View Full Version : Optima seats mounting

08-27-2010, 05:00 AM
I just bought the M polyester seat for my trike project from recumbentparts.com, made by Optima. I presumed that this seat has some metal mounting brackets incorporated in the shell, but I was wrong.
Now I'm looking for some details in order to make an idea about how I'm gonna mount it on my frame. Do I have to make holes in it? Are there some special mounting devices (brackets ore something) for this purpose? I don't know.
Could anyone help me with some pictures or info?

John Lewis
08-27-2010, 08:56 AM
Raol, Can you post some pictures, especially of the area of the seat where the mount will need to be.

I'm not familiar with the seat but once we see it some ideas will surely come to mind.

John Lewis

Odd Man Out
08-27-2010, 09:43 AM
I just bought the M polyester seat for my trike project from recumbentparts.com.
Do I have to make holes in it?
Are there some special mounting devices (brackets ore something) for this purpose?

Yes and Yes.
Recumbentparts.com sells the brackets you need (if you are mounting to an Optima frame that is -- otherwise the photos of the parts will help you to Zombify what you need. Here's the link:

Drill baby drill...

08-27-2010, 05:29 PM
Wow, guys, you are moving fast! Thanks for the quick replies.
First of all, Odd Man Out - I'm already familiar with the Optima products, and of course I know a bit about the Optima seat brackets. But not having dimensions or other details, I can only suppose how are they used for the shell mounting.
I reckon they are fixed upon the frame using the bigger hole with a screw, and the two arms are used for fixing on the seat's stiffening ribs that needs to be drilled in order to use a bolt/nut assembly. But I don't know if I'm right, are those ribs strong enough to sustain my hundred kilos only on the lower two bolts and other two at the upper shell's side? And yes, we are talking about the Optima seat indeed.
John Lewis - my project is in the development phase, I have some ideas about how my delta trike is gonna look. I begun the project in Autocad, it's safer building it virtually in 3D first, I can measure the distances, the angles (the Paterek manual's helping me a lot). So the images I have right now are coming from the drawing board, even though I already prepared the square tubes for welding/brazing, I have the crank set, braking disk, different sizes of wheels and three "sacrifice lambs".
But it's going to be a new project, different from the AZ models I saw till now.
First of all, what I plan is to use for steering wheel maneuvering a... steering wheel! Not the usually used handlebars. This will give the possibility of steering the front wheel more than 90 degrees, and will be adjustable for different arm lengths and user heights.
The other thing I plan to do is to give the user the choice of mounting different wheel diameters. That means the head tube will be adjustable, in order to maintain the trail in the comfort range. And all that the user will have to do is to change the front fork and the wheels, make the quick angle adjustments and... go, Silver! That means I won't go with the classic AZ type of custom made hubs and wheels, I have to give the possibility of picking them right from the shelf.
The pictures I'll try to provide are revealing only the basic shape of the frame, I didn't have the time to carry all the wheel types in Autocad in order to begin calculating the angles, design the adjustment devices and give the finishing touches to the frame's shape.

08-27-2010, 05:47 PM
Here's the seat, and here's the intermediary shape of my delta.
I used in the sketches a fork without rake, but after measuring the angles it results that for the 26'' wheel I'll need a fork with 35-40 mm rake.

09-01-2010, 12:54 AM
Just to have a better idea of the seat's shape and it's relative position.

09-11-2010, 10:11 PM
Hey, Odd Man Out.
I guess you know more about about the polyester rigid seats than I do.
Could you tell me, do I have to make holes through the shell's surface, or the stiffening ribs are the ones that need to be drilled in order to mount it upon the frame, using those brackets you told me about?
In fact, if you will have an advice for me, I know it could be the same "Yes, and Yes", but I'm not so sure, and I don't want to ruin the seat I was so happy to receive a while ago - you can see it in the picture below.
Thanks, raoul

Odd Man Out
09-12-2010, 01:53 PM
Here is a link to a picture (second one down) of a seat that is mounted. You can see the four silver rounded bolt heads;

http://www.novosport.de/en/?Products:Seats_%26amp%3B_seat_mats_%2F_cushions:S eats_for_%22lwb%22recs%2C_tricycles_and_quads

Yup, you do need to drill through. The key is to find out what type of plastic you have and adjust the drill speed to suit it. Too slow can crack it and too fast can melt it. Also, before you drill, take a very sharp knife and mark the drill points by pressing down and twisting on the point.

I know your fear about having to potentially destroy such an expensive piece. Just line up the mounting brackets and mark from the bottom. Start drilling with a smaller bit then progressively drill up to the size you need which should be almost exactly the size of the bolt itself. Good luck, you will do fine. I look forward to seeing your final creation.