Ahhh.....looking more closely at the pics answered the tire question.....still running a 240....

That might be true in the ideal case. But also a slightly inaccurate (non-parallel) alignment of the rear tire could force the belt further to the inside of the rear pulley, but maybe I am mistaken?

 

Ya I'm not sure either Ray..but even if that's the case, I would really consider going back to a 240mm on my next tire change to take advantage of this mod!!
Maybe a 1" pulley and a slightly larger spacer would work with the 260??
I just checked my HD edge cut pulley, it's 1 1/8" wide, but with the spacer it's out to where the belt gap is on the left side. I would think if LA Dog used a bigger spacer he would have the same result. With my stock gasser wheels, I think I could use a 1" pulley and my current spacer if I change to a 70t.

 

Eagle- you raise some good questions and fortunately there is a good answer- the only measurements you need to be concerned with are the outside edge of pulley and width of pulley (as in my photo sets, doing the offset measurements).

the belt will always ride to the outside of pulley, it is by design. jack up your bike and spin the wheel backwards. belt will track to inside of pulley. now spin it forwards. belt will track to outside edge. it is always like this.

note that even with your stock pulley, there is a gap on inside of pulley. the stock Breakout pulley is a tad over 1" wide actually about the same as the 70t I just put on (1.125") our belts are 0.98 (24mm) wide. so any 1" or 1-1/8" (1.125") pulley is fine.

So worst case with a 1-1/8" pulley, if i spin wheel backwards the belt can rub slightly on the tire sidewall. i have about 5mm gap between belt and 240 tire. it was the same gap clearance with the stock 66t pulley and 68t sportster pulley. with the 70t, nothing has changed in regards to clearances.

So let's say "worst case". With a 260 tire and the stock 66t pulley. you'll probably have 2-3mm clearance. but if you wanted more clearance, it is super easy. just pick up a 1/8" wheel pulley spacer and another set of stock length bolts.

let's say with my 70t, I decide to go nuts with a 280 tire. I would go pick up a 3/8" pulley spacer, remove the 1/4" spacer I put on, and use the new thicker 3/8" spacer and fresh set of pulley bolts. done. yes it is really that easy.

BTW you can get a compatible pulley in chrome or polished billet, that fits same years as the black one I used. there seem to be a lot of chrome HD pulleys for 2004-2006 FLHT- they are kinda ugly though- I'd opt more for the Ness 2004-2006 FLHT pulleys in polished. or one for 2006 Dynas from BDL, RSD, DNA, PM etc in chrome / polished.

 

Don't over think this too much guys! Use my photos to recreate the offset measurement. if what you have on the bike now works with the 260 tire, then the new 68t or 70t pulley will work the same as long as you have the new pulley sitting at the same outside edge offset.

For example, if you go buy the 68t stock sportster pulley and slap it on, and use the same spacer you have now for the stock 66t pulley- or no spacer at all if you were not using one- it is going to end up the same. with the 70t I bought, it does not come with any offset so it is up to the bike owner to determine the correct spacer needed.

I'm pretty sure the HD 70t pulleys for 2006 Dyna / FXDB or 2004-2006 FLHT have the offset spacer molded on the backside- at least that is what it shows in the pics, as with our stock 66 pulley an sportster 68 pulley.

but you do not need to go to a smaller tire for this mod.

on that note though, your bike will actually handle and ride better with a 240 vs a 260. the Pirelli Night Dragpns are without a doubt the best tires on the planet for this bike. they are strong, light weight, and sticky wet or dry / hot or cold.

going to a wider tire actually gives you less force per inch of tire contact surface. tires only work as well as the surface contact area. a smaller contact surface has more force per inch. just something to consider.

 

the belt will always track to the outside of pulley even if slightly off. you would have to mis-align the wheel so much the bike would be un-rideable. try it and see!

 

Hey LA_Dog, thanks for the reply and the clarification. Makes quite some sense the way you put it....and makes me worry a little less now

 

Eagle- yeh it's not as big a deal as it seems now that I've looked it all over. The most important factor is the wheel hub flange fitment, and the bolt pattern, and the pulley being wide enough for the belt. what's nice is all HD pulleys from 2001-up for FXS/FXD have the *same* hub flange size. and the pulley bolt size / pattern is also the same (7/16" bolt, 14 thread per inch x required length). Bolt lengths are different because some HD pulleys are thicker than others for the bolt holes in the pulley. As long as you have 1.25" of thread into the wheel then you're good.

So as long as you get a 2001-up HD compatible 68t or 70t pulley 1" or 1-1/8" wide, stock or aftermarket, then the only other parts you may need are (1) a pulley spacer and (2) appropriate length bolts. done.

I bought the Ness pulley solely based on it having the correct wheel hub size and belt width. Then as in my pics above, I calculated the spacer needed so it sits in the same outboard position as the stock pulley. then figured bolt lengths, and ordered those small parts, installed, done. Now that we know 100% that a 30/70 fits with the stock belt, this all became possible to do.

Again I'm pretty sure a stock 70t HD pulley will not need a spacer- the 68t sportster pulley did not. but there is limited selection in chrome / polished so the best bet is to go aftermarket and use a spacer.

 

Here is a master list of HD belt pulleys and belt widths by year / model.

http://catalog.zodiac.nl/en/Catalog/...S/Product.aspx (screenshot of table below with highlighted selections)

you should look at anything 2001-up, 68t or 70t, 1" or 1-1/8" width, non-IDS (cush drive) for cross referencing fitment in aftermarket pulleys. Axle size does not matter.

I sorta narrowed it down to the 2011-present Sportster pulley for 68t direct bolt on fitment, and 2001-2006 Dyna, 2001-2006 softail, 2004-2006 FLHT for 70t pulley fitment. Mainly because these pulleys are same hub size and wide enough for our 24mm belt but not too wide. anyone making an aftermarket billet / chrome pulley for these same bikes will equal the same fitment- the only caveat being that many of the aftermarket pulleys assume you are going to use a spacer and the correct length bolts given the spacer thickness. This is not an uncommon process for custom bikes. We can apply the same method and process here.

 

Great write up. Thanks for taking your time and posting.

 

Hey guys, after reading through the thread I can't assertain weather a rear pulley from a sportster will fit my 2016 Fatboy? Obviously the breakout is much wider on the rear than the fatty. Could someone please advise as I sure would like to pick up a bit more response/power for not a lot of hassle. Thanks