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

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Another ride , more miles...

Tilt#2 = 72 miles - retired - dangerous
Tilt#3 = 250 miles - retired - proved tilting concept
Tilt#4 = 37 miles

Ok pushing the envelope , well someone has to ....



No previous trike has got through this barrier , now I can with inches to spare , looks like I could do 26" instead of 24" and still get through ? more luggage space !
Really need to try with 24" wheels instead of 20" before committing though.



leaving mothers there is this , only previously usable on a 2 wheeler , sailed through it although definitely a 24" width barrier as the tarmac edging jostles the rear wheels.



the ghost in the machine :) bit faint , however you can see I am quite dressed up as it was very cold this morning [ cold wind as well ]

...and I had it on 2 wheels and it almost tipped over (n)

My fault and not dangerous I went through an old housing estate [ other side of the second barrier ] it is very short of down ramps however riddled with pedestrian short cuts [ like the second barrier ].
Once through the short cut I did not want to ride the pavement to the end so tried dropping off it onto the road.
old trike ride it @ 45' get front wheel down gently then on the brakes one rear wheel at a time ......
You can see where this is going , got front wheel down ok and left rear wheel when the whole lot tried tipping over to the left , not surprising really with 24" track and 18" seat height , luckily left leg not clipped in so shot it down and held the trike whilst the other wheel came off the pavement.

Obviously I should either approach it @90' OR get off ! now ain't that simple :LOL:

have a snagging list for when I am back from holiday , no more riding for a week[ish]

Paul
 
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OK reverted to Tilt'#3 for today's ride.

Tilt#2 = 72 miles - retired - dangerous
Tilt#3 = 262 miles - [semi] retired - proved tilting concept
Tilt#4 = 37 miles

Tilt#4 has a snagging list the most important item being the front BB extension is twisting and squeaking every pedal stroke , 2 x M8 bolts cannot hold the awesome power of the engine :giggle:




On the left is the old BB sadly to short to be raised and welded into the square tubing , so cut a newer one longer and drilled another 3 8mm holes [ making 7 in all ] I then hammered the cleaned up seat tube into the square section .



I added 2 pedal cranks and a M12 bolt and clamped that to the frame in the hope of getting & keeping it square while I welded it in 7 places.



Seemed to have worked so I applied some Hammerite to keep the rust at bay.



It is probable this will be ridden through the winter as time to build a definitive trike will be curtailed shorty due to lack of light and the voracious appetite of the wood burning stove ;)

Couple of more things to attend to and Tilt#4 will be back on the road maybe by Friday if all goes well.

Paul
 
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So Tilt#4 blinks in the daylight ...



pedal BB welded and a bit higher than before , now a couple of inches above the seat , should mean a bit more power.

bar extensions added and it has been ridden around the estate , seems much the same , or put it another way the changes have not affected it's excellent riding characteristics as far as I can tell from such a short ride.

Needs wing mirrors fixing and gear changer/hand grip untangling and fixing.

So Tilt#3 [ foreground ] Tilt#4 [ background ]



Numeric differences ?

PedalsSeat frontSeat backW/BTrack
Original Python15.5"8"??40"30"
Tilt#315.5"12"27.543" [ mistake and why it won't fit in car , should be 40" ]30"
Tilt#424"19"33.5"40"22"



Previous Python was as low as a snakes nipples and so design is more a matter of stopping parts hitting the ground , as the build gets taller all sorts of other problems rear their ugly head and so I have a ' odd ' front end and DannyC has packing problems of his own DannyC's 24" python ....maybe ?

