In Stock –
Progressive 412 Series Shocks
The 412 Series shocks are simply the best value shock on the market today. The 412's simple, durable design means they will be an improvement to your motorcycle's suspension performance for as long as you are riding it. The double-wall steel body construction with nitrogen charged, multi-staged velocity sensitive valving gives you smooth, consistent damping. A five position cam style preload adjuster lets you dial in your ride whether you're a light rider or heavy hitter. With multiple options, there is sure to be a 412 that's right for you and your bike.
- Sold in pairs for machines originally equipped with two shocks
- All steel double wall damper with multistage velocity sensitive damping
- 5 position cam style preload adjuster
- High pressure gas charged for consistent damping performance
|Color||Varies (make selection above)|
|Finish||Varies (make selection above)|
|Length||Varies (make selection above)|
|Material||Varies (make selection above)|
|Quantity||Varies (make selection above)|
|Spring Rate||Varies (make selection above)|
Fitment is guaranteed or your money back plus free return shipping. Don't waste time installing a product that doesn't fit. We worked hard ensuring that this product is an exact fit on the vehicles listed below.
- K 75 1986-1995
- K 75 C 1986-1990
- K 75 RT 1990-1995
- K 75 S 1987-1995
- K 75 T 1986
- K 100 1985-1986
- K 100 LT 1987-1991
- K 100 RS 1988-1989
- K 100 RT 1984-1988
- R 60/6 1974-1976
- R 65 1979-1984
- R 75/5 1973
- R 75/6 1974-1976
- R 75/7 1977
- R 80/7 1978-1981
- R 100 1979-1984
- FLD Dyna Switchback 2012-2016
- FLHR CVO Road King 2014
- FLHR Road King 1997-2016
- FLHRC Road King Classic 2007-2013
- FLHRCI Road King Classic 1998-2006
- FLHRI Road King 1997-2006
- FLHRS Road King Custom 2004-2007
- FLHRSE3 CVO Road King 2007
- FLHRSE4 CVO Road King 2008
- FLHRSE5 CVO Road King 2013
- FLHRSEI2 CVO Road King 2 2003
- FLHRSEI CVO Road King 2002
- FLHRSI Road King Custom 2004-2006
- FLHT Electra Glide 1982-1984, 1987
- FLHT Electra Glide Standard 1995-2009
- FLHTC Electra Glide Classic 1983-2005, 2007-2013
- FLHTC Liberty Electra Glide Classic Liberty 1986
- FLHTCI Electra Glide Classic 1996-2006
- FLHTCSE2 CVO Electra Glide 2005
- FLHTCSE CVO Electra Glide 2004
- FLHTCU Ultra Classic Electra Glide 1989-2016
- FLHTCUI Ultra Classic Electra Glide 1995-2006
- FLHTCUL Electra Glide Ultra Classic Low 2015-2016
- FLHTCUSE2 CVO Ultra Classic Electra Glide 2007
- FLHTCUSE3 CVO Ultra Classic Electra Glide 2008
- FLHTCUSE4 CVO Ultra Classic Electra Glide 2009
- FLHTCUSE5/BLK CVO Ultra Classic 2010
- FLHTCUSE6 CVO Ultra Classic Electra Glide 2011
- FLHTCUSE7 CVO Ultra Classic Electra Glide 2012
- FLHTCUSE8 CVO Ultra Classic Electra Glide 2013
- FLHTCUSE CVO Ultra Classic Electra Glide 2006
- FLHTI Electra Glide Standard 2003-2006
- FLHTK Electra Glide Ultra Limited 2010-2016
- FLHTKL Electra Glide Ultra Limited Low 2015-2016
- FLHTKSE CVO Electra Glide Ultra Limited 2014
- FLHX Street Glide 2006-2016
- FLHXI Street Glide 2006
- FLHXS Street Glide Special 2014-2016
- FLHXSE2 CVO Street Glide 2011
- FLHXSE3 CVO Street Glide 2012
- FLHXSE CVO Street Glide 2010
- FLT Tour Glide 1980-1984
- FLTC Tour Glide Classic 1980-1991
