Another FWD Delta trike.

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The three 24" wheels are all built and I need to make an honest trike of them with their marriage to a frame.

My Tadpoles (Nicor & Loki ) are all that I could possibly want in "Tadpole Triking" and I really don't fancy a "Fat-Taddy" just because it is the in-thing.

So it looks like I will either make another Python trike with a new 24" front frame (and try and resolve just how a little short person like me manages to straddle a 24" wheel); or, perhaps make a more conventional delta frame and employ a twisted chain fwd.

I am however very conscious that Paul (Stormbird) is making a Twisted chain FWD unit for his "MULE" and I have no wish to steal any of his thunder in him breaking new ground for the group and he did declare his intention first (so I would/will be copying I think).

Anyway..... a delta needs a front wheel and some forks, so today I butchered a pair of forks to arrive at this. The forks are widened from 100mm to 135mm to accommodate a Nuvinci N380 hub.
Since this picture was taken, all the slits in the fork legs have been filled. I may want (or need) to cut these dropouts off and shorten the forks and make my own dropouts.
I am yet to determine my actual dimensions (wheelbase and track) and how high the seat will be off the ground (short little legs here). :unsure:

But it is a start at least. ;)
 
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So it looks like I will either make another Python trike with a new 24" front frame (and try and resolve just how a little short person like me manages to straddle a 24" wheel); or, perhaps make a more conventional delta frame and employ a twisted chain fwd.
I suspect you need more seat time on a Python before you consider it a worth stable companion to your tadpoles ?

A twisting chain delta would be a great project , these are not main stream maybe 2 or 3 we know off in Finland and maybe a couple USA/Canada ? so off into the unknown ?

I am however very conscious that Paul (Stormbird) is making a Twisted chain FWD unit for his "MULE"
Wrong I am building a ZOZ 20x20 S-frame copy a 2 wheeler ! and do not have copyright on it !!!

Catch me up , it may encourage me to get my finger out ?

Anyway..... a delta needs a front wheel and some forks, so today I butchered a pair of forks to arrive at this. The forks are widened from 100mm to 135mm to accommodate a Nuvinci N380 hub.
A good start.

I am yet to determine my actual dimensions (wheelbase and track) and how high the seat will be off the ground (short little legs here). :unsure:
is the dining table free ?
 
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Wrong I am building a ZOZ 20x20 S-frame copy a 2 wheeler ! and do not have copyright on it !!!

Catch me up , it may encourage me to get my finger out ?
Oh yes, silly me, of course you are, please excuse my senior-moment. I shall try to remember in future. I hope it is going well?
is the dining table free ?
Sadly not. It has been reclaimed by the enemy and the casualty rate likely to be incurred in its recapture is just too much to contemplate.
I shall go "off-piste" and wing it (you should expect to hear bad reports of multiple failures) ;)
 
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Well today has been a mixed bag (mostly 💩, but some good bits).
The Cut-off Grinder turned its toes up mid-cut (carbon brushes all used up).
I finished my cutting with a 1mm disc in my dangle-grinder instead.
I was pushing the cut-off grinder a bit with 50mm x 10mm bar stock so I guess it was just time it went "pop".
Then I made the end-plates for mounting the Sturmey Archer Drum-hub backplates with the pieces I had cut.
A 16mm hole in each plate to accommodate the hollow axle-tube of the SA backplates. I was very impressed with the 16mm drill-bit from a no-name source. Branded "Silverline" but German made and very good quality and performance and easy cutting of such a large hole after a 4mm pilot had been done first. The holes are a good tight fit for the axle-tubes.

 
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Could a short length of 20mm od x 16mm id tube do the same job? It'd weigh a lot less.
I am sure it could. This will fulfill several functions and while I can "weight-weenie" like crazy, I am using what I have to hand and that I know will work.
Having had a part fail on me and cost me a shoulder in a 29mph cartwheel crash, I am averse to doing that ever again. But your point is taken and valid.
Wait & see what the finished piece looks like with the hub backplates mounted, then we can discuss swapping these for a single piece of 20-OD/16-ID tube. ;)
 
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I just weighed both pieces together 500g (so 1.1 pounds). It is a trifle on the "heavy" side, but I am happy with that as it Will be a solid unflexing mount for the wheels and the anti-turn element of the backplate as well as a place to drill & tap for removable mudguard mounts. True! - It could be done with much lighter materials but it is my neck and my risk so I am erring very much on the side of caution.
 
