Clanking Noise From Front

James Gross @jim-g, a little bit of history of the rig may possibly help, as in....who installed the LBS Leading Link ?

Where did you get that rig from ? Was it previously owned as a complete sidecar rig, or did you, or someone else assemble it to make a complete rig ?

How many MILES, or Kilometers are on that bike, and on the Leading Link?

These things are all relative, as it puts perspective on any issue with the LBS Leading Link.

Additional information: I purchased the R12 new in 2018. Sidecar installed with 15,000 miles on motorcycle in 2020 at a BMW dealer who was certified by Hannigan. A new LBS front end was installed at 19,000 miles in October 2020 by a trusted independent BMW master mechanic who has serviced Urals. The spoked rim was replaced with a cast rim but that did not help. I can feel a slight single pulse in the handle bar with each clank. Thanks for your help.

James @jim-g, okay, that info helps.

Now, moving forward, if you can FEEL a slight single pulse in the handlebar with each clank, then IMO, I would NOT drive the rig, until the issue has been resolved, simply as a safety precaution.

WHERE do you live ? Are you close enough to Hannigan's, to have this looked at ? Dave Hannigan is at Sturgis right now, so he can't help, and most of his seriously knowledgeable guys are with him in Sturgis, so there may be a week wait.

How far away from this "trusted independent BMW master mechanic" that did the Leading Link installation are you ?

And....how many MILES have you driven that rig, with the LBS Leading Link front end on it....in other words how many miles are ON that LBS Leading Link ?

Okay, here is the final question....if you can jack up the front of the bike, jack under the engine, to lift the front wheel 1" off the ground, and then rotate the front wheel....can you HEAR the clank ?  Can you FEEL the clank in the upper legs of that Leading Link front end ?????

Is it possibly the front wheel ABS sensor hitting the ABS ring that is mounted on the wheel? It is you wheel bearings? 

It is your canine friend that you forgot was in the sidecar, and he/she found an old Whitworth wrench that you meant to give to a friend of yours that has a 1960 Triumph, and you forgot the wrench was inside the sidecar, so your canine friend is now rapping on the inside wall of the sidecar, trying to get your attention, but your mind is on where the next Starbucks is located, so............well.....you get the idea.

I lived in New Mexico at the time of the above mentioned installations. I moved to South Dakota last August. I am 100 miles south of Sturgis. The LBS was obtained from LBS-USA. A few months after installation I had a leaking shock which LBS replaced at no charge.

The Whitworth wrench was from a 1968 BSA which I got rid of when I switched to BMW in 1972.

Any chance you can get the front end raised off the ground so you can manipulate the front end assembly? 

I'd start top down.  Head set bearing, strut ends that replaced the front Telelever shock, Telelever bushings, Ball Joint (to include ensuring the ball shaft is tight fitting into the Telelever bore), LL Swing arm bushings, Shock mounting points, Front wheel bearings. 

When I'm checking front suspension I use a long pry bar, and a huge set of adjustable pliers to get the leverage needed to find worn parts that don't feel worn when manipulated by hand.

Hope this is helpful, and the fix is quick & cheap! 👍 

Thanks. I am heading to Idaho tomorrow (by car). If I can't check today, I will check Tuesday.

I forgot to mention the noise is intermittent. Not doing it today. But it seems to me there is not enough preload on the suspension. Both sides can be rotated by hand (see attached video). Should I be able to twist it like this?

Without pictures I'm sorta winging it here, but you said you replaced the front spoke rim with a front cast rim.  If the cast rim is a 2018 R1200GS cast rim, then are you using the stock brake rotors?  If you're using the stock rotors, those are floating rotors and they're subject to excess wear around the bobbins.  When this happens, the front wheel will "clank." And the clanking will often come and go.  You won't notice this wear if you leave the calipers in place when doing a check.  So, remove the front calipers then see if you can manually move the rotors.  If the rotors can be moved easily, that's not right and they need to be replaced.  The rotors should only be able to be moved manually (with the calipers off) with effort and with resistance.

Shortly after installing the LBS leading link, the original rear wheel was moved to the front with the corresponding LBS brake modification: Larger single non-floating rotor on the left side with both calipers. Originally I thought the clank was related to braking but then I noticed that was not the case (I just noticed the clank when slowing to lower speeds which usually included using the brakes). Later I realized the clank continued after releasing the front brake.

Thanks.

James Gross @jim-g, does that forward braided brake line hit the stick on wheel weights, when the wheel rotates?

I can not SEE the wheel weights, can only assume that there are wheel weights, because NO BMW ever made came with perfectly balanced wheels from the factory, BUT...I can see that the forward braided brake line is very close to the inner circle of that wheel, so one has to ask the question....if that braided brake line hitting the wheel weights?

Weights at bottom

Any response to the spring preload question?

I don't have a LL on the BMW, but the springs on the Ural LL wouldn't rotate that easily.  What seems strange is no locking nut to hold the adjustment collar in place. The threaded collar is turning with the spring.  But again, no personal experience.

Are both shocks built the same way (as in no locking nut)?

Have you tried lifting the front end off the ground to see what is "loose".  I would expect the shock springs to have preload even at full extension.  So if they are "loose" they could create a clank.     

Hth, 🍻 

**ETA:  Went to the LBS website and there is a picture of the leading link.  It doesn't appear to have locking nuts on the shocks.  It also looks to have a lot less preload dialed in than what your video shows.  I'm surprised there isn't something to lock that collar in place so it doesn't rotate?

Think I'd reach out to them (i.e. Mike Paull) when they get back from the big EU road trip.   https://www.lbs-usa.com/kits    ******

I must concur....I say, I must concur....with my colleague from Utah. In my experience there should be a locking nut just above or below the one shown in your picture/video, so that the rotating adjuster does NOT come loose.

The origin of oddball sounds can be deceiving especially while in motion wearing a helmet.  I think I'd recruit a young person with good hearing to ride monkey with their feet in the cockpit and their upper body draped over the sidecar nose, then equip the young person with a mechanics stethoscope to see if they can pinpoint the origin.

https://www.amazon.com/Lisle-52750-Stethoscope-Kit/dp/B0015DLMOO/

Maybe do this in a big deserted parking lot for both safety reasons and reduced ambient noise.