Bad vibrations with SmoothSpyder installed

[IdahoMtnSpyder]

I don't find an answer here for this specifically, so will go ahead and ask.

I installed Jim's SmoothSpyder on my '13 RT last week. I guess it's the new style as it bolted into an existing hole, no drilling required. It was tough to get the idler force set as the scale moves quick at the point where the pulley just touches the belt, but I'm quite sure I got the force set somewhere close to 10 pounds. The belt tension was set at the dealer just a month or so ago and I'd ridden about 700 miles before installing the tensioner. Previously I had significant vibrations at about 69 mph (odo reading). I don't recall that I had occasion to drive at 80+.

I just finished about 700 miles these past 5 days on two lane roads and Interstate. The vibration at 69 is pretty much gone. But, here is the rub. I have real bad vibration in the speed range of 78 to 81 mph GPS speed (80 to 83 odo reading). This is exactly the speed I like to run on the 75 speed limit Interstate. The vibration isn't constant, but is present a good 10 to 20% of the time. It doesn't readily die off by either slowing down or speeding up. In fact I think it continued to around 84 or 85, odo reading, which is fast enough to get in trouble on a 75 mph Interstate.

What do I need to do? Increase the idler force to around 15 pounds maybe? Drop the belt tension? I have to make a change of some sort as this bad a vibration at 80 is unacceptable. That is the speed for a huge percentage of the Interstates I travel.

I just looked at the belt and the tension looks to have stayed at the same 240 pounds, Kriket reading, I measured right after the dealer adjusted it. The tensioner looks to have moved so that the outer flange of the idler is pushing the edge of the belt. In fact the belt is up against the flange on the wheel sprocket. It had been tracking about 1/8" away from the flange. Is the idler pushing sideways on the belt contributing to the vibration, or did the vibration cause the tensioner to move. I'm sure I had the idler pretty much centered on the belt when I installed it.

[Chupaca]

you need to realign the tensioner. I run about 13lbs but I have the belt tension at between 160/180 on the krikit. I know not all run the same and the factory changed the tensions but might check it again....:dontknow:

[Jeriatric]

Contact Jim. He is the expert and will help you work thru any issues. Have heard of him doing so on more than one occasion.

[IdahoMtnSpyder]

Contact Jim. He is the expert and will help you work thru any issues. Have heard of him doing so on more than one occasion.
I had in mind that he might respond here so others would get the benefit of his answer. If he doesn't in a day or two then I'll email him.

Also thought someone maybe has dealt with this issue and could share their experience.

[IdahoMtnSpyder]

I got the tensioner repositioned so that the idler is not pushing on the side of the belt. It helped, but not enough. I still get a large amount of vibrations between 80 and 85 (speedo number) but above 85 it's pretty much smooth as silk. There's one or two points around 60 and 70 where there is a touch of vibration, but not serious enough to fuss about.

[PMK]

I got the tensioner repositioned so that the idler is not pushing on the side of the belt. It helped, but not enough. I still get a large amount of vibrations between 80 and 85 (speedo number) but above 85 it's pretty much smooth as silk. There's one or two points around 60 and 70 where there is a touch of vibration, but not serious enough to fuss about.

Dumb question, could it be tires?

PK

[finless]

Try what I did so you can see what is going on. Strap a action camera or similar to the swing arm and video what the belt is doing. This is really the only way to know if the smooth spyder is the problem.

Bob

[IdahoMtnSpyder]

Dumb question, could it be tires?
Not a dumb question, really. I thought about that also, but I don't think so. The vibration comes and goes and I don't feel anything at all in the handlebars. Plus, like I said, it's smooth above 85.

[IdahoMtnSpyder]

Try what I did so you can see what is going on. Strap a action camera or similar to the swing arm and video what the belt is doing. This is really the only way to know if the smooth spyder is the problem.
I may try that, if my webcam will work. I don't have an action cam of any sort, and I sure ain't going to hang my $700 Nikon down there! :D

[capt.jim]

Hi WasWinger, sorry, I didn't see your post until I received your Email. Anyone with questions or needing help should call me, I don't get to read everything on here every day.

I'm not sure why you are still having vibration, if sounds like you may just be under tensioned and need more than 10 lbs.
Your belt is set at around 1050 Newtons according to the Kriket, which is right in the middle of the 2013 spec's and should be plenty.
Check your tensioner with the scale one more time.

To set the tension, pull the scale down slowly 1/2" past the belt and slowly relax the tension until it contacts the belt, at this point it should read 12-14 Lbs. It sounds like you just may not have enough tension.
Many will get by with 10 lbs., but many will need 12-14 depending on the severity of the vibration.

Yours has plenty of static tension, most of the 2013's are coming set at around 900N and the tensioner is working well for most as far as I know at the minimum of the 2013 spec's.

The belt should be close to centered on the idler, if it is running closer to the one side I would readjust the tensioner, which you have done according to your last post. The 1/16" spacers can also be removed if needed to fine tune the alignment to get it perfectly centered, but it's not that critical as long as it's not on the edge.

I haven't had any issues with the tensioners moving or shifting, the tensioner is pulling down, so there isn't a lot of side pressure.
There is no easy way to get a torque wrench in there under the belt, just tighten it well with a 3/4 wrench pulling towards you from the right side so the tensioner doesn't shift.
It should pull up snug next to the aluminum footrest assembly which is straight front to rear so your idler will be tracking straight with the belt.

As the manufacturer of the tensioner unit explained to me, there are many steps that go into the manufacturing of the belt and a little imperfection that is not noticeable to the eye can have an impact on vibration or noise.
Occasionally a belt can have a tight or slightly heavier spot in the belt that will set up a vibration over the length of a long belt.
This may explain why what works great on one doesn't work the same on another.

I have swapped Idlers from one spyder to another that were having excess whine and it was much quieter on the next spyder so their explanation sounds plausible.

I don't know how many are running 80-85 MPH, which is reasonable on the interstate if I'm traveling a distance, but normally the 72-78 MPH range of vibration is eliminated, I haven't heard of many vibration issues over that speed.

I have found that any residual vibration is usually not eliminated by raising the force on the tensioner up over recommended range of 10-14 Lbs.
My ST had the normal 72-78 MPH vibe's, after the tensioner I still had one small spot at 73 MPH that I couldn't remove even with 18Lbs. on a short test run.

If 10-14 Lbs. doesn't fix it, it is unlikely more will stop it.

At 12lbs. the 73 MPH vibration has since disappeared as things have worn in together.

There will always be a few that don't respond like the majority. 30 day satisfaction guarantee aside, send it back if your not happy or getting the benefits expected. As with many things on the spyder, they don't all react the same to changes we make. Call me if you can't get any improvement by raising the tension up.

[IdahoMtnSpyder]

Hi WasWinger, sorry, I didn't see your post until I received your Email. Anyone with questions or needing help should call me, I don't get to read everything on here every day.
That's what I figured. I didn't want to bother you until I had the tensioner repositioned, and so waited to email you. As I mentioned above I thought it would be good to get your comments here so others can benefit from them.

I probably won't have a chance to redo the tension and make a test run until next week, so don't look for an update before late next week. The Interstate with the 75 speed limit is 20 miles from home and I'm going out of town for Memorial Day weekend.

I conjured up a hook rod to pull and push the 3/4 box wrench through the floor board mounting slot. I'll post a pic of it later after I refine the shape and use it again.