Correct F3 Belt tension info

[Bruce B]

I have done comparison belt tension tests with my Gates Sonic gauge and a Krikit ll gauge and am happy with the results of the Krikit so don't stop using it if that's all you have.

Anyone that is trying to use the Krikit l on the Spyder belt don't it will not read high enough, plus it is not wide enough for a 28mm belt the Krikit ll puts pressure across the full width of the belt.

2015-16-17 the belt tension should be set to 775N +/- 150N


The correct settings for the Gates Sonic Tension Meter should be set to:
M= 008.0 W= 028.0 S= 0980


Unit Conversion Formulas
lbf x 4.4482 = N N x 0.2248 = lbf
lbf x 0.4536 = kgf kgf x 2.2046 = lbf
N x 0.1020 = kgf kgf x 9.8067 = N
lbf = Pounds force
N = Newtons force
kgf = Kilograms force
Inches x 25.4000 = mm
mm x 0.0394 = inches
mm = Millimeters

 

[jcthorne]

Well this service bulletin would indicate that BRP believes those settings are too high. They are now recommending much lower tension for the F3.

 

[Bruce B]

You believe and use what ever you want but those are what has been supplied to me and they did come from BRP.

Well this service bulletin would indicate that BRP believes those settings are too high. They are now recommending much lower tension for the F3.

View attachment 137373

 

[jcthorne]

You believe and use what ever you want but those are what has been supplied to me and they did come from BRP.

I posted a copy of the BRP tech service bulletin. If you don't believe me there is sufficient information on the bulletin for you to look it up in the BRP system yourself.

I do agree that BRP has posted far too many different specs for this and has caused all this confusion.

Overall, for a tooth belt drive design, you want to run the lowest tension that does not slip or set up harmonics in the operating range. Any tension above that just adds additional load on the bearings at both ends without accomplishing anything. The belt itself is happy in a very wide range of tensions.

 

[papanorm]

Many are waiting for the new F3 belt roller to help with their vibrations, however, the range of Recommended belt tension runs from 200N all the way up to 925N. Hmmmm, clear as mud.


Sent from my iPad using Tapatalk

 

[Lastchance]

I've been looking for a clear answer sense I bought mine a year ago, I guess there are none so I went with 180 on the ground and that's where it's staying no matter who comes up with whatever answer.

 

[stebrock]

JC's info was "updated" on 6/25/2015.
Bruce B's has a 2016 date.

It'd be nice if BRP would clear this up???

 

[BajaRon]

Most likely BRP is trying to balance proper belt tension with minimum vibration while keeping the bearings from blowing up. My guess is that the new BRP tensioner is going to allow lower tension specs while reducing vibration at the same time. So we might be in for another round of tension specs.

 

[jcthorne]

My F3 has been at the 300N shown in the bulletin for about 10k miles now. I do have a tensioner though.

It works fine and I have no undue vibrations or harmonics setting up. The lower tension will lend to longer bearing life.

 

[fritzer1]

I've been looking for a clear answer sense I bought mine a year ago, I guess there are none so I went with 180 on the ground and that's where it's staying no matter who comes up with whatever answer.

What does 180 on the Krikit compute to in Newtons??

 

[fritzer1]

JC's info was "updated" on 6/25/2015.
Bruce B's has a 2016 date.

It'd be nice if BRP would clear this up???

Oh where, oh where has Steve at BRP gone - oh where, oh where can he be??
Hi Steve - how about a really quick response to put this issue at rest, and to alleviate mucho frustration?.

 

[Bruce B]

What does 180 on the Krikit compute to in Newtons??

I did post this info at the start of this feed but here it is again get your self a calculator and read the info below.

Plus the info regarding the correct belt tension I posted above was the latest supplied by BRP
2015-16-17 the belt tension should be set to 775N +/- 150N


Unit Conversion Formulas
lbf x 4.4482 = N N x 0.2248 = lbf
lbf x 0.4536 = kgf kgf x 2.2046 = lbf
N x 0.1020 = kgf kgf x 9.8067 = N
lbf = Pounds force
N = Newtons force
kgf = Kilograms force
Inches x 25.4000 = mm
mm x 0.0394 = inches
mm = Millimeters

 

[Capt. Bob]

I have done comparison belt tension tests with my Gates Sonic gauge and a Krikit ll gauge and am happy with the results of the Krikit so don't stop using it if that's all you have.

Anyone that is trying to use the Krikit l on the Spyder belt don't it will not read high enough, plus it is not wide enough for a 28mm belt the Krikit ll puts pressure across the full width of the belt.

