keep things in balance. The other part is making sure that everything ELSE is in good shape, as if it's all in good shape and everything is properly mounted, the bike can certainly be stable at speed. That said, it doesn't take being much out of position to cause a problem.