Front end vibration

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heskelin2

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Yesterday returning from a couple of days roadtrip I noted my Classic had a small vibration on the front end. Barely noticeable but it was there around 70..80km/h. If I let completely loose the bar the amplitude of the vibration increases very fast and I need to grab the bar to kill it down or the whole thing will explode.

So, it's a Classic from 2022 with 15000km, half of that two up. Still with original tyres / the front is getting replaced soon, rear still has some life on it. Last BMW service was at 11000km a year ago and I was thinking of start servicing the bike myself from now on.

A quick roadside visual inspection revealed nothing out of order. Now the bike is in my garage so I can try to diagnose and fix the issue. Any ideas on where to start? Any similar problems?
 

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Suggest you put Ride-On MOTORCYCLE sealant and BALANCER in your front tire. It will quickly balance your front tire. Good idea to put it in the rear tire as well as it protects against flats. Cheapest and most effective way to hopefully solve your problem. Go to the Ride-On website to see how much is required for tire size. My R18 FE 19"/16" requires 10oz/13oz respectively. Just a suggestion.
 
Thanks. Got the front end up. The tyre is worn but looks ok. Seems some play 1-2mm when I push/pull from the fork like in the pic. The play must be in the bearing between the fork and body.
 

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heskelin2 said:
Yesterday returning from a couple of days roadtrip I noted my Classic had a small vibration on the front end. Barely noticeable but it was there around 70..80km/h. If I let completely loose the bar the amplitude of the vibration increases very fast and I need to grab the bar to kill it down or the whole thing will explode.

So, it's a Classic from 2022 with 15000km, half of that two up. Still with original tyres / the front is getting replaced soon, rear still has some life on it. Last BMW service was at 11000km a year ago and I was thinking of start servicing the bike myself from now on.

A quick roadside visual inspection revealed nothing out of order. Now the bike is in my garage so I can try to diagnose and fix the issue. Any ideas on where to start? Any similar problems?
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Did you notice that the balancing weights are still intact? Do you have spoke rims that need to be adjusted? Usually a good tire shop can straighten that out.....Personally I wouldn't fool around with this. Your riding on what 8-10 square inches of tire surface at 70 plus mph. I always had matched tires of top quality and kept them well balanced. You don't want to lose it over a couple of G damn tires....
 
Randy Kahn said:
Did you notice that the balancing weights are still intact? Do you have spoke rims that need to be adjusted? Usually a good tire shop can straighten that out.....Personally I wouldn't fool around with this. Your riding on what 8-10 square inches of tire surface at 70 plus mph. I always had matched tires of top quality and kept them well balanced. You don't want to lose it over a couple of G damn tires....
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Yep, the weights are still there. I have a new Commander III on the way, will change as soon as I got it.
 
heskelin2 said:
Need 12mm Allen key which me or my local shops did not have. Never done this before. How to adjust the torque correctly? Until there's no play? Until the steering becomes heavy?
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I really have no idea what the actual torque is ... I usually tighten mine down to where I can start feeling 'drag' ... but I have not had to do anything on the R18 in that direction ... I figure, take that top nut off (or at least loosen it up) and see if you can turn the one right underneath the top triple tree ... the top one just tightens down the upper tree part it, the 2 underneath the triple tree set the preload for the bearing, it is the ones the red arrows are pointing at ... looks like the bottom one sets the preload and the top one jambs it ... I hope that helps.
Oh and here is a visual ... looking at this you may have to take the top part of the triple tree off to get a good adjustment.
Screenshot 2024-05-08 at 08.30.19.png
 
Ulrich said:
I really have no idea what the actual torque is ... I usually tighten mine down to where I can start feeling 'drag' ... but I have not had to do anything on the R18 in that direction ... I figure, take that top nut off (or at least loosen it up) and see if you can turn the one right underneath the top triple tree ... the top one just tightens down the upper tree part it, the 2 underneath the triple tree set the preload for the bearing, it is the ones the red arrows are pointing at ... looks like the bottom one sets the preload and the top one jambs it ... I hope that helps.
Oh and here is a visual ... looking at this you may have to take the top part of the triple tree off to get a good adjustment.
View attachment 14355
Click to expand...
Thank you for taking the time to explain this, appreciated!
 
My first thought was an unbalanced front tire. I made the mistake of having the Walmart tire shop mount and balance four truck tires. Had a slight shake at 60. Then after waiting several months, I went to a Pro Tire store and had them balanced. Smooth as still water. Have not been to Walmart tire store in quite some time.
 
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Yea, I would say ‘new tyres please’. 15k is a good effort on original rubber. As the tyre tread wears away the original balance weights are bound to go out of whack, seems inevitable. I’ve had similar experiences with front wheel wobble (hands off) a few times over the years and it’s always been resolved by new tyres.
 
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