- FLTCU Ultra Classic Tour Glide 1989-1995
- FLTCUI Ultra Classic Tour Glide 1996
- FLTR Road Glide 1998-2002, 2007-2009
- FLTRI Road Glide 1998-2006
- FLTRSE3 CVO Road Glide 2009
- FLTRSEI2 CVO Road Glide 2 2001
- FLTRSEI CVO Road Glide 2000
- FLTRU Road Glide Ultra 2011-2013, 2016
- FLTRUSE CVO Road Glide Ultra 2011
- FLTRX Road Glide 2015-2016
- FLTRX Road Glide Custom 2010-2013
- FLTRXS Road Glide Special 2015-2016
- FLTRXSE2 CVO Road Glide Custom 2013
- FLTRXSE CVO Road Glide Custom 2012
- FX 1200 Super Glide 1973-1978
- FXD Dyna Super Glide 1995-2005, 2007-2010
- FXDB Dyna Daytona 1992
- FXDB Dyna Street Bob 2007-2016
- FXDB Dyna Sturgis 1991
- FXDC Dyna Glide Custom 1992
- FXDC Dyna Super Glide Custom 2005, 2007-2014
- FXDF Dyna Fat Bob 2008-2016
- FXDI35 35th Anniversary Dyna Super Glide 2006
- FXDL Dyna Low Rider 1993-2005, 2007-2009, 2014-2016
- FXDS-CONV Dyna Convertible 1995-1998
- FXDS-CONV Dyna Low Rider Convertible 1994
- FXDS-CONV Dyna Super Glide Convertible 1999-2000
- FXDWG Dyna Wide Glide 1993-2005, 2007-2008, 2010-2016
- FXDX Dyna Super Glide Sport 1999
- FXE Super Glide 1984
- FXEF Super Glide Fat Bob 1985
- FXLR Low Rider Custom 1987-1994
- FXR Super Glide 1986-1994
- FXR Super Glide II 1982-1983
- FXRS Low Glide 1982-1992
- FXRS-CONV Low Rider Convertible 1989-1993
- FXRS-SP Low Rider Sport Edition 1987-1993
- FXRT Sport Glide 1983-1992
- FXSB Low Rider 1984-1985
- FXWG Wide Glide 1980-1986
- KH Sportster 1954-1956
- Sportster XLX 1983-1985
- Sportster XLX-61 1984-1985
- VRSCA V-Rod 2002-2006
- VRSCB V-Rod 2005
- VRSCD V-Rod Night Rod 2006
- XL50 50th Anniversary Sportster 2007
- XL883 Sportster 883 2004-2009
- XL883C Sportster 883 Custom 2004-2010
- XL883L Sportster 883 Low 2005-2010
- XL883L Sportster SuperLow 2011-2015
- XL883N Sportster Iron 883 2009-2015
- XL883R Sportster 883R 2006-2010
- XL1200C Sportster 1200 Custom 1996-2015
- XL1200L Sportster 1200 Low 2006-2011
- XL1200N Sportster 1200 Nightster 2007-2012
- XL1200R Sportster 1200 Roadster 2004-2008
- XL1200T Sportster SuperLow 2014-2015
- XL1200V Sportster Seventy-Two 2012-2015
- XL1200X Sportster Forty-Eight 2010-2015
- XL Sportster 1957-1958
- XLC Sportster 1958
- XLCH1000 Sportster 1000 1970-1979
- XLCH Sportster 1959-1969
- XLCR1000 Sportster Cafe Racer 1977-1978
- XLH883 Sportster 883 1986, 1988-2003
- XLH883DLX Sportster 883 Deluxe 1994-1995
- XLH883HUG Sportster 883 Hugger 1987-1991
- XLH1100 Sportster 1100 1987
- XLH1200 Sportster 1200 1988-2003
- XLH Sportster 1958, 1960-1969, 1979-1980, 1982-1984
- XR1000 1983-1984
- XR1200 2008-2010
- XR1200X 2010-2012
- CB650SC Nighthawk 650 1983-1985
- CB750 Nighthawk 750 1991-1993, 1995-2003
- CB900C 900 Custom 1980-1982
- CB1000C Custom 1983
- CM185T Twinstar 1979
- CM200T Twinstar 1980
- CX500 1978-1979
- CX500C Custom 1980-1982
- FT500 Ascot Single 1982-1983
- GB500 Tourist Trophy 1989-1990
- GL1000 Gold Wing 1975-1979
- GL1100 Gold Wing 1980-1983
- GL1200 Gold Wing 1984-1987
- GL1500 Gold Wing 1988-2000
- GL1500C Valkyrie 1997-2003
- GL1500CD Valkyrie Deluxe 2001-2003
- GL1500CF Valkyrie Interstate 1999-2001
- GL1500CT Valkyrie Tourer 1997-2001
- VF500C V30 Magna 1984-1985
- VF700C V40 Magna 1984-1986
- VF750C V45 Magna 1982-1983, 1994-2003
- VF1100C V65 Magna 1983-1986
- VT500C Shadow 500 1983-1984
