I'm building an Aurora type seat for my trike, and I've seen the blue foam material that is used in the Aurora plans, but I can't remember where I have seen it before. Has anyone found anything that works well for seat bases as opposed to seat backs? and where did you find it?
sources for seat padding material?
- Thread starter Tillerman6
- Start date
Popshot- That's a great idea! I posted that inquiry because I ran out of the white closed cell foam I pirated from an old weight bench. That foam is about 1 inch thick too, but since my seat frame is almost vertical, it puts most of my body weight on my skinny buns. After about 20 minutes of riding, the backside starts to ache. I'm either going to have to cut the frame and re-weld it or find a much softer seat to sit on than the 1 inch foam over plywood.
I noticed most of your tadpole trikes are fairly reclined. Did you ever have that same problem with the buns aching after 20 minutes? is that why you designed your seats in a mostly laid back angle?
I noticed most of your tadpole trikes are fairly reclined. Did you ever have that same problem with the buns aching after 20 minutes? is that why you designed your seats in a mostly laid back angle?
Recumbent butt look it up on BROL ?
it is not the type of foam you are using , if your seat is almost vertical all your weight is on those muscles.
Aim for a seat back around 50' +- 5'
I think mine run about 45' more upright than most ?
Mine is on the left.
paul
Paul- I will HAVE to re-cut my steel seat tubing to get the angle back to 50 degrees. It may take some major surgery to pull this off, but I don't think there is any choice. This is all my own design and unfortunately the seat tubing ( 7/8" chromemoly) is supporting the trike fram on top of two shocks. if I cut it, th rpair will hav to b quit strong. The bottom of th shocks rid on th swing arm. I think my seat angle right now is 79 so a lot of chang is rquird. Sorry for th kyboard.Recumbent butt look it up on BROL ?
it is not the type of foam you are using , if your seat is almost vertical all your weight is on those muscles.
Aim for a seat back around 50' +- 5'
I think mine run about 45' more upright than most ?
Mine is on the left.
paul
Right now the seat frame is made like a lawn chair where the material is stretched tight across it ( or at least it was until this week) I was having trouble keeping the chain from rubbing the bottom of the seat if it was just stretched material I was sitting on, but when I laced in a plywood panel and added foam to that it raised the underside just enough to avoid the chain. So of course I did the same for the seat back and now my body does not rub on the tubing anywhere.
Paul- That seat you have there looks awesome! did you make it or buy it? I'm having the most fun trying to improve my seat overall. My delta trike has a tubing frame like a lawn chair and originally had a tight fabric stretched across that, but with no padding on the tubing itself and the upright angle of the seat back, it was a torture test for the backside. Now I have reclined the seat back to 60 degrees and raised the front of the seat base about an inch front to back. I also fabricated two plywood sheets to lace into the framework and added some closed cell foam over these to give the plywood some cushion. So far this has not added much weight, but the lacing is all around the edges and it takes some time to install/uninstall it for the modification /prototyping process. I have to admire the AZ seat arrangements on the Aurora and some of the other recumbents for it's simplicity and possibly a very comfy ride although I have not read that this is the case with any DIYers.Recumbent butt look it up on BROL ?
it is not the type of foam you are using , if your seat is almost vertical all your weight is on those muscles.
Aim for a seat back around 50' +- 5'
I think mine run about 45' more upright than most ?
Mine is on the left.
paul
This recline mod has helped the ride in two ways- it reduced the pain and also reduced the vibration I was experiencing with the more upright seating position. I'm not sure how this happened- possibly from slightly more loading on the rear shocks and maybe some springiness in the seat frame. My street is unfortunately made from "chipseal" which is a fairly rough form of pavement as compared with regular black top which has had a steam roller smooth it down as part of the road building process. I guess the next step is to reduce the tire pressure a bit and see how that affects the ride. Hopefully it will not increase the pedaling effort too much.
My seat is a bought one , just a plastic molded job like a refuse bin.
Whilst the AZ seats are easy to make they can lack lateral support needed on trikes [ as most don't lean around corners ] and they can be very sweaty as the temperature rises.
My seat has a Ventisit seat pad, sort of 3D plastic mesh that allows air to circulate underneath me , the material is made to go under mattresses in campers and boats to stop damp causing mildew etc
Ventisit
Paul
Whilst the AZ seats are easy to make they can lack lateral support needed on trikes [ as most don't lean around corners ] and they can be very sweaty as the temperature rises.
My seat has a Ventisit seat pad, sort of 3D plastic mesh that allows air to circulate underneath me , the material is made to go under mattresses in campers and boats to stop damp causing mildew etc
Ventisit
Paul
On Amazon look under furniture, its used under couch cushions to support older sagging foam.
SagsAway Regular 1.5in Thick Cushion Insert and .5in Posture Zone for Support of 1 Saggy Seat. Military Grade Foam to Add Thickness and Delay Replacing Sofa, Measure for Size to Fit Inside Cover https://a.co/d/1wMjjVM
SagsAway Regular 1.5in Thick Cushion Insert and .5in Posture Zone for Support of 1 Saggy Seat. Military Grade Foam to Add Thickness and Delay Replacing Sofa, Measure for Size to Fit Inside Cover https://a.co/d/1wMjjVM
Paul,
Thanks for the reply! The more information I can get, the better the results usually are. The seat has been a challenge from day one. The Ventisit seems nice, but I'm not sure how to approach the problems I'm having. One problem is that the back of my legs rubs the front edge of the seat base. It's mostly downward pressure and not rubbing side to side, and I'm experimenting with the cushion thickness , shape and composition to try and remedy that problem. Right now I have a 1 inch piece of closed cell packing material on the plywood base and there is a 3/4" thick piece of foam rubber on top of that then there is the seat cover which is breathable mesh. The overall angle is almost flat , but with a very slight nose high position overall.
