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

Joined
Feb 7, 2008
Messages
3,398
Location
Nottinghamshire England
Tilt#2 = 72 miles - retired - dangerous
Tilt#3 = 272 miles - [semi] retired - proved tilting concept
Tilt#4 = 115 miles

Only another 10 miles and no drama today , seems the trike has the most problems when on footpaths/pavements etc compared with roads , i think that is because they have the steepest and most numerous changes of level sometimes just oscillating between slope - no slope - slope etc .

Strange think happened Sunday , I sold an item on Ebay and a youngish lad turned up to buy the item and told me he did bump/pump bicycle stunts ? so he shows me a video on his phone where he bounces a bike high enough to land on the top of a UK postbox !!! they are tall ! 5' 4" or 162cm
However he had never seen a recumbent and was interested in Tilt#4 , I wheeled it into the cul-de-sac showed him where the brakes were and said to ride out the cul-de-sac turn right down to the bottom of the street and back , nope he made it to the end turned it around leap off and said ' you really have to lean ' and gave it me back !

Hey ho Paul
 
Joined
Feb 7, 2008
Messages
3,398
Location
Nottinghamshire England
Tilt#2 = 72 miles - retired - dangerous
Tilt#3 = 272 miles - [semi] retired - proved tilting concept
Tilt#4 = 125 miles

Bit late leaving so another different short route taken , bit more challenging couple steep down hills covered in leaves , slow and safe , couple steep but short up hills ditto the leaves slipping front wheel however we made it to the top without getting off so result.



Decided if I could get one side spot on why not the other ?

So cut off cleaned up and carefully welded on , much better and now assembled ready for riding , almost.



Handle bars to short although previous dimensions suggested they should be spot on ?

Re-measure shows:-

seatbarsdifference
Tilt#418"27"9"
Tilt#515"18"3"

So I need a new set of riser nearly 6" longer , usual method is to lengthen some MTB bar ends , they are getting harder to find on Ebay I had to buy a new set , apparently in the MTB world they were a short lived fad and now seen as ' old hat '. So if you have some hang on to them they are useful.

Paul
 
Joined
May 31, 2013
Messages
3,293
Location
South Benfleet, Essex, England, UK
Paul & I have been pondering why he has some difficulty getting SA drum hubs mounted on his trikes because my mounting method has never presented me with a problem.
Paul sent me one of his spare hubs and followed up with a brief sketch & e-mail explaining how he would like me to try to replicate and/or successfully resolve the problem and the mounting style he would like to employ.
Here's his sketch:


It is ok in theory but when measuring the parts and bolts/tubes Paul sent me it became clear that the precision tube would be too small an OD to work properly/well.

As I had some 20mm round bar in my odd's-n-sod's bin I fired up "Lathe Boy" and he made some replacements for the existing SA standard parts.
Basically I created my own 20mm OD 12mm ID tubes with a turned down section (19.75mm OD) at one end to fit into the casting of the SA backplate.
The end result looked much like the SA original but was much longer and stands the hub sufficiently off the face of whatever you are mounting the hub onto so that none of the operating parts foul on the mounting surface (which has been Paul's major problem).
Here is the replacement part and the hub bolted to a 3mm thick section of angle-iron (which I use as my wheel trueing stand. ;)


As you can see in this "profile-shot" the brake operating arm and its pivot bolt, the backplate anti-turn post etc. are all clear of the surface to which the hub is mounted.
The anti-turn post is just a stub of 12mm round bar that is drilled & tapped for an M6 button/flange-head bolt.
The hub spins freely, all parts are squared off and true, so I think we can call this a success.

A lathe would NOT be necessary If 12mm ID/20mm OD tube had been available as the required minor dimension change could be accomplished with a file/flap disk.

Here is a gratuitous video explaining what's what. ;)

 
Joined
Feb 7, 2008
Messages
3,398
Location
Nottinghamshire England
Tilt#2 = 72 miles - retired - dangerous
Tilt#3 = 272 miles - [semi] retired - proved tilting concept
Tilt#4 = 135 miles

It was some apprehension I took the dog out this morning as there had been a frost overnight , where I live was about +3c however the run to mothers in out in the country side and it could be considerably colder.
Luckily the frost appeared to be an air frost and none visible on the ground.
Cold enough for long socks over short , body warmer under jacket and silk gloves under usual gloves , otherwise nice to be out.
Again a 10 miles to get there early as mum going out early herself.
This shot is of part of the route , to the left of the brightly lit building on the left and to the horizon in line with the TV aerial is the finish.
Lovely cloud formation being lit from the sun rising behind me , about 7:25am


Always wanted to capture a ' long shadow man ' picture...