- VT500FT Ascot Twin 1983-1984
- VT700C Shadow 700 1984-1987
- VT750C2 Shadow 750 Spirit 2007
- VT750C Shadow 750 1983
- VT750C Shadow 750 A.C.E. 1998-2001
- VT750C Shadow 750 Aero 2004-2009
- VT750CD Shadow 750 A.C.E. 1998-2001
- VT800C Shadow 800 1988
- VT1100C2 Shadow 1100 A.C.E. 1995-1999
- VT1100C2 Shadow 1100 Sabre 2000-2007
- VT1100C Shadow 1100 1985-1996
- VT1100C Shadow 1100 Spirit 1998-2007
- VTX1300C 2004-2009
- VTX1300R 2005-2009
- VTX1300S 2003-2007
- VTX1300T 2008-2009
- VTX1800C 2002-2007
- VTX1800F 2005-2008
- VTX1800N 2004-2008
- VTX1800R 2002-2007
- VTX1800S 2002-2006
- VTX1800T 2007-2008
- EN450A 454 LTD 1985-1990
- H2 Mach IV 1972-1975
- KH400 1976-1977
- KH500 1976
- KZ250D CSR 1981
- KZ305A CSR 1981-1982
- KZ440A LTD 1980-1983
- KZ550C LTD 1980-1983
- KZ550F Spectre 1983
- KZ650D SR 1978-1979
- KZ650H CSR 1982-1983
- VN700A Vulcan 700 1985
- VN750A Vulcan 750 1986-2006
- VN1500A Vulcan 88 1987-1995
- VN1500A Vulcan 1500 1996-1999
- VN1500B Vulcan 88 SE 1987-1990
- VN1500C Vulcan 1500 L 1996-1997
- VN1500D Vulcan 1500 Classic 1996-1997
- VN1500E Vulcan 1500 Classic 1998-2004
- VN1500G Vulcan 1500 Nomad 1999-2001
- VN1500J Vulcan 1500 Drifter 1999-2000
- VN1500L Vulcan 1500 Nomad Fi 2000-2004
- VN1500N Vulcan 1500 Classic Fi 2000-2008
- VN1500P Vulcan 1500 Mean Streak 2002-2003
- VN1500T Vulcan 1500 Classic 2006
- VN1600A Vulcan 1600 Classic 2003-2008
- VN1600B Vulcan 1600 Mean Streak 2004-2008
- VN1600F Vulcan 1600 Mean Streak 2006
- W650 2000-2002
- ZG1200A Voyager XII 1986
- ZG1200B Voyager XII 1987-2003
- ZL600A Eliminator 600 1986-1987
- ZL900A Eliminator 900 1985-1986
- ZL1000A Eliminator 1000 1987
- ZN1100B LTD Shaft 1984-1985
- GN250 1988
- GN400T 1980-1982
- GN400TX 1980-1981
- GN400X 1980-1981
- GN400XT 1980-1981
- GN400XX 1980-1981
- GS250T 1981
- GS300L 1983
- GS400 1977-1978
- GS425 1979
- GS550 1977-1981
- GS650E 1981
- GS650G 1981-1983
- GS650GL 1981-1983
- GS850G 1979-1983
- GS1000G 1980-1981
- GS1100G 1982-1983
- GS1100GK 1982-1984
- GT185 Adventurer 1973-1977
- GT250 Hustler 1973-1977
- GT380 Sebring 1972-1977
- GT550 Indy 1972-1977
- SP370 1978-1979
- SP400 1980
- VS700GLEF Intruder 700 1986-1987
- VS700GLEP Intruder 700 1986-1987
- VS700GLF Intruder 700 1986-1987
- VS700GLP Intruder 700 1986-1987
- VS750GLP Intruder 750 1988-1991
- VS800GL Boulevard S50 2005-2009
- VS800GL Intruder 800 1992-2004
- VS1400 Boulevard S83 2005-2008
- VS1400GLF Intruder 1400 1987-2004
- VS1400GLP Boulevard S83 2005-2009
- VS1400GLP Intruder 1400 1987-2004
- VX800 1990-1993
- VZ1600 Boulevard M95 2005
- VZ1600 Marauder 1600 2004
- America 2002-2014
- Bonneville 2014
- Bonneville SE 2009-2013
- Bonneville T100 2002-2014
- Rocket III 2004-2009
- Rocket III Classic 2006-2009
- Rocket III Roadster 2010-2014
- Rocket III Touring 2008-2014
- Scrambler 2006-2014
- Speedmaster 2003-2014
- Thruxton 2004-2014
- FZX700 Fazer 1986-1987
- RD350 1973-1975
- SR250 Exciter 1980-1982
- SR500 1978-1981
- VMX1200 VMAX 1985-1986, 1988-2007
- XJ550 Maxim 1981-1983
- XJ550R Seca 1981-1983
- XJ650 Maxim 1980-1983
- XJ650L Turbo Seca 1982-1983
- XJ650R Seca 1982
- XJ700X Maxim X 1985-1986
- XJ750 Maxim 1982-1983
- XJ750R Seca 1981-1983
- XJ900R Seca 1983
- XJ1100 Maxim 1982
- XS360 1977-1981
- XS400 Maxim 1980-1981
