Vibration when Accelerating

[Southpaw58]

Happy Saturday,
I recently had all 3 tires changed. On the receipt the dealer indicated that they had adjusted my drive belt (Not my request. Service write said they always do on rear tire changes). Now, I am getting a vibration when accelerating between 60 mph and 65 mph. The rest of the speed range is smooth as glass. I have owned my 2018 F3-T since new and it has never had this vibration. I have read a lot of posts on belt vibrations and I don't recall any that said it was just on acceleration. It does not vibrate when slowing down. Is this the normal belt vibration?

Thanks in advance.
Bill

[BajaRon]

Tires can be changed without any belt adjustment needed. A much easier and quicker way to go. Not sure why they took that extra step. Unless they didn't do it right and had to do the adjustment.

Check your belt tension. The Gates Krikit II is a great tool for this. It is also sold under several other brands. As far as I know, they are all the same except for some color differences in the rubber and plastic components. Many techs over tension the belt. Also, check to see that your belt is running true on the rear sprocket. You need about a credit card width between the flange and belt.

Good Luck!

[Southpaw58]

Tires can be changed without any belt adjustment needed. Not sure why they took that extra step. Unless they didn't do it right and had to do the adjustment.

Check your belt tension. The Gates Krikit II is a great tool for this. It is also sold under several other brands. As far as I know, they are all the same except for some color differences in the rubber and plastic components. Many techs over tension the belt. Also, check to see that your belt is running true on the rear sprocket. You need about a credit card width between the flange and belt.

Good Luck!

Thanks Ron,
I had an hour ride from the dealer and I did check the alignment on the rear sprocket when I got home, it was fine. I also checked it after a 600 mile trip to Charleston, SC and back. I think they just tightened it up to specs. I'll look into getting a belt tension gauge and adjusting it. I'll have to search for the forum recommended tension, I can't remember it right off the top of my head

Thanks again.
Bill

[BLUEKNIGHT911]

Thanks Ron,
I had an hour ride from the dealer and I did check the alignment on the rear sprocket when I got home, it was fine. I also checked it after a 600 mile trip to Charleston, SC and back. I think they just tightened it up to specs. I'll look into getting a belt tension gauge and adjusting it. I'll have to search for the forum recommended tension, I can't remember it right off the top of my head

Thanks again.
Bill

Ron is absolutely correct ( and very Kind in His remarks about the dealer Tech )( me I'm Not Kind I'm truthful a lot of them S*uck ) there are many, many folks here who have successfully lowered the rear belt tension ( which eliminated most of the vibration ) to the 150 to 165 lb. range .... I always check the tension with the tire on the ground. I use 160 lbs with the KritKit .... Why bother lifting the tire when you can just use the " on the ground LB. number ..... good luck .... Mike

[BajaRon]

Thanks Ron,
I had an hour ride from the dealer and I did check the alignment on the rear sprocket when I got home, it was fine. I also checked it after a 600 mile trip to Charleston, SC and back. I think they just tightened it up to specs. I'll look into getting a belt tension gauge and adjusting it. I'll have to search for the forum recommended tension, I can't remember it right off the top of my head

Thanks again.
Bill

'Proper Belt Tension' has evolved quite a bit over the years. Though it has seemed to settle into an accepted range in the last 4 or 5. We still have a 'User Approved' tension quite a bit lower than the 'OEM Factory Tension'.

A belt and pulley set in good condition will not move much at all on the pulley's going forward. Don't ever check after backing up any distance. The belt will move around in reverse, it is meaningless. It's only after traveling forward for a fair distance (giving the belt a chance to settle into it's normal pattern) that you want to check clearance to the flange.

You can easily adjust belt tension by lifting the rear wheel off the ground, starting the bike and engaging 1st gear at idle. But be sure whatever you are lifting with is stable. You don't want the wheel falling to the ground while you're doing this. And you will want to remove the real wheel sensors or your VSS will through a fit. All easily and safely done.

I've checked a lot of belt tensions in the last year since my wife kicked me out of the house! Saying 'You + 4 employees are TOO Much! I can't keep the house clean. And the basement is so full of stock and assembly benches, I can hardly get to the washer and dryer anymore!' Can you believe having to move the entire operation to a retail shop over such trivial matters? The men I talk to are, understandably, very sympathetic to my position. Females, not so much (to put it mildly). And they say there's no difference between men and women!

On the other hand. All these years working out of my house I didn't get to meet many riders. I'm really enjoying that part of having the shop! To be honest, no one coming in for service leaves without getting a tension check. I even check (with permission) many who just stop in to say hello - which is also much appreciated!

Wow! What a rabbit trail that was!

Anyway. To get back on subject. 260~280 lbs. seems to be the current tension coming off the assembly line. This is too much for the 998cc models. But seems to work well on the 1330 models.

I've been told our belt is designed with an operating tension of up to 600 lbs. The bearings can't take nearly that much pressure. But explains why the belt lasts so long under normal conditions.

If you do decide to make an adjustment. I recommend 160~180 lbs. on the ground for all Spyders. I want to stress that all of these numbers represent an 'On the Ground' measurement, as Mike points out. Very important to keep our terms on the same page.

The factory gives 'Wheel Off The Ground' numbers. Which are completely different. Do not interchange these.

Though an Off The Ground measurement is a more accurate way to measure. It is inconvenient, to say the least. And practical results are so close with an On The Ground measurement as to make no real difference. Especially with the wide variation allowed in the tension range.

If you are happy with the amount of vibration, or lack thereof, with a 240~260 lb. tension on your 1330 model Spyder. I'd leave it. Changing tension can be a trial and error proposition. Though usually a setting between the 160~180 lbs. gives good results. It does not always eliminate vibration. Though it will almost always decrease vibration. It will many times move vibration to a different speed.

As with everything else. You'll get a good number of opinions. And, as always, it's your ride. Do it your way.

Have Fun!

[Woodaddict]

come down to my house Sunday................ I have a kricket gage. we can check it!!!!!!!!!!!!!