Seat Mod

[mzweili]

where to buy??

http://ademhr.com/index.html

 

[snilard]

My Thor seat has arrived. I am thinking how to mount it in way that maximalize vibration and shock absorption. I would like to avoid direct connection between frame and seat by screw.
Under back I can use rubber antivibration bobbins. There is enought space to fit properly large ones to avoid to much rocking. I will test ones with 20 mm - 30 mm in diameter and if it is not enought I can put 2 pairs there.
On front side of seat it is much harder task. Antivibration bobbins cannot be used there, Wings are not designed to hold weight of rider and there is not enought space to fit properly sized bobbins to avoid rocking. Of course I can do it as everyone else with plate of ruuber and long screws but I see this as last solution. I will try this: I will use small bobbins (15 x 15 mm) and cut rubber plate to fill space between frame end seat. 15 mm of height will be probubly to less so I will put rubber also between bobbin and seat. I hope that this will work.
I will be ordering rubber and bobbins tommorow and installing it next week.

 

[snilard]

I have one mechanical question.
I am thinking about mounting seat by antivibration bobbins but not at the very end of frame but about 15 cm to front where is space between big holes. My idea is that in this place surfaces of frame and seat are nearly parallel compared to the very end where seat is going up. Also on my Thor seat there is marked mounting place and it goes here. I see one big advantage of the very end, pressure from seat is hold not only by surface end edges but also by perpendicular end of frame. I can place some aluminium plate between frame and bobbins to spread pressure to larger area.
So my question is If it is safe to place mount point of seat 15 cm from the end of frame.

 

[Rick Youngblood]

That should be okay, I've mounted various seats at various locations for the rear mount.

 

[RojoRacing]

The shape of the seat isn't going to match the shape of the frame at all really. Your likely only going to have surface contact at your two mounting points and maybe the middle somewhere depending on how low you mount it so here's a suggestion. After you get the seat mounted un-mount it and make a note of where the frame material is solid, so in between the hole cutouts. Now mark 3-4 points on the new seat where you could add a rubber support piece between the seat and frame without it falling over one of those big holes. Now remount the seat and using a small 1/8" drill bit drill one hole at each point you wish to add support. Now with the holes drilled take a small rod or the 1/8" drill bit and drop it into the hole and get a measurement between the seat and frame. Make notes of each measurement on the seat then cut the appropriate thickness of rubber for each spot and glue it to the frame. Now you have support at 5-6 points along the full length of the frame. I think I have 4 added support points using this method and they measure 4, 6, 17 & 19mm thick.

 

[snilard]

The shape of the seat isn't going to match the shape of the frame at all really. Your likely only going to have surface contact at your two mounting points and maybe the middle somewhere depending on how low you mount it so here's a suggestion. After you get the seat mounted un-mount it and make a note of where the frame material is solid, so in between the hole cutouts. Now mark 3-4 points on the new seat where you could add a rubber support piece between the seat and frame without it falling over one of those big holes. Now remount the seat and using a small 1/8" drill bit drill one hole at each point you wish to add support. Now with the holes drilled take a small rod or the 1/8" drill bit and drop it into the hole and get a measurement between the seat and frame. Make notes of each measurement on the seat then cut the appropriate thickness of rubber for each spot and glue it to the frame. Now you have support at 5-6 points along the full length of the frame. I think I have 4 added support points using this method and they measure 4, 6, 17 & 19mm thick.

Is all this aditional support rubber needed? I would like to support seat only at 2 places.
Because I would like to use antivibration bobbins I need connected surfaces to be as parallel as possible to avoid unecessary tension in rubber. And this happens ~15 - 20 cm from end of frame.

 

[RojoRacing]

Needed? Probably not since I doubt many others have gone to the trouble. If your trying to build a soft luxury car that is going to have some body roll then two soft points of attachment should be fine. My setup is a nice solid anti vibration race car with zero body roll to help with sharp cornering.

 

[Rick Youngblood]

Is all this aditional support rubber needed? I would like to support seat only at 2 places.
Because I would like to use antivibration bobbins I need connected surfaces to be as parallel as possible to avoid unecessary tension in rubber. And this happens ~15 - 20 cm from end of frame.

The hard shell seat is designed with the two outer rib supports and only require two mounts fore and aft. However, you can have as many as you want. The intention of the seat is to suspend the mid area between the two supports which gives a little suspension. As Jason mentioned, the seats do not follow the exact contours of the frame.

 

[snilard]

Needed? Probably not since I doubt many others have gone to the trouble. If your trying to build a soft luxury car that is going to have some body roll then two soft points of attachment should be fine. My setup is a nice solid anti vibration race car with zero body roll to help with sharp cornering.

