GL1800Riders Forums banner

1 - 18 of 18 Posts

·
Registered
Joined
·
1,038 Posts
Discussion Starter #1
Brief History, New Metzelers installed, instant wobble, changed back to old front tire, no wobble. Reinstalled new Metzeler, wobbles again.
Long version of history

http://www.gl1800riders.com/forums/viewtopic.php?t=62515&highlight=

I used the wobbling Metzeler for 5-6k miles. I then had the time to install new pieces. By now the wobble was worse and the tire is cupping. The wobble is annoying with my hands on the bars. If I take my hands off of the bars at a steady 40 mph the wobble is severe, if I take my hands off at 45 when decelerating the wobble is incredibly evil.

DISCLAIMER I do not ride with my hands off of the bars. I only take my hands off to see how much of a wobble is there and to see what effect any changes might have had.

OBSERVATIONS
When going uphill the wobble is less. When going downhill the wobble is worse. If I hit the accelerate button on the cruise control the wobble is decreased under acceleration and is back to it's normal condition (noticeable wobble) when the bike attains the new speed. Probably explained by geometry changes because of suspension height changes.

TRAXXION
I installed the standard Traxxion fork springs. This raised the front of the bike by 1 1/4 inches. The wobble decreased by approximately 50%. I did not change fork oil, just installed the new springs.

ALL BALLS Tapered Bearings
I removed the front forks, handlebars and top triple clamp. Remember that I had previously torqued the stock bearings to 22 ft.-lbs. During my summer riding I decided this was too tight as at slower speeds the bike wandered. I rotated the lower triple clamp in the bearings and could feel notchiness in the bearings. I thought I would see damage on the bearing races however they looked fine with no pitting, indentations or wear pattern. I installed the tapered bearings and torqued them to 18 ft.-lbs. as a starting point. (Yes, the bearing races are fully seated.) I changed the fork fluid and reassembled everything. I noticed an immediate improvement with my hands on the bars. There is a slight feel of a wobble but it may just be the vibration of the cupped tire. However with my hands off of the bars the wobble is WORSE than it was. I decided to take the extra time to try different torque settings on the steering stem and report the results. I bought a fish scale and measured the pull on the forks according to the manual. The spec is 2-3.1 lbs. Mine measured 6.5. I removed the bars and top clamp and measured again as it is impossible to get rid of all of the friction caused by rubbing cables, hoses, wires, etc. The measurement was 3.5 lbs. I then made the measurement at various torque settings. Here are the measurements (these measurements were made several times, always with the forks centered and noting the pull required to start the forks rotating)
Torque Pull
15 3
18 3.5
20 4
22 4.5
24 4.5
26 4.5
I set the torque to 22 ft.-lbs. and reassembled everything again. With my hands on the bars I still noticed the slight vibration that I think is from the cupping. With my hands off of the bars the wobble was greatly diminished at both steady speeds and deceleration. I am leaving the torque at this setting and seeing if I have wandering issues. I am off on another 5000 mile trip and am debating whether to put a new front tire on or use this one up.

THOUGHTS About Traxxion springs.
I definitely like the increased ride height. The wobble problem was decreased with the springs. The ride is no better or worse with these springs except on big bumps that would bottom the stock springs. I believe that the stock compression damping is too stiff. A lighter weight oil would probably help for me as I am a 175 lb. when fully dressed rider. The replacement oil was the 10w Honda fork oil. My anti-dive valve does appear to be working. Part of my next ride includes stopping at Traxxion and riding their test bike to see if I want to spend the big bucks.

INTERESTING Question
Why did the bike wobble with hands on the bars with the Metzeler and not the old tire? With hands off of the bars the wobble seemed slightly worse with the old tire which was a Dunlop E3 with 15k miles.
 

·
Registered
Joined
·
661 Posts
One thing I didn't read. Did you check to see if you have "G" stamped on the sidewall of the Metz. If you don't it is a VTX tire and will wobble.
 

·
Registered
Joined
·
7,210 Posts
I would replace the front tire. Try a Bridgestone G709, it's a excellent front tire. I have also settled on 22.5ftlbs of torque with the All Balls. Have you checked the wheels with a dial indicator to see if they are true both in roundness and side to side? While you have the front wheel off to replace the front tire, change the fork oil by removing the bolts on the bottom of the forks, well worth the effort.
 

