Larry Lem Recumbent Bike Projects
Larry Lem's Recumbent Bike Projects

Larry Lem is an enthusiastic and prolific builder and racer of HPVs. The following chronicles his bike building, notes, and the problems he has learned from. 

   Glowworm Tandem Speedbike - 2012
   Flying Cucumber Speedbike - 2011
   Cyclops Speedbike - 2010

   Scimitar Speedbike - 2009
   Goliath Tandem Speedbike - 2008
   Beluga Speedbike - 2007
   Unofficial Lem Projects page

Pictures and text by Larry Lem

2001 - tandem from two bikes - 1st project using new, inexpensive, 115VAC Lincoln Weldpak 100 welder with solid steel wire and argon-CO2 shielding gas. I extended the frame to make both riders "crank-forward" in 04. 
2002 - 1st recumbent bike, didn't work so well but maybe that's because I didn't know how to ride recumbents yet. 
2002 - road scooter (kickbike), I made a half-dozen scooters and kept two. While coasting downhill at 45 mph, I realized that unlike on a bike, if I hit a bump, I'd be kicked off of the scooter, tumbling down the road. 
2002 - off-road scooter 
2002 - commuter bike - I learned to ride recumbents using this bike. 
2004 - a couple of years and modifications later 
Dec 02 - LWB that I built for my mother. It had too much fork flop and was too hard to start. 
Jun 03 - Mom's bike converted to SWB. It sat kind of high and I didn't use it. 
Aug 03 - And finally converted to midracer. I wanted to see how low I could go and still be comfortable with traffic. I concluded that this was too low. 
Oct 03 - First time racing on a velodrome, Encino Ca - "It was just like NASCAR, going around the high banks, nose to tail." photo by Dana Lieberman 
2003 - Exercise in tube bending - to make a 700C Penny Farthing, I made a bender out of plywood. Tubing: 1.5" dia mild steel, .063" wall. 
I packed the tube full of sand, used a chain link fence roller as a follower, and long 2x4s as a lever. 
mini-Penny Farthing 
6-foot Nick dwarfing the mini-Penny Farthing 
Feb 04 - Jig made from 10 foot long 2x6s, mild steel .120" wall. It was difficult making fixtures that were straight. I found that despite strategically-placed tack-welds, you still have to cold bend parts so that they are straight once they are removed from the jig. 
Mar 04 - Breaking in the jig, constructing dual 700C highracer 
Mar 04 - Highracer complete, except for stem height. I found that the more as you increase the angle of recline, the less upper leg you are able to use to touch the ground. I also learned how disruptive heel-to-front wheel interference is when making big steering inputs at slow speeds. 
Apr 04 - I converted this bike to a dual 520, a 520/406, and then a 700C/406 with a high bb, 12" above the seat bottom. 
Then I lowered the bb to 9" above the seat bottom, replaced the 700C with a 559, and installed a Pantour disk hub front wheel. I added a rack and this became my weekend bike/trainer. 
May 04 - I was inspired by the Cobra carbon fiber lowracer and decided to built a steel version. NoComs did not exist yet. Here is the fork. 
May 04 - Lowracer completed. I raced it in this configuration for two years, 12" bb to seat height. 
Jun 04 - Racing at the Encino Velodrome 
Lowracer, midracer, commuter 
2004 - SWB dual 406, or 305 front. This became my "guest" bike as it is very easy to start and ride slow. It is a bit of a handful at speed. 
 Nov 03 - For my first streamliner, I wanted to build a trike so all power could go to propulsion and none to control. I made this from 3/4" electrical conduit.
Jan 04 - Completed trike prototype 1 
I didn't leave enough room for my helmet. 
May 04 - trike prototype 2, LWB and multilink rear, 406 front, 349 rears. 
Trike prototype 2 multilink rear end 
Jun 04 - Colin Clark testing the trike at the Encino Velodrome 
Sep 04 - trike prototype 2 solid rear end with Razor scooter 100 mm wheels. It felt a little squirrely. 
I extended the rear end, adding 2 feet to see if it would help with the squirminess, but I still didn't like it. 
Aug 04 - Trike prototype 2 solid rear end with 349 wheels 
Aug 04 - Tom Amick test ride, Camarillo, California 
Sep 04 - I cut off the rear end of the trike and grafted/clamped it on to the tail of my lowracer 
Comparison to a Huffy Green Machine (only $80) 
Dana Lieberman in front of his store, BentUp Cycles, Van Nuys, California 
Aug 04 - lowracer with Razor single scooter rear wheel. I rode this 100 yards weaving all over the place, as if it was my first recumbent ride. I walked back home as it was too scary to ride and I didn't want to crash into parked cars. 
Close-up of Razor scooter rear wheel on lowracer 
Sep 04 - I decided to go with a short wheelbase and used my lowracer as a guinea pig. I cut the solid trike rear off of trike proto 1, added clamps and grafted it onto the lowracer. 
Lowracer with a pair of Razor scooter rear wheels 
Jan 05 - trike prototype 3 with Zootr scooter rear wheels 
