My life with Python trikes Mk1 , Mk1.5 , Mk2 ?

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Aha. Project creep. I love it. My projects operate the same way.
He has way to much ' thinking time '
And way to little ' doing ' time

Paul
 
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So grab a couple hours this afternoon , respite from ' honey do list ' ;)

Bunch of filing later and both lumps fit in the ends , 8 plug welds and 12" of TIG bead later and we have this :-



You can see the 2 temporary tacks on the outside to hold the plate whilst it was TIG'ed on the inside , they will be filed off to let the washers sit flush up against the face.

I did a quick ' lump removal ' with the flap disc on the ends and flapped flush the plug welds ..



Giving me this 20" tube for a 24" track [ tyre centre to tyre centre ]



Slapped my 3rd set of SA drum braked wheels on for a look see , does not look it but the track will be 6" shorter than the one I currently ride.
next up need some anchors for the brake back plates , need to look back and see how I did my last one's as I am always looking for a neat way to do them

all for now Paul
 
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He has way to much ' thinking time '
And way to little ' doing ' time

Paul
Hmmmmm......... Put up 24 fence panels and posts, moved over 30 tons of materials and laid a patio, destroyed a conservatory and rebuilt it as a mini-barn. Yes indeed, not much "doing" going on over here at all. :unsure:
 
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Hmmmmm......... Put up 24 fence panels and posts, moved over 30 tons of materials and laid a patio, destroyed a conservatory and rebuilt it as a mini-barn. Yes indeed, not much "doing" going on over here at all. :unsure:
.. and how much of that was Zombie time ?

Paul
 
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Hmmmmm......... Put up 24 fence panels and posts, moved over 30 tons of materials and laid a patio, destroyed a conservatory and rebuilt it as a mini-barn. Yes indeed, not much "doing" going on over here at all. :unsure:
Merely miscellaneous side issues that have detracted from trike building.
 
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Merely miscellaneous side issues that have detracted from trike building.
True... but very time & Energy-consuming.
...and it aint over yet. Now I have to fix all the MIL's plumbing issues because her son is a **cking-useless little $hit and sits at home moaning how he is a "victim". I can't win. :(
 
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About 72+ miles on tilter now

Gave the locking ring on the BB a belt with a chisel [ well maybe more than once ] and it has stayed put so far.

No real tilting issues , managed the uphill railings again no problem.

However Python problems are still rearing their ugly heads !
Foot steering is still an issue on the narrow paths with fast traffic alongside...
Some Pythons suffer from steering instability at speed , on mine this is usually when going that fast you cannot pedal.
Like all trikes steering becomes more sensitive as speed increases.



I was free wheeling at probably 24mph with a car behind when I got into a fast oscillating swerve , the legs are quite an imprecise steering method and it is very difficult to make small corrections.
I did think briefly I was a goner and would either swerve into the stone face on my left or into the oncoming traffic , thankfully the oscillations damped and I was able to recover it , a lucky escape.

Maybe a wake up call I really need to put more effort into finding a steering solution I am happy with and can use ?
I looked through my Flevobike/trike pictures and 18 different one's 13 had bars on the steering part and only 5 on the non-steering part [ one had both ] a hint I think ;)(y)

Paul
 
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About 72+ miles on tilter now

Gave the locking ring on the BB a belt with a chisel [ well maybe more than once ] and it has stayed put so far.

No real tilting issues , managed the uphill railings again no problem.

However Python problems are still rearing their ugly heads !
Foot steering is still an issue on the narrow paths with fast traffic alongside...
A know problem with all Pythons is steering instability at speed , usually when going that fast you cannot pedal.
Like all trikes steering becomes more sensitive as speed increases.



I was free wheeling at probably 24mph with a car behind when I got into a fast oscillating swerve , the legs are quite an imprecise steering method and it is very difficult to make small corrections.
I did think briefly I was a goner and would either swerve into the stone face on my left or into the oncoming traffic , thankfully the oscillations damped and I was able to recover it , a lucky escape.

