I have a 07 Ultra Classic, and am thinking that lowering the final drive gear ratio will help with my mileage and give me a little more power in the 75mph range. Is it better to change the front drive down a couple teeth and get a shorter drive belt, or change the compensater gear and chain in the primary? I will be doing the labor myself, so labor cost isn't a factor.

Thanks in advance.

 

I have one those 30t gears that EVO Industies makes for use in the primary but I haven't gotten it installed yet (the wife has had to many projects to get done this summer), I have done a lot of reading on this product and everyone that uses them seem to really like them.
They also have the added benefit of not only making the bike have more get up and go but also gets rid of the bang when starting the bike.

 

had the evo 30 tooth on an 07 street glide. made quite a bit of difference. don't think it will help with the gas milage though. rpm at 70 in 6th gear went from 2500 to 3000 if I remember right.

 

Thanks Jag1886 & Monkish...

Changing the primary appears to be a easier job than the drive pulley & belt. I'll check into the product. As long as it doesn't kill the mileage it will do what I'm needing both on the highway and around town.

Thanks again.

 

a lower gear ratio, making the engine turn at a slower rpm given the same speed, may improve your fuel economy, reduce vibrations, but it will also reduce the torque available to you. It will not give you more power. You will have to downshift if you want that.

a higher gear ratio, thus higher rpm, will cost you in fuel, due to increased driveline friction, but
it will give you more available torque and more possibly more vibration.

Hogdoctor

 

hogdoctor, I think it's just the opposite of what you said.

 

I may have been backwards, but a couple guys got what I was trying to do...

The only thing holding me back on this one is will an added 500 rpm in the cruise range kill my not so good mileage to make it even worse? I average 36-38 mpg when cruising at 75-80, and If I hit any headwinds, the mileage drops even worse, I've actually been shifting down to 5th, and slowing down a bit, and that helps some.

Monkish, hows your mileage on the road?

 

I went 2 teeth smaller on the compensator sprocket and love it, makes the bike feel like its 200lbs lighter. there was no need to change the chain, it increses rpm's about 3000 rpm

 

Blk,

I believe what you're looking for is right here for a SMOKIN deal too:
https://www.hdforums.com/forum/useless-threads/279295-andrews-pulleys.html

Seems the new approach is changing the rear sprocket to a 70 tooth and yeilding good results, as noted by some experimenters on Harley Tech Talk.

I personally have no experience in doing the aforementioned but I am trying to follow the outcomes of these types of projects as close as I can so proceed with caution.

 

It's too bad the aftermarket hasn't come up with a larger low gear to replace the one in the tranny. 10 mph low gear at idle is too dam fast.

Replacing the primary isn't the right way to go in my opinion, as that changes the rpm's in all the gears. If the problem is low gear is too fast, and not the rest, then change out the low gear to a bigger one. If the problem is not enough passing power at 70 MPH then go stage II big bore kit .

I tried the Evo. Ind. 49t tranny sprocket and lost my 6th gear light and cruise. So, I wouldn't try that conversion unless they have a work around for that.

Good Luck!

I ended up with the big bore stage 2 and couldn't be happier, but low gear still is still too dam fast, but, I now have the power to pull it..