Updating Dave Siskind's 1987 Homebuilt Recumbent

Return to March 2003 Meeting Updating Dave Siskind's 1987 Homebuilt Recumbent
Built by Dave Siskind - Rebuilt by Mark Stonich & Dave Siskind

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BEFORE

AFTER

Dave originally built this machine in 1987, basing it on this one I'd built in '86. Unfortunately, in '86 I didn't know what the heck I was doing. I didn't understand the importance of steering ergonomics and seat/BB drop. And I still believed that trail had a stabilizing effect on the steering of a 'bent.
Because I had advised Dave to build it the way he had, the poor ergonomics bothered me every time I saw it. So, I wanted to bring the bike into the 21st century.
First ride with new bars/stem showed bit too much reach. Moving the bars back an inch made the steering "sweet". Bars are Calhoun Cycle's EvoBar Pro. Stem/extension is similar to the Rans LWB setup.
26" rear wheel provides fender clearance and a lower seat.

Between the seat and the low BB, it wasn't very comfortable.
It wasn't very fast, as the low BB gave him the choice between an upright seatback, or a too open riding position.
Handling wasn't up to what we now know is possible, due to the ergonomics of the steel Wald "Chopper" bars and 1.7" of trail.
Since it wasn't a very good 'bent, and he has several fine upright bikes, he would usually be the only one riding a wedgie on our rides. Old Specs
Wheelbase - 60"
Head angle - 60 deg.
Rake - 3.60"
Trail - 1.7"
Seat Height - 27"
BB Height - 14"
Wheels - 27" x 1.25" & 451 x 37
Weight - 33 lbs (Estimated)
New Specs
Wheelbase - 61"
Head angle - 59 deg.
Rake - 4.67"
Trail - 0.62
Seat Height - 26"
BB Height - 19.5"
Wheels - 559 x 42 & 451 x 37
Weight - 31 lbs
I've built quite a few frames, and Dave just this one. So, I got to do all the fun stuff, like brazing and mitering, while he did all the dirty work.
We put cantilever brakes on the back. But, because the cranks now overlap the brakes, we kept the narrower centerpulls on the front.
The shorter derailleur tube requires the use of a "top swing" Shimano front mech.
Adding over an inch of rake reduced trail, eliminating wheelflop.

A more laid-back position, ergonomicaly correct bars and Trek/Rans seat should make this a good "All day" ride. Important, as Dave averages 15,000 miles a year.
Silver brazing the barrel on the brake bridge, after the bridge is inplace, simplifies accurately adjusting brake angle to compensate for added rake.
Fillet brazing was done with 3/32" GasFlux C-04 rod and GasFlux Blue flux. Mitering done using holesaws on a lathe.

Ugly bend. Time for a new raking block, with a tighter radius near the tips.
The long head and steerer tubes reflect the need to use "off the shelf" wedgie stem and bars. None of us had tube bending equipment in '87.
1.25" x 0.035" bottom tube, small front "triangle" and 1.125" x 0.035" top tube add up to a frame that strongly resists flexing due to pedalling forces.
I'd like to build a similar machine, using 0.028" tubing and 4 lightweight seatstays

BEFORE		AFTER
Dave originally built this machine in 1987, basing it on this one I'd built in '86. Unfortunately, in '86 I didn't know what the heck I was doing. I didn't understand the importance of steering ergonomics and seat/BB drop. And I still believed that trail had a stabilizing effect on the steering of a 'bent. Because I had advised Dave to build it the way he had, the poor ergonomics bothered me every time I saw it. So, I wanted to bring the bike into the 21st century.		First ride with new bars/stem showed bit too much reach. Moving the bars back an inch made the steering "sweet". Bars are Calhoun Cycle's EvoBar Pro. Stem/extension is similar to the Rans LWB setup. 26" rear wheel provides fender clearance and a lower seat.
Between the seat and the low BB, it wasn't very comfortable. It wasn't very fast, as the low BB gave him the choice between an upright seatback, or a too open riding position. Handling wasn't up to what we now know is possible, due to the ergonomics of the steel Wald "Chopper" bars and 1.7" of trail. Since it wasn't a very good 'bent, and he has several fine upright bikes, he would usually be the only one riding a wedgie on our rides.	Old Specs Wheelbase - 60" Head angle - 60 deg. Rake - 3.60" Trail - 1.7" Seat Height - 27" BB Height - 14" Wheels - 27" x 1.25" & 451 x 37 Weight - 33 lbs (Estimated)	New Specs Wheelbase - 61" Head angle - 59 deg. Rake - 4.67" Trail - 0.62 Seat Height - 26" BB Height - 19.5" Wheels - 559 x 42 & 451 x 37 Weight - 31 lbs	I've built quite a few frames, and Dave just this one. So, I got to do all the fun stuff, like brazing and mitering, while he did all the dirty work. We put cantilever brakes on the back. But, because the cranks now overlap the brakes, we kept the narrower centerpulls on the front. The shorter derailleur tube requires the use of a "top swing" Shimano front mech. Adding over an inch of rake reduced trail, eliminating wheelflop.
A more laid-back position, ergonomicaly correct bars and Trek/Rans seat should make this a good "All day" ride. Important, as Dave averages 15,000 miles a year.	Silver brazing the barrel on the brake bridge, after the bridge is inplace, simplifies accurately adjusting brake angle to compensate for added rake.	Fillet brazing was done with 3/32" GasFlux C-04 rod and GasFlux Blue flux. Mitering done using holesaws on a lathe.
Ugly bend. Time for a new raking block, with a tighter radius near the tips. The long head and steerer tubes reflect the need to use "off the shelf" wedgie stem and bars. None of us had tube bending equipment in '87.		1.25" x 0.035" bottom tube, small front "triangle" and 1.125" x 0.035" top tube add up to a frame that strongly resists flexing due to pedalling forces. I'd like to build a similar machine, using 0.028" tubing and 4 lightweight seatstays