Building a Recumbent Weight Weenie Stick Bike Highracer
Carbon High Racer
Construction and Evolution

By Warren Beauchamp

In 2010 the Stick Bike bike was cut up and rebuilt as a 20 lb Z framed highracer bike. This version of the bike worked great for riding on roads and paved trails, was fast on flat roads and climbed respectably due to it's low weight. I put thousands of miles on this bike over 10 years of riding it. Here's the process of converting it from a stick bike to a Z framed highracer. 

In addition to the highracer build below, this bike was rebuilt as a Z-frame gravel bike in 2021.


Here's the final drawing. It shows that I need to add 6 inches to the boom, and tilt it down 15 degrees. After doing that, I need to Z the frame to keep the same 8" height distance from seat bottom to BB. Oooh. Seat height is reduced from 24" to a comfortable 19", CG is close to 50/50, Tiller is short.
To ensure a good mechanical connection between the old a new boom sections, I needed to make a sleeve. I made a sleeve mold from a chunk of aluminum tubing, and used some foam to press the CF into the sides of the tube.
This is the boom with the sleeve holding the old section to the 6" extension. To attach the 6" extension to the main frame, I will need to use an inner-tube to bladder mold a few layers of CF to the inside of the tube at the 15 degree bend.
I cut and pasted myself onto the final drawing to make sure the riding position is the same and that my head is forward of the rear tire patch. Yes!
CFed the boom back on and hacked the main tube to bits. Here it is taped hack together with a 5" section of tubing added
Checked with the seat and idler to ensure the fit. I will need to revise the seat stays.
I put the wheels on to check the angles.
I put a single layer of CF on the top joint to hold it together while I add the Kevlar sleeve to the added section.

The white bandages are peel ply tape that I use to mash all the layers together. Any excess epoxy weeps through the fabric weave. The epoxy doesn't stick to the peel ply tape so it can be removed after it all cures.

Time goes by and I have Kevlar and CF wrapped the rest of the joints. Sorry no pictures, they would just be of more black tubes wrapping in bandages. Next I will need to add new seat stay mounts to the rear stays, re-route the brake and shifter cables, and then start re-adding the parts.
I peeled off all the peel ply, put the wheels back on and did the bounce test. Not bad, it's as least as stiff as it was in stick bike format. Made some CF seat stay tabs using CF plate I got from Mark Anderson. Very stiff!. Hacked 6" off the old seat stays and JB welded the assembly in place in preparation for actual bonding. Hacked over a foot off the tiller handlebars and JB welded into (hopefully) the right position.
The bike looks nice, like a lowracer with an impossible large front wheel.
Here's the bike after copious generation of carbon dust, and partial assembly. The test ride across the basement went well, the bike now handles fine.
Due to lots of reinforcement, The bike is stiffer now than when it was a stick bike. Weight with everything but the brake housings is still only 20 lbs. Cool!

Next I have to re-run the brake and shifter lines.

I raced this bike (without the flag) at the Iowa HPRA races in September. Average speed for the hour race was 23 MPH, which is about 2 MPH slower than the NoCom, but 3 MPH faster than the Bacchetta ti-Aero I raced there last year. It handles nicely at speed, but due to the lower chain's interference with the front wheel, it does not go around corners well at low speeds. Also the frame is a bit flexy, which is good for bumps, but bad for power transfer. I still have some more tweaks to do, but it's a decent ride.
I decided I needed to actually see where the flex was occurring, to see if I could fix it easily. If it's in the joints I can cut a slot lengthwise through the joint and then bond in a carbon plate. Click here for the full size video.

I'm also going to use an idler to raise the non-power side chain, as it restricts the wheel movement too much in the "down" position.

I moved the idler behind the seat in hopes that it would help the frame flex. Cranking on it, it does seem to flex less.

In conversations with Larry Lem, he notes that his fastest TT times were on his dual 650C highracer with dual disk wheels. I will try this bike with dual disk wheels next year and see how it fares.

I have been riding this bike weekly all year, and really like it. It handles well, goes up hills easily because it is so lightweight, and seems fast. It's certainly not as fast as the Nocom, but is much more civilized.
Here's the rear view. I ride with that light day or night. It is very bright and can be seen for miles, even in the day. It's a magic shine tail light.

Weight: 20 lbs
Seat height:19 inches
Wheelbase: 48 inches
Seat angle: 25 degrees

The BB mount aluminum front derailleur post finally cracked enough times that it was not worth epoxying together again, so I made a derailleur mount out of CF plate. It took several days of tweaking but it seems solid now and the alignment is close enough so that it works well.

I need to reinforce some of parts I attached with JB Weld with some real epoxy and CF, but it seems to be strong enough for a test ride now. I also added short CF tubing stub to mount the headlight to. The CF plate is pop riveted to the boom tube and epoxied.

I'm getting the bike ready for the 2013 riding season. I added a Bacchetta Brain Box bike bag to the back of the seat to replace the water bladder bag hanging on the side of the seat which was probably less than aero. Also I obtained a used rear CF aero wheel, with power tap hub. I looked on Ebay for a front CF wheel to match the rear for  a couple months and finally got disgusted and bought a new wheel direct from China.
Update - I have been riding this bike at least weekly (except in the winter!) for almost 5 years. It has been holding up well. Occasionally I sand the CF tubes and add another layer of epoxy as they are still a little rough but it's not very noticeable. It had been very reliable until yesterday when the front derailleur mount failed due to a JB weld failure. Today I re-glued it and reinforced it a bit with some chopped CF. Also I have to buy a new front tire. The old one has a bulge in the sidewall due to getting worn through by contact with the chain, which rubs when I turn sharply..

Next: This bike gets converted to a Dual 26" FWD Gravel Bike

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