30 tooth pulley/ sprocket
Ultimate HDF Member
Joined: Jan 2008
Posts: 6,532
Likes: 132
From: SoCal
About 90-100 rpm more revs at the same mph. I ran by a speed trailer a few times to see if the mph changed , at 35 indicated on the gun it was about the same on my speedo as before the change, 38ish. I would like to see it on another gun at a higher speed like 60 as before the change I read 65 at that speed.
Road Warrior
Joined: Sep 2009
Posts: 1,267
Likes: 6
From: Northern Michigan
About 90-100 rpm more revs at the same mph. I ran by a speed trailer a few times to see if the mph changed , at 35 indicated on the gun it was about the same on my speedo as before the change, 38ish. I would like to see it on another gun at a higher speed like 60 as before the change I read 65 at that speed.
Thats about 1/3 of what I got with the 30T front. 300 rpm and around 5 mph speedo error.
Im pretty sure HD streached out the distance from the front pulley to the axel making it longer on the '09s, hence the longer belt
Seasoned HDF Member
Joined: Oct 2006
Posts: 5,977
Likes: 85
From: Nevada
About 90-100 rpm more revs at the same mph. I ran by a speed trailer a few times to see if the mph changed , at 35 indicated on the gun it was about the same on my speedo as before the change, 38ish. I would like to see it on another gun at a higher speed like 60 as before the change I read 65 at that speed.
Stock already read 3-3.5% fast
Tourer
Joined: Jun 2011
Posts: 417
Likes: 3
From: Watauga, TX
Speed Vs RPm's for various pulley configuration on 07/08 FLHTC
Stock 32 front /Stock 66 rear pulleys 70 mph 6th gear= 2660 rpm
Stock 32 front /+2 larger 68 rear pulleys 70 mph 6th gear= 2740 rpm
Speed is from GPS. Speedo with 32/68 pully's is about 8.5% higher than actual speed. GPS=70 speedo = 76 ish.
I'm also still using the stock belt with the +2 68 tooth rear pully on my 08. I may eventually go to a 31T on the front, this would make RPM's about 2830 @ 70 mph actual (GPS) in 6th gear.
Stock 32 front /Stock 66 rear pulleys 70 mph 6th gear= 2660 rpm
Stock 32 front /+2 larger 68 rear pulleys 70 mph 6th gear= 2740 rpm
Speed is from GPS. Speedo with 32/68 pully's is about 8.5% higher than actual speed. GPS=70 speedo = 76 ish.
I'm also still using the stock belt with the +2 68 tooth rear pully on my 08. I may eventually go to a 31T on the front, this would make RPM's about 2830 @ 70 mph actual (GPS) in 6th gear.
Last edited by Moneywoes; Jan 23, 2012 at 11:28 PM.
Seasoned HDF Member
Joined: Oct 2006
Posts: 5,977
Likes: 85
From: Nevada
Speed Vs RPm's for various pulley configuration on 07/08 FLHTC
Stock 32 front /Stock 66 rear pulleys 70 mph 6th gear= 2660 rpm
Stock 32 front /+2 larger 68 rear pulleys 70 mph 6th gear= 2740 rpm
Speed is from GPS. Speedo with 32/68 pully's is about 8.5% higher than actual speed. GPS=70 speedo = 76 ish.
I'm also still using the stock belt with the +2 68 tooth rear pully on my 08. I may eventually go to a 31T on the front, this would make RPM's about 2830 @ 70 mph actual (GPS) in 6th gear.
Stock 32 front /Stock 66 rear pulleys 70 mph 6th gear= 2660 rpm
Stock 32 front /+2 larger 68 rear pulleys 70 mph 6th gear= 2740 rpm
Speed is from GPS. Speedo with 32/68 pully's is about 8.5% higher than actual speed. GPS=70 speedo = 76 ish.
I'm also still using the stock belt with the +2 68 tooth rear pully on my 08. I may eventually go to a 31T on the front, this would make RPM's about 2830 @ 70 mph actual (GPS) in 6th gear.
size or slight difference in ECM calibration could be why.
I like the minor but noticeable change with the 68T but agree that adding a
31T up front would be nice.
