Help me experts !!!! need to know the correct belt size

[evo58]

im sick and tired from the rear chain, this week was the last time i had a problem,
i have  in the engine spkt 24, the clutch 37, the tranny  spkt 24 and the  rear spkt 49 , thats was the way i liked, in the highway is fine, im planning to instal 32 on tranny and 65 on the rear( almost the same as 24/49 ), the question is:
whta is the size of the rear belt? the bike its an FXR and i would like to install a TC belt ( 1 1/8 )
thanks for all advanced.
Evo

[JohnS_Rosamond]

This is rather a difficult question.  The thinner belts were not run on FXR; the only thing that I can related it to is Dyna and they don't run the pulleys that you wanna run.  The Softails run the 32/65 but the have different length swing arms than the FXR/Dyna.  I'm guessing you have an earlier model FXR.  Your stock belt with a 32/70 would be 136 tooth.  When I went from 32/70 to 34/70 it pulled the rear wheel almost all the way forward in the adjustment notch in the swingarm (and the 139 tooth belt was too long).  For a 65 tooth rear pulley, I am guessing that you would need a belt that was something like 133 tooth but I can't be sure.  Also, you might have to run a custom spacer on the rear wheel to keep the thinner belt properly aligned with the front pulley.

[evo58]

John,
thanks for the reply, the only problem its a rear spacer to the rear pulley?
i have on these here on stand, i think all i need to do is find the correct width, and cut this spacer,
the belt 1 1/8 will allow the 150 rear tire, beside this , its stronger than the 1 1/2.
i think 133 are for TC , im not sure.
Evo

[Ajayrk]

A belt driven stock FXR would have a 32x70 tooth arraignment and would use a 136 tooth belt.  So somewhere between 130 to 133 teeth.

A close approximate is to measure the center distance of the pulleys, calculate the circumference of each pulley.  Add twice the center distance and 1/2 of each pulley  circumference and divide that by 14mm which is the distance between each tooth.   14mm = .551.

Check out the links below.

http://www.hoverhawk.com/polychain.pdf

http://www.wisc-online.com/objects/ViewObject.aspx?ID=ENG21906

[evo58]

Thanks Ajayrk,
i liked what Jonh says when went to the 34 , 70/34  means means 2,06 , my 49 / 24 means 2,04 VERY close,
he say almost all the way on the swingarm, this its not a problem, beside this i can enlarge the eggshapped hole on the swingarm, just a little,
so will be 34/70  with a 136 belt.
the only doubt is theres a 136 1 1/8 belt?
Evo

[evo58]

i seached theres no HD , 136 1 1/8 itsmade by Gates,  with 135 1 1/8 HD only.
can i thust in Gates brand?
Evo

[SnS107]

     I have experimented with various front and rear pulleys over the past 65,000+ miles on a 1986 FXRD, all with the same size OEM belt (136t X 1.5" wide). It was originally 32/70T; I installed a 34/70t, and later a 34/65t. With the 34/70, it was necessary to shift the rear wheel almost max forward in the axle adjustment range. With the 34/65, it went rearward quite a bit farther than the original 32/70. I began with a 35,000 mile bike and original belt and swing arm bushings, and later replaced the bushings and belt (another OEM 136t), and things still fit pretty much the same.

     Looking at total tooth count of front and rear pulleys as one way to measure, it seems there is a range of tolerance for a given belt on a given frame style, i.e. FXR. The 32/70 is a total of 102; the 34/70 is 104, and the 34/65 is 99, but they all fit with with the same belt on the same bike, at least in my case.
     
     I also understand there is no difference between tooth pitch & interval on the 1.125" and 1.5" belts, so it seems possible to calculate your needs using other FXRs' OEM belt length and gearing for reference, as long as the frame dimensions are the same, which I am not sure about.

Joe   

[Ajayrk]

i seached theres no HD , 136 1 1/8 itsmade by Gates,  with 135 1 1/8 HD only.
can i thust in Gates brand?
Evo

I'm not sure what you mean, but...

H/D part no 40571-04 is a 136 tooth x 1-1/8 belt.

Dayco has a 136 x 1-1/8 belt.

[evo58]

thanks again for both guys,
i will buy this pn, 40571-04 and use the 34/70,
thanks
Evo

[Pushrod]

i seached theres no HD , 136 1 1/8 itsmade by Gates,  with 135 1 1/8 HD only.
can i thust in Gates brand?
Evo

Gates are Top Quality, nothing to shy away from,

[evo58]

i always suspect Gates does the belts for Moco.
Evo

[evo58]

To JohnS_ Rosamond,
John, this 136 belt for TC, its the same for Sportster??
they are 1 1/8 both with 136 T, let me know, anybody know?
thanks
Evo

[JohnS_Rosamond]

That part is too futuristic for me, I fell out in the late 1990's.  I can't see as there would be a difference, but don't know the answer to that one.  There never was a difference between the belt on the FXR and the FLHT (unless you got the "side-car only" belt that was reinforced).

[evo58]

John,
i agree. i searched  today  , saw FXR HDI has 32/65 with 133 or 136  belt,  as i ever liked cruisin highways thats the way will work.
Evo

[evo58]

back here to thanks a lot the guys that help me on this choose,
and to John S when talked about the 133 T ,
i installed on my FXR ,32/65 with 133T , with no problems.
and the brand was Gates( just like the HD )
thanks for all
Evo