- XS400S Special 1980-1982
- XS650 1975-1981
- XS750S Special 1978-1979
- XS850 1980-1981
- XS850S Special 1980-1981
- XS1100 XS-Eleven 1978-1981
- XS1100S XS-Eleven Special 1979-1981
- XV535 Virago 535 1987-1988, 1990, 1993-2000
- XV700 Virago 700 1984-1985
- XV700C Virago 700 1986-1987
- XV750 Virago 750 1988-1997
- XV1000 Virago 1000 1984-1985
- XV1100 Virago 1100 1986-1999
- YX600 Radian 1986-1990
Questions & Answers
Are these sold in pairs?
For machines that are equipped with two shocks, they are indeed sold in pairs.
Sell in pairs?
Yes, Progressive 412 Series Shocks are sold in pairs for machines that come the factory with two rear shocks.
Do these come with the bushings?
If it's the bushings that go between the upper and lower shock mounts on your machine, then yes, they're indeed included. In fact, depending on what bike you're mounting the shock(s) onto, the kit may include a myriad of bushings to fit since one set of shocks may fit more than one machine.
I have a 2006 Street Glide. How many inches of travel do these Progressive Shocks have?
Travel varies, depending on which shock length you select to install on your bike. In the case of the 2006 FLHX street glide shocks, the length of travel for each shocks is as follows:
1.85" for the 11.5" shocks
2.35" for the 12" shocks
2.85" for the 12.5" shocks
3.48" for the 13" shocks
3.98" for the 13.5" shocks
As you can see, the greater the shock's length, the more travel that's available for your bike. And don't forget to choose the correct spring rate to fit your particular riding needs. With Progressive's 412 shocks, heavy-duty springs are best suited for solo riders over 220lbs. If you ride two-up and/or with a full load of luggage at least 50% of the time, you'll certainly want to go with the heavy-duty springs to cover that extra weight.
2001 Road King classic 5-speed. I want the same length shock as original. Would that be the 13" length?
Yes, according to the data I have from Progressive, the 2001 model year Road King Classic shipped from the factory with 13" length shocks, so you'd certainly want to order shocks from that are of the same length to avoid having to fool around with suspension geometry. Another important factor to consider is your weight, and whether or not you plan to travel heavy (two-up and/or with a full load of luggage). If you're over 220 lbs, and/or travel two-up/heavy at least 50% of the time, you'll want to choose the heavy-duty spring rate. Otherwise, the standard rate shocks will do an excellent job.
I have a 05 Honda VTX 1800 N with a batwing fairing and saddle bags. I will be adding a trunk in the near future. What wold be thw best for my needs. I do ride 2 up aboit 40% of the time.
By: Rick R.
Progressive recommends that heavy-duty springs are to be used for solo riders over 220 lbs. Furthermore, if you ride two-up and/or with a full load of luggage at least 50% of the time, heavy-duty shocks are also recommended. Since you're two-up 40% of the time, you should certainly consider the additional weight of the batwing, saddlebags and the trunk you want to add later on. Just add those items to your own weight and, if that puts you at 220 lbs. or more, then you'd certainly be wise to go with a heavy-duty spring rate.
