Audible vibration at low speeds and reverse

[ruralgirl]

A couple weeks ago, my 2015 RT-S SE6 began audibly "vibrating" at very low speed, such as in first gear starting out, or approaching a stop. When starting out or doing slow figure 8's etc, my brake obviously isn't engaged, but when stopping, obviously it is. The feel and noise is the same whether the brake is applied or not. I can feel the vibration in both foot boards, either together or singly, as well as through the brake pedal, if engaged, and it's accompanied by a low frequency noise that's hard to explain, as "hum" seems too soft, but "buzz" seems too harsh. On the occasions when it's not happening, I can usually trigger it by traveling 20' or so in reverse.

I'm trying to determine whether our recent 90s weather and high humidity is causing something to swell and rub, but just when I think I'm seeing a connection, the problem either occurs or disappears unexpectedly.

The belt varies from lightly contacting the inner flange at the rear and outer flange at the front to just barely not contacting either flange (I attribute this to our extremely bumpy roads?), and my Missing Belt Guard, which has always slightly contacted the belt, is wearing thin on that edge, so, if anything, I figure its contact should be decreasing.

Any ideas??

[Bob Denman]

Could it possibly be in the engagement clutch?
If it's right down by your feet: that location puts it in the realm of the "possible suspects".

[ruralgirl]

Could it possibly be in the engagement clutch?
If it's right down by your feet: that location puts it in the realm of the "possible suspects".

Thanks, Bob. How would I check that?

[Bob Denman]

From a "Backyard" sort of method: start the bike, and let it settle into it's normal 900 rpm idle.
Click it into first (or reverse), and VERY slowly bring the revs up to just the very beginning of the engagement point.
If you feel the vibration: that's the cause.
If not: you're back to square one.
Oh! Try putting a tiny dab of grease on the cogs of the drivebelt: they've been known to squeal, and a bit of vibration might just go along with it.

[ruralgirl]

Okay, thanks! I'm out the door to run the test ......

[ruralgirl]

Nope, no judder. Whew! So it's back to square one, I guess. Will consider the dab of grease. Thanks again, Bob.

[Bob Denman]

So much of this is simply "Eliminating the possibilities; until the cause is found."
It takes time, but it does work!

[Ex-Rocket]

I think I had the same noise on my 2015 RTS. Going down the road you couldn't hear or feel it but at real slow speeds, like coming to a stop you could fell and hear the vibration. On mine it was the drive belt rubbing on the inside flange on the rear sprocket. There needs to be a little gap between the belt and the inside flange. I guess a good way to test that would be to apply some grease to the inside edge of the drive belt and see if that stops the vibration and noise. Good luck

[ruralgirl]

What you describe does indeed sound like what I'm experiencing, and now that I've been checking regularly, I'm seeing that my belt is usually touching the rear flange. I'll test as you suggest. Thank you!

[IGETAROUND]

What you describe does indeed sound like what I'm experiencing, and now that I've been checking regularly, I'm seeing that my belt is usually touching the rear flange. I'll test as you suggest. Thank you!

If your belt is touching the inside flange of the rear drive sprocket then you need to adjust the belt so it tracks properly. you should have a gap the thickness of a credit card. refer to your owners/shop manual for proper procedure to make the adjustment. Let us know how you make out.

[ruralgirl]

You're right, I just need to bite the bullet and get the belt aligned. Thanks to Georgia Bill's great thread, I've ordered a belt cricket, and as soon as it comes, my mech eng husband will test the tension and do the alignment. Thanks for your input!

[ruralgirl]

Okay, my husband and I are ready to align my belt, but Bill would like some clarifications first, so he's written the following:

With Wendy’s Spyder, the belt tension seems really high according to my intuition. The Kriket says 260# with the rear wheel on the ground, which I think is now considered to be high by a factor of two. However, it seems that belt tension is not really too critical within reason, as it mainly determines at what speed ranges a belt resonance might occur. Nothing else. In our case, the belt is commonly (but not always) hard pressed against the rear wheel inner flange and I see wear marks from the belt cogs onto the pulley.
I’ve read through all of the posts on belt tensioning and alignment, but still have questions:

1. Do the left and right axle nuts both need to be loosened? I think yes, but this depends upon how the wheel is supported upon the axle via its bearings. I am thinking that the left and right are tightened/loosened independently. Right?
2. I understand that the belt tensioners work by pulling the axle to the rear, left and right. Hence when tightening these nuts, one would want to orient the wrench so that the force on the wrench handle will push the axle forward on that side against the tensioner mechanism. This would mean for the left side upon tightening, the wrench handle will be below the axle (assuming that this is a right-hand thread). Opposite for the right side. There is a post that describes this process, but in the opposite direction, and hence my concern.
3. For my specific situation, I think that loosening the tensioner on the left a bit, will both loosen the tension AND cause the belt to track more to the outside. That would be my first step, and other adjustments that follow might be different. Any comments?
4. Apparently belt tension is adjusted to a specification with the rear wheel off of the ground and the swing arm fully in the down position. This requires that the Spyder be jacked from the frame rather than from the rear shock mount which would not allow the swing arm to be fully down. Correct?

