Wobbly Rear Wheel Rim - how to fix?

Thanks Saco! I had forgotten about this video. Maybe I'll change the gear oil too, while I am at it, since it is just taking 4 more bolts off and drilling a hole...

Today I installed the new rim and tire combo. They are significantly less wobbly than the original set. Also, the rear tire, being brand new, is now smooth rolling even when the bike is leaned (yes, I can still feel the thread getting more coarse with increasing lean angle, but it does not feel like an off road tire any more). The new wheel and tire combo is also pretty much perfectly balanced without any weights, where the old one I had quite a few.

I don't think I will ever use another tire with a thread pattern like the Pirelli GTS - they just wear off due to cupping too unevenly too fast in the rear. Perhaps they are fine if one seldom pushes the bike into corners hard-ish. But I like to take some safe corners a bit on the fast side, just for fun (nowhere near the limits of traction, just faster than a slow, sedated pace).

The change did not fix the steering wobble, unfortunately. It is still there from 35 to 45mph and virtually absent at slower and faster speeds. So I will be replacing my front tire with a Michelin City Grip soon (and keep my new Pirelli GTS in the rear for this season and maybe part of next, until it becomes bumpy due to cupping again.

EDIT: forgot to mention that with or without the heavy Givi cargo box, there is not really a difference - the front still wobbles a lot. Mentioning this, because one of the troubleshooting steps in the Vectrix manual for a wobbly front end is to remove the cargo box - does not do anything for the wobble in my case. And for those who don't know what this wobble is, because you never let go off both handlebars at the same time - it only is present if you let go with both hands within a certain speed range. It's cause is subtle, so even a slight touch of one fingertip on either handlebar eliminates it. So, if you never let go off the handlebars, that wobble is not a concern at all. I usually don't let go either, but sometimes when I have forgotten to zip-up my jacket and the wind starts flapping it about, it is very convenient to do that on a safe and deserted stretch of road ;)

Fingers crossed. A Michelin City Grip front tire is in the mail... The rear Pirelli feels great and smooth for now, being brand new on a brand new and straight rim...

However, that new Michelin on the front won't fix the slightly wobbly rear rim that I removed :( I was asking if someone has suggestions on how to straighten it.

I had the wobble only with the Pirellis - with the Michelin's the wobble was gone. Simple...

Yes, it was concentric, with just a lateral runout. And yes, the replacement is not perfect either, but considerably better. I did mark the two rims and the casing, so I might experiment with rotating the rim relative to the casing. The tire on the old one was also not perfectly mounted, seemed to have a slight twist/not perfectly evenly seated in the rim when mounted. The new one seems good enough - no vibrations and runs true enough, and the tire is properly seated on the rim. I'll experiment with mounting positions on my next tire change in the rear, this one's good enough for now. If the gearbox casing has lateral runout, I think it will be relatively easy to make a jig and file off a bit off the sides that protrude and to bring it to "flat", if simply rotating the rim relative to it does not compensate.

If the rim is perfectly concentric and just has lateral run out it should be possible (with access to the right equipment) to fix it by re-machining the inner flange surface in relation to the rim section.

As the replacement wheel rim is "significantly less wobbly than the original" I presume it is not running perfectly true either.
There is also a possibility that the machining on the surface of the gearbox casing flange where the wheel rim seats may have been machined slightly out of true slightly as well.

If both the wheel rim and the gearbox casing flange are slightly out of true, it might be possible to improve the run out simply by bolting the wheel in a different position in relation to the mounting studs. There are six positions to choose from and each one could produce a slightly different result.

I tend to mark everything prior to removal or dismantling

Alan

Today I replaced the Pirelli GTS front tire with a Michelin City Grip of the same size. Unfortunately, that did not completely remove the wobble of my handlebars. I think it is a bit less than before and shifted to slightly lower speeds and narrower range of speeds. I think it has something to do with the tire balance. After I installed the new tire, I did not remove the three weights and the wobble was noticeable. After removing the three weights, the wobble diminished. So I might need to experiment with balancing the front tire a bit better, though I do not feel any vibrations at speed.

A quick video of me changing the tire without special tools (almost - had to use a high-volume air compressor to seat the tire on the rim):

https://youtu.be/QFC0bCs4HXk

I did not look-up the torque specs for the front - played it by feel this time (though, I did follow the torque specs for the rear wheel/brake caliper though - they are in the video link a few posts up). If someone has them handy, please share. Nothing was too tight - the caliper bolts were a bit tighter than the main axle and they felt something like 25lb/ft when I removed them, and the little bolt holding the axle in place could not have been more than something around 15lb/ft

Interestingly, when I let off the handlebars, the bike tends to lean slightly to the left now. To go straight I now need to shift my weight a bit to the right if I am not holding the handlebars. I had not noticed this to be the case before with the Pirelli tire. I don't feel it with hands on the steering, but it is pretty obvious when I let go. I have to troubleshoot this ...

