Help to diagnose vibration at very low speed?

Squibb

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Aug 10, 2014
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784
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Bedford, UK
Like others, I initially focussed on the front end, suspension/wheels/spokes/discs warped/seized calliper pistons, but so much of this made no sense, as it is a low speed issue, that isn't apparent as speed builds up we are told.

Then I wondered about the story - why has the bike been sleeping in a garage for so many years - can the previous owner help. Was the bike stored clean, or had it been out in wet/salt & just left.

Finally, along came @SkunkWorks mentioning the drive shaft, which clicked with me as an occasional issue with RTs & GSs. Could the UJ not be spinning up & centring freely, maybe the bearings are dry, or it has settled/corroded slightly off centre. Sometimes these can be resurrected & lubed, provided the rollers aren't corroded.

It's part 43 - Cross Joint comp. on this diagram .........

.......... https://www.fowlersparts.co.uk/parts/5448301/xt1200z-2011-23p8-europe-vivid-purplish-blue-cocktail-5/drive-shaft
 

randomdude

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Sep 12, 2020
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Gothenburg, Sweden
Maybe you could take a video (or have a passenger take it) while you're riding that shows what the shaking looks like on the bike? I don't know if it'll help or not, but being able to see it might lead to some new ideas....
You're right, mate, no matter how much I try to describe the issue, it would be better to make an attempt to document it in order for the rest of you to get the picture. My bike is stuck in a public garage now because of the freezing temperatures outside lately and it's basicaly dark down there but I'll do my best with my phone= all I got. I thought of attaching a zip tie or something onto the accesory bar at the front end, to exagerrate the wobble while filming. I'll try to capture the wheels spinning too, in order to show you that they dont seem to be awfully off, sideways or up & down, at least visually.
 
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randomdude

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Sep 12, 2020
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Gothenburg, Sweden
By the way, I 've now done some work on the bike, just to exclude some things more from the potential list of causes,

Checked most things I could for tightness, everything seems to be nice and tight.

Re-torqued the spokes down to specs. Now, Im aware that I'm far from a specialist so the wheel's truness should be "meeh" at the best case senario, if not ruined..
But like others said, it seems unlikely that the wheel vibrates multiple times in a single revolution at walking speed if the runnout is not literally centimeter(s)?

Grabbed and tried to give the front plastic subframe a good shake, it feels solid. I 've come across several threads of them being cracked etc, so I have kept a close eye on it since I bought the bike.

Checked the front fender/fender extender, no contact with the wheel, nore any sound coming from there when the bike is moving
 

randomdude

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Sep 12, 2020
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Gothenburg, Sweden
Based on what you are describing (with the vibration only happening at around 6-mph) I doubt it would have anything to do with the wheels or suspension.
The wheels are rolling too slowly at this speed to feel anything from them. (unless they were physically bent way out of true)

The only thing I can think of that would possibly vibrate at this speed (especially since it seems to happen with the engine OFF) would be the Driveshaft.
I am unsure of the exact rear drive ratio, but it would spin 3+ times for every wheel rotation.
Now, with that low of mileage on the bike, it would seem very odd to have a driveshaft problem? But who knows what the previous owner could have done to the bike, or even if it was put together correctly?
There could be a slight possibility that the front u-joint or the splines could be causing a binding in the front coupling.
The fact that you stated it vibrates multiple times in a single wheel rotation makes me think it could be driveshaft frequency.
If it was anything in the wheels/tires or suspension it would be felt much more prominent at higher speeds.

For these bikes it is almost unheard-of to have a driveshaft problem, but just giving you another angle to look at.
At the very least, it wouldn't hurt to have a look.
Like others, I initially focussed on the front end, suspension/wheels/spokes/discs warped/seized calliper pistons, but so much of this made no sense, as it is a low speed issue, that isn't apparent as speed builds up we are told.

Then I wondered about the story - why has the bike been sleeping in a garage for so many years - can the previous owner help. Was the bike stored clean, or had it been out in wet/salt & just left.

Finally, along came @SkunkWorks mentioning the drive shaft, which clicked with me as an occasional issue with RTs & GSs. Could the UJ not be spinning up & centring freely, maybe the bearings are dry, or it has settled/corroded slightly off centre. Sometimes these can be resurrected & lubed, provided the rollers aren't corroded.

It's part 43 - Cross Joint comp. on this diagram .........

