Does asymmetry affect bike behavior?

Ulrich

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Sep 12, 2019
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Kharkiv, Ukraine
Here's an update in case it might be useful to someone.

The issue was caused by the front tire that had uneven wear and was squared off. The previous owner ran that tire on a damaged rim for several thousand miles, and that rim seems to have damaged the tire as well.

I put on a new tire today, and I am impressed with how the steering has improved! Also, the bike finally goes perfectly straight as it should :)
 

EricV

Riding, farkling, riding...
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Before you fully decide this a surface area of the bags issue that you are noticing, take the top box off and go for a ride with both side cases still in place.

It is a very well known and documented issue of minor instability, increasing with speed, from the air flow around the top box and side cases w/o a passenger. That gap between the rider and the top box creates a laminar flow that induces instability. Yamaha has made warnings about solo riders running high speeds with top box and panniers. It's just a liability thing, but it is real. Most people notice a weave at high speeds or a slight pull to one side. The effect is eliminated by having something mounted in the space between the top box and rider, tail bag, sleeping bag, pillion, etc.

For most, it's not a significant issue. Edit - Glad the new tire corrected what you were feeling. Tire issues account for a surprising number of different 'feel' issues.
 

Longdog Cymru

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Here's an update in case it might be useful to someone.

The issue was caused by the front tire that had uneven wear and was squared off. The previous owner ran that tire on a damaged rim for several thousand miles, and that rim seems to have damaged the tire as well.

I put on a new tire today, and I am impressed with how the steering has improved! Also, the bike finally goes perfectly straight as it should :)
Glad to hear that you have resolved the problem Ulrich and you have found it was nothing to do with the Givi cases, it just gives you confidence in your equipment and motorcycle and peace of mind So you can enjoy the ride.:)
 

SHUMBA

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ONTARIO, CANADA
Here's my luggage set up
Completely waterproof, total cost about $260. CDN. Amazon.
No drag issues.


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twinrider

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Yokohama
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You gotta weird slant thing going on SHUMBA, that's what happens when you buy crap made in China.

Here's what made in Italy looks like.

givi s10.jpg
 

SHUMBA

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Well, when the bike is on the centre stand it appears very symmetrical. I rolled it up to about a buck seventy five (km) yesterday and no vibrations or any issues observed.
For my purpose, these suit me just fine.
My OEM panniers have a speed restriction of 80 mph or 130 kph, and these OEM boxes look awful. JMHO
But thanks for your comment, beauty truly is in the eye of the beholder.
SHUMBA

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WJBertrand

Ventura Highway
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I was going to suggest loosening all the fork and axle clamps, bounce the front up and down a bit and then re-torque to spec. Changing the front tire might have also have corrected any issues if things weren't previously torqued correctly. Glad it's fixed just the same.
 

SHUMBA

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You could be correct
My pannier install does not create any instability when riding at higher speeds.
I mentioned earlier the speed Yammy states a speed restriction of 80 mph / 130 kph when the OEM boxes are installed.
SHUMBA

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Sierra1

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Nov 7, 2016
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Joshua TX
Oh, just an after thought, stand in front of a mirror, sans clothes, and you will see the left bag hanging lower than the right bag.. . .
Pretty sure I'm the opposite. Depends on the last time the house was cleaned maybe. :rolleyes:
 
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