Maybe a wake up call I really need to put more effort into finding a steering solution I am happy with and can use ?
I looked through my Flevobike/trike pictures and 18 different one's 13 had bars on the steering part and only 5 on the non-steering part [ one had both ] a hint I think ;)(y)

Paul
Scary stuff. That road is not for the faint-hearted. Glad you made it out OK. (y)
 
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Ok after much cud chewing with DannyC he rightly reminded me I was going to try having 2 sets of bars ? instead of wasting lot's of time designing & building a 2 in 1 set as proposed by Popshot

So as I want to butcher the front end of the tilter anyway it was deemed useful to swap the Python front end onto the tilter gaining handlebars on the steering bit more gears and a parking brake:-


So I had built them to be interchangeable how hard can it be ?

Bl**dy as it turned out , tilter simply disconnected brakes and remove long bar ends containing the controls from the handle bars mounted on the non-tilting part [ nearest picture red stripped grips ]
Remove steering damper and mounting bracket from frame 2 x M12 and Houston we have separation.

Python bit easier as disconnect brakes and 2 x M12 and we have separation.

Wheel them past each other and try to bolt Python front to tilter pivot mount , top bolt goes in and lower one does but no threads showing ? puzzled I noticed the more I backed out the top bolt the more threads available on lower bolt , eventually dawned on me the front frame cross piece was fouling on the pivot strengthening ribs bummer !
With an extra nut on the M12 rod ends I could just get enough thread to fasten the nuts on , however no thread visible through lock nuts so unlikely doing any locking ?

result ? well NO now I have very limited steering lock , however brain said [ on reflection I had spent to long in full sun at this point ] no problems we have lean steering what can go wrong ?

Brakes connected we were ready for a sortie ?
Now steering bars mounted on front part with all controls and fixed bars on ' fixed part ' no controls however able to hold tilt whilst feet get clipped in and then a good push off and swap hands from fixed to steering .

Anyone a betting man as to what happened next ?

Manged to get it off drive using fixed bars , move hands to other bars struggling to keep it moving vertically and straight ahead , never made the first 90' right , lack of steering locked forced me onto someone's drive which I had to Flintstone off and ride on the pavement to get back on road.

Wobbled around a car till I reached turning circle on my right , usually set tilter up for a sweeping 90' right and 360' left [ very Red Arrows ] , never made it around the right ! it tilted that much [ no feeling of controlling tilt at all ] almost fell out of seat whilst I scrabbled to unclip right foot and get it planted on the ground.

So back onto drive very gingerly and tried a track stand something I could do quite easily with non-steering bars , couple seconds then a wobble tilting to right began again almost fell out of seat whilst I scrabbled to unclip right foot and get it planted.

That ride is +/- 250 yds/mtrs !

So I can ride the tilter with no bars on the steering 72 miles [ 115 Km ] with only 1 really serious incident , and now I can't ride it 250 yds

This is further than I recall every getting with bars on the steering when trying before causing me to settle on bars on the non-tilting part.

What I don't understand is WHY ?

It would be simple to assume :-
a) years of riding Python trike made hands free come relatively easy ? [ had to so go on with it ]
b) I am actually trying to ride this like a Flevo BIKE which is something I cannot ride ? - so maybe I got a long way for a non rider ?

What next ?

Any ideas what is happening

regards Paul
 
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Joined
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Ok after much cud chewing with DannyC he rightly reminded me I was going to try having 2 sets of bars ? instead of wasting lot's of time designing & building a 2 in 1 set as proposed by Popshot

So as I want to butcher the front end of the tilter anyway it was deemed useful to swap the Python front end onto the tilter gaining handlebars on the steering bit more gears and a parking brake:-


So I had built them to be interchangeable how hard can it be ?

Bl**dy as it turned out , tilter simply disconnected brakes and remove long bar ends containing the controls from the handle bars mounted on the non-tilting part [ nearest picture red stripped grips ]
Remove steering damper and mounting bracket from frame 2 x M12 and Houston we have separation.

Python bit easier as disconnect brakes and 2 x M12 and we have separation.

Wheel them past each other and try to bolt Python front to tilter pivot mount , top bolt goes in and lower one does but no threads showing ? puzzled I noticed the more I backed out the top bolt the more threads available on lower bolt , eventually dawned on me the front frame cross piece was fouling on the pivot strengthening ribs bummer !
With an extra nut on the M12 rod ends I could just get enough thread to fasten the nuts on , however no thread visible through lock nuts so unlikely doing any locking ?

result ? well NO now I have very limited steering lock , however brain said [ on reflection I had spent to long in full sun at this point ] no problems we have lean steering what can go wrong ?

