I've been linked

Jon Senior said:

http://www.chiark.greenend.org.uk/~armb/cycling/diyrecumbent.html

Further research revealed...

Alan Braggins. Hi there. ;-)

Jon

Jon Senior said:

Over the weekend, I met up with Becky and David (Of Laid-back
cycling). David sent me off for a spin on his recumbent, but clearly
missed my protestations of "I do know what I'm doing". It was quite
funny to hear the voice behind me going "OK. Now I'll just hold on to
the seat until you get going... oh... you've gone."

Jon

Jon

Well done. David's Laid Back Ligfiets Recumbent Tours is sponsoring the next
25 riders to do the Arthur's Seat Challenge. I am going to take the
recumbent challenge (ie get on one and try to ride it) at some point this
Summer - David's tours look ideal.

I know how it feels to have a running commentary on your cycling. A
commissaire last week actually tutted at me over his loudspeaker when his
encouraging suggestion that I "dig in" failed to produce the desired
improvement in my performance. I bet Lance has never been tutted at over a
PA.

Tom.

Tom Orr said:

Well done. David's Laid Back Ligfiets Recumbent Tours is sponsoring the next
25 riders to do the Arthur's Seat Challenge. I am going to take the
recumbent challenge (ie get on one and try to ride it) at some point this
Summer - David's tours look ideal.

If you're around this weekend, David has said he might be at the
Treefest thing in Inverleith park doing a simple recumbent try-out.
Failing that, I'll be there on the saturday with mine. He was also
handing out flyers for the challenge so you may get some more takers.

And I managed 4m56 on the bent. I'll try and find out how much it weighs
so that I can do the power calcs.

Quoted message said:

I know how it feels to have a running commentary on your cycling. A
commissaire last week actually tutted at me over his loudspeaker when his
encouraging suggestion that I "dig in" failed to produce the desired
improvement in my performance. I bet Lance has never been tutted at over a
PA.

:-)

Jon

Jon Senior said:

While searching for details of a rip-off of the HPVelo Body-link seat
(Which I failed to find!) I found the following site:

http://www.chiark.greenend.org.uk/~armb/cycling/diyrecumbent.html

At the bottom of which was a familiar story... mine in fact. He he.

And in the thection on tandemth there is a familiar thtory ath well.

...d

In article said:

While searching for details of a rip-off of the HPVelo Body-link seat
(Which I failed to find!) I found the following site:

http://www.chiark.greenend.org.uk/~armb/cycling/diyrecumbent.html

At the bottom of which was a familiar story... mine in fact. He he.

Link now updated to mention your new version.

I have to confess I've made no progress at all for a while on building one.
On the one hand I have been to D.Tek to try a load out, on the other hand the
20" wheel that was supposedly going on the front of the recumbent is now
on my folder as a result of talking to Kevin, and I didn't come away with
any clear ideas on what sort of bike I preferred.
(Milton tip had another 20" wheel child's bike yesterday morning when I had
no cash with me, but it had gone by the evening. Grumble grumble.)

in message <[email hidden]>, Jon Senior

jon_AT_restlesslemon_DOT_co_DOT_uk ('') said:

While searching for details of a rip-off of the HPVelo Body-link seat
(Which I failed to find!) I found the following site:

http://www.chiark.greenend.org.uk/~armb/cycling/diyrecumbent.html

At the bottom of which was a familiar story... mine in fact. He he.

Congratulations!

The wooden bike is still lying on its side in the shed, but the bottom
bracket is now epoxied in, and as soon as the poxy has gone off it will
come upright for the first time. Then the bulkheads and the rear
dropouts get fitted, and it goes on the turbo-trainer while I mess with
the chainline, the seat and the steering.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

The Conservative Party now has the support of a smaller proportion of
the electorate in Scotland than Sinn Fein have in Northern Ireland.

in message <[email hidden]>, Simon

Brooke (') said:

in message <[email hidden]>, Jon Senior

jon_AT_restlesslemon_DOT_co_DOT_uk ('') said:

While searching for details of a rip-off of the HPVelo Body-link seat
(Which I failed to find!) I found the following site:

http://www.chiark.greenend.org.uk/~armb/cycling/diyrecumbent.html

At the bottom of which was a familiar story... mine in fact. He he.

Congratulations!

The wooden bike is still lying on its side in the shed, but the bottom
bracket is now epoxied in, and as soon as the poxy has gone off it
will come upright for the first time. Then the bulkheads and the rear
dropouts get fitted, and it goes on the turbo-trainer while I mess
with the chainline, the seat and the steering.

Bother! Made the main bulkhead too narrow for my shoulders. Ho hum,
another sheet of ply... It doesn't _look_ much like a bike.

--
[email hidden] (Simon Brooke) http://www.jasmine.org.uk/~simon/

;; So, before proceeding with definitive screwing, choose the
;; position most congenital.
-- instructions for fitting bicycle handlebars

Alan Braggins said:

Link now updated to mention your new version.