Sun distorting my image however you can see balancing with no hands on the bars and bars and track appear to be the same width [ shame about rubbish in picture ] taken outside new Amazon warehouse.

Old bar height ;-


new bar height :-


Can't use all height as the cables for the gears are not long enough and the old bars need to go back to assemble Python Mk2 when it is time to pass it on.



these are the old bars and Dan's [ bless his cotton socks ] constant puzzle when in Holland the first time.

Dan - So how did you make the bars ?
Paul - I cut some bar ends and took some lawn mower handle bar filed it down and hammered it in.....
Dan - yes but how did you fix them in ?
Paul - I took some lawn mower handle bar filed it down and hammered it in.....
Dan - yes but how did you fix them in ?
Paul - well I hammered it in............

See Dan's splendid efforts above to get me a reliable - repeatable fixing for my drum brakes , what a trooper.

Paul
 
Joined
Feb 7, 2008
Messages
3,398
Location
Nottinghamshire England
Tilt#2 = 72 miles - retired - dangerous
Tilt#3 = 272 miles - [semi] retired - proved tilting concept
Tilt#4 = 135 miles - [ semi ] retired - maybe born again ?
Tilt#5 = 12 miles

Ok so 12 miles on Tilt#5 - changes made to it are ?

it now has the same track as Tilt#4
Seat 3" lower - feels a little safer
3" height difference between pivots and seat - unsure I can feel that
otherwise much the same as Tilt#4 .. except who stole the turning circle ? it feels like a oil tanker compared to Tilt#4

So currently mulling over re-jigging Tilt#4 to lower seat by about 3" , then putting it back into service.

Been asking on BROL what happens to other tilters when they encounter lateral variations in height of the rear wheels ?

Anyone on here ride a tilting trike

No definitive answer yet , although I think it depends a lot on the way tilt is implemented ?



The old adage trotted out that tilting 3 wheeler's ride like a 2 wheeler obvious is NOT true for all tilters ?

In the above [ quite common in my part of the UK ] a 2 wheeler would either chose path A or B and not notice the speed hump.
A trike whether it tilts or not is forced to ride one wheel path A and one path B ?
So what happens to a free tilter in this situation ? does the bicycle style riding cause the rider to remain vertical because the tilt can absorb the height difference ? or is the rider forced to tilt with the trike ?
i can see a parallel tilter maybe reacting differently to say Magic2 where the rear wheels are rigidly coupled [ almost like mine ]
Mine the whole under frame is rigid and so looks like the drawing , however I actively tilt the seat so I remain vertical.

paul
 
Joined
Feb 7, 2008
Messages
3,398
Location
Nottinghamshire England
Tilt#2 = 72 miles - retired - dangerous
Tilt#3 = 272 miles - [semi] retired - proved tilting concept
Tilt#4 = 135 miles - [ semi ] retired - maybe born again ?
Tilt#5 = 24 miles
Total = 503 tilting miles so far..

Nice ride on Tilt#5 despite drizzle in some parts.
Learnt a nice trick today , I approach a roundabout that has 2 lanes of traffic onto it and the far lane invariable has queuing traffic and they park across my in the middle up ramp.
I noticed they were always close to the white line on their left and so I can ride between the cars and then do a 90' turn left and I am now narrow enough to squeeze between the curb and the car to get to my up ramp.
[ I do make sure I catch the eye of the driver capable of running me over , so they can see what I am doing 👍]



Nice !

So Tilt#4 is having a seat reduction exercise dropping it's height from 18" to 15".



The rear part will be rolled over so the main boom is below the dead axle and not above as picture.
C will be chopped off and re welded to meet part 1



This drawing implies that will work ? [ Psst don't tell Dan I can do scale drawings , I have told him I ALWAYS wing it ! ]

Currently cut up awaiting elastomer mounts being welded to new upper side and part labelled ' New Piece ' being welded to trimmed down pivot mount , then they can be propped up level and marked where they meet.
Couple cuts and a weld and we should be back in business again.

Let the adventure continue.

Paul
 
Joined
May 31, 2013
Messages
3,293
Location
South Benfleet, Essex, England, UK
This drawing implies that will work ? [ Psst don't tell Dan I can do scale drawings , I have told him I ALWAYS wing it ! ]
We suspected you were cheating! ;)
 
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Feb 7, 2008
Messages
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Location
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Ok got some done , cut off pivot mount , trimmed it and reversed elastomer mounts , tack welded a short stub to old pivot mount



just enough on the stub to trim to meet main boom ?