.......... https://www.fowlersparts.co.uk/parts/5448301/xt1200z-2011-23p8-europe-vivid-purplish-blue-cocktail-5/drive-shaft

SkunkWorks, Squibb, Thank you so much both, this somehow feels to be a good catch: I can't really put the right words into it but I'll give it a try: the vibrating force feels too enaging and persistent, directly connected and strong enough to rythmically shake the whole 600lb mass of the bike rather than it being just some loose part swinging around. In fact I thought first that it could be a final drive issue and a buddy who rode my bike suggested the same but I didn't dare to mention it here so far because of my lack of knowledge, baah.. The fact that no other failure has been reported beside some leaks as I 've been through most of the shaft related threads here and Advrider didn't help either. Only a few case of some GS's as you pointed out, had symptoms quite similar to mine

The previous owner had luckily kept the bike in a warm, well ventilated garage and this can be seen on the plastic/rubber parts that for an almost 10 year old bike appear to be fine, not dried out/grey or brittle. No signs of rust on the frame either or corrosion on the aluminium. Reason why he didn't ride it was bad hips unfortunately for him.

The only thing I have done so far with the shaft was when I changed the tires, pulled out the pumpkin and I re-packed the splines with high pressure lithium-soap grease and tried to get rid of some of the rust/pitting from the gear coupling cylinder, carefully with a scotch brite and WD40. I made sure to put everything back as it was, the vibration problem was there before me, doing that, nevertheless.
I got myself a service manual now and I will try to dig into it and figure how the shaft/U-joint works and what adjustments can be done, check for corrosion etc as you very well said. I will report back.

Thanks again for the precious help.
 
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SkunkWorks

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Sep 13, 2018
Messages
777
SkunkWorks, Squibb, Thank you so much both, this somehow feels to be a good catch: I can't really put the right words into it but I'll give it a try: the vibrating force feels too enaging and persistent, directly connected and strong enough to rythmically shake the whole 600lb mass of the bike rather than it being just some loose part swinging around. In fact I thought first that it could be a final drive issue and a buddy who rode my bike suggested the same but I didn't dare to mention it here so far because of my lack of knowledge, baah.. The fact that no other failure has been reported beside some leaks as I 've been through most of the shaft related threads here and Advrider didn't help either. Only a few case of some GS's as you pointed out, had symptoms quite similar to mine

The previous owner had luckily kept the bike in a warm, well ventilated garage and this can be seen on the plastic/rubber parts that for an almost 10 year old bike appear to be fine, not dried out/grey or brittle. No signs of rust on the frame either or corrosion on the aluminium. Reason why he didn't ride it was bad hips unfortunately for him.

The only thing I have done so far with the shaft was when I changed the tires, pulled out the pumkin and I re-packed the splines with high pressure lithium-soap grease and tried to get rid of some of the rust/pitting from the gear coupling cylinder, carefully with a scotch brite and WD40. I made sure to put everything back as it was, the vibration problem was there before me, doing that, nevertheless.
I got myself a service manual now and I will try to dig into it and figure how the shaft/U-joint works and what adjustments can be done, check for corrosion etc as you very well said. I will report back.

Thanks again for the precious help.
One thing to note when performing the service that you outlined above.

When you reassemble the shaft and "Pumpkin" assembly back onto the swingarm. You have to absolutely make sure that you only assemble the 4 cap-nuts that hold the pumpkin to the swingarm "Loosely" until you assemble the wheel assembly and axle and torque the axle to spec. Then go back and torque the cap-nuts tight.
Failure to do it in this order will introduce a "Binding" in the alignment of the final-drive and wheel assembly.
Just something to keep aware of when working on the shaft and pumpkin assembly.
 

scott123007

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Jul 27, 2012
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1,242
Location
Jupiter, Florida
Well, if you really want to narrow it down to the shaft, all you have to do is put it on the center stand and either spin the wheel by hand to feel anything abnormal, or just start it up. It should spin the back wheel enough, even in neutral, to duplicate the situation. If not, try 1st gear, give it a little rev, and then put it in neutral and see what it does as it slows.

If it is not the shaft, there is still an "extremely remote" chance that it could be the tires. The ones you took off (I'm assuming you changed both) could have been worn to a point to cause that "feeling" and the new ones, being a more aggressive tread pattern could be doing it also. I know that's grasping for straws, but a regular knobby feels just like what your describing at very slow speeds.
 
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randomdude

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Sep 12, 2020
Messages
16
Location
Gothenburg, Sweden
One thing to note when performing the service that you outlined above.

When you reassemble the shaft and "Pumpkin" assembly back onto the swingarm. You have to absolutely make sure that you only assemble the 4 cap-nuts that hold the pumpkin to the swingarm "Loosely" until you assemble the wheel assembly and axle and torque the axle to spec. Then go back and torque the cap-nuts tight.
Failure to do it in this order will introduce a "Binding" in the alignment of the final-drive and wheel assembly.
Just something to keep aware of when working on the shaft and pumpkin assembly.
That's a good call, I made sure though I tighten then cap-nuts after the axle thanks to Checkswrecks' instructions in a thread here. The alingment is to be double checked soon however, for the peace of mind
 
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randomdude

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Sep 12, 2020
Messages
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Gothenburg, Sweden
Well, if you really want to narrow it down to the shaft, all you have to do is put it on the center stand and either spin the wheel by hand to feel anything abnormal, or just start it up. It should spin the back wheel enough, even in neutral, to duplicate the situation. If not, try 1st gear, give it a little rev, and then put it in neutral and see what it does as it slows.