Furthermore, we strongly recommend the installation of a matching set of fork springs to go with any Progressive Shocks. Should you choose the standard-rate rear shocks, then the standard rate Progressive Fork Springs will do the job nicely. If you go for the heavy-duty spring shocks, we recommend Progressive Heavy-Duty Fork Springs. In doing so, you'll be sure to balance the front and rear spring rates equally, which in turn, minimizes the back-and-forth wallow that's common anytime front or rear spring rates are mismatched. This becomes more noticeable the faster you go and with bigger bumps.
I have a Kawasaki Voyager ZG 1200 XII with air shocks. Can I use those without air?
Yes, you can indeed use Progressive 412 shocks without air since. The shocks themselves actually have no provision for air, so there's no need to worry about hooking them up to that system.
I have a 1993 Xlh883 needing shocks soon. I think the 412's would be perfect. Would 12.5's give me a little extra travel without buggering up the geometry?
The standard 1993 XLH883 comes with 13-1/2" shocks from the factory, so you'd actually be reducing the amount of travel available if you were to select the 12-1/2" long shocks. In addition, you would be changing the bike's steering geometry since you'd be lowering the rear end of the bike.
While more suspension travel is nice, the best thing you can do is order springs that are of the correct rate for your weight and riding needs. That is to say, it's not the shock's length that effects travel as much as spring rate does. A properly sprung bike will rarely bottom out. If you spend most of your time riding solo and weigh less than 220 lbs - then a standard rate shock will do the job. If you travel two-up and/or with a full load of luggage on the bike at least fifty percent of the time, you'll want to order a set of heavy-rate springs.
If changing the bike's geometry is of a concern, then you should order a set of 13-1/2" shocks so as not to make the bike handle differently. Again, the most important factor for resisting bottomg is to choose the correct spring rate for your needs. With that, regardless of the spring rate you choose, you'll find the bike will not bottom out.
what is the stock shock length for a 2000 FXD?
The 2000 model year Harley-Davidson FXD shipped from the factory with shocks that measured 12.6" eye-to-eye.
2009 sportster XL1200c. I'm looking for a more comfortable smoother ride. Something to soften the bumps on my back. What would you recommend I go with ?
There are two things that you can do to get the best possible ride for your needs. The first is getting the correct spring rate for your weight and riding needs. Heavy-duty rate springs are advised for solo riders that weight more 220lbs. Furthermore, if you ride two-up and/or with a full load of luggage at least 50% of the time, be sure to choose heavy-duty springs as well. Just about all of Progressive's shocks, including the 412 Series Shocks, are available in standard and heavy-duty spring rates.
The second important factor, and this is especially true if you decide to go with heavy-duty shocks - is to match the fork springs to the shock. In this way, you're assured that both ends of the bike will react the same to irregularities in the road since progressive-rate springs act differently than the OEM straight-rate springs in the forks. In this way, the bike will wallow less over bumps and you'll notice it tends to track very true when hauling it around corners. Of course, the faster you go, the more noticeable these differences will be come.
The difference between straight-rate and progressive-rate springs is that, with the former - no matter how much you compress the spring, the amount of force it exerts remains nearly the same. Progressive-rate springs, on the other hand, exert more force the more they're compressed. In other words, the bigger the bump, the better job the progressive springs do in quickly slowing those forces without the heavy jolt you'd feel with straight rate springs over the same bump.
Be sure to choose the correct Progressive Standard Weight Fork Springs or Progressive Heavy-Duty Fork Springs from our website if you want to get the best ride possible.
And, I did fail to mention - there's one solid rule about suspension that applies anytime you're comparing the stock item to an aftermarket part. That rule is that that you don't know what good suspension is until you've tried it. You will find that Progressive shocks are a significant improvement over the stock items, no matter where you ride or how you ride. And if you're looking for the best possible ride, we implore you to match the shocks with a set of Progressive fork springs as well.
I have a stock 1969 sportster, its 13.5" eye to eye. I weigh 150Lbs. no riders, solo only
will this 412 work and can I get it in all black. I am pretty sure the studs are 5/8th of an inch. Please give the the exact item # so i can order these. Thanks in Advance Bill
Yes, the 412 shocks will indeed fit your 1969 Harley Sportster. Considering your weight and the fact that you'll be riding solo, the standard rate shocks will do the trick for you. Each set of Progressive 1969 Sportster shocks come with the appropriate bushings to fit your bike, so there's no need to order any additional parts. With regard to an all-black set up, unfortunately, the only shocks we have to fit your machine are available in chrome only.