Now to the giant bluebottle in the liniment ?



From the forward elastomer to the end of the seat sub frame is about 5" , from picture above this one I have less than 1.5" 😥

However all is not lost as the surgery seems to have shortened the w/b to about 37" I want at least 38" and could live with 40" I reckon.

That does mean sleeving the front of the main boom and adding a few inches in there , however this is only a prototype and if it is not done it is not ridable so I think the answer is obvious.

What is less obvious is how much lower did I get the seat for all this work ? maybe 16" and not 15" ?

So I may look into a different seat sub-frame to gain a bit more seat drop and seat mounts that angle more backwards at the front [ if that makes sense ?]

Paul
 
Joined
Feb 7, 2008
Messages
3,398
Location
Nottinghamshire England
Tilt#2 = 72 miles - retired - dangerous
Tilt#3 = 272 miles - [semi] retired - proved tilting concept
Tilt#4 = 135 miles - [ semi ] retired - maybe born again ?
Tilt#5 = 36 miles
Total = 515 tilting miles so far..

Usual 12 miler this morning , a little fine drizzle however just nice to be able to ride somewhere.
Odd happening the lower pivot bolt came loose , I rode it about 2 miles like that before I was at a suitable point to tackle it luckily I had not lost the lock nut [ despite being know to re-use them to many times !
The inner nut was loose , it allowed the front end to move from side to side with every pedal stroke , I tried my best to ride it smoothly without the rocking and failed miserably.
Perhaps I am not cut out for riding a real Python ?



So extending the front end this is one of the 4 sides I tackled first , I left it clamped up in an attempt stop it bending whilst cooling.
2 of the sides are cause for concern , to find room for a inside piece across the joint I had to cut though a old hole for the elastomers and ended up with this.



You can see the internal round tube however the hole looks a bit big for filling with TIG ?

I may look at drilling it to M10 and adding a nut and bolt , then I just have to join their sides to the outer rim of the big hole ?

Or maybe I have a washer that fit's ?

Any other idea's ?

Paul
 
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You can see the internal round tube however the hole looks a bit big for filling with TIG ?
Get the MIG spray-gun on it (he said helpfully). ;)
 
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Solution I used was to just weld around the outside , leaving a sort of belly button depression in the middle ?
I figured any weld in the middle would not be adding much to it's strength/integrity ?

Paul
 
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Messages
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Ok good afternoon of tinkering ...



Mocked up rear and front propped up at <>0' and main boom overlapping forward to give a wheelbase of 41" , I was shooting for 40" however the extra inch will increase the luggage space at the expense of maybe not fitting in the car un-assembled[ we can live with that ]



So normally you would dissect the angle and weld each half together ? however that is 2 cut pieces to get right and 4 raw edges to weld together ? would it be easier and stronger if the cut followed the line the left part makes on the main boom ?
Quick angle check shows the fwd stub @ 34.6' so taking it from 90' gives a pivot angle of 55.4' I think we can live with that :whistle: after all it ain't rocket science !



So I made 2 long and 2 short cut's and ended up with this , must have beem my lucky day as this is how close I came to the inner joint reinforcement :giggle:
A touch with the flap disc got that out of the way and after welding I had this.



Next up is to decide how to finish it off ? I could cut to the black line both sides and plate the hole with some 3mm for strength ?
Or instead I could cut vertically in the hatched are from the lower point up to the boom and use a smaller piece of 3mm ? jurys out at present I think I prefer the shorter cut leves more material in a high stress area ?



An so the obligatory hand tightened bolted together , I have not sat on it as I was running a tape measure over it.

Seat 16" was shooting for 15" [ could shave 1" almost of the seat sub-frame if needed ]
W/B 41" was shooting for 38" to 40"
Seat front to BB 32" was shooting for 28" Tilt#5 [ my inside leg is only 32" ]
I will see if I can ride it , if not without any modification to the seat mount/subframe there is 2" of seat adjustment fwd before the rear seat mount hit's the rear elastomer and I have about 1/2" of adjustment left at the front.

So onward and ever upward....

