Author Topic: High speed instability  (Read 1163 times)

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#10

Offline MongrelGuts

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Re: High speed instability
Reply #10 on: December 29, 2021, 11:54:42 AM
*Originally Posted by lospsi [+]
My thoughts on the subject (although I've sold the R and got an XR):

When I had the bike (which was a non DDC one), I never had this wobble, even at top speed. I'm a heavy (110kg) and tall (1,97m) guy and I also wear jackets that fit me tight. That said, my buddy rode it once and reported the wobble, he's about 20Kg lighter than me and also had a backpack during his test. So, I believe the problem lays in aerodynamics (many people wear loose touring jackets for instance or ride with backpacks) and spring preload settings. It seems that the bike is affected by stiffer spring preload, the guy who bought my bike also told me he had wobbles, I suggested to reduce preload and check again but unfortunately lost contact with him.

Interesting. The guy I bought it from hadn't touched F&R preload. It is basically all the way out. Presumably stock.
He's also a big lad, bit less at 1.85m and 96Kgs.

The bike has a tallish Wunderlich screen to note re aero.

Steering damper may assist with this issue. If not I'll perhaps get a Tuono if i can afford one.

It's simple not acceptable for me a BMW having this instability issue. Dam shame I love everything else about it.
Last Edit: December 29, 2021, 11:59:24 AM by MongrelGuts

#11

Offline SimonUK

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Re: High speed instability
Reply #11 on: December 29, 2021, 01:10:37 PM
*Originally Posted by MongrelGuts [+]
The bike has a tallish Wunderlich screen to note re aero.

have you tired it without the Wunderlich screen??

#12

Online podders

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Re: High speed instability
Reply #12 on: December 29, 2021, 01:15:04 PM
*Originally Posted by SimonUK [+]
have you tired it without the Wunderlich screen??

Good shout.

My bike was defo more stable at near
Maxium speed /top speed with the stock screen Vs my MRA but day to day, the additiional protection of the MRA screen was far more useful.

The bike only become twitcy past 140 so I lived with it .

#13

Offline Hooligan

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Re: High speed instability
Reply #13 on: December 29, 2021, 01:31:45 PM
*Originally Posted by podders [+]
Good shout.

My bike was defo more stable at near
Maxium speed /top speed with the stock screen Vs my MRA but day to day, the additiional protection of the MRA screen was far more useful.

The bike only become twitcy past 140 so I lived with it .

Def more noticible for me with the Wunderlich sports screen vs stock. Kept the screen, added the Ohlins damper which resolved it for the most part.   

#14

Offline MongrelGuts

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Re: High speed instability
Reply #14 on: December 30, 2021, 08:03:24 AM
Thanks all contributors.

Helpful advice, I'll be sourcing an adj new S.Damper. The Ohlins seems well priced.

There is a Toby brand which I'l be looking into also https://suspensionsrus.com.au/index.php?route=product/product&path=97&product_id=178

Hopefully something will be avail in stock locally down here in Australia....

#15

Offline windyrun

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Re: High speed instability
Reply #15 on: December 30, 2021, 12:51:23 PM
Some people use and like the Hyperpro RSC Steering Damper so you may want to consider this as well. I think there are different versions so you may want to research it.

Here is a thread on this product https://www.s1000r.co.uk/index.php/topic,10069.msg101472.html#msg101472
Last Edit: December 30, 2021, 12:54:10 PM by windyrun

 



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