Tom Porter's Recumbent Bike Plans - SWB versions
Tom Porter's Recumbent Bike Plans 2005
After building the three bikes that I originally designed and posted in early 2004, I found after riding and racing the various bikes over a year's time that improvements were in order. 

RWD DUAL 700c Design Issues:
  • High altitude seat
  • Corresponding high BB
  • Tweener bars( a pain to get your knees up in and out of the way when starting, I’ve seen many people bang their kneecaps on these babies)
  • Rear suspension is really not necessary for the majority of my riding.

FWD 650/700c Design Issues:

  • Frame flex leading to stress crack behind headtube
  • Rear suspension same as above

TOURING Design Issues:

  • Weight (way to heavy)
  • Two sizes of tires
  • Too slow
  • . . . although the full suspension is nice it needs more development specifically for a recumbent

New Frame Design

In July ’05 I started to develop drawings for a single main frame design that would accommodate all the various tire combinations and seat/bb heights I wanted to use. This single main frame design will build 4 or 5 different bikes over the next several months, which will be explained and photographed. The benefit of this design is that I will just duplicate the main frame tubes with adjustments for the rear stays.

DUAL 700c
Seat height: 20”
Bottom bracket height: 29”
Seat height: 18”
Bottom bracket height: 26.5”

The purpose of this design is to be able to take advantage of the wide variety of wheels and tires available for the 55/MTB 26” size, from 1” to 1.5” in width.
451/700c LOWRACER
Seat height: 13.5”
Bottom bracket height: 22.5”

This is a lowracer built to use the 451/20” BMX front tire (Primo, Stelvio, IRC) combined with a 700c rear.
406/700c LOWRACER
Seat height: 12”
Bottom bracket height: 21”
Full Size Drawing Of Main Frame Angles

Main tube butt joint angels and headtube angle.
Notice that the two angles are identical to simplify frame construction by duplicating parts. The headtube angle when matched with proper fork rake will yield desired trail.

There will be a few other drawings further along in their proper place for making parts or jigs.

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