·
Registered
Joined
·
152 Posts
Wobble

No wobble on my`02 with hands on the bars. Nasty at 40mph if I remove them. I had a 709 on the front and liked it. Needed a front tire and couldn't find a stone so I put on an e3. Put progressive front springs plus went to Suzuki 8wt. fork oil. Measured 51/2 inch down from top of fork in the vice. Stock bearings. This combo was a big improvement. Was it the oil? Tire? Beats me. Ride safe
 

·
Registered
Joined
·
661 Posts
Kandgo said:
RedStreak said:
One thing I didn't read. Did you check to see if you have "G" stamped on the sidewall of the Metz. If you don't it is a VTX tire and will wobble.
I just went thru the same thing, the new Metzlers will indeed have a GL stamped on them and they weigh something like 1 1/2 lbs more than the same size that goes on the VTX C. Goodluck,,Rick
The VTX tire has one less ply in the sidewall. You put the two side by side and they look the same.
 

·
Registered
Joined
·
525 Posts
I believe that the stock compression damping is too stiff.

Absolutely, otherwise it could not be so harsh on high compression bumps with such soft springs. When you ride the Traxxion demo you will find it firmer in low compression bumps and softer in the high compression bumps as it should be.

I had the same conditions on a Suzuki AN650. It had damping rods only in the forks. I put in new springs and Race Tech cartridge emulators. This improved the ride significantly but was not as dramatic an improvement as the Traxxion setup on the Wing.

I have not had a wobble on my bike either with tire changes or before or after the Traxxion mod.
 

·
Vendor
Joined
·
2,337 Posts
Jack D said:
OBSERVATIONS
When going uphill the wobble is less. When going downhill the wobble is worse. If I hit the accelerate button on the cruise control the wobble is decreased under acceleration and is back to it's normal condition (noticeable wobble) when the bike attains the new speed. Probably explained by geometry changes because of suspension height changes.

There is a simple explanation for this...

When going uphill, you have the throttle open, which squats the rear of the bike, and extends the front fork. This significantly increases available suspension travel (and trail), and allows the wheel to move up and down without starting any side to side oscillation.

When going downhill, you have the throttle closed (most likely), which makes the bike coast in an "engine braking" mode. The drag from the drivetrain loads the already inadequate front suspension down to the bottom of the travel, which leaves little or no effective suspension, and the minimum amount of available trail. Then the only thing left to absorb bumps is the tire. At this point, the tire will follow any irregularity in the road, and will begin to wobble.

Having effective suspension eliminates this problem. That is why you noticed a significant improvement with the spring upgrade.

Stock bearings, in new condition, with proper torque will work without a wobble. But they loosen quickly, then degrade, and then require replacement. Ball bearings are not sensitive to torque. The just cannot have any mechanical slop.

Tapered roller bearings are extremely sensitive to torque. We use 25 ft.lbs and I have seen bikes wobble even when set this way (with both races seated... we have a $250 tool that makes it impossible to fail).

We have loosended the bearings and retorqued to the exact same spec, and had a dramatic change (for the better). I suggest anyone who still has a wobble after installing the tapered roller bearings try this.

The only time you should be able to feel excessive bearing torque is at road speed. The symptom is "wandering"... the bike will want to guide itself to the left or right and will require input from you to make it go the other way. In other words, it won't want to go straight by itself.

8)
 

·
Registered
Joined
·
1,038 Posts
Discussion Starter #8
Absolutely, otherwise it could not be so harsh on high compression bumps with such soft springs. When you ride the Traxxion demo you will find it firmer in low compression bumps and softer in the high compression bumps as it should be.
I would want the opposite, light damping for the small stutter bumps and firmer on the big hits such as potholes. You can absorb the small bumps and not notice them and on a big hit the rapid aceleration of the fork compressing would restrict the fluid flow and slow the forks compression so as not to use all of the travel and bottom out. Maybe we are saying the same thing and I misunderstood your statement.
 

·
Vendor
Joined
·
2,337 Posts
Jack D said:
Absolutely, otherwise it could not be so harsh on high compression bumps with such soft springs. When you ride the Traxxion demo you will find it firmer in low compression bumps and softer in the high compression bumps as it should be.
I would want the opposite, light damping for the small stutter bumps and firmer on the big hits such as potholes. You can absorb the small bumps and not notice them and on a big hit the rapid aceleration of the fork compressing would restrict the fluid flow and slow the forks compression so as not to use all of the travel and bottom out. Maybe we are saying the same thing and I misunderstood your statement.
Hi Jack,

He did say it right.

What you think you want, is the worst possible scenario. That has traditionally been the way suspension has been setup, and it has been all backwards.

You want SPRINGS to do what you are describing.

Soft over small bumps, and firm to avoid bottoming. This is accomplished by a relatively stiff spring, with very little preload on it.


You want DAMPING to do the opposite of what you are describing. It should be firm and controlled for low speed movements (braking, turning, accelerating), and the be very soft or "blow off" over sharp harsh jolts.