Brakes connected we were ready for a sortie ?
Now steering bars mounted on front part with all controls and fixed bars on ' fixed part ' no controls however able to hold tilt whilst feet get clipped in and then a good push off and swap hands from fixed to steering .

Anyone a betting man as to what happened next ?

Manged to get it off drive using fixed bars , move hands to other bars struggling to keep it moving vertically and straight ahead , never made the first 90' right , lack of steering locked forced me onto someone's drive which I had to Flintstone off and ride on the pavement to get back on road.

Wobbled around a car till I reached turning circle on my right , usually set tilter up for a sweeping 90' right and 360' left [ very Red Arrows ] , never made it around the right ! it tilted that much [ no feeling of controlling tilt at all ] almost fell out of seat whilst I scrabbled to unclip right foot and get it planted on the ground.

So back onto drive very gingerly and tried a track stand something I could do quite easily with non-steering bars , couple seconds then a wobble tilting to right began again almost fell out of seat whilst I scrabbled to unclip right foot and get it planted.

That ride is +/- 250 yds/mtrs !

So I can ride the tilter with no bars on the steering 72 miles [ 115 Km ] with only 1 really serious incident , and now I can't ride it 250 yds

This is further than I recall every getting with bars on the steering when trying before causing me to settle on bars on the non-tilting part.

What I don't understand is WHY ?

It would be simple to assume :-
a) years of riding Python trike made hands free come relatively easy ? [ had to so go on with it ]
b) I am actually trying to ride this like a Flevo BIKE which is something I cannot ride ? - so maybe I got a long way for a non rider ?

What next ?

Any ideas what is happening

regards Paul
The fact that you have ridden a Python trike so successfully and happily ride "hands-free" and can grab the bars for tight turns and situations requiring "precision steering" says to me that these elements are "innocent".
Having the tilt function present in the mix are you transferring some portion of the "steering" effort into unconsciously "pulling" yourself over into "tilt" while not meaning to?
Controlling the beast AND monitoring what is going on at the same time is not going to be easy. You need an independent camera on it so you can observe yourself in action I think.
Glad that you escaped unscathed. :)
 
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The fact that you have ridden a Python trike so successfully and happily ride "hands-free" and can grab the bars for tight turns and situations requiring "precision steering" says to me that these elements are "innocent".
I assume you mean tilter not Python ?
lack of ' precision steering' is missing when bars are on fixed part.

Having the tilt function present in the mix are you transferring some portion of the "steering" effort into unconsciously "pulling" yourself over into "tilt" while not meaning to?
Are you talking about bars on non-tilt ? or bars on steering ?

Controlling the beast AND monitoring what is going on at the same time is not going to be easy. You need an independent camera on it so you can observe yourself in action I think.
Hmm it would not be a great help as it would not see any feet steering effort of hips doing tilt correction ?
Glad that you escaped unscathed. :)
Dog walking/thinking time a few thoughts ?

a) I don't think I understand how with the bars on the non tilting part the trike un-tilts coming out of a turn
b) With the bars on the steering part am I unconsciously adding tilt when not required ?
c) is it the angle of the bars ? all Flevo's with bars on the steering part have them horizontal and not almost vertical as mine are ?



I think you can get far more force against tilt when bars horizontal ?
d) maybe bars on the non-tilting part and a steering damper would do?
e) I have a plan for even more tilt damping to try !

However need to grind it out and find more steering lock first...

regards Paul
 
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I assume you mean tilter not Python ?
No, I did mean that riding a Python trike with bars on the front presents you with no problems and you choose whether to go hands-free or hands-on at any time.
Are you talking about bars on non-tilt ? or bars on steering ?
I meant when you transfer your hands from the non-tilt bars (affixed to the static rear/lower half) to the steering bars. I thought you said it was only with your hands on the bars attached to the steerable element that it all went haywire. Maybe I misunderstood.
Wobbled around a car till I reached turning circle on my right , usually set tilter up for a sweeping 90' right and 360' left [ very Red Arrows ] , never made it around the right ! it tilted that much [ no feeling of controlling tilt at all ] almost fell out of seat whilst I scrabbled to unclip right foot and get it planted on the ground.
Is where you said it all went pear-shaped.... isn't it?