So above show's important points :-

A & 2 are axle height from ground - DannyC has problems due to no ' inside leg ' to speak of AND wanting 24" wheels - dictate frame members height from ground
B seat height - decided to ignore that and let it find it's own place - seems to have worked out ok for me high enough with the available frame parts in the right place.
C rear frame pivot mount , bit of a kludge - it works however from an engineering point of view it is mass of steel over elegance - it may remain ! it is out of the way and not bending.
1 front frame pivot mount
2 front axle
3 BB

1 & 2 & 3 need an elegant frame to join the 3 parts together , this is not it.
2 can limit the horizontal frame members height and so the pivot height - limiting if pivot wants to be mounted higher as seat is higher ?
3 wants to be level or about 2" above seat base - hard to achieve if 2 forces front frame to low - made worse by trying to get from frame parallel to ground - with shown pedal height introduces frame/chain interference as well
Pivot needs some space under seat - and in this case seat needs to be able to slide along for leg length.
However it now shows me what will work and giving me some pointers on how to improve it ?




This may be better as frame sides are only 2 parts [ in blue ] and no chain interference , however have to be careful angle for welding to front pivot part 1 is not that tight I cannot get in to weld all the way around [ high stress ]

all for now Paul
 
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This may be better as frame sides are only 2 parts [ in blue ] and no chain interference , however have to be careful angle for welding to front pivot part 1 is not that tight I cannot get in to weld all the way around [ high stress ]

all for now Paul
A good analysis of the issues (as always) Paul.
If you make your own frame in the manner proposed it might be necessary to add some strengthening struts/stays to the bit that goes down towards the axle?
 
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Tilt#2 = 72 miles - retired - dangerous
Tilt#3 = 272 miles - [semi] retired - proved tilting concept
Tilt#4 = 37 miles

Tilt#3 again short trip to mothers feeling a bit under the weather , probably yesterdays Flu jab :(

The ride contained some mild peril ! on a route I have taken at least 8 - 10 times during my tilting miles.



I approached down the hill on the left on the pavement and pass through the couple with the dog and exit stage right , quite some camber on this bit and lot's traffic on road [ morning rush hour ] I hit a very slipper patch either the metal bits on the grate the dog is stood on or the grate behind him ?
So the trike is tilted to the right and I am at maximum tilt [ I think ] to the left all seems very safe when the front wheel slides to the right about 4" , took me by surprise however nothing else of note happened and my journey continued maybe with me breathing a bit harder for a few yards :whistle:

So previous drawing showing proposed new front end is a load of bull !
If you draw in the chain [ in green ] it can be seen there will be chain interference where the front end has to tuck inwards to get behind the chain wheel ?



The blue parts are simply to high to avoid that.

Another solution would be to copy the Flevo Racer geometry but married to my python pivot ?



that would work , nice and simple and plans/tube sizes etc are readily available for this ?

Flevo plans



need to get some wood and mock this up from the existing BB position across the wheel and the 330 bit will need to be longer till I meet my pivot height ?

all for now Paul
 
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Tilt#2 = 72 miles - retired - dangerous
Tilt#3 = 272 miles - [semi] retired - proved tilting concept
Tilt#4 = 47 miles

So Tilt#4 back into the fray ?

I lost the snagging list so did as much as I could remember and got it rolling again.

Another 10 miles , and whilst the start point and destination are always the same there are many paths to get there ,with any new trike I always start off easy , less steep hills, wider paths , little road work , little traffic and no technical till I have a few miles in.

However Tilt#4 is only Tilt#3 on stilts ? so lets tackle some technical for a change !



Relatively easy bridal way 90' at top and a 45' then a good downhill , no problems.



There are 3 of these to get through , pull mirrors in [ safety precaution , in case I am not mm central ] and breezed the first 2 this was the last no problem either.

Hmm not very technical you say ?

However to get to this point there is a set of steps [ no don't be silly it can't climb steps [ well I don't think it can ]] so :-



Can you see behind the post there is a very narrow sloping path with 4 small radius 180' degree bends , this is actually the first one !

So how far did I get ?



All 4 bends aced , however I could not climb this straight after the 4th bend [ yes at at the bottom of the hill behind the trike ], just to steep and no grip.
Still very happy , this is NOT tadpole territory ;)

So whilst contemplating a from scratch Flevo Racer front end for Tilt#4 I decided to revisit this :-



It will actually be much more vertical than this with the seat tube being horizontal.