:)
 

·
Registered
Joined
·
238 Posts
My bike didn't have the wobble until I went from a 70 series rear tire to a 60 series. I bought my bike used and it had the 70 on it. I ruined that tire by running it when it was flat. The guy I bought the bike from gave me the OEM tire when I bought the bike and I put it on to finish the season. I now have the decel wobble (probably had it before but just wasn't as pronounced so I didn't notice it). I can feel it wobble with my hands on the bar, but it is not what I would concider to be dangerous. Just thought it was interesting that lowering the rear of the bike brought out the wobble.
 

·
Registered
Joined
·
19,065 Posts
My bike had no wobble with stock Dunflop D 250s. They wore out at 10K

I replaced with Dunlop E3s. I think/thought they grip better than the D250s but they sing in the corners and they have a small 40 mph wobble first noticed at 6K on the new tires. My 250s never did this. The 250s drifted more on rain groves.

My bike is apart - I am putting in the ALL BALL BEARINGS and Progressive Springs

If the wobble goes away OK

If not I will do the TRAXION thing.

I am not married to these tires YW says the Bridge 709 Front with Metz on the rear is the ticket. I may try when these wear more.

All bikes do not have a wobble and this is not normal. Mine is small and your hands have to be off the bars
 

·
Registered
Joined
·
694 Posts
Along with everything else wouldn't the rider weight effect the equation? i.e uphide wigiht back, downhill weight forward (and on the forks).
 

·
Registered
Joined
·
525 Posts
You want DAMPING to do the opposite of what you are describing. It should be firm and controlled for low speed movements (braking, turning, accelerating), and the be very soft or "blow off" over sharp harsh jolts.
What he said. And, it works.
 

·
Registered
Joined
·
1,038 Posts
Discussion Starter #14
You want DAMPING to do the opposite of what you are describing. It should be firm and controlled for low speed movements (braking, turning, accelerating), and the be very soft or "blow off" over sharp harsh jolts.
Max, I could wait to ask this when I am there in a week or so after Key West but I am curious where is the (Traxxion forks) damping on a washboard road? i.e. firm or blown off. Or when crossing cracks on the road? This is what I was considering low speed movements to be by my definition. I am definitely not arguing but trying to rethink my 1980s dirt bike school of thought.
 

·
Registered
Joined
·
2,082 Posts
What is funny is I had the wobble with the stock 250 Dunlops, changed those at 8500 miles or so and put on Metz 880's and the wobble is gone for about 4000 miles.
 

·
Registered
Joined
·
1,457 Posts
My '03 wing had no wobble with OEM Stones, went to Metz 880 and instant wobble for next 9k miles. Went to Dunlop and no wobble. With my '05 I had no wobble with OEM Dunlop 250 and no wobble with 8k on my E3's. I've ordered another set of E3's and once the current ones are worn I won't ride the bike 'til they come in. I've heard some say that the E3's wobble but my experience with the Metz and reading others comments are that its more common with the Metz. Also my trusty friend/service manager at Honda said he'd wait for the E3 also.


Steve
 

·
Registered
Joined
·
19,065 Posts
Bikes back together. All Balls Bearings installed spings , no rear work *8K on E3s. Results are in-NO WOBBLE-Hurrah!!!!!!!!!!!!!!!!!!!!!!!!! I think its the tapered bearings.
 

·
Vendor
Joined
·
2,337 Posts
Jack D said:
You want DAMPING to do the opposite of what you are describing. It should be firm and controlled for low speed movements (braking, turning, accelerating), and the be very soft or "blow off" over sharp harsh jolts.
Max, I could wait to ask this when I am there in a week or so after Key West but I am curious where is the (Traxxion forks) damping on a washboard road? i.e. firm or blown off. Or when crossing cracks on the road? This is what I was considering low speed movements to be by my definition. I am definitely not arguing but trying to rethink my 1980s dirt bike school of thought.
Hi Jack,

Anything that is "square edged" like a washboard, or a crack in the pavement is "High speed damping", and that is when our system is blowing off.

(You may already know this... but in case)....

High speed damping is referring to how fast the shock or fork is moving, not how fast the bike is moving. So...

Running over a 2x4" piece of wood at 5 mph in the road is high speed damping. Railroad tracks, potholes, braking zone washboard (at stoplights and off ramps).

Low speed damping is when you accelerate or decelerate. Also riding along the freeway at 70mph if you have a floating, wavy feeling, that is low speed (lack of it).

Yes it is the way people thought suspension should work for a long time.

Soft springs, tons of preload. No low speed damping, tons of high speed.

We do it EXACTLY the opposite of that. :shock: :)
 
1 - 18 of 18 Posts
Top