I installed a set of Progressive's lowering monotubes on my '12 RGC, here's some observations that hopefully will help.
The scoot is a 2012 FLTRX with 21F/17R wheels and stock rear shocks.

Lowered 1" and used 3 pre-load spacers on each leg as per the instructions.
IMHO this is a must do when going with a 21" front wheel;

1. The bike now looks and feels perfectly balanced.
2. Not top-heavy, easy to get off the side stand.
3. Slow speed manouvering feels normal again!
4. Able to use my centerstand and the sidestand holds at a normal angle again.
5. Handling feels greatly improved, planted and responsive but not harsh.
6. No clunks or strange noises and the nosedive is gone!
7. Hardest part of the job for me was getting the top plugs out as I didn't have a vise to hold them properly. Went to a buddy's shop, covered them with a towel to avoid scratching, locked them really tight in the bench vise, took an open wrench to them and voila! plugs out! Once you exchange the innards of each leg the rest is cake.
8. Must use the impact wrench and 6mm long allen on the bottom screw of the right leg and u can use a regular 6mm allen (socket drive) for the left leg (rider's perspective).
9.I put 5oz. BelRay 15 weight (because that's what I had laying around) in each leg, go slow, pump slow or you'll make a mess and won't get all the needed oil in them.
10. Either be very careful, follow the service manual procedure exactly or have the alignment tool on hand when removing the ignition switch selector ****. If the switch's tumblers go out of alignment it can turn into a cursing festival ...8-)
11. Some specific tools needed for a "smooth" install include a 1 3/8" socket, 6mm long drive socket, torque wrench, workbench vise, bike specific service manual and a electric or pneumatic impact wrench.

Not involved in any way with Progressive Suspensions. These are just my obsevations while riding my scoot, hope they help whomever is on the fence regarding these.

 

Plan on installing these with my new 21. What made you decide to go with the 17 in the rear rather than the 18?

 

Couldn't agree with you more. Only difference is I used the Progressive Springs and used SE Heavy fork oil.

If your doing a 21" up front, this mod is a must. I'm 5'11" and could flat-foot with no problem without the lowering kit, but putting the kit on brought it back to stock.

 

SG>> having a 29" inseam it was all about height. The folks at HogPro told me a 17x6.25", 200/50-17 setup would actually lower the rear 1/4" from stock so I went with it. I can flat-foot the scoot very comfortably and relaxed with this setup.

ramn>> by what I've read it seems the critical thing with the oil is the quantity (5oz./leg) not so much the weight. It's there just to lubricate some parts not for dampening and it makes sense, regardless, I wouldn't use any crazy or extreme oil weights in this setup. First thing I noticed is how natural and easy the scoot came off the side stand, before it felt like a dump truck ...8]

 

Agree 100%.

 

You got any pics of your wheel setup? I'm ordering the exact same setup now and just curious of the 17" rear

 

do you need to use any of the bushings from the old fork tubes when installing
the monotubes?
do you need to replace the fork seals.
thanks

 

I put Progressive 940's in the rear too, besides the mono's in the front when I did the chrome front end.
I figured it was a great/no better time to do it since it was apart for the chrome front end swap.
It was a $1 K mod for all three items but was/has been well worth it over all.

 

Lionsm13
what parts did you have to reuse from the old forks when installing the
monotubes, or do you disreguard those parts.
also do you need to install new fork seals.
thanks for you help

 

I did the chrome exhange with ***** Shiny: http://www.willyshiny.com/
I bought a site member's lowers and upper cans and sent them in for the exchange along with my stock rotors for polishing. I thought that there would be too much disparity w/out having the rotors polished too with the new chrome front end.
I used new seals but that's about it.