Since we switched the topic to front wheel/handlebar vibrations, I got a question for you folks. I still have a lot of vibration - yesterday it was worse than the day before and apparently my wheels are not directly under me as I need to lean slightly to the right in order to ride in a straight line. I had the vibrations before changing the tire, but my bike was centered.

So I looked at the front fork/tire today to see if there is something odd or loose. No loose things, all is tight and smooth and the tire rotated nicely and is round and true.

However, is there supposed to be a space between the fork and the wheel bearing spacer outside? Or a washer between the spacer and the wheel bearing or the spacer to fill that gap that I see?

See the photo: I get a 2mm gap on the side opposite to the disk brake. Do you have that on your bikes? The wheel is 2mm more to the right (towards my right hand when riding), assuming the forks are centered. That would explain the tendency to lean to the left when left unattended... Of course, I don't know if the forks are centered.

The wheel is secure and flush with the right-hand side fork (under my right hand when riding) - it is held in place by the threaded axle. I can move the left-hand side (under my left hand when riding) fork in and out, if I loosen the small hex screw that fixes the fork in position side to side. But to have the left-hand side fork flush with the spacer, I need to push pretty hard, which I don't think is good and the retaining bolt might not hold it in position where it does not want to naturally be.

If there is no washer on the sides, is there adjustability in the fork halfs? I don't see a way to adjust them in-out (only up/down and twist left to right)

and a slightly closer view:

Thanks for the photos - looks like mine.

Thank you for the torque specs! Usually the most critical to get "right" are the small ones, like under 10lb/ft - very easy to strip such bolts with a big-lever wrench ;)

Well, it's a mystery... The front tire definitely has something to do with the handlebar wobble, but not with all of it. Today I put a brand new OEM Pirelli tire/rim/brake disk combo (factory installed and balanced) to temporarily replace the Michelin to see if that makes any difference. It did, for the worse. Wobble was much more pronounced - stronger and active in a wider range of speeds. And looks like I did a better job installing the Michelin than the factory did for the Pirelli - the Pirelli tire is not as evenly seated as the Michelin, showing slight wobble/twist here and there. So I put back the Michelin set and the handlebar wobble is again greatly minimized but not 100% gone. With both tires there is a tendency for the bike to lean ever so slightly to the left if left to its own devices. Just like with the handlebars wobble, this slight left-leaning bias is not noticeable if I hold the handlebars, only if I let go with both hands at the same time.

I think I'll just leave it at this - both the lean and the wobble are so minor, that they are not a practical problem (and essentially unnoticeable with at least one hand on the handlebars)...

Good logic (I was actually thinking wrong until you explained it - the wheel moving to the left would make it have to lean left to balance itself, which will make it turn left)! It is probably the charger's weight high on the right - plus the brake disks are also on the right, though the motor is on the left... I don't have a spirit level of enough accuracy to try your test. I might try to pull the fork a bit to the outside and give it a try over the weekend (expected heavy rains tomorrow so, unlikely to be able to test-ride it).

Simply undoing the pinch bolt and pushing the fork further onto the axle to close the gap should reduce the offset by half of the actual gap reduction.
If the gap between the fork and the spacer is 2mm, the wheel would move laterally by 1mm by closing the gap. It is simple enough to try this just to see if it makes any noticeable difference. If it makes it worse, try slacking the pinch bolt and pulling the fork out to increase the gap even more and then tighten the pinch bolt and try it on the road again.
I suspect that any additional sideways force then acting upon the sliders/stanchions would probably still be a great deal less than the leverage force exerted by the weight of the front end acting downwards through the forks in conjunction with their rake angle.

If the wheel is definitely offset 2mm to the right of centre between the forks, placing a 2mm thick washer between the spacer and the fork on the right hand side should then put the wheel back in the centre, but I think this might increase the pulling to the left rather than improve it.
The gap on the left hand side should be reduced by 2mm when the fork is tightened onto the axle in its natural floating position without any sideways force being exerted on the fork sliders/stanchions.

There is another possible cause, if the bike itself is not perfectly balanced on each side, then it will tend to steer the way it is already having to lean to counteract any lateral imbalance.

I have just clamped a spirit level to the front disc and with the steering as straight as I can get it and gently holding the bike in the balanced position with equal finger pressure on each bar end, and sure enough, the spirit level indicates that the bike is leaning slightly to the left by around 1.2°:

This means that the centre of gravity must be very slightly offset to the right of the bike's vertical centreline causing the bike to balance while leaning slightly to the left.
Perhaps the leaning to the left is simply a result of a big heavy charger unit being mounted way off centre and high up from the ground on the front right hand side of the bike?