Just got around to looking at the new link... ;-)

Jon

On 10 Jun 2005 11:22:17 +0100 (BST), [email hidden] (Alan

Braggins) said:

In article said:

Alan Braggins said:

Link now updated to mention your new version.

Just got around to looking at the new link... ;-)

So, crossing over with the "for fork's sake" thread, how does one
go about deciding on things like appropriate trail for a recumbent?

Depending on the style, take an average of 'what's out there', try it,
and go from there. There's not really much else you can do really, as
you've get differnt opinions from different people. What is useful [as
you mention] is to take an existing fork and weld an adjustable
slide-like- bracket for the wheel nuts capable of going from say zero
to 2 inches trail, and experiement to see what you want and then
calibrate another set of forks to this measurement. Point is, some
people like stability more at slow speeds than fast and so is the case
visa versa.

Very important to remember that it's not only trail that affects
handing: weight distribution, steering layout, centre of gravity etc
all come into play in ways that is completely behond me.

On the first one I built, I had head tube angle of 71d, and trail of
about 1 1/2 [which was kind of average for a swb], and it was all over
the place, and I felt [censored]-scared riding it. Set on changing
everything I looked for help from the gurus on Brol and it was
suggested to me that my very elabroate steering system [a lever
system] might be causing the problem. This did in fact prove to be the
case, when I changed it to something much simpler, it felt like a
different animal, no problem.

The only thing that appears to be an absolute constant is the fact
that when you build one recumbent, thinking you'd got everything
sorted from hours of research and trying different bikes, when yoiu
finish it, it proves to be not the case, and you end up building
another. Par for the course, and all part of the game.

Garry

Quoted message said:

For something like http://www.ihpva.org/com/conKit/ or
http://www.atomiczombie.com/plans/book-bonanza/koolkat-pic5.htm
then the geometry is just that of the donor bike.

But for something like Hooves, with a 20" fork, do you want the same
sort of trail as the bike the fork came from? The same sort of ratio
of trail to wheelbase? Something else?

Short of building something with adjustable headset angle and offset
like http://www.terracycle.com/adj_geom.htm, or just copying something
you like, how do you decide?

Alan Braggins said:

So, crossing over with the "for fork's sake" thread, how does one
go about deciding on things like appropriate trail for a recumbent?

Pick a number. :-)

Quoted message said:

For something like http://www.ihpva.org/com/conKit/ or
http://www.atomiczombie.com/plans/book-bonanza/koolkat-pic5.htm
then the geometry is just that of the donor bike.

But for something like Hooves, with a 20" fork, do you want the same
sort of trail as the bike the fork came from? The same sort of ratio
of trail to wheelbase? Something else?

The geometry of Hooves is roughly[1] that of the HPVelo Streetmachine.
Basically, I designed it around the wheelbase. The main tube angle is
set to be perpendicular to the headtube. This turned out to be 30
degrees. This version ended up with a slightly longer wheelbase than
intended (Bad jig), which has resulted in slightly reduced trail. I've
tried riding no-hands but I've yet to try it on a slope so I'm not
pedalling. There is still enough trail to mean that the direction of the
front wheel can be guided by leaning the bike when pushing it.

Quoted message said:

Short of building something with adjustable headset angle and offset
like http://www.terracycle.com/adj_geom.htm, or just copying something
you like, how do you decide?

Either copy something you like, or make it up. Knowing what I know
now... I'd consider building a wooden prototype (ala Simon's bike) which
would allow me to verify such things before construction.

Jon

[1] Within the bounds of error introduced by my less-than-perfect jig
and setting by eye!

Alan Braggins said:

So, crossing over with the "for fork's sake" thread, how does one go about
deciding on things like appropriate trail for a recumbent?

You could see what this on-line calculator suggests:
http://www.wisil.recumbents.com/wisil/trail.asp

Mike

Mike Causer said:

Alan Braggins said:

So, crossing over with the "for fork's sake" thread, how does one go about
deciding on things like appropriate trail for a recumbent?

You could see what this on-line calculator suggests:
http://www.wisil.recumbents.com/wisil/trail.asp

One fiddle with a tape measure later, 80 degree head angle with the forks
reversed for -5cm offset looks plausible, in theory. It would help if
I could remember where my drawing instruments (with decent protractor)
is, the mount for the laser level isn't really designed to measure angles
later. And the cg is guesswork of course.

Alan Braggins said:

One fiddle with a tape measure later, 80 degree head angle with the forks
reversed for -5cm offset looks plausible, in theory. It would help if I
could remember where my drawing instruments (with decent protractor) is,
the mount for the laser level isn't really designed to measure angles
later. And the cg is guesswork of course.

As a data point, my Ross with 20" wheel and zero offset has around 65
degree head angle, and as you know it's a bit twitchy.

I have taken back my stance that it doesn't like counter-steer. It does,
but only very gently. A good shove (such as works very well on a
motorbike) just makes it protest, so I suspect some flex somewhere.

Mike