That make sense. You have probubly much better roads. My power is meybe one third lower than yours, I am lighter and also I don't win century races. So what is luxury car suspension for you may be sport car suspension for me.
Rubber is orderd so I will test it soon.

@Rick Youngblood , @RojoRacing , thank you for support.

 

[ratz]

I'm excited to see how this turns out.

 

[LMT]

I'll be excited to see this seat get some good use. Glad your seat mod is coming along @snilard

 

[snilard]

I have fitted my new seat. No photos yet. First ride shown that seat mount is flexing as I pedal so some support under lower back will be needed. So @RojoRacing thanks for advice. Without it I would not put my hand between seat and frame and sense ~3 mm movement.

 

[Rick Youngblood]

I have fitted my new seat. No photos yet. First ride shown that seat mount is flexing as I pedal so some support under lower back will be needed. So @RojoRacing thanks for advice. Without it I would not put my hand between seat and frame and sense ~3 mm movement.

A little vertical flex is okay and should only come into play when you hit bumps or uneven surfaces. This is part of the intentions of the seat.

However, it can be eliminated with a 3" x 1" x whatever height peice of rubber block mounted to the back of the seat with double sided tape, to eliminate drilling seat and frame.

Good luck, looking forwarded to pictures.

 

[snilard]

A little vertical flex is okay and should only come into play when you hit bumps or uneven surfaces. This is part of the intentions of the seat.

Flex is from pedaling and it is horizontal. I can feel that V in this configuration is not as responsive as it was with seat directly supported by frame. So I will add hard rubber support under lower back.

 

[snilard]

I have tested my new seat and this is my support setup: ~9 mm under front part of seat, 5 mm under lower back, 20 mm under upper back.
I like better view and upper part shape but I am experiencing same problem as on my other recumbent: RECUMBENT BUTT
With original seat this was not a problem. I hope that lowering seat angle will help. Only other difference from original seat is that original is flat but Thor has bowl on seating section.
Next experiment with new seat will follow after 2 weeks in China.

 

[RojoRacing]

I don't know what recumbent butt is so do you mind clarifying? The only issue I experienced and only once was some serious chaffing of my hamstrings from the very front of the seats edge. What happened was the ventist pad was too long and having just that extra 1" of pad sticking past the seat edge was enough to interfere with my legs. I didn't notice the issues until many hours into my ride but by that time the damage was done. I adjusted the pad back an inch and the problem has never come back.

 

[snilard]

I don't know what recumbent butt is so do you mind clarifying? The only issue I experienced and only once was some serious chaffing of my hamstrings from the very front of the seats edge. What happened was the ventist pad was too long and having just that extra 1" of pad sticking past the seat edge was enough to interfere with my legs. I didn't notice the issues until many hours into my ride but by that time the damage was done. I adjusted the pad back an inch and the problem has never come back.

I am experiencing ride soreness and post ride stiffness of upper part of my glueus muscles group.
Vendetta seat was like miracle after riding years with sore butt.
I will lower upper support to 10 mm and if necessary to 5 mm.

 

[RojoRacing]

Weird because that's basically what I experienced with the stock seat and the Thor fixed it completely. Sucks your having this issue in the opposite order as us because it makes it hard for us to relate. Maybe look into the other parts of your bike related to fit like boom length and such. You sound like you have enough experience to sort it out but maybe you issue could be fixed by changing something else to match the new seat instead of changing the seat to match the bike.

How much rubber padding do you have under the very front mounting point? I've only got around 5mm up front so the seat is about as low as it'll go up front then just touches the frame in the middle with the 20mm I have at the rear mounting point. I started by mounting the front as low as possible then added just enough pad to the rear so somewhere in the middle it was just touching. Then I added the other middle pads on the other areas with large air gaps for extra support.

 

[Rick Youngblood]

I am experiencing ride soreness and post ride stiffness of upper part of my glueus muscles group.
Vendetta seat was like miracle after riding years with sore butt.
I will lower upper support to 10 mm and if necessary to 5 mm.

Can you take a picture of you on the seat with with your leg fully extended? As we discussed in other threads, you don't want contact with your upper thigh and the seat when fully extended. Even the pad bouncing against that area will cause the glutes to burn after awhile.

I don't get recumbutt on the Silvio or Vendetta, but have on more upright recumbents like the Tour Easy.

+1 on Jason's post, you may need to look at adjusting the bike, boom, etc.

 

[snilard]

Can you take a picture of you on the seat with with your leg fully extended? As we discussed in other threads, you don't want contact with your upper thigh and the seat when fully extended. Even the pad bouncing against that area will cause the glutes to burn after awhile.

Not now. But I know soreness from contact of tights with seat edge and this is different. I have mounted seat as back as possible. Screws are ~6 cm from seat edge.