Recumbent stability

Dear Cletus,

You have made a very good point. All of us can accommodate to most machines. However, a new rider
may feel shocked at the lack of feedback on some bikes. These are the guys that will try a recumbent
once and never come back.

Believe me, many supersonic jet pilots would consider the controls of some recumbents as 'wet
noodles'. The F-16 has a control spring of 7 1/2
lb. per inch. Fighter pilots accomplish precise maneuvers and fly under some pressure. They don't
fly with finger tips.

I don't comment on individual production machines. Unless I'm paid.

quote from Cletus

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I'd like to hear your evaluation of the geometry of the bike in question: a Lightning P-38.

While I would advise riding and steering using just the fingertips for the neophyte. That is just to
overcome some negative "deathgrip" habits that many DF riders seem to bring to 'bentdom.

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My my suggesting to you is to take your bike to an empty parking lot and practice weaving smoothly
left and right.

What you have to learn is the point of weight transfer as you turn. On an upright you probably
learned how to transfer your weight as you turned as a kid and it comes as second nature without a
thought. It is much like skiing or snowboarding.

On a bent you have to use your body differently to get the same weight transfer but once you have
learned that you won't even notice it.

Once you learn to apply the weight transfer, this middele point you feel between weight transfer is
where place/balance your weight to continue straight. After a while you won't notice that you know
how to balance your self.

I got my bike in April 02. Had the same problem you had and then I went to the empty parking
lot. When it rained a week later and I could not you my bike outside, I tried it on rollers.
Could not do it.

At the end of the season in Fall 02 when I brought my bike backe in, I got on the rollers. I was
surprised that I could stay on the rollers almost indefinitely after a few tries, if I concentrated.
Now I do the rollers with clipless pedals.

Riding a bicycle where "body english" is not an option requires developing a whole NEW set of reflexes.

Hmmmmm... Well I have a large body (200+ lbs) and I am English.

I will work on it ;-)

Brian.

Bill,

Thanks for your comments and advice. As far as I can tell after 140 miles, the bike has little or no 'control spring'.

I will try reversing the fork but think this is a stop gap approach until I can control the bike (like training wheels!).

Brian.

Some folks like the reversed fork idea and others feel that it gereates too much 'fork flop'. Please
let me know how it turns out.

I had to do the reversed fork thing on our tandem with great success. But then, I'm a ham fisted
old pilot.
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George,

Quoted message said:

I agree with Professor Patterson wholeheartedly, that by and large commercial recumbents could be
a lot less sensitive to steering inputs.

I also agree with Bill. After building a bunch of 'bents, many with my dad, I got a pretty good feel
for what makes a bike stable.

So I was shocked when we received my wife's factory direct V-Rex back in 1995. I could ride it
'no-hands' slaloming around cars in the school parking lot. This was due to very little wheel flop.

But at speed it was terrifying. There was almost no "control spring".

This bike had a narrow, light, high pressure front tire, but most important, there was very little
trail. You could almost turn the fork with your breathe! Later V-Rexs got more trail, and fatter,
heavier tires.

But you can get solid stability even with tiny, skinny tires. Just increase trail until the desired
control spring is reached. Unfortunately, to do this right requires steepening the head angle as you
increase trail....not easy without an adjustable geometry frame.

Quoted message said:

I have ridden motorcycles quite a bit over the last 22 years,

Fortunately, for my longevity, I gave up riding motorcycles in my 20's. :-)

Warren

[QUOTE]Originally posted by Bill Patterson
[B]Some folks like the reversed fork idea and others feel that it gereates too much 'fork flop'. Please
let me know how it turns out.

Bill,

I reversed the fork and it made a big difference. The faster I went the more stable it felt.

However, the front v brake interferes with the chain idler so I could only try it out briefly. I will see what I can do to move the idler position.

I have also changed to a heavier front wheel that was suggested and that also helps.

Thanks again for your advice.

Brian.

Robert Siegel said:

... However, the P-38 does require your full-time attention and focus. No hands free riding, no
distractions. Ever....

I would hardly characterize the P-38 that way (at least the XL size with an ISO 406-mm/ISO 622-mm
wheelset). It is certainly a much more directionally stable bike than the first generation ATP
Vision 40-series, and no more difficult to ride than a RANS Rocket or V-Rex.

Tom Sherman - Planet Earth

The P-38 was not "difficult" to ride ... I liked it a lot. however, it required my ongoing focus and
attention, as does my new Volae Team and as did my former Challenge Taifun.

It's just the nature of the SWB recumbent design, I suspect.

In comparison, my Ti Rush is considerably more forgiving and does not require such close attention.

Bob Siegel in Gainesville FL "Tom Sherman" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Robert Siegel said:

... However, the P-38 does require your full-time attention and focus. No

hands

Quoted message said:

Quoted message said:

free riding, no distractions. Ever....

I would hardly characterize the P-38 that way (at least the XL size with an ISO 406-mm/ISO 622-mm
wheelset). It is certainly a much more directionally stable bike than the first generation ATP
Vision 40-series, and no more difficult to ride than a RANS Rocket or V-Rex.