Paul
 
Joined
Feb 7, 2008
Messages
3,398
Location
Nottinghamshire England
Tilt#2 = 72 miles - retired - dangerous
Tilt#3 = 272 miles - [semi] retired - proved tilting concept
Tilt#4 = 135 miles - [ semi ] retired - maybe born again ?
Tilt#5 = 48 miles
Total = 527 tilting miles so far..

usual ride this morning , no drama , I do think the brakes are improving a bit ?
Before they had very hard lever pressure for little stopping power ? now the pressure seems less and they are beginning to have some bite and seem a bit better at light braking instead of all or none.
Looks like they need some miles to bed in ? mileage is Tilt#3 + Tilt#5 so currently 320 miles .



Got this plated today , now ready for paint.
I was to cut along the blue line and plate the resultant hole , however that is a high stress area so I decided to cut to the red line and plate the end with some 3mm , it will be hardly visible when the trike is back together.

Paul
 
Joined
Feb 7, 2008
Messages
3,398
Location
Nottinghamshire England
Tilt#2 = 72 miles - retired - dangerous
Tilt#3 = 272 miles - [semi] retired - proved tilting concept
Tilt#4 = 135 miles - [ semi ] retired - will be born again Tilt#6 ?
Tilt#5 = 58 miles
Total = 537 tilting miles so far..

Nice ride squeezed through somewhere not usually accessible despite this having less of a turning circle than Tilt#4 so well please.

Tilt#6 has been assembled , ran out of time to connect brakes and give it a run ditto take some pictures , maybe tomorrow...

Paul
 
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Feb 7, 2008
Messages
3,398
Location
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Ok we have Tilt#6



It is ridable , however not by me very far the seat to BB distance is almost 30" and for my comfort i need 28".
I can ride it until I come to a tight turn then I cannot extend my leg enough on the outside of the turn , I realise if I set off on my usual run I would soon have knee problems due to over extension.
So I need to lose the 2".



One option of course is to move the seat forward , however the current configuration has run out of forward adjustment.
As can be seen @ B the seat sub frame is as close to the pivot mount as possible, and the seat is as far forward as it can go on the current sub frame ?
I could make this work if I made a mount to follow the red lines instead as that would put the seat mounts as shown between the elastomers allowing it to move forward ?
i discussed with Dan the idea of dropping seat adjustment , in all honesty I have only ever adjusted my seat once in probably 10 years [ and that did not work as it could not go far enough forward ] so as I know I want 28" BB to seat front I could build that in and drop some of the seat fixing hardware maybe making it lighter/simpler in the process ?



Another option could be to take a huge slice out of the front BB post , this would not stop me needing the other rings etc , however it would both move the BB rearward and lower it which might also be useful.
Question is can I remove enough to get the 2" reward needed ? bit of cardboard aided design needed to prove one way or the other ?
On a minor note the handlebar grips are a bit to high now , as can be seen in the pictures there is plenty of scope to drop them down between 2" & 5".

Every time I lengthen the rear frame/put the seat further forward I increase the storage behind the seat ?



I found this box that almost fit's ? it is H 67cm x w 42cm x D 25cm so is 84 litres a good start
Red lines = square it up to the left of the hub I end up with another 47 lites
Blue lines = square it up to the right of the hub I end up with another 8 litres
So total is approx 140 litres not to shabby

green lines = area under the frame 56cm 12cm 50cm which is another 33 litres so worth going for if I need more space ?

Obviously some of this space will be lost shaping the box to match my shoulders and giving it some outside shape [ so less well box like ? ] however it will be a good place to mount some soft mud guards to deflect the water away from me and the back of my arms ?

Paul
 
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there may be a quick and easy way out of the missing 2" , over leg length ?



The gap between the 2 green lines is 3" , if I cut the BB off where the square tubing ends [ lower green line ] I can rotate the BB towards the seat and cut 2 1/2 circles in the square tubing and weld it back on .
It will then be horizontal[ish] and achieve moving it a bit closer to the seat and lowering it all in one job.
it could be win - win , it will still be as ugly as hell however it should work,
Who say's you can't turn a pigs ear into a pigs ear then ! [ paraphrasing [ possibly ] The Reverend Jonathan Swift (1801) ;) ]

Paul
 
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Who say's you can't turn a pigs ear into a pigs ear then ! [ paraphrasing [ possibly ] The Reverend Jonathan Swift (1801);) ]
Indeed. Fugly, but functional :)
 
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Sep 4, 2009
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Location
Columbus, GA
you may not be able to shorten the distance completely but looks like you could use shorter crank-arms, those look to be at least 170's, (every little bit helps) and shorter cranks seem to be better on the knees and hips.
 
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