GS-Riders International

For this project I had several sheets of orthopaedic temper-foam of the grades medium-firm, medium and medium-soft ordered from Dynamic Systems . Shipping to Singapore, payment, and everything was flawlessly handled. For the following passenger seat modification I used the medium grade. For more info about the foam material see also the story about my seat mod for my V-Strom DL1000, clicky.

The original foam block for the passenger seat:



The seat pan, a good one in my eyes:



Marked the area I planned to cut off:



A good quality bread knife will do the job, an electric kitchen knife is more
comfortable, but not necessarily easier to use:



After the cutting:



My secret tool to smoothen the surface, and for detailing the shapes:



Works like a charm:



This is what is going to be on there, the Sunmate foam:



Placed the seat upside down onto the temper-foam pad, and marked the outline:



The pad ready cut to size using simple scissors:



A piece from the cut off foam makes for a nice rear elevation, to provide better
passenger comfort:



Before the "secret tool" treatment (to be honest I don't know the English term for this piece):



And after:



Fits!

Now back to the temperfoam. I glued it with a spray glue to the foam block,
and allowed it to set for about 15 minutes:



Ready for a test fit, I realized the BMW cover being made from an excellent,
very stretchable material ..



which is actually done very well! It kind of keeps in shape by itself:



It has a rubber band sewn around. I like that. One of the many things where I
can spot the differences to Japanese bikes. It's a small difference, but a great help for me.
This feature also eases the job fitting the cover back tremendously! For the first check
I just slipped it on and mounted the seat to the GS:



The test with the cover was successful. Proceeded detailing the shape of the new foam layer.
With the help of my secret tool, and a sanding block of grade 30 it is an easy job:







The tacker in the background is a Rapid R33 , which is more than up to the job:








Finished! About 3 h work with unprofessional tools. Curious 'bout what my wife will say about it.

Here the end product. What do we see?




Almost nothing

Now to the rider seat. This is more complex shape.

First a look under the seat pan. Compared, the underside of my previous (Japanese) motorcycle looked like a mess. Of course it still did it's job perfectly well. But it looks good, and it make me feel good to own something which is crafted nicely.



Wish I could buy stainless steel staples here in Singapore. The naked seat:





I did not find the bad foam quality which others are complaining about. And the molding also is done very well. Of course there is nothing man-made in the world that can not be improved on. To my subjective opinion what hampers this seat are actually three relative dumb design flaws:

1. The seat surface is not level


2. The rear end has a design flaw
This may be the most serious issue for tall riders. More to it later.


3. The foam is likely too soft for heavy people
This is not a problem for me, as I am only 80 kg / 170 lbs. Dealers do have a story to tell about test-seating customers and their comments, if the seat comes to firm form the factory. But now to my upgrades.


Some guiding lines to help me cutting straight



I start carving out the rear end



then I do a straight (level) cut through the foam towards the front.



I smooth the cut surface with my magic tool. No need to be too accurate here; smaller holes and dents will be easily covered up by the later foam layers.



A layer of medium-firm sunmate builds the bottom:



Now that I know how high the foam will be standing up, I cut the front part more level as well, and then curve out the joining surfaces at the rear:



This is sufficiently accurate:



Next please! Next is a layer of medium-soft sunmate



which builds the cushioning. After a bit rough trimming



... I thought it's better do a test-ride first, before fixing anything.



Nice ... or whaaat?



to be continued ...

1. The seat surface is not level
2. The rear end has a design flaw
3. The foam is likely too soft for heavier people


The naked rider seat with a guide line symbolising a level seat surface



The slanted seat surface causes pressure points at the wrong places, mostly from the rear side onto the butt bones, not from beneath where our butt bones are used to carry the weight. This is probably a known issue to many of us. When I cut the foam material to create a level seat surface, this came to daylight:



The seat's pan is curved up, and the amount of cushion material around there is not much



which for taller guys may lead to additional pressure on the extended backbone.

The cushioning material itself is no different from any other material used for modern motorcycle seats.

I myself had no probs with the rider seat (except the slanting). With my 1.75 m and 80 kg my butt did not touch the 'thin' zone. Depending on the individual seating position (adjustment of the handle bars, arm- and leg lengths, etc.), this could as well be a problem for shorter guys however.

continued: Rider Seat Modification

This is where we left the seat project for a day of test riding:



with this under the temporary fixed seat cover:



The test went successful, I continued with the detailing job. The line visible across the seat is
from a cutting mistake I did. I was trying to correct an untidy cut, but that went wrong. Therefore
I cut a strip away from the rear. I prepared a matching strip and glued it into the gap.





Thank to my magic tool from the kitchen drawer, this is a breeze:



I dished out the center portion, so that the sides are a bit elevated and provide side support.
I took material off until the seating area was almost level when the seat is mounted onto the bike.
Since I am not intending to glue the cover on, the dish will not be visible later.





When doing other seat projects I spent too much effort into finishing the surface perfectly smooth. This is not necessary, if a layer of sponge material is used as the final layer. The sponge layer balances out for smaller corners and gaps. Now I have more experience, and know when I can leave it. I used glue from an aerosol can on both seat and sponge.



Under the flashlight appearing remaining uneven spots are only visible, because I did not have glue everywhere applied evenly. I knew as well this does not matter. The stretch of the seat's cover will later take care of that.



Cover stapled on:



... to be continued

Here is what the end result looks like:



Rider seat in up position:



Low position:



And no more unsightly gap (from adjusting the front rail high and the rear rail low):




To the materials used:

Passenger seat: Medium grade resultet in a seat which is slightly firmer than the factory one. I choose one grade higher than I should according to the weight of my wife. I decreased the passenger seat height, therefore I felt I need a firmer foam, avoiding her bottoming onto the seat pan. On the first day she said she feels it's not much different to the factory seat. Or more precise she felt a difference, but she could not say which is better. Phuuu ... relieve ... at least she does not say it's bad! On the second day she commented it is good, and also she like that she sits a little lower.

Rider seat: First layer is medium-firm grade to avoid bottoming onto the seat pan. The upper layer is medium-soft grade for comfort. This resulted in a seat which is quite soft. It is clearly softer than the factory seat, but not the disturbing loose and wobbly feeling as what ordinary soft foam provides. Very hard to explain ... it is a sort of firm-softness, due to the characteristics of the Sunmate foam, and also the stabilizing effect of the first layer.

- 3 sheets Sunmate foam = ea U$ 18.50 = US$ 55.50 / Euro 38.50
Source: Dynamic Systems

- Contact cement (1 tube)
- Aerosol adhesive (1 can)
- Staples
- White spounge 3 mm
all ~ US$ 16 / Euro 11