Recumbent Seats

[llile]

What have people done for Recumbent seats? Any aftermarket seats that have worked well for homebuilt frames? I've had more trouble with seats than any other part of a shop-made recumbent frame.

The problem is, there is a certain part of the butt that is made for sitting - right at the sitz-bones. That part of the pelvis is made to take your weight. If you have weight just a little forward of that point, your legs go numb from pressure on some nerve or blood vessel or something. Has anyone else struggled with this problem in recumbent seats? What did you do?

I've attached a detail of my current seat. It has been surprisingly successful, given that it isn't very conventional as recumbents go. It starts with a big cushy standard seat, turned around backwards so the horn is facing rear. The Sitz bones go on the cushy pad that is normally at the back of such a seat. i ground out the shape so my tailbone isn't sitting on anything, but my pelvis is, then covered it with a waterproof cover, that also happens to be an American flag pattern from an old camping chair. You can either think that I am very patriotic, or that I am sitting on the flag in complete disrespect, and that interpretation is up to you, I am going to be mum on the issue of politics.

The back is supported by two tubes, covered with closed cell foam from a gym equipment manufacturer. This is surprisingly comfortable, given that it is very firm. It also supports the back surprisingly well, as it sort of locks around the backbone.

The whole assembly is adjustable front and back, so taller or shorter riders could potentially use the bike. There is a bike downtube repurposed into a rear clamp, and a seat-tube running horizontally at the back of the seat, allowing front-to-back adjustment. At the bottom there is a rail with a 1/4" bolt that allows the seat to slide. Although adjustable, the assembly is quite rigid, allowing lots of force to be applied to the seat in hill climbing. So far I have never used this feature, leaving the seat in one place once I had it adjusted.

I have had zero luck with making mesh seats, and once tried to make a seat with lawn chair webbing, with equally poor results. A bike takes more force than a lawn chair (depending on how many twinkies one has eaten, I suppose) and the webbing swiftly failed. I haven't made much effort to look for an aftermarket seat, although I have had some luck buying 'bent replacement parts and using them on a shop-made frame.

 

[www.recumbents.com]

This is probably your best bet for an e-bike.
http://www.gaerlan.com/bikeparts/parts/seats/seat.html $184

http://www.amazon.com/Sun-EZ-1-Replacement-Seat-Assembly/dp/B0040DRGQY $132!!!

Comfy and strong but not particularly light...

-Warren.

 

[MattyCiii]

Some years ago I wanted to build my own recumbent. I got as far as sourcing/buying a seat. It's a hard shell, fiberglass over foam I think, and it's probably still available (bought it directly from some outfit in FL, paid a little over $100 I think).

It came with about 2" of padding - a prickly, spongy matrix like padding like you'd see in an air filter or the green "scrubber pad" side of a sponge. Supportive, but designed to not absorb sweat. The padding is not pictured.

Side view, showing the curves

Bottom view - those ridges are for structure/rigidity. It has no holes or mounts for fasteners.

Front view. Glossy black does not come out very well in photos.

Another front view. There are velcro strips to attach the padding to.

I never built that 'bent, so I can't say anything about the comfort of that seat. I ended up getting an HP Velotecnik Grasshopper instead - one with a similar hard shell seat

 

[amberwolf]

I built two so far, and both work well. I only really stopped using the first one because it was hot, water would puddle in it if it rained, and I didn't build it well enough so the supports cracked. There's pics of both on my CrazyBIke2 thread, and on the http://electricle.blogspot.com blog of the builds of each.

The first was based on a pair of "L"s cut out of 1/2 or 3/4" plywood (I forget which) that was donated as scrap from someone else's stuff. I spent a little time finding comfy positions to sit in in a regular chair, and added various folded and wadded up clothing and sheets and towels to fill in spots between me and a chair to get the basic shape I'd need to fit me, which ended up essentially the same as that S-curve you see on most good 'bent seats. Then I traced and cut that shape out on the Ls, and then set them up one per each sit-bone and carefully sat in them on the ground, trying not to fall over :lol: and figuring out where it pressed too much and where not enough, and sanded/cut until they fit more or less "perfect" to me. At least, as close as I had patience for.

Then I took a partial sheet of 1/4" plywood, cut to about the width and length needed to make the seat, and soaked it for days in the bathtub, so it would be more pliable and not just snap at the base of the main curve. When I ran out of patience (too early) I laid it on the two Ls and began screwing it into them from one end, with a screw every inch or inch-and-a-half. The Ls were only a hands-width apart, so that they would just clear a tire on the back, and coudl be bolted to the frame and a seatpost as needed. Unfortunately while screwing the sheet down, it did crack a little along the main bend, but it didn't snap all the way across, and was still usable even when I stopped using that seat.

The original intent was to gather some closed-cell foam of uniform thickness, and then seal that to the seat with a naugahyde-type cover I had from something else, stapling the cover to the back of the seat tightly. Never got enough foam, so I used seat-pillows instead. Worked well enough, and still fit me comfortably. But the lack of drainage or air ventilation in this type of cover meant it was hot and sticky in the summer here, and unbearably so when left in direct sun (it had to be shaded or misted with water to be able to sit on it, or risk a burn on any exposed skin!). Water would pool in it when rained on, or ridden in the rain, so it was like riding in a puddle.


So I turned to a mesh seat instead, with the frame made from the pieces of the one planned for the abandoned ReCycle lowracer 'bent project (which itself was made from an old bedside toilet seat frame, which is very strong and pretty light), using some green plastic (nylon?) mesh in a folded-double layer off of an awning project that had been destroyed by my youngest sister. I didn't have reinforcing rings for the holes, so I just melted them with a soldering iron so they wouldn't fray, and then laced the mesh taut on the frame using old paracord I got in a box of Freecycled stuff. I am still using this seat today, with the only modifications of bending the frame a bit on the back to more comfortably fit me, and a bleacher-back chair top added to the top of it for a headrest, and a folded blanket against the back-center to better support my mid-back (even though this is hotter), because the frame doesn't have any mesh there, and it isn't bent in teh right shape yet.

I'm 150lbs, and I have infrequently also ridden with 40-80lbs of dog food on the seat with me, and haven't destroyed the mesh yet. :lol: I do have to occasionally retension the paracord, as either it or the mesh stretches over time (dunno which).


If you can bend tubing to the S-curve common in 'bent seats, you can easily make your own mesh seat that will work great. If you don't have or can't find mesh that will work well, you can use denim instead, either new or from old jeans, as it is very tough stuff, and should hold up at least as well as my mesh, probably better.

 

[recumbent]

You can purchase just the parts or material to make your own seat at: www.hostelshoppe.com

I upgraded my old seat and just bought the cover that wore out. Check other stores to compare, not cheap, but reasonable, and good quality.

The standard recumbent seat i have is soo comfy that after two hours of riding still leaves no sore spots. My seat has holes drilled in the area of seat where the boney part of your arse goes, yet is only made of high density foam.

I've also heard that air cushions work well, which are available at the Hostelshoppe.

 

[ebonr]

Hi .. I'm new to the manufacture of my recumbent bike, and reading in the forum I found the article to you, and it turns out I've had the same problems with seats, rigid, the mesh, etc. .. so I think your seat is the perfect solution. I would greatly appreciate if you could send me some kind of drawing or print details of the measures and type of material you used, also, if possible, photos with detail Clamping. it may be one of the best choices for warm climates, as in my case, instead of mesh ... thank you, thank you very much .. I hope you help me on this possible.

Sincerely Eduardo Bon .. If you prefer can sent to my e-mail... ebonramirez@gmail.com