Signature Series Smooth Rider Seat and Backrest

Part Number 51985-08


Finish / Color: Black



The perfect combination of foam density and shape has created our most comfortable seat for long-haul touring. Both rider and passenger will be comfortable riding to Sturgis and back with wide seating area.

  • Smooth styling
  • Seat features an easily removable adjustable rider backrest that folds down for easier passenger mounting
  • Rider backrest has a 5-position height adjustment with 1.5" range
  • Wide range of forward/back angle adjustment with the quick twist of the control knob
  • Seat width 16.0"
  • Stop by a participating dealer and test out this seat today as part of our Seat Demo Program –
    contact your local dealer for details


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  • Model
  • Adjustable

  • Material Content

  • Seat Width

    16.0 Inch
  • Pillion Width

    14.0 Inch
  • Warranty

    1 year limited warranty – Go to for full details
  • Sold in Unit

  • In The Box

    Rider backrest, grab strap, seat bracket, and all necessary mounting hardware
Signature Series Smooth Rider Seat & Backrest is rated 3.4 out of 5 by 5.
Rated 1 out of 5 by from Like sitting on a 2x4 I could not ride more than an hour at a time on this seat it is hard the front is to narrow. The backrest was great but it went down hill fast after that. I wasted a lot of money on this seat!
Date published: 2017-09-26
Rated 5 out of 5 by from Nice seat I am 5-9 (on a good day), 175 lbs. I am not gifted with a lot of padding on my rear, so I need a good seat on a long ride. This seat allows for a full days ride if I stop every 100 miles or so. It has plenty of lower back support without using the included backrest, and even more back support with the easily adjustable backrest. The forward portion of the seat provides perfect support and plenty of room to move around and change seating position. Yet it does not interfere with putting your feet down when needed. The width of the seat is also excellent, and provides ample coverage for my rear. Overall, for me the seat is an excellent fit and shape. No seat, including the one in your living room, will provide all day comfort, without getting out of it a few minutes, every hour or two. Great seat.
Date published: 2016-06-17
Rated 5 out of 5 by from Signature Series Smooth Rider Seat & Backrest reduced rider fatigue I ordered this seat to see if it would reduce rider and passenger fatigue on long rides. I got my answer on the first ride, YES. Both my passenger and I were pleased to find that we could stay in the saddle longer and arrive more rested with the extra support and padding this seat provides. This seat fit well on my 2008 Fat Boy and also reduced my reach and leg to peg distance just enough to make a big difference. I ordered the seat through the on-line HD store and shipped it to my local dealership who phone me when it arrived, no shipping fee, installation was a snap.
Date published: 2014-08-22
Rated 2 out of 5 by from If momma aint happy, nobody's happy. From an operator point of view this seat has just two redeeming qualities, the backrest and most importantly it prevents your nether regions from being probed by the seat post. I’m not certain who the designers of this seat are but someone needs to remind them there is an oilbag on Softails and it gets hot. This seat has so much cut out from the operator’s seat that it drops you down right on top of it. I’ve had to add a fur as to prevent burning the backside of my right thigh. In addition this seat is hard as a rock. As to the forward positioning this seat provides, it makes the bike feel like the bike has mid controls and cramped. While only 5’ 10” I do have to admit to having long legs so this is probably a fault of my body type and not a seat design issue. All in all these issues makes riding with this seat uncomfortable and I immediately put the stock seat back on after every two-up adventure. And now the reason why I haven’t returned this item: the healthy width and padding on the passenger seat. My wife won’t ride on the bike for more than 10 miles unless I swap out to this seat. If momma aint happy, nobody's happy.
Date published: 2014-06-30
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Is there more foam/cushion on this seat? ( more or less comfortable)

Does the seat move you more forward or just more upright? I'm 6'2" and don't want to lose leg room. Without the ability to try before you buy I need more information. Thanks
Asked by: Don15
I just bought a 2016 Softail Deluxe. I put this touring seat on in place of the stock seat. I am 5-9, 175. Here's the seat comparison. The touring seat adds more foam and is more comfortable. It adds more lower back support, not so much pushing forward as supporting a more upright position. Also the seat area around your thighs seems better fitted, less pressing but still comfortable. The touring seat allows me to more easily reach the ground and move the bike as needed. The seat also allows me to more easily shift to slightly different positions while riding. Finally, the remove able back support adds more positions and can be adjusted to fit quite easily. For me, this is a definite improvement for long rides.
Answered by: Rob44
Date published: 2016-08-20

i have a fxstc with the stock seat if i wanted to change seats for more rider comfort what do i have to do in reguards to a passenger back rest?

Asked by: murphy1dog
If you're not looking to put much into it beyond the seat, just add this backrest: part #52361-07. This will fit on your stock bar. If you want a more substantial backrest you have a bit more work and a few parts. 1. Sideplates 2. Upright 3. Pad
Answered by: tkn3600
Date published: 2014-08-30

Does the rider backrest adjust forwards and backwards ? If so how much ?

Asked by: newrider
Yes it does adjust both forward and backward and up and down. The way it moves forward is by turning a small thumb screw at the rear of the backrest. This thumb screw is item 6 on the diagram listing all parts in the instructions that come with the seat. (Click on "More Info" on the web page for the seat to bring up a copy of these instructions.) The thumb screw pushes against the post that slides into the seat and pivots the entire backrest forward and backward about an inch or so. The backrest pivots in its mount, freely changing it's contact angle with your back as you move it fore and aft. This really does give you lots of adjustment. There is also a small knob on the back of the backrest (not shown) that pulls outward and allows the backrest to slide up and down within the 4 holes (pictured) on the mounting post, giving a couple of inches adjustment in vertical positioning.
Answered by: Rob44
Date published: 2016-08-20
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    Prices listed are generally the Manufacturer's Suggested Retail Price (MSRP), excluding taxes and shipping. Prices at local dealerships may vary. All online orders will be fulfilled and shipped by
    Harley-Davidson Motor Company as the agent for the Selling Dealer.