Feels like oscillating

[Guest]

OK here is what I have as of now. "Laden" sag is only 3/8" on front forks.
<snip>

I think my next move is to change the spacer in the forks to create more sag.

You definitely need more sag than that. How much preload did you have when you put the springs in? I am in the process of installing Sonic springs and cartridge emulators in my 1100E and the instructions suggest 12mm (1/2") of preload as a good starting point.

Yes I did, twice. But I do think I got the wrong ones and maybe should have purchased the 1.0's.

1.1's are for pretty large riders and/or heavy bikes. I weigh 185lb without gear and got the 1.0kg/mm springs.

Are you talking about the bike on the centerstand? That seems to be full extension in my mind.

If you weight the back so that the front wheel is in the air then that is fully extended. It is convenient to measure from the bottom of the lower triple clamp to the top of the dust cover for your numbers.


Mark

 

[alke46]

I believe its the root to my speed wobble issue.....

click vid

I agree, there is a lot of slop in that video.

 

[alke46]

You definitely need more sag than that. How much preload did you have when you put the springs in? I am in the process of installing Sonic springs and cartridge emulators in my 1100E and the instructions suggest 12mm (1/2") of preload as a good starting point.




1.1's are for pretty large riders and/or heavy bikes. I weigh 185lb without gear and got the 1.0kg/mm springs.




If you weight the back so that the front wheel is in the air then that is fully extended. It is convenient to measure from the bottom of the lower triple clamp to the top of the dust cover for your numbers.


Mark

Oh to be back to 185 again. I currently weigh 200 without gear and yes my instructions called for 1/2" of preload and that is where I am.
I think I need to read up on the sag measuring so I am sure I am doing it properly.

 

[alke46]

Alright, let's try this again and let me know if I am doing something wrong.
As I was sitting on the bike in riding position, no center stand or side stand, I was balancing myself by holding onto the side of my truck, I had my wife put a mark on the fork tube
right at the dust boot. Then I put the bike on the center stand, using a bottle jack under the engine, I raised the front wheel just off the floor. Measuring from the previous mark
on the fork tube down to the dust boot gave me a measurement of 1.375 (1 3/8").
Does this sound like the proper way to measure sag?

 

[Guest]

Alright, let's try this again and let me know if I am doing something wrong.
As I was sitting on the bike in riding position, no center stand or side stand, I was balancing myself by holding onto the side of my truck, I had my wife put a mark on the fork tube
right at the dust boot. Then I put the bike on the center stand, using a bottle jack under the engine, I raised the front wheel just off the floor. Measuring from the previous mark
on the fork tube down to the dust boot gave me a measurement of 1.375 (1 3/8").
Does this sound like the proper way to measure sag?

That sounds pretty reasonable. The only thing I would add is to bounce the front end of the bike up and down a few times and then let it settle before measuring to help minimize stiction problems. At 1-3/8" (35mm) you are on the low side for sag. You can remove some of the 1/2" preload you put in to give a bit more sag, but I wouldn't reduce preload below 1/4". You never want the springs to come free as it can cause problems. Reducing preload will give you a 1:1 change in your sag, so at most you are going to get to around 1-5/8" (41mm) which is at the low end of what is considered good. It sounds like you do need the 1.0kg/mm spring rate instead of the 1.1's.


Mark

 

[alke46]

That sounds pretty reasonable. The only thing I would add is to bounce the front end of the bike up and down a few times and then let it settle before measuring to help minimize stiction problems. At 1-3/8" (35mm) you are on the low side for sag. You can remove some of the 1/2" preload you put in to give a bit more sag, but I wouldn't reduce preload below 1/4". You never want the springs to come free as it can cause problems. Reducing preload will give you a 1:1 change in your sag, so at most you are going to get to around 1-5/8" (41mm) which is at the low end of what is considered good. It sounds like you do need the 1.0kg/mm spring rate instead of the 1.1's.


Thanks for your helpful advice and I have just sent a message to the sonic spring company. Probably will be ordering the 1.0's tomorrow.

 

[Ray916MN]

Now you're cooking with gas on measuring sag. You need to measure the rear too. Based on the front measurement, I really doubt that sag is the cause of your oscillation problems. Let's hear what the rear sag measures.

 

[BurntKittyForge]

Now you're cooking with gas on measuring sag. You need to measure the rear too. Based on the front measurement, I really doubt that sag is the cause of your oscillation problems. Let's hear what the rear sag measures.

-Maybe something with the rear suspension , sounds like damper/ rebound messed up there(?)...

-could be low air pressure in the tire(s) (sounds like), tires loose pressure this time of year from cold. Usually through the shrader valve, could be damaged/faulty as well...

-a /some wheel weights could've fallen off....

-brake caliper could be sticking...

-"brand new Shinko" LOL...(Saw one with exact tread as the old Metlers' , wish there was a speed rated one in my size though ...questionable tire though)...

-Maybe the bushing between the bearings fell out of place replacing tire/wheel mounting and is bobbing around loose inside the rim even(?)

-Oh, could have fluid inside the tire too (possible IF the tire-changer was sloppy and slopped filthy watery crap on it)...

I'm on OP's "ignore list" but stuff to consider for others reading/ my .02 is all.

Maybe it has some twinkie(S) stuck/stuffed to it.
Ever heard about the fat lady who went to the clinic with stinky rash and mold on her body and they found a very old twinkie in a fold and embarrassed she admitted it was a game of "Hide the food [in folds]" (never found/ forgotten for MONTHS, got left there!

 

[habsdoc]

Now that is just down right disturbing, no more reasons to eat any "twinkies" here.

 

[alke46]

Now you're cooking with gas on measuring sag. You need to measure the rear too. Based on the front measurement, I really doubt that sag is the cause of your oscillation problems. Let's hear what the rear sag measures.