If it is not the shaft, there is still an "extremely remote" chance that it could be the tires. The ones you took off (I'm assuming you changed both) could have been worn to a point to cause that "feeling" and the new ones, being a more aggressive tread pattern could be doing it also. I know that's grasping for straws, but a regular knobby feels just like what your describing at very slow speeds.
Maybe I'm in a hurry to start narrowing things down here, points taken. But wouldn't the U-joint be more engaged and/or behave differently under load? I already tried to spin the wheel when off the ground and it seemed fine..

Tires: Remote chance or not, that's a legit thought. I don't really know, a friend with experience on dirtbikes who rode mine again said that it's not supposed to feel like this from any tread pattern.
On the other hand the old Anakee 3 tires were totally squared and down to the wear indicators in the middle. Perhaps the problem was already there and got more prominent when I put the new stiffer springs on? The thought has been swinging in my head for quite a while so I took the bike on some soft dirt ground with some "give" with the new MotoZ GPS tires on and the vibrations were still there..:confused:
 

randomdude

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Sep 12, 2020
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Hi everyone for once more,

Okay, I had to put my pieces together to get back here & report, in case it helps someone in the future. Long story short, after literally taking apart half of the bike ( checked bearings, re-adjusted spokes, final drive therefore swingarm/schock etc etc) I figured that everything looked brand new. So I'm 99,9% sure that the motoZ Gps tires are causing the shimmy/vibes:oops: I think the alternating tread blocks fight for which direction they want you to go. Now that I know, I'll try to get used to it, as it's completely gone once you start moving..
The only thing worse than this now, that I've done during my motorcycling years was when I took apart a carburator from another bike that refused to fire up, cleaned the jets only to find out eventually that I had ran out of gas and that was all...:rolleyes:

Oh well, on the positive side, I've now learned more things about my bike, connected to it more by fiddling on it for hours
..So back to the initial conclusion from my ownership so far: An XT1200Z super tenere more likely won't present any serious issues out of nowhere.

**Thanks a lot-a lot to everyone who tried to help out with this (..even those who thought of it but couldn't come up with anything useful to add:))


IMG_20200530_201709_9.jpgWhatsApp Image 2020-07-27 at 09.25.38 (1).jpegthumbnail_IMG_20200711_164323_6.jpg
 

PhilPhilippines

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Joined
Jun 20, 2020
Messages
920
Location
Philippines
Hi everyone for once more,

Okay, I had to put my pieces together to get back here & report, in case it helps someone in the future. Long story short, after literally taking apart half of the bike ( checked bearings, re-adjusted spokes, final drive therefore swingarm/schock etc etc) I figured that everything looked brand new. So I'm 99,9% sure that the motoZ Gps tires are causing the shimmy/vibes:oops: I think the alternating tread blocks fight for which direction they want you to go. Now that I know, I'll try to get used to it, as it's completely gone once you start moving..
The only thing worse than this now, that I've done during my motorcycling years was when I took apart a carburator from another bike that refused to fire up, cleaned the jets only to find out eventually that I had ran out of gas and that was all...:rolleyes:

Oh well, on the positive side, I've now learned more things about my bike, connected to it more by fiddling on it for hours
..So back to the initial conclusion from my ownership so far: An XT1200Z super tenere more likely won't present any serious issues out of nowhere.

**Thanks a lot-a lot to everyone who tried to help out with this (..even those who thought of it but couldn't come up with anything useful to add:))


View attachment 77080View attachment 77082View attachment 77083
I don't know if this is helpful, but I have Metzeler Sahara tyres on my Husky Terra. When new, I can feel each block through the bars when physically rolling the bike quite prominently. Once above rolling speed it smooths out.
 

randomdude

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Sep 12, 2020
Messages
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Location
Gothenburg, Sweden
I don't know if this is helpful, but I have Metzeler Sahara tyres on my Husky Terra. When new, I can feel each block through the bars when physically rolling the bike quite prominently. Once above rolling speed it smooths out.
It does help a bit, in my case with the MotoZ it almost knocks me off my balance, specially on slow U turns and generally at the same rolling speed you mentioned. The alternating tread pattern causes some weird lateral wobble. In fact I dont know how to feel about these tires anymore, I also noticed quite some bad traction on wet pavement as well and a fair amount of squirming(compared to other 50/50s)
However to be fair I've only rode on them for about 700milles because of the winter here, so maybe better days will come.
 
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