Need to give the front end an overhaul.

[Yamanatic]

Check for a warped brake disc.

[renegade_xs11g]

Shedding some light on this 'BOUNCE'

Now that I've gotten the kz650 motor tear-down almost complete (my 27mm socket is AWOL)
AND most of the XS750 in piles....
I decided to put a little time into 'the monster'

the right caliper was dragging a little, I can feel a 'click' if you will, in the bearing in the triple tree

BUT....I also found the tire, well, probably the cause....
spinning wheel after the brakes were removed.....
there IS a spot where it (the tread) will shift to the left (that' the 'shimmy')
AND....there is a 'high' spot on the tread, only just barely noticable (but I think that's my 'bounce')

also, I did this



only 1, I know, but I think I like 'em

[Yamanatic]

Well THAT should light your way! If the front end bounces a little, it will look like you have the strobing headlights too. It kind of gives a retro/police bike look to the front end too.

I had a warped disc that took me a while to track down, because it gave no indication by lever or braking feel. A bumpy tire would seem more logical though, because the balance would be right on at low speed, but would amplify the hop as speed increases (and we all know how much fun it is increasing speed on an 11!).

C'mon spring
Warren

[renegade_xs11g]

and, so it begins.....



I feel a click, when the Triple Tree hits the center.
kinda like a swivel head on a rachet,
when it hits center, I would think this is a problem with the bearing inside the tree......

Yamanatic....2 of those lights, 55 watts each, and the Halogen 60/55 watt should light it up a little.
I hope the bounce goes away, but yes the strobe effect may be cool!!!!!!


the rotors seem to be ok,
and I didn't hear or feel a 'pop' when I loosened the forks....

are there any TECH tips on the forks???

[TopCatGr58]

Hey Renegade,

You'll probably just have to do some FORUM searches for front forks, seals, triple tree bearings and such. Danny Meyer posted some stuff a while back about the notches in the bearing races in the triple tree!

Mine had sat outside for 9 years before I tore into it, and the steering felt very notchy when turning it left/right, but fortunately it was just old hardened grease and such. Once I took it apart, cleaned up all the bearings and races, they were nice and smooth, just put it back together and it was just fine and smooth, no notching at all! So...I suggest doing the same, and look and feel for notches in the races. As long as it feels smooth, then you should be able to just R&R the bearings.
T.C.

[Ken Talbot]

Re: and, so it begins.....

Originally posted by renegade_xs11g

I feel a click, when the Triple Tree hits the center.
kinda like a swivel head on a rachet,
when it hits center, I would think this is a problem with the bearing inside the tree

That's right - bearing race has a spot worn in it. Time for new bearings and races.

[somesuch]

I think the lower bearing is is 32006x and the top I am not sure, but I think it is 32005x......do double check. The lower bearing is the same as old (83-85) Toyota Celicas rear inner wheel bearing (with independent suspension)

So get them from an auto parts place ....cheaper, most likely better quality, and they will probably have them in stock.

I just did them on my 2003 GSXR1000 which has both bearings same as the lower XS1100 bearing. I bought the Japanese version.
--Nick

[somesuch]

If there is too much "stiction" in the front forks or if the fluid is too viscous and the resulting damping it high you would probably see what you are seeing with the front end jumping like that. Seems that your suspension is not able to react to small bumps as the _slider_ speed increases. Stiction could be from bent components, but it is also an old design fork. Newer designs pay a lot of attention to reducing friction, increase rigidity, and lighter weight, so that the wheel would be better able to react to the road bumps.

After checking that the forks are straight and have the right fluid in them, I would opt to either replace the forks with a some newer forks, or at least have them re-valved or have cartridge emulators put in. Flexible forks like ours probably would do better with softer suspension settings, ie less air, lower fluid viscosity, softer springs.

--Nick

[somesuch]

I thought I would also add that hard anodizing the inside of the sliders helps a lot in reducing the stiction. The best place to get all the
_right_ info on this subject is probably LE Lindeman Engineering in Campbell CA. I believe zip is 95008. Jim does suspension work for a lot of the big names in AMA and the forks that he had done for me were hands down the best forks I have ever had. TRAXXION Dynamics on the other hand, produced a horrible set of forks for me (and they charged a lot of money!), that I had to eventually replace because the bike handled so poorly!

--Nick

[firecrackerboom]

I havent been riding since October/November, but I bought my Eleven last summer and noticed that above 60 or so it would start to get really shaky as well. I havent changed tires or anything on this bike yet. I will have to look into all of this stuff.

[Yamanatic]

I have been reading in interest about all the issues and fixes concerning the XS11 front fork assembly, and am quite surprised that the suspension is put up to be such a load. In the best of spirits, I have always found the forks to be quite good!

I have had more than a few first generation Standards & Specials, and the same formula always works stellar for me; fresh fork seals at the first sign of weeping, and Type F Auto Trans Fluid at the prescribed volume. I throw in a 1 inch spacer on top of the spring if a fairing is fitted, and just as supplied if bare.

