Site is currently being rebuilt from scratch. Thanks for understanding!

How to Shave Your Dirt Bike Seat

I originally wrote this article for CRFsOnly.com’s form. It is a sticky on that site. Since the original post, I have taken photos of another seat that I shaved and modified the content. The basic instructions are the same.

Before you begin

Shaving your dirt bike seat is a one-way ticket. You may be able to take more off, but you cannot put more back on. A shaved seat is a good alternative, or addition to, lowering your bike by using a lowering link or internal suspension work. I can pretty much guarantee that it will not look stock, and it will make your seat harder. If you have a KTM, the latter will not matter much as you are already sitting on a plank.

For me, I have found that shaving the seat provides a wider base that is actually more comfortable than some stock width foams. I also like that I can ‘roll’ the edges of the foam by sanding it for an even more custom fit, although you can do this without “shaving” the seat. The largest advantage is the ability to save myself from tip-overs because my feet are a bit closer to the ground. Having some additional clearance when things get rough is an added bonus. Still, a shaved seat is not for everyone and it can be costly if you mess up.

Before you proceed you may want to consider an aftermarket seat foam in either low, or soft. Durelle Racing, Guts Racing, and Enduro Engineering, and likely others, make some nice alternatives. I have personally owned seats from Durelle and EE. Both are high quality foams. Soft gel foams are heavier than stock seats but you simply cannot get a more comfortable units. However, there is a cost beyond time and there are no assurances that you will like a lowered seat. I am also not a fan of most seat covers, including the ones that come with those seats. I am pretty sure one of them was nothing more than vinyl – your cover should have some stretch to it. If you are looking for a new cover regardless of the reason, give SDG a look. I have been more satisfied with their covers over any other that I have purchased. Having said all that, if you are planning on buying an aftermarket lower seat but are just not sure if the lower height will be a benefit, go ahead and whack your stock unit down and see how if feels. You can always replace it with a stock height from the aftermarket companies, or the OEM.

If you decide to take the plunge, take your time. I am sure it goes without saying, but remember you can take more foam off but you cannot put more foam on. Okay, technically you could add foam, but we will stay away from that one for this article.

Tools, Time, and Materials

This list seems a bit long, but I am guessing you will have just about all of it on hand. It takes about 60 to 90 minutes of your time depending on how the cover replacement goes. This does not include any dry time for glue should you find the need to repair any splits in the foam.

  • Power sander (finish sander is preferred) or sanding block
  • 120-180 grit sandpaper
  • 60 grit sandpaper for use by hand (no power, no block)
  • Flat blade screwdriver
  • Permanent markers, 2 colors are better
  • Hammer
  • Long sharp knife, or electric carving (preferred) knife – you could probably use a hot knife foam cutter foam wire but it may be harder
  • Pliers
  • Ruler, preferably something with some flex
  • Sharp scissors
  • Shoe Goop or similar flexible adhesive
  • Spray paint, cheap in any color, just not the same as the seat foam
  • Staple gun, electric, pneumatic, or manual with a strong hit is required
  • Stiff wire, aluminum tie wire is best
  • Masking tape (optional)
  • Electrical tape (optional)
  • Punch (or use the screwdriver)

Making the Cut Lines

Cutting and Forming the Foam

Reinstalling the Seat Cover

Detailed instructions for making the cut lines

  • Unbolt and remove the seat, and place it on a sturdy work surface. Being careful to not tear the seat cover, use a flat blade screwdriver and lift up each staple. Ideally, you should try to lift each staple evenly rather than only lifting one side. If you can lift the staples evenly they will likely pull out the remainder of the way by hand, else you will need to use pliers and pull them out of the seat plan. Set the cover aside.

Careful not to ruin the cover!

  • To find the seat pan, I use wire and pierce the foam until I find the pan. Poking the wire through the top will give you an idea of how much foam you have to work with but it is a bit difficult to visualize where you are going to cut by only measuring the depth from the top. You should do this anyway so you can approximate if trimming will even be worth it - note that even 1/2" makes a difference. If this is your first shave job, I recommend you mark the pan from the side by taking a piece of stiff, thin wire and poke it through the side of the foam so as to find the top of the seat pan. Try to put the wire straight in at a 90 degree angle being careful not to wiggle it. Once you are sure that you have the wire straight in from the side and at the top of the seat pan-- it should scrape the top of the pan rather than bump into it --take the permanent marker and mark the hole so you know where the top of the pan is for that section. Make additional holes and marks as needed until you have marked the pan about every 4 inches. When you are done you should be able to look at the seat from the side and visualize where the pan is inside the foam.
  • If you trim too much foam off the pan you will undoubtedly split the foam. Suffice to say, this would be a very bad thing. Take your time and check your depth from the top if needed.

