Does anyone have a spare radial tyre to help solve a bike issue?

[__YANNICK__]

Hi there,

I have a slightly uncomfortable question. I've been having a wobble on my '08 BMW F650GS TWIN bike at 85mph+ since installing Dunlop Trailmax Missions. I have done everything I could think of except replacing the tyres to try and figure out what is going on (balancing tyres, bearing replacement, steering head bearing replacement and adjustments, wheel alignments, lateral and radial runout, inspected and repaired the front rim, chain tension, suspension, rotated the tyres, re-seated the tyres, ... and it's still there, so I feel like it's most likely the new tyres.

They are bias ply and our bike needs two radials. Since I threw away my old tyres too quickly I didn't give myself the ability to reinstall them to check if the issue disappears, so I am trying to find some used 110/80 R19 and 140/80 R17 Tourance Metzler tyres to put on to test wether that fixes the issue. The missions were so expensive, I can't see myself buying new tyres without being sure that's the problem.

Does anyone...have some spare that I could buy or borrow from them to do a test ride?

I could buy you a beer or kombucha depending on your tastes.

This is (amongst others) the thread where I discussed the issues: https://www.advrider.com/f/threads/f658gs-twin-80-mph-wobble-running-out-of-ideas.1667583/

Yannick

 

[Bem]

Hi there,

I have a slightly uncomfortable question. I've been having a wobble on my '08 BMW F650GS TWIN bike at 85mph+ since installing Dunlop Trailmax Missions. I have done everything I could think of except replacing the tyres to try and figure out what is going on (balancing tyres, bearing replacement, steering head bearing replacement and adjustments, wheel alignments, lateral and radial runout, inspected and repaired the front rim, chain tension, suspension, rotated the tyres, re-seated the tyres, ... and it's still there, so I feel like it's most likely the new tyres.

They are bias ply and our bike needs two radials. Since I threw away my old tyres too quickly I didn't give myself the ability to reinstall them to check if the issue disappears, so I am trying to find some used 110/80 R19 and 140/80 R17 Tourance Metzler tyres to put on to test wether that fixes the issue. The missions were so expensive, I can't see myself buying new tyres without being sure that's the problem.

Does anyone...have some spare that I could buy or borrow from them to do a test ride?

I could buy you a beer or kombucha depending on your tastes.

This is (amongst others) the thread where I discussed the issues: https://www.advrider.com/f/threads/f658gs-twin-80-mph-wobble-running-out-of-ideas.1667583/

Yannick

Just read your thread on ADV - I had a 658 for several years and carried out numerous mods and tire changes.
Given that the wobble was noticeable after a minor off and a tire change then it could be a multitude of things.
Mine had alloy wheels - you spoke of being out of true and being repaired, so was that on an alloy?
I did not see any mention of front/back truing or alignment using either a string or an extended straight edge.
You have refitted the front end several times, including the "bounce" so it is reasonable to suppose this has been done right.
You also spoke of replacing the chain and sprockets - I went for the "800" sized front sprocket (down one) and this delivered slightly better acceleration but more importantly changed what I would call "resonant frequencies" (but probably has a different name) - vibrations from the moving assembly. It was conspicuously smoother all the time.
If you want to carry on playing with the front end then you could drop the forks by another 10mm and see where that takes you.
HTH.