Alan

It probably depends on how they are mounted and probably other factors. I did try brand new OEM Pirellis front and rear (factory mounted, on brand new, balanced rims) and the wobble was worse vs. same new Pirelli rear and new Michelin front. My bike is fairly new - was under 3k miles then. So I put back the Michelin on the front and kept the Pirelli in the rear.

I also confirmed that with big Givi case the wobble is worse, as the manual says.

Lastly, now that I've put a few hundred miles on the rear Pirelli, I think it is less smooth when ridden in a straight line than it was when new - I feel the thread rumble...

I had the wobble only with the Pirellis - with the Michelin's the wobble was gone. Simple...

Not so simple, actually.

My Vectrix has done 29000km. I had quite bad steering wobbles like everyone else has described with the Pirellis, but I never used to when I first bought the bike.

I just replaced the rear tyre for the second time since I bought the bike and the front tyre for the first time....with the same OEM Pirelli tyres and the wobble is gone. I had a feeling it would be because of the worn tyres, and I was right.

What I don't know, of course, is if the Michelin will also get the wobbles when they wear.

Really???

I'm very tired of enterimg VisforV and see that the vibration//wooble problem it has not been resolved.Ok , the solution to this problem is soo simple , and so common on the motorcycle world that will make you all sorrow.The problem with the vibration can be solved if you go to a mechanic and ask him to weight and calibrate your front tire.He wil put your front tire in a machine , and the machine will spin your wheel , and he/she will put lead/zinc weights on the wheel trim.This problem ocurrs because the tire is more worn in some places than other , making the wheel desequilibrate thus making vibration in the handlebar.

That's a good video. I might try to manually check the balance. But it only solves the weight difference on the vertical axis. I suspect the wobble is due to side-to side disbalance. On cars, this is called "dynamic balance" - it matters on which side (left or right) is the weight placed, not just where along the circumference of the wheel. The video can't help with that.

Also, both tires/wheels I have tried on my bike have been balanced by Vectrix at the factory - they have lead weights from that process attached to them. Were they perfectly balanced? Probably not, but they were balanced by a mechanic on a machine...

The vibrations I'm talking about are side to side, not up-down like you get from a disbalanced wheel. The handlebars don't vibrate if you hold one finger gently to them. And they do it at only one narrow range of speeds. A disbalanced tire/wheel is felt through the handlebars differently. Mine is smooth rolling at all speeds and there is absolutely no vibration if I hold the handlebars.

I had a disbalanced rear wheel at one point and I could feel the vibrations from the wheel at certain speeds. I balanced it with the wheel off and measuring the wheel hop, then adding weights to counterbalance that. Worked pretty good. My new rear wheel is much better balanced from the factory and it does not vibrate on the road or off the ground on the stand. So I know how it feels to have a vibration from a non-balanced wheel.

With all my respect aircon , had you solved the problem?Because it seems that nobody in this forum has solved it.I totally get rid of the vibrations with this.

http://youtu.be/egNxGIAfwic

Here is a video in spanish , you will see a mechanic using a wheel equilibrator.

Imagine a wheel , that weights 200-300 grams more in one side than in other.Now imagine what wheel happens the same bike cruising at 70-80 kmh with this little diference in the wheel.What do you think that happens?

Obviously I'm talking about the rubber of the wheel , not the wheel base.

He does *not* do a side to side balance. Only up/down. I don't understand what he is talking about for 25 minutes, but the balance part https://youtu.be/egNxGIAfwic?t=14m10s is just making sure the weights are on the lightest area along the circumference. Yes, he puts weights on both sides of the rim, but he could have just as well put them both on one side and "balanced" the wheel just the same in the video.

Yes, on a narrow motorcycle wheel a dynamic balance with side to side considerations probably does not make a huge difference compared to an 8" wide rim on a car, but that means he's simply ignoring the effect. The rig in the video simply cannot balance a rim left to right.

For example, if my valve is on the left side of the rim and that side is heavier, this type of balance as on your video will not know that. It will just know that the area where the valve is heavier. He can stick a weight on the left side of the rim to counterbalance that, and his wheel will now be even heavier on the left side vs. the right compared to before the balance (but will show perfect balance on his rig). In motion, at higher speeds on the road that creates a dynamic disbalance, which can't be detected by the "static" balancing method he uses.

A wheel that is disbalanced up and down but is perfectly balanced side to side will not create a side to side wobble. A wheel that is disbalanced side to side will create a side to side wobble even if it is perfectly balanced around the circumference.

His video shows an easy and very accurate method to statically balance the wheels and for narrow wheels that' probably all it takes. But let's not claim it is more than what it is.

Mec! You are wrong , it solved my vibration in all directions...the calibration is in both axis...now it's up to you.