Tom Sherman - Planet Earth

Bob,

We have built SWB bikes that were twitchy at one end to those that felt like trucks at the other.
It's a matter of geometry not wheelbase.

Quote,

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t's just the nature of the SWB recumbent design, I suspect.

In comparison, my Ti Rush is considerably more forgiving and does not require such close attention.

Bob Siegel in Gainesville FL
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I think "wheelbase" is part of the "geometry" of bike design and performance.

jd

"Bill Patterson" <[email hidden]> wrote in message
"]news:[email hidden]...

Quoted message said:

Bob,

We have built SWB bikes that were twitchy at one end to those that felt like trucks at the other.
It's a matter of geometry not wheelbase.

Quote,

\\\\\\\\\\

t's just the nature of the SWB recumbent design, I suspect.

In comparison, my Ti Rush is considerably more forgiving and does not require such close
attention.

Bob Siegel in Gainesville FL
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Ha Ha,

You are absolutely correct. I should have said "other" or "front end".
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[QUOTE]Originally posted by Bill Patterson

'Now we have a whole generation of riders that think it's good to be at complete attention when
riding and that they must hold the handlebars with their fingertips. It isn't necessary for our
bikes to be so light handling. '

Is it possible to ride any recumbent 'no hands'? Surely that would be the best definition of stability. I could ride all my uprights, except our tandem, with no hands - even my track bike.

Has anybody achieved this on a recumbent or is it just not possible?

Brian.

blacktom said:

Is it possible to ride any recumbent 'no hands'? Surely that would be the best definition of
stability. I could ride all my uprights, except our tandem, with no hands - even my track bike.

Has anybody achieved this on a recumbent or is it just not possible?

It /is/ possible, but it depends enormously on the bike as well as the rider. I've done several
miles hands-off on a couple of borrowed low racers, but couldn't get my Kingcycle to travel
more than two feet hands-off before succumbing to terror and grabbing hold again.

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The current CAlPOLY student streamliner can be ridden along at walking speed, it can sprint to 50
mph and can be ridden hands free (not by me).

I am writing an article about it's geometry now.
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blacktom <[email hidden]> wrote in message
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Quoted message said:

Originally posted by Bill Patterson

'Now we have a whole generation of riders that think it's good to be at complete attention when
riding and that they must hold the handlebars with their fingertips. It isn't necessary for our
bikes to be so light handling. '

Is it possible to ride any recumbent 'no hands'? Surely that would be the best definition of
stability. I could ride all my uprights, except our tandem, with no hands - even my track bike.

Has anybody achieved this on a recumbent or is it just not possible?

Brian.

On an upright, "no-hands" steering is accomplished by angling your torso relative to your legs. This
doesn't really work on a recumbent- you can't get leverage with your legs out in front of you.

That being said, I've seen Mike Wolfe ride his Tour Easy clone for blocks with his hands behind his
head. He's a superb bike handler to begin with, and his clone had slightly different geometry from
the standard Easy Racer setup. It was a combination of rider and bike that made this possible.

Jeff

You are correct, That equation only points to the need for more "control spring". Fat tires, more
trail, more tiller and other methods can be used to gain the needed control spring. Remember, that
equation only one of 4 derivatives that must be satisfied to make a nice handling bike. Wheel base
does enter into the other factors.

Also, adding too much trail causes more fork flop and reversed control spring at low speeds.
Designers may be willing to accept high speed problems in order to solve the low speed ones.
Who knows?

I too, was amazed that wheelbase fell out of the derivation. That may be why short wheelbaase bikes
must be designed more carefully.
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blacktom said:

Originally posted by Bill Patterson

'Now we have a whole generation of riders that think it's good to be at complete attention when
riding and that they must hold the handlebars with their fingertips. It isn't necessary for our
bikes to be so light handling. '

Is it possible to ride any recumbent 'no hands'? Surely that would be the best definition of
stability. I could ride all my uprights, except our tandem, with no hands - even my track bike.

Has anybody achieved this on a recumbent or is it just not possible?

I can ride my recumbent Dragonflyer [1] without using my hands. I can even talk on the phone while
doing a no-handed trackstand. 😉

On an invitational ride a few years back, I witnessed someone ride a 1996 RANS Rocket (square tube
frame) for several miles without touching the handlebars. It should be noted that the rider also
rode unicycles on a regular basis.

[1] < ihpva.orgdf1a.jpgOpen ↗ >

Tom Sherman - Planet Earth

Hi,

I purchased my first recumbent in July. Managed to get 500 miles in by Sept. I had the same problem with my Vision r40 with USS. I cured it by easing up on my grip. And as oterhs have mentioned, sit back and relax. You'll have stability in no time.

John,

Quoted post said:

Originally posted by blacktom
I am a newcomer to recumbents and I am having difficulty riding my new Lightning P 38 in a straight line.

I have been touring and racing uprights for 50 years and this is my first (and long awaited) venture into recumbents. I now have ridden 100 miles and have tried adjusting the tilt steering, with some slight improvement, but I still feel unsafe.

Is it something that will come to me in time or am I missing something obvious?

Brian.