It lead to these strange marking on the front path , what this tell me is to get the BB in the same place from the seat front the new axle will be 6" further forward than the existing wheel.
So the trike will be no longer but the wheel base will increase from 40" to 46" , unfortunately I cannot shorten the trike by the whole 6" as these inches would have to come out of the luggage space behind the seat.
However I may cut out 2" so adding 24" wheels won't increase the length enough to stop it fitting in the car.



My preferred method is adding to the drop outs with some 4mm sheet and then welding tubes from those to the pivot area.
So drop outs trimmed to square them up , need so 4mm sheet next to fashion the extensions.

Paul
 
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Messages
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Tilt#2 = 72 miles - retired - dangerous
Tilt#3 = 272 miles - [semi] retired - proved tilting concept
Tilt#4 = 47 miles

So Tilt#4 back into the fray ?

I lost the snagging list so did as much as I could remember and got it rolling again.

Another 10 miles , and whilst the start point and destination are always the same there are many paths to get there ,with any new trike I always start off easy , less steep hills, wider paths , little road work , little traffic and no technical till I have a few miles in.

However Tilt#4 is only Tilt#3 on stilts ? so lets tackle some technical for a change !



Relatively easy bridal way 90' at top and a 45' then a good downhill , no problems.



There are 3 of these to get through , pull mirrors in [ safety precaution , in case I am not mm central ] and breezed the first 2 this was the last no problem either.

Hmm not very technical you say ?

However to get to this point there is a set of steps [ no don't be silly it can't climb steps [ well I don't think it can ]] so :-



Can you see behind the post there is a very narrow sloping path with 4 small radius 180' degree bends , this is actually the first one !

So how far did I get ?



All 4 bends aced , however I could not climb this straight after the 4th bend [ yes at at the bottom of the hill behind the trike ], just to steep and no grip.
Still very happy , this is NOT tadpole territory ;)

So whilst contemplating a from scratch Flevo Racer front end for Tilt#4 I decided to revisit this :-



It will actually be much more vertical than this with the seat tube being horizontal.



It lead to these strange marking on the front path , what this tell me is to get the BB in the same place from the seat front the new axle will be 6" further forward than the existing wheel.
So the trike will be no longer but the wheel base will increase from 40" to 46" , unfortunately I cannot shorten the trike by the whole 6" as these inches would have to come out of the luggage space behind the seat.
However I may cut out 2" so adding 24" wheels won't increase the length enough to stop it fitting in the car.



My preferred method is adding to the drop outs with some 4mm sheet and then welding tubes from those to the pivot area.
So drop outs trimmed to square them up , need so 4mm sheet next to fashion the extensions.

Paul
Paul,
That's exactly where I chopped my dropouts. Mine were not flat above the cut-line like yours though.
I hope it goes well. :)
 
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Dan

Sorry I think you have the wrong end of the stick ?



The black lines only represent the size of the front pivot to axle member NOT cutting lines , plan 1 was to weld some 4mm [ blue hatched ] to the squared off drop out and attach the front tubes to that like Python 1.



Whilst contemplating that I though it would be a good opportunity to correct the upward facing axle slot ?

It only needs one more piece welding in looks to have plenty of weld area , and it will save having to use lawyer washers to hold the wheel in [ always a pain in the bum IMHO ]

Paul
 
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Oh. Silly me.
 
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Oh. Silly me.
No really the black lines could have been seen as cutting lines , they show me where on the drop out the 40mm tubing might be to maintain the same pivot height at the frame end.

This front end needs to be a bolt on replacement for the one in use.

Mine is not flat above the upper line ? look at the leg on the left , also I want the longest weld possible ? the drop out is quite narrow there.

Paul
 
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Tilt#2 = 72 miles - retired - dangerous
Tilt#3 = 272 miles - [semi] retired - proved tilting concept
Tilt#4 = 57 miles

So Tilt#4 back into the fray.

I am having problems riding Tilt#4 ? there is a nagging worry that all is not well some how/where.

