Mesh Seat & Bell Flag

I did another 12-miler.  That original design seat just isn't comfortable enough for me to ride long mileage on it.  So I decided to pull a mesh seat off another one of my recumbent bikes.

Here it is with mesh seat and Bell flag ...

A closer view of the seat.  Need to make a newer mesh cover for it.  I need to make those EMT bars that are wider horizontally and then come up vertically instead of at a slant.  That's so I can get a little tighter turning radius.

I welded some tabs on and bolted the seat to them where the rear fork meets the main frame.

Here's the bracket I made to attach the bottom of the seat to the frame main tube.

Chain Drive 1

Okay, so I mounted a chain on the frame with idlers.  Only one gear on the front (the smallest one).  Only gear on the back (also the smallest one).  Took some photos.  Then rolled it out to the flat road out front, then took off riding down the street, turned right into the driveway, and rode down behind the shop.  It moves out pretty good.  I won't really know how well it will actually perform, until I get shifters, shifter cables, brake levers,  and brake cables on it.

In order to clear the tie-rod under the frame, I had to make this adapter.

This didn't turn out very focused ... bottom view of the trike.  I have a 3" idler roller (v-belt pulley) on the rear.  And a 2-5/8" idler roller (v-belt pulley) on the front. 

A view of the steering (trike upside down).  Front chain idler (2-5/8").  Brakes mounted.

Steering turned all the way to the right.  I can achieve these steering angles while riding (without the wheel hitting my leg).

Steering turned all the way to the left.

A view from the front (trike right-side up).  Clip on pedals are a must! (Crank Brothers Candy 2)

Here it is just before I took off riding.  Next addition is the return chain tube, some means to keep the drive chain from popping out of the idler rollers (it kept coming out of the front one), and brake levers & cables.

Seat Support Rods

I bought these at the big-box store ...

Try Lowes, Home Depot, TSC ...

They are aluminum -- 1/2" tubing & 3/8" rod.

used for the upper seat support.

The rod slides into the tube ... buy 2 tubes and 1 rod.

You will have to adjust these for length ...

One end of each tube is mashed down (use hammer & vise) to become a flat surface thru which you drill the hole for the bolt to attach it to the dropout. Use an 8-10" length of rod for each side ... mash down one end of each rod (use a BIG hammer and many hits ... ) The rods are attached to the upper seat support bar bracket (those things you welded on the bracket that poke down ...)

see brackets in the previous post below ...

Up near the top of each tube, drill a single hole. Mark your rod with 1" lines (use Sharpie permanent marker) ... slide rod into tube until line is visible thru hole and drill a hole through the rod

(large enough to accept a small/medium "hitch pin")

It helps if the rod is attached to the bracket & seat when you do this ... so it doesn't rotate on you ... (same same with the tubing - attached to dropout).

This part isn't explained really well in some instructions.

Anyway, it makes it adjustable for a more comfortable ride (no you don't want the seat to be vertical) ... you do want the seat leaning back somewhat ...

Seat Brackets

Some people have had questions

about attaching their seat to their main tube.
Here are some ideas ...

Turn your head 90 degrees to the right if you have a hard time visualizing this ...

This is a bottom seat bracket to go on a round main tube.

The section to the right was made from 2 pieces of 3/4" EMT tubing ... or just one piece cut in half. The wall thickness is too thin otherwise.

I adjusted one piece to fit snuggly to the other ... then adjusted the whole thing to fit around the seat tube.

Tack welded the 2 EMT pieces together.

"Adjust" = use hammer to tap it around another tube or rod used as a mandrel to spread it slightly.

Here's a support bracket for the upper back of seat ...

It's upside down ... because the seat is laying on the ground.

You think the photographer could have taken the foto the other way around ...

bracket was made using the same "adjusting" technique.

Just to be consistent in upside-down fotos ...

This bracket was made by tack welding a "U" bracket

to a piece of tubing.

Further Along, but ...

There it is with a mesh seat cover, rear derailleur, and crank & pedals on the front.  Almost looking like a real recumbent.  