Road Captain
Joined: Aug 2011
Posts: 575
Likes: 4
From: SouthWestern Ontario
My stock 137T belt was on the tight side getting it around the pulley but tensioned OK once on (32T/68T on a '07 using the stock belt).
Ultimate HDF Member
Joined: Jan 2008
Posts: 6,532
Likes: 132
From: SoCal
Yes I love the 68 and I agree on adding the 31t trans pulley. I hope I never need to get into that area for repairs but if I do the 31 will be added when the other work is being done.
Tourer
Joined: Jun 2011
Posts: 417
Likes: 3
From: Watauga, TX
Your discussions on the 68 tooth pulley were what prompted me to do it.The differance in 7.6% vs 8.5% at 80 mph would only be about .72 mph. Honestly its been awhile since my eyes were good enough to reliably see a variance that close.. My stated engine RPM's for given speed are also only relitively close approximations. Its hard for me to see those little lines on the speedo and tach going down the road. Figuring the RPM vs speed and Speed Vs RPM's via formula's come out very close to what my tach and GPS show though.
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Road Captain
Joined: Sep 2009
Posts: 551
Likes: 10
From: Toronto, Ontario
Here is some info from Andrews website about final drive ratio's-
BIG TWIN TRANSMISSION BELT PULLEYS (1985-2011)
Part #290290 (’85-’93)
Part #290320 (’85-’93)
BIG TWIN TRANSMISSION BELT PULLEYS (1985-2011)
Pulleys: 2007 - 2011 Baggers
Final Drive Ratio (’07 & ’08) = 2.79 with stk 32 T pulley
Final Drive Ratio (’07 & ’08) = 2.97 with AP 30 T pulley
Final Drive Ratio (’07 & ’08) = 2.79 with stk 32 T pulley
Final Drive Ratio (’07 & ’08) = 2.97 with AP 30 T pulley
Final Drive Ratio (’09 & ’11) = 2.87 with stk HD 32T pulley
Final Drive Ratio (’09 & ’11) = 2.97 with AP 31T pulley (OK w/stock belt)
Final Drive Ratio ('09 & '11) = 3.06 with AP 30T pulley
Higher final drive gear ratios mean more power!
New pulleys need belt lengths checked at time of installation
New pulleys need belt lengths checked at time of installation
New in 2010:
31 tooth pulley on ’09 -’11 bagger
changes the final drive
ratio from 2.87 to 2.97
31 tooth pulley on ’09 -’11 bagger
changes the final drive
ratio from 2.87 to 2.97
POWER PULLEYS
:
30 Tooth..............................6.4% More RPM
(200 RPM increase @ 60 MPH - hi gear)
30 Tooth..............................6.4% More RPM
(200 RPM increase @ 60 MPH - hi gear)
Part #290306
(All ’07 - ’11 & ’06 Dyna)
Part #290304
(’94-’06) except ’06 Dyna
Part #290300
(’85-’93)
29 Tooth................................ 9% More RPM
29 Tooth................................ 9% More RPM
Part #290294
(’94-’06) except ’06 Dyna
Part #290290 (’85-’93)
POWER PULLEYS:
31 Tooth. . . . . . . . . . . . . . . . . . . . 3% More RPM
Part #290316
(’07-’11 & ’06 Dyna)
Part #290314
(’94-’06) except ’06 Dyna
Part #290310
(’85-'93)
New for 2011
32 Tooth. . . . . . . . . . . . . . . Stock Replacement
32 Tooth. . . . . . . . . . . . . . . Stock Replacement
Part #290326
(’07-’11 & ’06 Dyna)
Part #290324
(’94-’06) except ’06 Dyna
Part #290320 (’85-’93)
I realize their website says stock belt okay for the 31T, but I guess there are some variables from bike to bike, because my indy mechanic said it was close, but a no go. At the time, I just had him install the SE compensator so it wasn't a total waste of his time/my money, but I this year I'll have him do it all over, and put the 31T pulley and 139T belt on.
I definitely learned a lesson- I should have ordered the 139T just in case.
Last edited by North Star; Jan 24, 2012 at 05:04 PM.
