21 RTL Handlebar shake at 45 mph. Running out of ideas. Any suggestions?

[WDAVEY]

Update on my handlebar shake issue.

Update on my tire balance issue. I took them to a shop in Ft. Myers, FL for a "road force" balance. They found the balance was fine on the tires, BUT the left tire had radial and lateral runout. The right tire had only radial runout. Also found some confusing codes for build dates on the tires. Both tires have two sets of numbers, one is 4720 that seems about right for a bike purchased in March 21. The second number is 0210, just to the right of the 4720. Tire gurus any opinion?

NOW, where to find decent replacement tires? Tire Rack is out of Vredesteins until January (maybe). Continentals are back ordered until the end of November (if you believe them). This was for 165/60-15 tires since they don't have any tires in 165/55-15 size. Has anybody found tires other than Kendas somewhere?

 

[Peter Aawen]

...... Also found some confusing codes for build dates on the tires. Both tires have two sets of numbers, one is 4720 that seems about right for a bike purchased in March 21. The second number is 0210, just to the right of the 4720......

The Date Code on a tire should be the first 4 numeric group stamped/embossed into the sidewall soonest after the letters DOT - there'll usually be a couple of intervening alpha-numeric codes identifying the manufacturer/factory & the tire batch, but except in a few 'special circumstances', those intervening codes are clearly alpha-numeric groups & the Date Code is the FIRST 4 numeric code found after the DOT stamp.... hyea:

So in your case WDAVEY, I think you can safely ignore any numeric groups stamped "just to the right of the 4720" - & for those not yet aware, that 4720 Date Code identifies the particular tire as being made in the 47th week of 2020. :thumbup:

 

[PMK]

Update on my tire balance issue. I took them to a shop in Ft. Myers, FL for a "road force" balance. They found the balance was fine on the tires, BUT the left tire had radial and lateral runout. The right tire had only radial runout. Also found some confusing codes for build dates on the tires. Both tires have two sets of numbers, one is 4720 that seems about right for a bike purchased in March 21. The second number is 0210, just to the right of the 4720. Tire gurus any opinion?

NOW, where to find decent replacement tires? Tire Rack is out of Vredesteins until January (maybe). Continentals are back ordered until the end of November (if you believe them). This was for 165/60-15 tires since they don't have any tires in 165/55-15 size. Has anybody found tires other than Kendas somewhere?

Seems a bit concerning that you had a second set of loaner wheels / tires installed from a demo Spyder and you still had the same vibration or shimmy.

Curious about your tire balance, more specifically the balance weights. Are weights installed only along the rims centerline or have weights been installed at the inner and outer flange area of the rim?

Still, and I hate going against a fancy road force tire balancer, but I suspect you have an imbalance causing a precession type shimmy. A tire can be in balance, but still precess or wobble like a slowing top if the weights are not positioned as needed.

 

[WDAVEY]

Peter, thank you for clearing up my lack of knowledge. The guy at the tire shop pointed it out to me, so apparently he doesn't know either!

 

[WDAVEY]

PMK, The latest balance attempt ended up with no balancing being done. The guy showed me how the left tire had visible runout both radially and laterally. By that I mean I could see the tire tread rise and fall when viewed from the side. When viewed from in line with the tire I could see the tread move back and forth from side to side.

Like you, I don't know why the demonstrator wheels didn't make this issue go away. There is very little weight on either wheel, but both weights are close to the inside of the rim. I know this is not ideal.

Precession is a word I haven't heard since my Navy days when being trained on a Sperry gyro-compass.

When I find some quality replacement tires, I be sure they are properly balanced.

Thank you for your help and expertise.

 

[PMK]

PMK, The latest balance attempt ended up with no balancing being done. The guy showed me how the left tire had visible runout both radially and laterally. By that I mean I could see the tire tread rise and fall when viewed from the side. When viewed from in line with the tire I could see the tread move back and forth from side to side.

Like you, I don't know why the demonstrator wheels didn't make this issue go away. There is very little weight on either wheel, but both weights are close to the inside of the rim. I know this is not ideal.

Precession is a word I haven't heard since my Navy days when being trained on a Sperry gyro-compass.

When I find some quality replacement tires, I be sure they are properly balanced.

Thank you for your help and expertise.

Entirely your call on how to proceed.
Curious, how much up and down run out did you notice?
Side to side lateral run out, how much?

Typically, when I balance oem Spyder Kenda front tires, they often exhibit both of these variations. Even higher end tires can have those issues and be fine. Granted, if there was a failed internal belt, that would be a large unacceptable run out.

When the tires are correctly balanced, at least those that I have balanced, the concerns are gone. As I mentioned previously, the last Spyder had the same issue you describe, dealer could not fix it, then refused to work on it any further. The owner asked me to look at it. After correctly balancing both tires, the issue was gone. His test ride was over 80 mph. Upon returning from his 3 week trip, he messaged and we spoke. He told me no shakes even into triple digits.