The new owner has a 28-inch inseam ... which places the seat up very close to the steering stem.  AND, he wants the seat almost vertical.  It is tilted back just barely enough for the chain line to clear the bottom of the seat fabric.  HOWEVER, I can just barely squeeze in between the seat and the steering stem.  And getting back out (getting the bike to drop down off me) is very difficult ... it would almost be easier to flop over sideways onto the ground and crawl out (OUCH!).  

SO, I have to do something about making a tilting steering mechanism.

Here is the rear derailleur attached to the dropout.

There are two other smaller holes that I had to tap threads into for use of the seat stays and a possible future rear rack or Golden Eagle gasoline engine.

Here's looking at the threaded holes from the inside of the frame.

Seat Support Update

Notice that this time around, we have clearance for the chain.

Here's the sideview a.k.a profile

Building Seat Support -- Twice

I made this seat support piece and mounted it on the frame.
Then I stood out to the side and looked at it ...
Then I went inside and brought out a long length of chain ...
Put the chain around the large gear on the back and stretched it up over the top chain roller ... there's a problem ... it's pushing upward against the seat support unit.

I also saw that I couldn't mount the brakes on the top of the frame ...
same problem -- chain conflict.
Which means I'll have to adjust the rear dropouts forward ...
I haven't welded them on yet.

Here are the two seat support units side-by-side.
The one on the right will provide enough chain clearance.
If you are wondering what all the little tack-welds are for ...
I found that if I use a single layer of EMT tubing,
it bends when you sit in the seat and move side-to-side.
So, I split the tube down the center ... took one half and using a hammer to tap on it on a round section of tubing. This flairs the outside piece so that it will fit snugly against the other half. Then I tack-weld them together and they make a much more rigid seat support tube.

Here all by itself is the seat support unit that I am going to use.
Good thing I didn't start drilling holes in the main tube yet ...
I'll use this as the jig to drill the holes for the bolt that will lock the unit firmly in place at the proper distance for the new owner.

Not Much Different ... But Changes

The Mach2 doesn't really look much different from last time ...
Still waiting on cables ...
Having ridden it several times ... I made some small changes
that are important to me.

It seemed like a good idea that the steering could be moved up and down ... But after riding it several times ... all that movement really irritated me. So, I pulled out the delrin (plastic) plug and cut the middle out of some funky handlebars. This foto shows that piece welded in where the delrin used to be ... and clamped solid at a good ride-able height. Just one less moving thing ... and it rides better because of it.

Even though the seat support bracket was hose-clamped to the main tube ... it tended to rock from side-to-side. If you off-balanced, it would roll to the side (like a horse saddle that wasn't properly cinched) ... and down I'd go. I centered it where it felt right ... then tack-welded it at the corners so it wouldn't move anymore. Way much better!

Mach2 - latest changes

At this stage ... I have a different fork on the front ...
Not sure if it is raked too much ... have to ride it and see.
I used an adjustable angle pyramid neck.
And I stuck a seat on it.
I need to throw a few more parts on it, ride it, and see what to do next.

Rather than 90° bending a tube ...
I heat bent a "U" which connects thru a delrin plug/tube.
That's a 1" EMT tube welded to it.

At the top end of the steering tube ...
I inserted a smaller tube with an inside diameter of abt 7/8".
So I could insert the steering gooseneck and handlebars.

Here's a sideview of that front fork ...
I'm still thinking about that ...
may go with a different fork ... we'll see.

Seat Mount

My grandson just had to have this fiberglas seat that I got from S&B Recumbents ... the bottom mount was sawed out of a Direct TV mounting bracket ... I kept a bit of the bend in the rear for rigidity. Welded to the frame ... there is no flex in it ... and it's wide enough to give good support to the seat bottom.

About halfway up the seat back ... look inside the purple rim ... and you'll see the bracket that came with the seat. I just welded it to the frame. The seat is a compromise angle that will meet the needs of the grandkids. Next to work on the steering.