[ByronM]

Lamont has a good description :http://www.spyderlovers.com/forums/s...elt-adjustment

[IGETAROUND]

Okay, my husband and I are ready to align my belt, but Bill would like some clarifications first, so he's written the following:

With Wendy’s Spyder, the belt tension seems really high according to my intuition. The Kriket says 260# with the rear wheel on the ground, which I think is now considered to be high by a factor of two. However, it seems that belt tension is not really too critical within reason, as it mainly determines at what speed ranges a belt resonance might occur. Nothing else. In our case, the belt is commonly (but not always) hard pressed against the rear wheel inner flange and I see wear marks from the belt cogs onto the pulley.
I’ve read through all of the posts on belt tensioning and alignment, but still have questions:

1. Do the left and right axle nuts both need to be loosened? I think yes, but this depends upon how the wheel is supported upon the axle via its bearings. I am thinking that the left and right are tightened/loosened independently. Right? The rear axle is one piece, the left side is the head and the right side loosens to allow adjustments.
2. I understand that the belt tensioners work by pulling the axle to the rear, left and right. Hence when tightening these nuts, one would want to orient the wrench so that the force on the wrench handle will push the axle forward on that side against the tensioner mechanism. This would mean for the left side upon tightening, the wrench handle will be below the axle (assuming that this is a right-hand thread). Opposite for the right side. There is a post that describes this process, but in the opposite direction, and hence my concern the tensioners are only to give lateral movement to the wheel. With the axle loose adjust the right side to allow the tire to move towards the left in the swingarm. Do this in eighth to quarter turn adjustments. Then rotate the tire forward for at least 10 rotations, and the same number in a reverse direction. This should let you see where the belt is going to track while under power. When you have the belt tracking properly; then you can check the tension with the cricket gauge. When it is adjusted to the tension that you desire (somewhere around 200 is about right, but check the forum by searching for belt tension) Then comes the tightening of the axle bolt to it's torque specks which will be in your owners manual (around 177 sticks in my mind as being the magic number). recheck your belt tension and tracking then lower to ground and take cricket readings on the ground. this will allow you to adjust in the future if you want on the ground.
3. For my specific situation, I think that loosening the tensioner on the left a bit, will both loosen the tension AND cause the belt to track more to the outside. That would be my first step, and other adjustments that follow might be different. Any comments? yes if you adjust the left first this will reduce the over all tension; you will also need to loosen the right an equal amount to keep the wheel square in the swing arm.
4. Apparently belt tension is adjusted to a specification with the rear wheel off of the ground and the swing arm fully in the down position. This requires that the Spyder be jacked from the frame rather than from the rear shock mount which would not allow the swing arm to be fully down. Correct? Yes that is correct, the shock bolt is not intended to be used as a lift point and to do so runs the risk of bending the bolt. See # 2 above for adjustments of belt tracking
5. Hope this is helpful. When you get it all done and it consistently tracks where you want it, then you need to look around for where you can go to get it Laser aligned so it will go straight where you point it. It will make a noticeable difference in both cornering and straight line driving; money well invested in my opinion.

1. Do

[ruralgirl]

Thanks, Byron and IGETAROUND! We're working on it now. PITA to get around the muffler, so we can't use a socket or impact wrench. Will see how the box wrench works. Thanks again! Will update soon ..........

[MisterP]

I really believe it is your missing belt guard. I installed it carefully and started to have the same sounds. The belt had worn away part of the guard. I think you are having the same issue. I removed mine.

[ruralgirl]

Thanks, MisterP. That was my husband's hunch a month ago when I first complained of this, and you may be right. To me, however, the noise and vibration seem to be too much for it to be from that flimsy piece of plastic, but we'll see. We're adjusting and readjusting the alignment now. I just popped back in the house to get my license so I can start testing on the road ... gravel road.

[ruralgirl]

I'm back after a 40 mile ride, and am thrilled to say that, SO FAR, I experienced zero vibration and buzzing. But, JEEZE OH PETE, what a ROYAL PITA the adjustments were!! We just could NOT get that stupid belt to settle into the ideal position of one credit card width. After at least a dozen attempts to get both the tension and the alignment perfect, I cried UNCLE at 220# tension (with the wheel on the ground, and down from 260#) and 2 credit card widths of belt clearance. If Spyke doesn't like it, she can run away from home.

MisterP, my missing belt guard was definitely part of the noise I was hearing, so Bill trimmed off the rear edge with tin snips. We'd done a bit of trimming the day we installed it, but its interference had gotten worse. Additional noises were indeed the belt rubbing against the inside rear flange, as others suggested.

IGETAROUND, the single most helpful tidbit for Bill was your telling him that the left "nut" was actually the axle head.

Thanks again, everyone!