So I am thinking why and why now ? having done 272 miles apparently worry free on Tilt#3 ? partially I think DannyC's horrific accident and it's repercussions are causing the old [ make that very old ] mind to dwell to much on what ' might ' happen [ to me ].

Not helped by the knowledge that Tilt#4 is both higher and narrower than Tilt#3.

Thinking back to riding my 2 wheeled recumbent when I built Tilt#1 I discovered that it was impossible to get the 2 wheel recumbent to ride in straight line and be tilted over , in other words you could only get it to tilt when cornering otherwise it resisted tilting when riding in a straight line [ unexpected stability ] .

Now my tilters do not behave like that , they tilt at the drop of a hat even when going straight [ unexpected instability ] , also they are very sensitive to one wheel either rising or falling [ normal ] however when the rider can tilt this requires you to tilt to stay vertical if you don't you run the risk of either falling out of the trike or [ if it narrow like TILT#4 ] the trike tipping over.
I wonder if the narrower track of Tilt#4 is making this more obvious/sensitive ?

So the reason for tilting was a :-

narrow track to get through barriers
higher seat to get me out of the rain and dirt
higher frame to get the trike out of the rain and dirt

PedalsSeat baseSeat backW/BTrack
Original Python Mk2
15.5"8"??36"30"
Tilt#315.5"12"27.5"43"30"
Tilt#424"19"33.5"40"22"
Tilt#5 proposal ?19"14"29"40"24"

May be Tilt#3 needs to become Tilt#5 ? a trike between Python Mk2 and Tilt#4 ?

It does get me higher than Python Mk2 however the main frame is still the same height even though the seat is now 4" higher
I could try a track of 24" should still get through the barriers ?

I don't want another prototype , however the whole point of the trike is to ride it through any winter conditions



I rode the non tilting Mk2 in this



So the question is would I have tackled these conditions on Tilt#4 , I don't think I need to answer that !

Paul
 
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I do think it is right to be cautious. At our age broken limbs etc. take a long time to heal.
You have got a lot of good knowledge out of the tilt adventure, and clearly you are intuiting the safest combination that you feel most comfortable and secure with.
A "best-of" melange of all the tilters sounds ideal to me.
 
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Tilt#2 = 72 miles - retired - dangerous
Tilt#3 = 272 miles - [semi] retired - proved tilting concept
Tilt#4 = 69 miles

So Tilt#4 back into the fray.

So another run to mothers , the longer usual way this time.

No problems as such , I notice my distrust of it tends to be when the route is very bumpy , so the tilting is not intuitive as when cornering , instead you are thrown from side to side and just have to hang on till it is over.
Caught out by lack of traction :-



I approach from the right do a 90' and then tried climbing the wet grass bank by the fence so zero speed and stopped 1ft from the top ! bit tricky as I don't want to roll back into the road so have to stand whilst holding the brakes then swap one hand from the brake to a pedal to stop it rolling back, On the other trikes I could reach the wheels and wheelchair it up onto the level part , however not on this trike.

Not much else done , the approach of winter brings more jobs around the house to be done.

paul
 
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Could some of the odd feeling on #4 come from the higher tilt pivot?

I think I remember Jensen / purplepeopledesign on 'bentrider commenting that the key to making his "Magic" tilting trike feel like a bike was getting the tilt pivot as low as possible. Bikes naturally tilt from pavement height; tilting trikes like ours tilt from some point above the pavement, which may feel odd.

It can also mean that if we corner hard enough, no amount of tilt will keep us from flipping. From a blog post about the "Magic" tilter:
In the case of a simple tilter like the Magic, the pivot height cannot exceed half the rear track width or you can have a rollover condition with high lateral G force. The only reason my tilter has such a narrow track is that the pivot is about 5 inches from the ground. Most single-pivot designs have the pivot at axle height, forcing a track width at least 20 inches.
By that metric, I think your tilt pivot (rubber blocks) should be no more than 11" off the ground for a 22" track width? My current tilter pretty much meets that requirement, but the FlevoTrike may not, and it isn't too prone to lifting a wheel in hard turns - I think Jensen uses the Magic for racing, so he may be a little more reluctant than I am to slow down when turning.