Find the top of the pan using the wire

Mark the holes before you pull out the wire
  • If you have a logo on the seat cover and want to retain it, you will need to mark its original location to make sure it will still show once the cover is back on. While it is rare that you will be trimming that far back on the seat-- many riders build a bump in the back to keep from sliding off --in some cases keeping the logo is just not a realistic option. If you want to give it a try, the best way to do this is place the cover back on the foam and roll the side up until you get to the bottom of the logo. Make a mark on the foam indicating this bottom position, then continue to roll the cover until you get to the top of the logo, and mark that position as well. Make additional marks for the beginning and end of the logo. Only mark one side of the seat since the chances of you getting it just right on both sides is slim. Give it a look and decide how far down you can trim and still retain the logo.
  • You can make the line by trying to be precise, or just get it close and work things out in a trial and error fashion. For me, it really comes down to the seat that I am working with. For the newer style (nearly flat) seats, precision is a must as the foam has very little give, which will translate to very noticeable/wavy cut lines if you are not near exact in your measurements. For the older style seats that lip up at the tank, you should have more foam to work with so you can be a bit loser with your marks. Regardless, use the electrical tape to mark where your "cut line" will be. The cut line is above the seat pan meaning if you want to keep 3/4" (just a number, make good decisions) of foam above the pan, you would run the tape 3/4" above the dots. The electrical tape is flexible enough that you can get a good contour line. It may take a few attempts to get it where you want it. Once you are satisfied, run the marker down the "cut" side (bottom) of the tape.

Measure, tape, and mark the cut line

Also mark the logo area if needed

Draw the contour lines on the top of the seat

KTM seat that requires a bit more precision

Cutting and Forming the Foam

Detailed instructions for cutting and shaping the foam

  • Make thin cuts in the foam using a whatever method you choose (sharp knife, electric carving knife, ...). Go slow so as to avoid tearing the foam. Keep taking material as you work towards the cut line, being sure to stop before you are on the line as sanding later will be take things down to the line. Be sure to pay attention to what the foam is doing. Some parts of the foam will already have splits that require you to go really slow. This is especially true if you have used the seat. Others areas will just split regardless of how careful you are. Just keep the damage to a minimum as you will fix any non catastrophic splits after the initial sanding.

Trim by making thin passes

I have not tested a hot wire foam cutter on seat foam - sanding may be difficult if you use that method
  • Lightly mist the top of the foam with spray paint. All you want is enough color to create a "guide coat" that will tell you when things are getting smooth - presence of paint means a low spot. Don't chase every bit of paint. The objective is not to make all the paint go away, it is to get it smooth enough. Use your head (and your hands) and decide if it is smooth enough. Either 120 or 180 should be rough enough especially if you are using a finish sander. Keep some of the sanding dust as filler.

Sand using guide coat

Do a test fit so you can see the new lines

  • You now will want to round the side of the foam so that it has a comfortable feel. Take the masking tape and tape the top of the seat foam a little bit inside from the new foam line. Unlike the electrical tape, masking tape will stick to the foam well enough so that it should not peel back when hit with the sand paper. The amount that you round-off is up to you, but I suggest 3/8-1/2 inch as a start. To make things easier, I like to take a marker and color in the area that I want to curve, with the marker acting as the 'guide coat.' Once you have the curve marked, take the 60 grit sand paper and sand the curve by hand. Follow up with 120-180 grit to smooth things out.

Round the edges

  • While small cracks are normal, Shoe Goop mixed with some of the sanding dust can be used to fill larger cracks that were present before you started cutting, or that developed during the process. Being careful to not make things worse, score the inside of the cracks with 60 grit sandpaper them with Shoe Goop. While the glue is still wet, cover them with the sanding dust and gently push the dust and the crack. You don't need to be perfect here. The intent is to glue the cracks together and keep gaps to a minimum. You can add more glue/dust to the top if it shrinks too much. Once the glue is dry enough, sand it down if needed.

Fill the cracks

Sand down the fill spots

Detailed instructions for reinstalling the seat cover

  • Do not start this step until the glue is completely dry! Refit the cover onto the foam. Starting at the front, then rear, staple the cover. You staples should be about 1/2 inch apart. Some spots are hard to get the gun to rest completely against the pan so the staples may be high, although with some practice you may be able to get them all to seat. If necessary, use a punch and hammer to tap the staples in the remainder of the way, or at least get them to lay flat. Staples that are very bent should be removed and replaced. Once you have the front and rear in place, start about 1/3 of the way back from the front and pull the cover taught against the pan and staple it, followed immediately by pulling and stapling directly across on the other side. Work forward and backward on the seat repeating this pull/staple process. If needed, remove staples and re-position the cover. Be sure that you staple far enough in on the pan so that the staples do not poke out the side of the cover as the foam at the edges of the pan it rather thin. Once you are are happy with the effort, trim the excess cover. If you have bolt tabs on the seat pan, refrain from trimming too much around the tabs else the cover will likely roll up and expose the seat pan.

Staple by starting at the front

Trim the excess without taking too much off

  • Now bolt that sucker on and go ride!
Close Panel