Sure, soon as I can get some help with it.

 

[alke46]

Rear sag is only 21 mm and that is with the new hagon shocks set at the middle of 3 settings. I originally had them set on the 1st setting and felt it needed more so I went up to the 2nd and now I am on the low end of the sag numbers.
I will have to go back and start all over again after I change the front springs. Jeff at Sonic is offering to exchange my 1.1's for some 1.0's. After I get those in I will have to play with the shocks on the 1st setting and go from there.
Results will be posted but not for a week or more.
Thanks again for all the suggestions.

Rear sag is 40mm with the shocks set at the lowest setting.

 

[Ray916MN]

35mm at the front 40mm at the rear is close enough in my book that I'd say it isn't your problem. 35mm at the front with 21mm in the rear might possible result in oscillation. This sag, places the rear end high. which steepens the steering angle and reduces rake which reduces stability. The primary purpose of springs and setting sag is to get your suspension to operate in the proper range from full extension to full compression (suspension doesn't top out or bottom out) relative to rebound and compression damping (suspension valving and oil) which are responsible for damping out oscillations.

A trick to check your steering head bearing when they are lose is to put the bike on the centerstand and lift on the front end while moving it through its steering arc. With the bottom bearing pushed up against the race in the steering nexk, if the race and bearings have developed a flat spot you should be able to feel it.

 

[alke46]

Many thanks for all the good information so far. It appears that the steering stem nut had just a bit of slack in it to cause the slight movement at the bottom of the forks when moved forward to backward.

After reading about the tension on the stem nut in the FSM, I am confused as to how I should proceed. I have removed the stem and did a thorough inspection of the bearing and it's race and both appear to be in good state. It is obvious by looking at it that someone before me had replaced the original bearings. I now have the bearings cleaned and will repack with waterproof grease but I need advice on how to properly set the tension on the stem nut.

What kind of wrench is required to set it at 36 lb-ft of torque, then reset it to zero and finally it sounds like it should have just enough tension on it to remove any movement of the stem. Then to finalize it, I need to torque the stem center bolt to 26-37.5 lb-ft.

When I removed the stem center bolt, it had very little, if any, tightness. At least it wasn't ham fisted by whoever had it apart before me.

I should ask this: is there a way to tighten the stem nut without purchasing the Suzuki "special" tool?

Thanks in advance.

 

[alke46]

Also, I have hi-temperature grease suited for wheel bearings but it is not waterproof grease. How important is it to use the waterproof stuff? If necessary, I have no qualms about buying it, just wanted the opinions of the bearing gurus here. Thanks.

 

[Guest]

What kind of wrench is required to set it at 36 lb-ft of torque, then reset it to zero and finally it sounds like it should have just enough tension on it to remove any movement of the stem. Then to finalize it, I need to torque the stem center bolt to 26-37.5 lb-ft.

<snip>

I should ask this: is there a way to tighten the stem nut without purchasing the Suzuki "special" tool?

Well, my manual shows them using the special tool and a standard torque wrench to apply the seating torque. I would use a hook wrench and torque wrench in combination and just set the torque wrench at 90 degrees to the hook wrench to cancel out the extra length added with the hook wrench.

Also, I have hi-temperature grease suited for wheel bearings but it is not waterproof grease. How important is it to use the waterproof stuff? If necessary, I have no qualms about buying it, just wanted the opinions of the bearing gurus here. Thanks.

The stem has seals top and bottom so it isn't crucial that it be waterproof grease but you will end up repacking the bearings sooner with non-waterproof grease. It is there mostly for corrosion protection, so as long as the bearings are covered in it that is the most important thing.


Mark

 

[alke46]

Bump to the top. So is the consensus here that I need to purchase the Suzuki special tool?

 

[Sandy]

You shouldn't need the tool, the bearing races are already seated. All you need to do is snug up the bearings to remove any slop, that's all. Snug up the bearing so you have just a very slight drag on it. If they're worn you'll feel some notchyness when moving the bars from side to side in which case they'll need replacing. To adjust loosen all the bolts on the upper triple clamp and you can tap the adjusting nut with a punch or screwdriver to get the slack out and then retorque everything and check again.

 

[alke46]

Thanks Sandy, that is the information I wanted to see in print. So the special tool is used primarily to seat the bearing into a newly installed race, correct?
My bearing and race are in good condition so I will just remove the play from the stem and then torque the stem bolt.
When I removed the stem bolt it was not loose, but there was no measureable torque to it. I don't know how long it had been like this but for some reason the lack of torque must have caused the stem nut to loosen a bit. Glad I caught it before it did any real damage.
Thanks again.

 

[Guest]

So the special tool is used primarily to seat the bearing into a newly installed race, correct?

According to the manual, yes. As I said, you can use a generic hook wrench instead of the special tool and it will work fine as well.

I don't know how long it had been like this but for some reason the lack of torque must have caused the stem nut to loosen a bit.

The stem head nut is acting as a jam nut on the stem nut (with the upper triple clamped in between them), so it not being tight would certainly allow the stem nut to work loose. It doesn't take much movement on the stem nut to allow the forks to move a bit and mess up the handling, it is very sensitive to the preload the stem nut is keeping on the bearings.


Mark

 

[alke46]

Time for an update. I received the 1.0 sonic springs and installed them with the 1/2" preload and then measured the sag and am now at 40 mm front and back.
I will take it out for a test ride tomorrow and see how it feels. I suspect a new front tire may be necessary to smooth out the ride completely. We'll see.
If necessary, I will change out the Shinko front for a Continental just to see if I get the desired improvement. Even though there is a lot of mileage left in the Shinko.