-Darin Wick

P.S.: I've been trying to figure out how to make an RWD tilting delta for tandemizing (linked-delta-tandem requires RWD, but my stoker likes tilting trikes & high seats). I had been puzzling over this for a while, and a few days ago I realized that your tilting seat contraption might be an easy answer, so it's possible I'll jump on your bandwagon sometime soon here.
 
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Darin

Thanks for your input and much food for though , I had forgot Jensen's writings and I need to revisit them.

Tilt#3 does not need to tilt ! it is the old Mk1 with a track of 30" and a w/b of about 43" whilst it proved the seat on elastomers could work it did not need it to be ridable.
Tilt#4 is all things and probably does need tilting of some sort to be safe , the idea was floated of locking the tilt out and seeing if it was still safe ? [ the pilot has not felt the need to try that yet ! ]

In contrast:-
Tilt#3 has elastomers 6.5" off floor [ to bottom of them ] and a seat height of approx 11.5"
Tilt#4 has elastomers 13.5" off floor [ to bottom of them ] and a seat height of approx 18.5"

Whilst I have yet to have a ' fright/incident ' on Tilt#4 my gut feeling is under some circumstances I may loose control of it and at that height it may not end well ?

I will re-asses my requirements and may come to the conclusion I can live without tilting ?

Although there is a unexpected benefit , the ride is much smoother with the elastomers and much less unevenness is being transmitted to the ride , although having a pair does mean it is not a full Flevo suspension experience I do have a plan to try something similar on Tilt#3 watch this space :LOL:

thanks Paul

ps does the sail work ? that rig looks heavily loaded ?
 
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Ok done a sketch:-



First example 15" height made up of 8" seat height and 7" navel height [ your navel may vary ? ]
track is 30" so effectively angles are 90' 45' 45' trike will tip when dotted line leaves triangle [ moving right in drawing ] , trike can tilt 45' before falling over ?

2nd example track reduced to 15" angles now 90' 30' 60' so trike now only capable of tilting 30' before falling over.

3rd example track reduced again to 15" now however height acting through a pivot that is half track width high ?
This takes us back to 90' 45' 45' so trike can tilt 45' before falling over.

I realise this is only static and simple dimensions , however is it proof of Jensons claim ?

In the case of a simple tilter like the Magic, the pivot height cannot exceed half the rear track width or you can have a rollover condition with high lateral G force.

So I wonder what my figures are ? these angles seem very extreme , in the real world 15' of tilt was scary ?

We need that Arduino tilt meter ASAP to see what we are riding @ me thinks.

Paul
 
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Ok done a sketch:-



First example 15" height made up of 8" seat height and 7" navel height [ your navel may vary ? ]
track is 30" so effectively angles are 90' 45' 45' trike will tip when dotted line leaves triangle [ moving right in drawing ] , trike can tip 45' before falling over ?

2nd example track reduced to 15" angles now 90' 30' 60' so trike now only capable of tipping 30' before falling over.

3rd example track reduced again to 15" now however height acting through a pivot that is half track width high ?
This takes us back to 90' 45' 45' so trike can tip 45' before falling over.

I realise this is only static and simple dimensions , however is it proof of Jensons claim ?

In the case of a simple tilter like the Magic, the pivot height cannot exceed half the rear track width or you can have a rollover condition with high lateral G force.

So I wonder what my figures are ? these angles seem very extreme , in the real world 15' of tilt was scary ?

We need that Arduino tilt meter ASAP to see what we are riding @ me thinks.

Paul
I will get the bits and pieces of the Tilt-O-Meter out and revisit it.
 
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I will get the bits and pieces of the Tilt-O-Meter out and revisit it.
Dan

Well it is kind of you to offer , however I do have the parts for my own :whistle:

Paul
 
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Dan

Well it is kind of you to offer , however I do have the parts for my own :whistle:

Paul
Good to hear. I am a bit busy with my fencing all week. I hope you will share the code etc. :)
 
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