Doing a 3.37 primary gearing setup, DO NOT hesitate! Do it!
Road Captain
Joined: Sep 2006
Posts: 500
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RE: Doing a 3.37 primary gearing setup, DO NOT hesitate! Do it!
you CAN get better mileage with lower, higher number, gears. True, running 4:11's in our cars probably won't help, I have 4:30's in my Cobra by the way. If you are geared too low, you have to lug or rev to get moving, but lowering the gear, you reduce the effort to get going. That will also get you to cruising speed faster. It will allow you to be in overdrive at a lower speed. Thus, you could be turning say 40 mph in 5th or 6th vice 40 mhp in 4th. If you change by a small ration, like going from 3.15 to 3.37, you should not see much change, and possibly an increase in mileage. It's counter intuitive, but it's true. Especially if you have a 6 speed. You now have two overdrives that are usefull around town and not just on the freeway.
Extreme HDF Member
Joined: Nov 2006
Posts: 13,389
Likes: 26
From: Windham,Maine
RE: Doing a 3.37 primary gearing setup, DO NOT hesitate! Do it!
It is true about gas milage your motor is in the range it likes to run thus more effecient.My big motored bikes are geared in the 2.03 to 2.05 range and they or I should say I love it.Cruising is much more bearable on the highway.
Seasoned HDF Member
Joined: Jun 2006
Posts: 28,565
Likes: 3,957
From: Vermont
RE: Doing a 3.37 primary gearing setup, DO NOT hesitate! Do it!
Anyone change to a 3.37 in an 07 or 08 six speed tranny yet? Might be something I might look at now that I have a six speed
Grand HDF Member
Joined: Nov 2004
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RE: Doing a 3.37 primary gearing setup, DO NOT hesitate! Do it!
I pretty sure that 03 was the last year for 3:37 gearing, my freind has a 03 EGS and he turns about 300 more rpm's than I do at 70 mph.
Also like already stated, 3:37 and a 6 speed would seem pretty good, maybe a little later on I will consider this.
Also like already stated, 3:37 and a 6 speed would seem pretty good, maybe a little later on I will consider this.
6th Gear
Joined: Aug 2007
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RE: Doing a 3.37 primary gearing setup, DO NOT hesitate! Do it!
sounds likea very nice idea! But before HD i used to ride Hondas. and i used to change the primary gearing dropping it down a tooth or 2 in the front for a few dollars! Im new to HD and the gearing process is there not enough belt to do this ? Any input would sure be appreciated!
Thanks
New HD rider about 12 years! Loving every minute of it!
Keep the Shiny side up and the Rubber to the ground!
Thanks
New HD rider about 12 years! Loving every minute of it!
Keep the Shiny side up and the Rubber to the ground!
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Road Captain
Joined: Sep 2006
Posts: 500
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RE: Doing a 3.37 primary gearing setup, DO NOT hesitate! Do it!
Unless you have an 07+, you can do this. It's cheaper too. Not sure why it isn't heavily touted on the forum. Maybe someone here will tell me.
40200-02
$109.46
$134.95
SCREAMINâ EAGLE RACE USE PRIMARY GEARING KIT
This is the kit that will help you get the holeshot at the race track. This kit increases vehicle acceleration by allowing the engine to spin higher RPM at any given vehicle speed. This new combination results in a 1.7:1 primary drive ratio, versus the stock 1.44:1 ratio. Requires separate purchase of Primary Cover Gasket Kit includes 21 tooth compensator (25 tooth is stock) sprocket and primary chain. For race application only. Fits '94-'06 Touring models ('99-'01 fuel-injected models require 36 Tooth Clutch P/N 37707-98A).
40200-02
$109.46
$134.95
SCREAMINâ EAGLE RACE USE PRIMARY GEARING KIT
This is the kit that will help you get the holeshot at the race track. This kit increases vehicle acceleration by allowing the engine to spin higher RPM at any given vehicle speed. This new combination results in a 1.7:1 primary drive ratio, versus the stock 1.44:1 ratio. Requires separate purchase of Primary Cover Gasket Kit includes 21 tooth compensator (25 tooth is stock) sprocket and primary chain. For race application only. Fits '94-'06 Touring models ('99-'01 fuel-injected models require 36 Tooth Clutch P/N 37707-98A).
Extreme HDF Member
Joined: Apr 2006
Posts: 10,449
Likes: 46
From: Roswell, GA
RE: Doing a 3.37 primary gearing setup, DO NOT hesitate! Do it!
The SE 21 tooth compensating sprocket kit is cheaper, but it also adds about 800 rpm at 70-80 mph over the 3.15:1: 3200 rpm at 70-80 mph becomes 4000 rpm with the 21 tooth sprocket. That's why I wouldn't use the 21 tooth. Now, that 21 tooth sprocket with a six-speed, overdrive 6th would be a very fast set-up without the 800 rpm penalty. The 3.37 gearing adds only 200 rpm at 70-80 mph--quite a difference IMO.