I'm thinking of swapping out my 70 tooth rear sprocket for a 65 tooth on my 91 Electra trying to get a better hwy RPM

Anyone try this? Did you have to change belts? and did you notice a big difference?

Thanks Dan

 

Dan,
I'm thinking about going the same way you are on my FXR. Changing the trans pulley from a 32T to a 33T netted about a 150 RPM drop. Another 100 possibly with a 34T pulley, but my belt is fairly new and the 34T would not fit. With my primary gearing overall stock was 3.37 and the change dropped it to 3.27 still pretty low. If the 34T would have fit the final drive would have been 3.17

With the 65T rear and 33T trans, the final drive will be 3.03 and with the 32T trans 3.13. The FXR is a lighter bike and with the engine mods planned I'm trying to decide if I can get away with the higher ratio. Not sure about your case, mine will require a belt change from the current 127 to a 130 or 133. I'll be interested in further replies as the primaries and swingarm will have to be removed. I only want to do that once for awhile. I do have a NIB 65T rear on the shelf when the time comes. I'll be looking forward to some input as well.

 

S h i t, you guys are killing me. My cheap a s s is still wrestling with the big bore kit and just when I'm ready to do the primary chain you bring up this pulley thing. I already decided that lowering my RPMs with a 6 speed wouldn't make me happy. My Night Glide is a lot heavier than an FXR, so what works well for Buddy might not be right for me. I assume that dropping the sprocket would reduce RPMs more than dropping the trans pulley one tooth. I'll be watching for more info on this.

 

The gear ratios that I posted are pre 93. I can post the ratios for 94 and later if that would help you. One thing that would help me wouldbe to change to a 25T engine sprocket. Then I would have to change the clutch basket as the tooth count is different. Ialready have a new compensator setup,37T clutch basket, hub and clutchsitting on the shelf. If I had thought about that sooner I could have purchased the later model setup.

 

Did it on my 1994 Springer. Originally a 70 tooth but someone put a 61 tooth on it before I got it. Changed that out to the 65 tooth. I like it alot! My 1993 Softail has a 61 tooth rear, but has a different front sprocket or a different comp sprocket, not sure of which but man I love that gearing. Sstill fast out the hole with lower rpm at high speed. All the 1993 Softails came that way from the factory, it was the set up on export bikes. Only did it one year, not sure why they changed back to the 70. Then a year later they went to the 65. YES you do need a new belt. GOOD LUCK!

 

Harley_ Dude,
Perhaps you can be more specific as to what your engine sprocket tooth,clutch basket tooth and primary pully tooth count you are using and what RPM's your are reading. I might be really helpful to make a selection.

Here are some additional overall ratios for you guys. I think the biggest change was made after 93 when HD went to a 25T engine sprocket, not sure what the clutch basket count is after 93. I do know that you have to change the clutch basket on the earlier models in order to run a 25T engine sprocket. You can see the difference in overall ratios between the pre 93 and the later models. It's quite significant when you really look at the numbers.

For instance I would have to run a 32T trans pulley and 65T rear on my 93 FXR to achieve a final of 3.13. 94 to present would be 3.15 with the stock32T trans 70T rear. 33T trans on the later models, 70T rear final would be 3.06, I would be at 3.03 with the 33T trans I already have and changing to the 65T rear.

1994 to present 32T trans 70T rear 3.15 overall
33T trans 70T rear 3.06 overall.
34T trans 70T rear 3.00 overall.

1994 to present 32T trans 65T rear 2.92 overall.
33T trans 65T rear 2.84 overall.
34T trans 65T rear 2.75 overall.

1994 to present 32T trans 61T rear 2.75 overall.
33T trans 61T rear 2.66 overall.
34T trans 61T rear 2.58 overall

I also have the numbers for 29T, 30T and 31T transmission pulleys. Feel free to askif you are looking ata specific combo andneed them.

 

Mark you're right about the gearing on the 93's with the 61T rear pulley, I had a 93 FX Springer and it ran great with that set-up. It had plenty of pull off the line and was great running down the Hwy. I know after the 90th. in Milwaukee when we were heading back we ran between 75 & 80 mph. on I-90 between Milwaukee and Madison stopped in Madison to fuel up and even at the speed we were running the Springer still got 60 mpg. The other three guy's I was running with were running shovels and couldn't believe how well that Springer ran and still got that kind of mileage.

 

Checkout Harley Parts and Accessory Bulletin # 524. It gives all the belt,sprockets ,guards part numbers. Also gear ratios and info using 61,65 and 70 tooth rear sprockets with a 32 tooth front sprocket. This info is mainly for pre-1994 Evo's.

 

I run a 65T rear sprocket with a 135T belton my 1991 FXLR. The motor is mildly breathed on. It has a Andrews #3 cam, S&S E carb, 5-angle valve job, .010 stock HD pistons, 2 into 1 Suppertrapp with a open end cap [23 discs], S.E. Coil, S.E.plug wires, S.E. ignition module,Carlini Torque Arm [$$ but it works] and stock 80/90/21 and 130/90/16 Metzeler 880 tires. IMO FXRS' with 32/70 stock gearing are geared too low for interstate/highway cruising. I didn't want to use other than 32T tranny sprockets because the belt tends to rub on the swingarm or tranny casting. That left me with basically one choice- change the rear sprocket and belt. 65T isa little tall geared. I have to be going 67 mphor faster on a flat toshift into and cruise in 5th gear. On a good hill I have to go over 75mph to pull it in 5th. I spend a lot of time in 4th gear on secondary roads. That's a small discomfort to be able to cruise effortlessly at 85 mph!! It would be worse with a Dresser or heavily loadedSoftail.FXRS and Dressers have an 8 pin shorter primary chain than a Softail or Dyna. FXRS'are lighter and have a good weight to power ratio. I'm happy with this setup and I like the quick handling of the bike. I built it this way in 1996 and see no reason to change anything. I see folks falling for the wide rear tire fad and only gain bad handling and a lighter wallet.

 

pan957,

Thanks for chiming in with some real experience with this setup.I feel a little disturbed now as my engine combo should make more power than yours, but it will be useless if the bike is logey through the gears.

Your overall ratio with the 24T engine, 37T clutch basket, 32T trans and 65T rear should be 3.13-3.15 depending upon who's data you use. Stock was 3.37 overall and I agree with you thatthe stock gearing is too low. It would be even worse running my current 33T trans with the 65T rear as the overall would drop to 3.03.

How does your bike act around town (accelerate) or running perhaps with some friends? I'd also like to know where your rear axle sits in the adjustor with the 133T belt and if you had any clearance issues with the belt guards. Thanks....