As I mentioned, you are basically 1 1/2 hours west of me. Easy to check, but entirely your call.

 

[Mikey]

One things for sure that I can see after reading this whole post is that enough hands have touch this bike, swapped tires, balanced the heck out of them and the issues still there!!! My gut wants to think it's still the tires and maybe a new set is the answer, time will tell, if that doesn't do the trick then a good look at the bike is where you'll have to go! The part I don't understand is when the dealer swapped out your tires with another set, off the other bike some thing should have change the picture, BUT it didn't!!!! I did a brake bleed for a friend with a RTL this fall and took his bike out for a test ride, he had the same problem you have, I asked my friend what's up with your bike, he said it's done that for ever, I said it shouldn't!!! We took his tires off and had them rebalanced, all is good!! Good luck with your issue, keep us posted, I would like to see what it come out to be!!!:2thumbs:

 

[baxter]

If I read the beginning correctly, he did not have this issue the first 3000 miles but only after he “made changes “ to the bike. Follow the bread crumps back as to all the “Changes”

 

[PMK]

If I read the beginning correctly, he did not have this issue the first 3000 miles but only after he “made changes “ to the bike. Follow the bread crumps back as to all the “Changes”

I do agree somewhat, but typically on that 3000 first inspection, it is more of a walk around and not much gets done.

Suspect though, that many folks, regardless of the vehicle, tend to notice more closely after work is accomplished. I can not count the number of times I have repaired an aircraft, as an example, the brakes, and have the customer insist his now new problem with the engine is something we did while working on the brakes. Just an example, but I think you understand.

Myself, I still believe this vibration is a shimmy of the front tire(s), but again, the owner has his plan.

 

[WDAVEY]

PMK, Thanks for your continued efforts to help me. The runout observed was approximately 1/8 inch in both axis. Maybe a little less. Based on your feedback, I think I'll try the last shop and have the wheels balanced correctly with the weights in the proper places. I'm assuming a failed belt would be visible or able to be felt?

Is there clearance to the caliper for stick on weights all across the rim?

 

[PMK]

PMK, Thanks for your continued efforts to help me. The runout observed was approximately 1/8 inch in both axis. Maybe a little less. Based on your feedback, I think I'll try the last shop and have the wheels balanced correctly with the weights in the proper places. I'm assuming a failed belt would be visible or able to be felt?

Is there clearance to the caliper for stick on weights all across the rim?

Failed belt should be apparent. Consider though, you are more likely to have tires improperly balanced on the 4 you have rolled, than multiple failing belts.

You should have adequate clearance to place the weights.
While Road Force balancing is new technology, I am not sure how well it will work in this application. You might be using a NASA computer when a solar powered calculator can accomplish the task with fewer decimal points.

You are more than welcome to ride or drive over and actually see the numbers yourself. My balancer is the type race teams used, spins by hand and can balance within 0.1 oz if needed. The hand spin is nice in that you can truly easily see the tire as there is no safety shroud. I have some aircraft repair work this week, so message me if you want to come over. Essentially, I am at SR80 where SR7 intersects, do a search for Lowes, Royal Palm Beach.

Again, entirely your call.

 

[WDAVEY]

PMK,
You have been so generous with your help, I couldn't inconvenience you any further. I will go back to the guy who found the runout and ask them to do the road force balance. They seemed knowledgeable and more importantly, they really were trying to solve my problem.

If that fails, I may take you up on your offer. Google says it's only 2.5 hours away.

I'll let you know how I make out.

 

[PMK]

PMK,
You have been so generous with your help, I couldn't inconvenience you any further. I will go back to the guy who found the runout and ask them to do the road force balance. They seemed knowledgeable and more importantly, they really were trying to solve my problem.

If that fails, I may take you up on your offer. Google says it's only 2.5 hours away.

I'll let you know how I make out.

If they can do an old school dynamic balance that may be better in this situation. Road Force balancing Kenda tires, as I explained may be overkill. Honestly, with the wimpy construction, and sometimes less than accurate machining on the rims, the balancer may never find actual happiness. Road Force balancing, done correctly, makes sense for performance vehicles with performance tires. Kendas certainly are not a performance tire, and the Spyder is more cruiser than performance based.
Then again, if you do have them Road Force balanced, will be curious how well it works in this application.

 

[WDAVEY]

Well, the results are in. After road force balance the handlebar shake is dramatically reduced, but not gone. They put 2 ounces on the right and 1.5 ounces on the left, both are more than was originally there. I'll ride it like this until I can find better quality replacement tires. The Vredestines and Continentals are backordered at Tire Rack. Thanks to all, especially PMK that helped me along this journey.

 

[WDAVEY]

PROBLEM SOLVED! Today I installed Vredestien Quatrac front tires on my '21 RTL at 4,800 miles. The shake at 45 MPH is gone. Crappy Kenda tires are now on the burn pile. Thanks to all who tried to help me along this drawn out mess. Most of you were right from the beginning, but I was too stubborn to change out brand new tires. I should have listened a long time ago.