I think tomorrow I will try and round down the front edge nearest the pedals and see if that helps at all. I do not have any medical issues with my legs or circulation, but on an hour's ride I have to stop and stand up for a few minutes to get the buns to stop aching. I do not normally ride fast or hard, so my effort level should not be a contributing factor as far as I know.
I do still love to go riding, but I hope I'm not doing permanent damage to my back side by not stopping more often to recooperate. Sometimes at night it feels like my back side is too tight- and those muscles are tensed up, but I think it's just lack of circulation.
Changing the bike seat angle was a big chore, but it did help delay the onset of the aching probably about 50%. right now the angle is at 56 degrees relative to the backbone of the frame which is almost parallel with the ground. I may have to go ahead and lower it some more, but you would not think that just 6 more degrees would make much difference in the comfort level? I could be wrong.
I'm shooting for a bike that you could ride all day without having to stop and rub out the ache. I don't know if that's possible, but that's my goal.
I'm 6ft tall and 155 pounds so nothing with a weight problem. however being 73 is probably not in my favor.
On your seat- does any part of the back of your leg touch the seat? It might be that my pedals are too low ( I built this delta trike from scratch without a computer assist- my main concern at the time was to have the chain not need any guide rollers to change the angle. - And for the years I've had this trike, that goal has been achieved. However, if I was to raise the bottom bracket even 10mm, it would probably cause the chain to rub on the underside of the front of the seat tubing- depending on what gear pair I was using at the time. So that would ruin my peace of mind really fast.
i think it is possible that the ergonomics are still a problem and I will need to end up with a guide roller like everyone else's design to keep the chain off the seat tubing while still having a full leg extension without hitting the back of my legs on the top of the seat tubing on the down stroke. Actually the leg femur is dropping too close to the seat frame in the front and the muscles there are having to deform to finish the rotation at the bottom of each stroke.
There are other factors with the mechanics of this trike frame too like the height of the derailer off the ground and the seat to chain clearance, so any changes I make now will have to be done very carefully if I am to not make things worse. Main concern is chain noise and I absolutely will not tolerate any of that.
Well without pictures it is very hard to comment and make the comments relative to your problem ?
maybe your seat base is to long ?
maybe you don't have your pedals higher than your seat ? [ a must in my world ]
and yes I can ride mine all day [ 60 - 70 miles easy ] all I get is warm knees !
It is far easier to build a delta trike with no pulleys , I would say almost impossible to build a tadpole like that unless it is FWD
Paul
maybe your seat base is to long ?
maybe you don't have your pedals higher than your seat ? [ a must in my world ]
and yes I can ride mine all day [ 60 - 70 miles easy ] all I get is warm knees !
It is far easier to build a delta trike with no pulleys , I would say almost impossible to build a tadpole like that unless it is FWD
Paul
Popshot
0
Chain noise is almost a given on a tadpole unless you make substantial compromises in the entirety of the design. You could always purchase a purpose made seat. I use these. There are many others.
OK- if the pedals are higher than the seat? That could be the problem. Even if the seat base is too long front to back - by raising the pedals it would stop the leg problem, but it would also raise the chain line and there just isn't any room for that unless I move the jack shaft forwards and down. Can you elaborate on which part of the pedals should be higher than the seat? I am assuming that you DO NOT run an idler pulley? Let me take some pics and post them so you can see the situation- it might be very different from what you would expect.
OK- if the pedals are higher than the seat? That could be the problem. Even if the seat base is too long front to back - by raising the bottom bracket, but the chain will also raise with it. Here are a couple of links to photos:
here's a better shot of the seat frame: I think I could shorten it a couple of inches front to back without affecting anything else. your comments are much appreciated!
Thanks Stormbird! Hope that was not too much trouble! My experiment today was to install a seat base with more stiffness (stays rigid) when suspended in the frame - so it does not sag at the aft end. This was causing part of my problem- The plywood was two layers and not glued between the layers- so it was slightly flexible which caused a bow in the middle which I could not see. So yesterday I glued the two layers together with epoxy and also added a crosswise stringer to add even more rigidity to the aft edge of the seat base- Result was that my legs do not touch the front of the seat frame at all! But this also moved me to the rear about 1/2 or 1 inch which reminded me that sitting higher also moves your body back because of the 58 degree sweep back seat angle. At first try I was sitting on 2 layers of closed cell packing material and I could not really reach the pedals! It was like "What did I do?" So half way down the driveway I jettisoned one layer- Then I could reach the pedals with just a little stretch. But I have another seat back that sits proud of the seat frame towards the front. This now has a stiffener glued to it which should keep it from cracking in half (I hope) and a 1 inch piece of foam which covers the entire front surface of the plywood backer.
I'm not sure how much foam it will need to make everything fit perfect, but I'm now pretty sure that I won't have to cut the seat frame shorter to keep my legs from hitting it. That seat base sag must have been almost an inch inside the frame which made it like sitting in a bucket.
So this afternoon I will try the "new and improved" seat back which will move me closer to the pedals- hopefully not too close!
I'm not sure how much foam it will need to make everything fit perfect, but I'm now pretty sure that I won't have to cut the seat frame shorter to keep my legs from hitting it. That seat base sag must have been almost an inch inside the frame which made it like sitting in a bucket.
So this afternoon I will try the "new and improved" seat back which will move me closer to the pedals- hopefully not too close!