Trike prototype 3, open-face motorcycle helmet, used for fairing side profile shape 
Apr 05 - Using 1x2s to build a form for expanding foam 
Adding thin plywood to the form 
2-part foam from Aircraft Spruce. I used a lot of foam for this. Later, I determined that I should have created some type of hollow space in the center to reduce the waste. 
Forms removed 
Shaped foam - difficult to keep straight and uniform without any frames of reference. I eventually covered this with drywall compound. I bailed out on the trike idea after BM 2006 when I saw that the Orange Varna in trike form didn't go very fast with Eric Ware (stronger than me) riding. Raymond Gage and Chuck Royalty would later show in 2008 that trikes have potential. 
Nov 07 - Cleaning up an old mess - cutting apart the foam plug (making room for Goliath 2) 
Sep 04 - Crank-forward cruiser. It wasn't much fun to ride. 
Sep 04 - I recalled the KrazyKar from kindergarten and made one out of wood, and 20 mm thru-axle MTB front hubs. I think this was the "funnest" vehicle I had ever built. I named it the Spin Cycle. 
Oct 04 - Alice Broome at the Halloween Hydrobowl, Marine Stadium, Long Beach, CA hosted every year by Bill Gaines 
Aug 05 - Fearing the 2x4s would snap, I built another Spin Cycle out of 2.5" mild steel. After sitting outside for a year or two, I gave it to Bill Martin, on permanent loan. I might build another someday, with simpler wheels. 
Close-up of 20 mm thru-axle front disk hubs and crankarm adapters. 
Aug 05 - I decided to build a tailbox for my lowracer. In doing so, I figured I'd sit up a little for better vision. I lowered the crank to 10" (from 12") above the seat bottom, and raised the seat at the support by a half inch. 
Tailbox framework. I decided to attach it to the seat. I'd need to build a wider seat, too. 
Chicken wire over framework 
Fiberglass and Bondo over wire. Stillborn project 4 year later. 
Aug 06 - Jim Verheul getting set to draft and pass at Encino 
Dec 05 - I built a layed-back stationary trainer. It sits in my living room. It is as boring to ride as any trainer. 
Sep 05 - Drag trike. The most torque I ever put out was on my beach cruiser, standing straight up with the bars at my side. I wanted to use the same position in a quarter mile standing start racer. I chose a trike as I wanted stability from the outset. I found that I could not apply the same power lying down as standing up, the trike needed more development, and I had other things to work on. 
Jun 06 - FWD with wide skateboard truck in the rear. Very difficult to control. 
Aug 05 - I was fascinated with the Mango and postulated that it could have been more stable with a long wheelbase. I wanted to build a family of vehicles, a single, and back-to-back tandem, then a side-by-side quad (4 people, 4 wheels). 
Sep 05 - I built this mule, rode it through Jan 06, but could not get used to the "upright" position. All power came from the glutes, not the quads. 
Nov 05 - I built an upright seat for the stationary trainer so I could train every night for at least a few minutes in the Mango position. Here it is shown with a slightly layed back seat. 
Symptoms of bike-building disease. 
May 06 - I gave up on the Mango position and decided to build a conventional 700C/406, RWD, see over the knees with canopy streamliner. This became the Beluga 
Oct 06 - WHPSC at Battle Mountain. My fastest speed was 56.22 during a very cold night. I went 58.60 with some help from the wind 2 days earlier. 
Nov 06 - I made an eccentric 507 front wheel in 2001. I finally stuck it on a BMX bike with a 27" fork. I then made a set of eccentric 406 wheels using square tubing for spokes. But I wanted to disrupt the "in-phase" bobbing so I switched back to the larger front wheel. 
I initially made the rear wheel 1.5" off-center on the radius. But this was too bouncy and I reduced it to 1". It is still too bouncy. The front alone would probably be fine. 
Nov 06 - Baby jogger for adults. Not enough weight over the rear, very hard to "wheelie" and steer. 
Baby jogger front view  
Dec 06 - Baby jogger with front caster wheel 
Dec 06 - I made a dual 406 crank-forward bike for my mom. If I did it again, I'd use a Nexus hub. 
Feb 06 - This is Goliath, my first back-to-back bike. It worked pretty well, but weighed 70 lb. It was a flatland speedster. It was fun riding in the May 06 Fiesta Island 20k TT, finally passing all the upright TT riders. Tom would smile and wave as we passed them. But it was a tank on courses with climbs. 
In 2008, I built a new frame and bike called Goliath 2. I used the Beluga fairing molds. Tom and I went 67.06 mph on the same warm night that Sam Wittingham set a new world record of 82.33 mph. We missed beating Fred Markham and Chris Springer's Easy Racer Double Gold Rush multi-rider record of 68.91 mph. 

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