Larry Lem builds the Scimitar Speedbike
Scimitar Speedbike

Pictures and Text by Larry Lem

Plug Molds Fairing/Frame Canopy Paint WHPSC 2009
Female Molds


Plug covered in wax and PVA, 4 layers of 10 oz fiberglass and over a gallon of epoxy. After curing, I sanded down the jagged cloth overlap areas. 

Swimming pool noodle halves hot-glued and held in place with motorcycle tiedowns 
Covered in 3-4 more layers of fiberglass 
July 2009
The bottom plug followed the same process 
To make wheel covers, I used assorted, smooth conically-shaped items, made female molds, and then parts. 
 I mounted the parts to a flat surface at a height to match the wheel dish and built up a plug, a female mold, then finally a finished wheel cover. 
Fairing Layup and Frame 

Top fairing layup - Wax and PVA inside female mold, wet layup, 1 layer of 1.45 oz and 1 layer of 9.66 oz fiberglass, 2 layers of 5 oz Kevlar around the rider, and a final layer of 9.66 oz fiberglass. I still haven't learned to vacuum bag and make monocoque structures. Maybe next year starting from the same plug pending the performance results of this vehicle.

Taping on corrugated cardboard takes too long. I decided to make "skins" by laying Kevlar and fiberglass over the plug. 
My backyard: top fairing, bottom crash panel on plug, bottom fairing, bottom female mold 
Top crash panel 
August 2009
Top and bottom fairings together (bottom fairing construction used the same process as the top) 
This year, I decided to build the frame after the fairing instead of the other way around. I made my own 1.5" x 3", 0.065" wall mild steel rectangular tubing. 
I made another Swanson seat clone
Dennis Grelk made me a 68t, 110 mm chainring. I now had 60, 63, 68 and 73t chainrings 
Production line for 1.5" dia tubing clamps 
Front fairing to frame mount 
Middle fairing to frame mount 
Rear fairing to frame mount 
I forgot about leaving clearance for the rear brake when installing the rear fairing to frame mount. Fortunately, a V-brake cleared. 
I must have mismeasured the rear wheel QR length when making the plug and the stuck through the fairing. 
Middrive cassette machining by Tom Amick. The middrive stuck up higher than expected. I had to lower the middrive and get rid of the upper derailleur so it would clear the top fairing. I was going to use the middrive for 3 or 4 gears; now I only had the hub for gears (5 inner cogs). 
I cut the front frame section and remounted it upside down. This positioned the boom in a more horizontal orientation so that when the bottom bracket was adjusted fore and aft, it would stay fairly centered with respect to the fairing. 
View looking in from the nose window. 
View looking forward from inside - I could not see anything but my legs. I could not even get a glimpse of the nose windshield while pedaling. Time to implement the backup plan - adding a canopy. 
Mid drive is now just a single gear multiplier. 
With the narrow nose, I now had to install a Sean Costin narrow bottom bracket for foot clearance. This drove the primary chain into the final drive chain when in top gear. 
So I moved the crank to the left side and replaced the middrive cassette with a bottom bracket and two old cranks. 
Sean's bb welded to a bracket to mount to the frame. 
This is a mockup of a narrow bb with Snap 130 mm cranks. Q width is less than 4". I don't know if anyone is running a smaller pedal box with a conventional crank. 
To provide extra toe and heel clearance, I bought one-size-too-small shoes, which were almost 3/4" shorter than my normal shoes. Without the chain on the crank, I could pedal fairly wildly and not hit the fairing with my feet, but my knee could easily graze the top. A real test ride was required. 
Next: Building the fairing  

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