It does appear that without a fixed/static and unmovable set of reference "anchors" against which you can push/pull your arms/body to influence the amount & direction of tilt that you are in "free-flight" with the motion forces and gravity dictating what happens. :(

Any flat recreation parks/fields where you can practice without traffic/hard unyielding concrete?
 
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So out with the grinder...



rear end about to get some butchery...


Ground out the arc both sides and got enough clearance to replace the extra nuts with 3 washers and now have the nut's holding the front end on into the locking part.

Did not have the mental fortitude to try it out ,so assembled it and backed it into the garage , whilst pondering what is happening.

Paul
 
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No, I did mean that riding a Python trike with bars on the front presents you with no problems and you choose whether to go hands-free or hands-on at any time.
True

I meant when you transfer your hands from the non-tilt bars (affixed to the static rear/lower half) to the steering bars. I thought you said it was only with your hands on the bars attached to the steerable element that it all went haywire.
It is

Is where you said it all went pear-shaped.... isn't it?
Yes

It does appear that without a fixed/static and unmovable set of reference "anchors" against which you can push/pull your arms/body to influence the amount & direction of tilt that you are in "free-flight" with the motion forces and gravity dictating what happens. :(
yes probably..
If I asked you what causes a 2 wheeler you are ridding to get vertical after it has tilted to go around a corner could you answer ?
When the bars are on the non-tilting part I am conscious of adding/exaggerating the tilt , however I don't feel conscious of what causes it to un-tilt when cornering is over ?
I cannot ride hands free [ yet ] with the bars on the no-tilting part so obviously the bars play some part in keeping the whole think on an even keel when going in a straight line even if I am not concious what part they play ?

Any flat recreation parks/fields where you can practice without traffic/hard unyielding concrete?
Not that I can easily get to , 1 mile ride and crossing a dual carriageway , also not going to learn much in 30 minutes compared to the riding time for 70+ miles ?

Have a few ideas I need to explore , however without understanding what is happening it will be hard to find a solution ?

Paul
 
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True


It is


Yes


yes probably..
If I asked you what causes a 2 wheeler you are ridding to get vertical after it has tilted to go around a corner could you answer ?
When the bars are on the non-tilting part I am conscious of adding/exaggerating the tilt , however I don't feel conscious of what causes it to un-tilt when cornering is over ?
I cannot ride hands free [ yet ] with the bars on the no-tilting part so obviously the bars play some part in keeping the whole think on an even keel when going in a straight line even if I am not concious what part they play ?



Not that I can easily get to , 1 mile ride and crossing a dual carriageway , also not going to learn much in 30 minutes compared to the riding time for 70+ miles ?

Have a few ideas I need to explore , however without understanding what is happening it will be hard to find a solution ?

Paul
I feel your pain (or at least, your frustration). Keep going, you are doing valuable research for all of us. :)
 
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We need to include this research of course.
 
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Hi all

So after some digging I found this :- Adventures of Greg lean steer

he has this to say ?

I increased the pivot angle today and discovered that the greater angle, the more steering input you have (duh!). However, because my pivot is so far back, it results in a negative trail and that makes for a very unstable ride at faster speeds. Positive trail would have the "X" shown in the photo slightly in FRONT of the wheel - positive trail is a requirement because when you turn the wheel while moving, forward motion wants to return the wheel to straight - thus providing a balance for your steering input. If the trail is NEGATIVE as it is in this photo, then forward motion wants to continue a steer which could result in some very scary moments. Don't try this at home.



So does this basically tell me why my python is unstable at speed ?
is my 56' pivot angle ONLY acceptable because I have handle bars on the steering part ?

So I wonder if the solution lies elsewhere ?
i.e If I could get rid of this instability perhaps I could happily live with the bars on the non-tilting part ?
Maybe a change of the pivot angle would increase the stability ?
or maybe a Python front end is not the way to go after all ?

Paul
 
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Ok I think I understand this ?



Assume the blue and red by the axle are the offset between the steering axis and the axle generation the trail/
blue positive trail ?
red negative trail ?

Any trail is a lever increasing the force applied to the wheel either in front of or behind the steering axis ?

So assume his trike is turning right and the wheel encounters a force [ say a bump ] hitting it in line with the steering axis ?

The trail increase that force on the wheel.

positive trail tries to push the front of the wheel to the left straightening it
negative trail would try and push the rear of the wheel to the left actually increasing the turn [ that is probably very bad ? ]

Sleepy off to bed...
Paul
 
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