Can anyone verify if sportster sport lower legs (2005 or so) are the same length as the FXR3? I am waiting dual disc setup that I can put newer bagger calipers on.
Thanks.
All FXR front-ends from '87(?) - up are 39mm. Not 100% sure, but I believe the first three model-years ('82-'84 Shovelheads) and '85-'86 Evo models were 35mm.
Sportster lower legs thru '07 model year are the same front axle size as all stock FXRs --3/4". They are also the same length as the FXR lowers. The length difference between front ends occurs with longer fork tubes and maybe springs, such as those that came with the '00+ FXDX. FYI, If you want black lowers, a Sportster '05 model came stock with black dual-discs lowers, not sure if any '00-'03 Dyna models came with black dual-disc lowers.
As an aside, Slight difference is that all '00-up wheels come with sealed bearings and not the timken bearings which all FXRs have, except ofcourse,bfor the 2000-model-year FXR4. The other difference is that all FXRs, except again for the FXR4 had front-wheel drive-unit speedos, i.e., the '99 and earlier wheels had a notch for the sepeedo drive-unit tang to fit into the wheel. The '00+ model year wheels do not have that tang, as speedos did not require the drive-unit.
Ahhh, the inevitable brake upgrade....Highly recommended by many, especially if you've got the single piston - single caliper Evo / pre-'00 style brakes. Those that were lucky / smart enough bought those Evo models with the dual disc-set-up. It's a wonder we haven't all crashed and burned with such inferior brakes....

The single-disc four-piston upgrade swap is less expensive and easier, as you don't need to purchase an extra chrome lower, caliper, floating rotor, sintered brake pad, dual disc brake line and 11/16" master cylinder for the FXR3.
Regardless of a dual-disc or single-disc upgrade, both require the '00-'07 Sportster or '00-'03 Dyna lowers, (finding whichever of those models came with dual-discs does require some research), all of which will accommodate the three 21st-century generations of brakes, beginning in '00. If avoiding aftermarket brakes and staying w/ the MoCo brand, then there are three dual-disc upgrade conversion options:
Option #1 is the MoCo standard '00 - '07 style brakes. They came stock on the FXR4 and various other models, dual-disc and otherwise. Not sure if they were 2-piston or 4-piston, but they are an upgrade. This is the least expensive way to go but require the later model lowers. FXR4s came stock with these brakes in a dual-disc set-up.
Option #2 is the 4-Piston Nissin calipers with H-D logo, which were found on the Sportster XR-1200 models, a fast-performance scoot which is roughly the same weight as an FXR. You can retain your stock 11.5" / 292 mm floating rotors, so all that is required are the '00+ lowers and the Nissin calipers. These look badass.

Option #3- The '08-up touring model / '07-up Dyna and '07-up V-Rod made by Brembo for Harley. These require the '00-up lowers as well as the 11.8" / 300 mm rotors, which will require more $$$. But they do look cool and are the latest generation the MoCo has to offer.
***Last but not least, if you're going to upgrade the brakes, you might as well upgrade the front-end suspension by installing a '00 -'03 FXDX adjustable cartridge front-end, or drop in some Progressive gold cartridge emulators and springs in the FXR front-end or drop in some Works Performance springs / cartridge front-end.
Once your brakes and front-end are current, all you'll need now is a more powerful motor to test out your new upgrades. And I'm not referring to a Stage 3 hopped up 80" Evo. No, I'm talkin' 'bout dropping in one of those 100+ c.i. monsters such as an S&S 111, 113, 124" or an Ultima 127...