2015-16-17 the belt tension should be set to 775N +/- 150N


The correct settings for the Gates Sonic Tension Meter should be set to:
M= 008.0 W= 028.0 S= 0980


Unit Conversion Formulas
lbf x 4.4482 = N N x 0.2248 = lbf
lbf x 0.4536 = kgf kgf x 2.2046 = lbf
N x 0.1020 = kgf kgf x 9.8067 = N
lbf = Pounds force
N = Newtons force
kgf = Kilograms force
Inches x 25.4000 = mm
mm x 0.0394 = inches
mm = Millimeters

Bruce B., If you go to my write-up yesterday of my visit to Doc's Spyder Alignment in Georgia, there are some added pieces of information to the data that you have reported. As you know, the Gates Sonic Meter readings are taken with the rear tire off the ground for proper readings and the operator rapping the underside of the belt with a small hammer to get the belt to vibrate to take sonic readings. Doc informed me that the measurement procedures to be as accurate as possible require an averaging of the three values of belt tension of the three trisections of the arc of my rear sprocket with the belt. Doc placed tape 120 degrees apart on the rear sprocket and then proceeded to take three readings that were all different due to the interface of the belt's teeth with the sprocket's teeth positions and then came up with an average value. He also mentioned that the belt tension values increase with the rear tire on the ground and the factory specs are for measurements with the rear wheel off the ground for readings that are meant to correlate with factory recommendations. For me, that value turned out to be 550N. When I used a KrikitII in only one position of the belt, I got a reading of 140 pounds with the rear tire in the air. To get a more accurate correlation with the sonic meter, I will need to raise my rear tire and take and average of the Krikit readings with the belt/sprocket in the three positions of the rear sprocket's arc to determine the more accurate Krikit reading. Taking only one Krikit reading with the rear tire on the ground will provide a less accurate evaluation of the true belt tension because the operator is not taking the combined readings of the belt/sprocket throughout its 360 degree rotation and thus will give the operator a less than accurate measurement of the true belt tension. However, I just realized that I can mark the rear sprocket with the trike on the ground and just roll it into the three positions of the rear sprocket's rotation and get average Krikit readings with the rear tire on the ground (doh). Hope this helps clear up some of the confusion that many of us have been experiencing in terms of what the correct procedures are for measuring belt tension. Additionally, what the optimal belt tension may be is I think still a "moving target" issue due to the differences people feel in terms of vibration and the concerns of premature damage from a too tight belt to the transmission output shaft bearings and/or rear sprocket/wheel bearings as described in the tech bulletin I mentioned in my other thread. BTW, several years ago, Doc posted on the an Ipad/Iphone Gates app that he demonstrated yesterday that appears to work just about as good as the expensive Gates Sonic Meter when you add a microphone along with the Ipad to measure the frequencies of the drive belt in Hertz and then make the conversions with a formula. Here is the link: http://www.spyderlovers.com/forums/...lt-tension-APP-for-Iphone-Ipad-and-Ipod-touch Bob

 

[Capt. Bob]

I tested my belt tension on my F3-S with my KriKit II and the Spyder on a flat/level surface this morning. I marked every other spoke on the rear sprocket with a piece of blue painter's tape and then proceeded to take measurements with the taped spoke in the downward position and rotated the tire through a 360 degree circle stopping at each blue-marked spoke in the downward position to take readings. Placing the KriKit on the underside of the belt, I got readings of 200lbs., 190lbs., and 180lbs. respectively in the three positions of the rear sprocket relative to the ground. These different tension levels were described to me by Doc of Doc's Spyder Alignment in SE Georgia who advised that the sprocket/belt tooth interface values change at the different contact points in the 360 degree rotation of the sprocket relative to the belt. I know from testing with Doc yesterday using very precise sonic measurements that my average belt tension reading was 550N with the rear wheel off the ground. With the trike on the ground, my average Krikit readings were 190lbs this morning. So, now that I have a known proper reference from factory spec'd testing procedures, I can use the slightly cruder "old school" Krikit gauge to determine if I am staying in the 550N range for belt tension. I think I finally got the answer I needed for how my KriKit correlates with sonic measurements for my Spyder. If it wasn't for Doc's patience in explaining these issues, I would not have had a clue as to how to proceed and arrive at the answer to a question that has been somewhat hounding me since these belt tension issues have been kicked around on this forum. Thanks Doc!

 

[BajaRon]

What does 180 on the Krikit compute to in Newtons??

800 Newtons.

Here is a great little conversion tool that I use. And it's free!

https://joshmadison.com/convert-for-windows/

 

[fritzer1]

800 Newtons.

Here is a great little conversion tool that I use. And it's free!

https://joshmadison.com/convert-for-windows/

Thanks - that is close to the 750n setting on my F3T.

 

[Devious56]

800 Newtons.

Here is a great little conversion tool that I use. And it's free!

https://joshmadison.com/convert-for-windows/

Thanks Ron, that is a great converter.

David