Gearing?

[Drifter.]

Do all the belt drive Sportys have the same gearing, same pully sizes?

Is there any model or year that has the tallest, meaning lowest cruse rpm if so what are the pully sizes?

Will big twin pullys fit sportsters if so what model and years?

[rabidchimp]

You may get some flak if you haven't done some looking around before asking, but here's my version of the gearing story:

I've got a 97 1200c, stock gearing. I wanted to get taller gearing for the bike too, did some hunting around on this forum, and found that the Euro Spec Sporty (1200 only?) has a rear sprocket that has 60 or 61 teeth on it, compared to the 66 thats stock for US model Sportsters (rigid mount). You'll need a corresponding drive belt to go with the pulley. Will give you about 10% taller gearing.

I ordered the pulley through my local dealer, but the part number for it is at my shop. I still need to get the proper belt to match. You can swap the front pulley from a 883, but that will only lower your gearing. As far as I know, nothing out there in terms of front pulleys to make the gearing even taller.

-Aaron

[Drifter.]

Thanks RC, cant you take up the slack of the smaller rear pully with the adjusters? Even if there is not enough wouldent it be easier to change or make some adjusters that would work with the stock belt? 10% would be a nice change, and better gas mileage.

[Folkie]

See here (it's a sticky, not too hard to find):

Gearing Charts: Speed vs RPM In Each Gear

[wookster]

The euro 1200 sportys also have a 30 tooth front pulley. One tooth larger than a stock USA 1200.I found one on ebay, makes a big difference in highway riding, about 400 rpm difference or so. That doesn't sound like much but it is a noticeable change.

[Folkie]

That thread I linked to will show you how much difference that 30T sprocket makes.

[stocker883l]

But, remember, the MoCo engineers geared and built them with said sprocket sizes so as to obtain and maintain the proper rpm for the gear and speed. You are gonna get an ear full in a few: So be ready.

[rabidchimp]

I wasn't aware that the front pulley on the Euro bikes were a tooth larger. Good to know.

Drifter, with the Euro pulley installed, you simply can't get any kind of tension on the belt with the wheel pulled all the way back in the swing arm axle slots. Maybe the slots could be elongated, but there isn't that much meat back there.

Stocker, maybe you're being facetious, but I think we'll be fine.

-Aaron

[Drifter.]

Folkie, do you have a chart showing what combinations will work with stock belt sizes? Both US and Europe. What are the standard belt lengths?

[Folkie]

The 883 bikes with 28T sprockets have a 136T belt. The 1200s with 29T and 30T sprockets have a 137T belt.

Some people who've changed to a 29T sprocket on an 883 have have reported keeping the 136T belt and say they didn't need to change to a 137T.