My rides involve dirt as well as paved roads, asphalt and concrete, and even a few cobblestone avenues to boot, and the old girl is smooth and compliant. Granted, it is not set up for any one specific road type, but takes most everything thrown at it in stride; a good all around fork!

IMHO, if everything is put together right, the forks are ideal for the chassis & weight; I think Yamaha did their homework on this one... Please do take my opinion with a grain of salt, as this post is not intended to undermine any efforts to improve on a good design :-)

Cheers,
Warren

[somesuch]

Hi Warren, the limitation of a damping rod style fork is that above certain speed (suspension movement, not the speed of the bike) the suspension will become hydraulic locked. To avoid such locking on some reasonable bumps/bike speed the holes in the damping rod (or viscosity of the fluid, hence you are using Type F ATF) need to be kept fairly large (to have reasonably low "high speed" damping) and correspondingly one looses "slow speed" damping.... so the damping rod fork is a very big compromise. Add to that the flexibility, stiction, and the weight of the unsprung parts (ie wheel, slider, half of the spring, etc) and it really becomes tempting to go with some newer forks/wheels. Gold valve would probably be significantly better, but I have not tried one in this application.

Most suspensions are setup to have about 1/3 of the available travel used for sag (rider on the bike) and have at least 5mm of free sag (rider off the bike) so I assume the 1" spacer gives those values with the fairing. Air (spring) is used to get the right sag values for different loads. There is a lot more to it though.

--Nick

[Yamanatic]

Hey Nick,

Thanks for the excellent reply; obviously you have much time, effort, and experience invested in tuning suspension! Yes, the front end can be substantially improved over the original design with modern parts and technology, but considering the era, Yamaha did an excellent job with 1978 engineering.

In the early 1980's the mighty Eleven was one of my roadracers, and has seen the likes of Daytona, Gainesville, West Palm Beach, Savannah, Road America, and Mid Ohio, within the rules structure of Modified Production with AMACCS, FGPRA, AAMRR, and WERA. Best to stay as stock as possible to get through any and all tech inspections.

During the 3 years covering '81, '82, & '83, many attempts were made to find the best combination of valving, spring rate, preload, air pressure, hydraulic viscosity, and bracing. Surprisingly the best setup was virtually stock with ATF! The damper rod holes saw a lot of soldering and drilling, Bushings were shortened, and the pile of various springs grew ever larger, but the best all around combination was found to be very close to what Yamaha came up with.

Granted, the rigors of racing are far from the comfort desired in a street fork, but the old girl was equally as, if not more, stable and forgiving than the competition. The hydraulic locking was welcome when crossing rumble strips at 100+ mph, and the softness was not prohibitive when the pegs were dragging. The massive wheels slowed the steering to a very forgiving level, and with the biggest & heaviest bike out there, keeping the beast off it's side was a huge advantage. I remember dropping into fast sweepers with 'the pack,' and watching the Kawasaki's and especially the Suzuki's (Honda's were uncommon) start to wallow and patter, and not infrequently leave the rider on the asphalt after being spit off; they just couldn't keep up with the gyrations of their flexi-flyers!

IMHO, anything you can drive that hard and still remain upright and out in front is a durn good handling bike. I would never dream of riding that agressively on the street, but it is nice to know that if trouble arises, the bike is up to the task. As an aside, the one single most significant improvement to handling was the addition of a fork brace; the double arch solid bolted variety.

I still enjoy an occasional track day, just not on the Eleven. It would be humiliating to be so eaten alive by modern machinery! I guess my point is that the entire bike is dated compared to today's standards, but none the less a fine, safe, fast, reliable bike representing the best Japanese offering of the time. And thanks again for the insightful reply!

Cheers,
Warren

[somesuch]

Warren,

I certainly see your point and share your views about the bike....that's why I got one again about a year ago (after not having one since 1999) even though I have a GSXR1000 to ride.

I like XS1100 for what it is and I enjoy looking at it and just having it. But getting on any new sport bike you quickly appreciate the modern technology, and it makes me want to go and start changing the old beast

I think eventually, keeping the bike as close to stock as possible, will be what I will enjoy most

I also feel that stock forks with ATF is probably the best compromise, I would one day like to get the Gold Valves in there just so the bike still looks stock, but hopefully handles a bit better. (that is if I don't sell it for the lack of storage area)

Wallowing Hondas are very familiar to me, I had six CB900Fs and they become a handfull!
--Nick

[renegade_xs11g]

I may have gotten lucky

I've pulled the steering stem,
the bearings had been repacked, I found new grease
the 'double' nuts, were way too tight...
clymers says they should be around 9 ft lbs, these were ~50 or better
the proper torque for the stem (the single nut that holds the 'tree-top' down)
is around 60 lbs isn't it???????

this should cause the 'click'