What length rear shocks to replace factory installed on my 2010 HD Sportster 1200XL Custom
By: Randy Mc.
The 2010 Harley Sporstster XL1200C shipped from the Kansas factory with 11-1/2" long shocks on it. Mind you, aside from XL1200C shock length, be sure to choose the correct spring rate for your needs. If you're a solo rider at least 50% of the time and 220lbs or less, go with the standard rate shocks. If you're bigger than that, or ride with a passenger quite often, you'll want to get a set of Progressive Sportster shocks with heavy-duty springs.
Will these fit on a 96 fxds-convertible
is the top to wide for the bike or doesn't stick out far enough from the fender strut?
By: Brent R
Progressive's 412 shocks will indeed fit the FXDS Dyna Convertible. The tops won't be too wide to fit, either. We've sold quite a few of these to fit that particular bike and I'm not aware of any interference issues between the fender strut and the shocks. Nor has there been a problem with the shocks being too wide to fit. Everything you need to complete the installation is included in the box.
What size spanner wrench do I need to adjust these shocks
There's no need to purchase any spanner wrench in order to adjust any of the Progressive shocks that we sell! They all come with one in the box that'll allow you to make the required adjustments. The included shock spanner wrench is specially shaped to fit the shocks you purchase which makes tuning it a snap!
I have a 1999 Vulcan Nomad 1500 I would like to lower it down a couple of inches would a shorter shock be the answer to that and would it still right?
The OEM shocks for the 1999 Kawasaki Vulcan 1500 Nomad measure 13" eye-to-eye. Choosing any shock that's shorter would, obviously, lower your bike. With regard to have the bike still right, you should seriously also consider Progressive Fork Lowering Kit as well. In doing so, you retain the bike's stock steering geometry and the way the bike handles would not change at all. We always recommend that, whenever you lower the rear, you also lowers the front of the bike as well. Progressive's Fork Lowering Kit has everything you need to adjust for this in that kit.
2013 Suzuki s40
I am about 5'8" and weigh 230 pounds. Would this shock be right for me? If not what would you recommend?
In the case of the 2013 S40 Suzuki's stock suspension, you'll find that these shocks are s significant improvement over what came with the bike. Based upon the information you've provided, you'd want to get the shocks with heavy-duty springs.You'll find the bike rides a whole lot better with the heavy-duty shocks installed.
What length shock is the 1983 flhtc stock ?
The 1983 FLHTC came with 13" long shocks from the factory.
What is the stock shock length on a 2006 HD Road King Custom?
I want to order a set of these shocks but not sure what size I need. Would like to go a little lower than stock...
The 2006 model year Harley FLHRC Road King Custom shipped from the factory with shocks that measure 13" at full length. Also, regardless of the shock length you choose, be sure to choose the correct spring rate for your riding needs. If you ride two-up at least 50% of the time, and/or with a full load of luggage, you will want to opt for heavy-duty shocks. This also holds true if you weigh over 220lbs. If those conditions don't apply to your needs, then the standard-rate shocks will more than be up to the task.
I ride a 2014 street glide special. 95% of the time i ride solo. I was trying to see witch shock would work for me , The 412 or the 430 series. I did the front forks already.
So long as you weigh less than 220lbs, the standard rate shocks from either, the 412 or 430 series will be ideal for your needs. If you weigh more than that, go for the heavy-duty shocks.
As for the differences between the 412 and 430 Street Glide Special shocks, the main difference between them, other than appearance, is the internal valving and the way you adjust spring preload. On the 412 shocks, you need to use the included shock spanner wrench to adjust preload. The 430 series shocks can have their preload adjusted by hand, which makes setting proper static sag very easy. The valving differences are quite significant. 430 shocks use a floating piston to separate the shock fluid from the pressurized gas chamber. In doing so, damping action is improved over the 412 shocks. And that's not to say the 412s are bad - they're great, especially when compared to stock. 412 shocks use a standard working piston instead of the floating design.
No matter what you choose, and especially since you've updated the fork springs, you'll find that the bike handles a lot better than it did in stock configuration. It'll track true through the