LONG WHEELBASE CLONE

WITH

STEEP HEAD TUBE

 

I continually monitor the net for recumbent news. A. D. Carson posted details  http://www.recycledrecumbent.com/  on a“flip-it” LWB clone, whereby the head tube portion of the donor frame is inverted, resulting in a steeper head tube, with less tiller effect. Here’s a picture, from his web site, of the flip it frame contrasted to the conventional Easy Racer Clone.

 

    http://www.recycledrecumbent.

 

Mark Stonich   http://www.bikesmithdesign.com/ (my frame building hero and, on occasion, consultant) posted a page on designing a LWB recumbent from scratch. He also posted his opinions regarding using the “flip it” approach. Most noteworthy was his comment that using a “step through” frame for the head tube portion was a “Good Thing” ™. (note: Step through means ‘girl’s bike’ to most of us)

 

Since I had just come into several 24” step through MTB donor bikes, I decided to give it a try.

 

This time, I tried to actually design it before letting the sparks fly. This is the only sketch that remains. (the wheelbase was too short, so I cut and pasted (physically) to lengthen. No copies were kept, but you get the idea, right???

 

Then, the discussion of pedal clearance hit the message boards.

 

After thinking about that and Marks comments that front wheel pedal clearance was NOT a problem, I moved the bottom bracket as close to the head tube as possible. In wound up four inches  (on center) behind the head tube.

 

I fabricated the head tube/ bottom bracket assembly. Then I tried to get an idea of  where we were headed by laying out the major parts on the floor. Here’s a picture of that. The long light colored piece is a mop <G>

 

I know!! The photography is terrible. That’s a theme here. Live with it!!!

 

At this point, it dawned on me that I was approaching the RANS V Squared in design, so I actually looked at the design.  Here’s a picture of My friend’s wife on her V 2

 

 

 

 The most notable difference was the triangulation of the three tube frame at the rear. I decided to do that.

 

I am delighted in the design process. If you take some time to think as you progress, directions you didn’t think of when starting begin to emerge from the fog.

 

Here are some pictures of the frame in progress.

 

 

(On the photography theme, it is really hard to find a good site for these photographs. There’s always something in the background, or bad light, or clutter. Such is life.)

 

 

With chainstays added and wheels on, during alignment:

 

                                                                                                                 

with steering and upper seat stays                                             

 

 

           

 

This week, I fabricated the seat frame and mounted it. The seat is a modification of the vision design. The back angle can be varied independently from the seat base. The seat base is triangular, so the back of the legs don’t  hit. I call it “The Perfect Seat (TPS)”

 

 

 There were some questions about the details of the front triangle, or whatever it’s called in bent terms. I mean the head tube, bottom bracket area. Here’s a close up

 

 

 

And the assembly, which is beginning to take shape.

 

 

 

Sunday, March 21, 2004: I added a chain and used the seat cover from my Tour Easy Clone. The bike weighs about 29 pounds. That’s lighter than I expected.

I had to remove some of the tiller from the steering to eliminate knee strike.

It only lacks brakes and a front derailleur to be complete.

 

 I took a first “Kamikaze” ride. (Kamikaze because no brakes. I just can’t wait any longer to taste the new bike when I get this close!!!!)

 

The bike handles and accelerates well. Single speed (40 front 16 rear) spins out okay. That’s about 17 to 18 miles per hour, per the gear charts.

 

March 30, 2004:

I added the seat cover. Installed one brake. Brazed on the derailleur stub.

OH! OH! The top tube IS in the way of properly positioning the front derailleur. So much for the accuracy of my eyeball. Pictures of completely redoing the front sprang into my head.

 

 I trimmed up an old derailleur and it about fits. Looks like it will be okay. Here’s some pictures of the nearly completed bike. Weight is about 32 pounds

 

I need to braze on the front brake mount and the cable stops and fabrication is done. (famous last words)

 

Saturday, I changed the rear freewheel to a tour cluster (14/27) for wider gears. DAMN!! The slightly larger sprockets caused chain line interference. I added an idler to deflect the chain a bit, but my eyeballs were off again. The chain won’t stay in the pulley. We’ll do better on revision 1A.

 

I added the cable stops for the front derailleur. I HATE TWIST GRIP SHIFTERS FOR THE FRONT!!!!!

. (Sorry to shout.)

 I have never gotten one to shift easily. This ongoing problem covers the last three bents I have built.  I tried several different derailleurs this time All of them require the strength of Atlas to operate with the twisters and the available travel won’t cover all three rings.

 

After hours of fiddling, I pulled a Queen Of Hearts:” Off with their heads!!!!” I screamed!!

 

 I installed an old thumb shifter. BINGO!!!! Works great. “snick, snick, snick!!!”

 

I also brazed on the front canti pivots. Haven’t rounded up cables yet.