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OK, so sometimes we do just "Goof", simple as that.
Today I cut a section of square tube to act as the rear cross-beam and nailed the end plates on with some tacks from my liquid-metal nail-gun.
I was really pleased with myself.
Until...... I realised I had cut the cross-boom a bit short and maybe a delta trike on this track width might be a personal injury liability, perhaps, maybe, possibly?
What was I saying earlier in this thread about risk? :whistle:
I guess it might depend on how rearward and "tucked-in" I place my corpulent carcass in-between these two monster wheels?



Here are all 3 in a simulation of the flying formation ;)
 
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Here are all 3 in a simulation of the flying formation ;)
Dan the idea is to sit in front of the axle and NOT behind it ?

I'll get my coat .....
 
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Dan the idea is to sit in front of the axle and NOT behind it ?

I'll get my coat .....
Ahhhh...... good to know where I am going wrong. Thanks ;)
 
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So, notwithstanding yesterday's adventure into "too small/narrow-land", today we went into "Essex Wide-Boy" mode and redid the dead axle beam in a newer, wider size (would you like to go large with your order Sir?").

First I cut off the tacks holding the previous version together (good penetration on all the welds (I am happy to say) we do like a bit of penetration don't we?


Then after I cleaned the plates up again I cut a fresh section of tube to provide me with a 34" track (same as a Hase Catweasel, and yes, I know it isn't a Catweasel, but I like that name).
Again, it was just lightly tacked and then I put the wheels back on and had some further fun with more tube and some clamps in assembling more bits together to look like a 24" wheeled Delta Trike.
You can see how it "dwarfs" the tadpole behind it. The track is 34" and the wheelbase is 55" in the mockery mockup shown here.

All angles/distances etc. are just guesstimates by eye at this time with no science behind any actual "fitting" to yours truly. Especially the bit of tube holding the seat-back up in the air. :eek:

Anyway, it is a "start" at least.

 
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Wow a mans trike !

You could walk under that with a top hat on :LOL:(y)
 
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Wow a mans trike !

You could walk under that with a top hat on :LOL:(y)
But then a bloke of my limited stature can walk under any trike with a top hat on. ;)
It looks a tad LARGE to me. I need to take some measurements from the Python and the Tadpole regarding seat to cranks distancing and then see how it looks then (i.e. where the seat ends up).
Traditionally the rider's COG needs to be towards the back end of the trike I believe.
I "could" put the seat way back and run a dummy crank at a mid point and then drive a more forward chainring set over the top of the forks remotely via a captive chain-loop if I needed to I suppose?
 
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Traditionally the rider's COG needs to be towards the back end of the trike I believe.
Simpler than that ? for either tadpole or delta it needs to be as near as possible to the widest point of the contact triangle.

That makes it as stable as possible in the roll over scenario ....

However it is not always better for traction.
 
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Simpler than that ? for either tadpole or delta it needs to be as near as possible to the widest point of the contact triangle.

That makes it as stable as possible in the roll over scenario ....

However it is not always better for traction.
Sounds like a compromise is always required as I've never seen a Tadpole rider sat over the top of his X-beam either. ;)
I need to get some angles and dimensions on a scale drawing.
I can take the rider's seat-to-cranks off the tadpole and the Python and work backwards from that to see how close to the rear axle that puts me.
 
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Well nothing much has really progressed other than a lot of thinking has been done.
The main keel cannot be a straight line and the rider ideally needs to be towards the rear and the widest part of the trike so a couple of arrangements sprang to mind.

Firstly:
Given the limitations of my inseam and the requirement to keep the pedals within reach I have decided to split the drive into 2 parts.
The Seat mount, and the rider driven 3-speed cranks will be mounted AV-Style on movable brackets to allow maximum flexibility for rider positioning and adjustment.
The final-drive to the front wheel would be self-contained and linked to the riders input cranks and chainwheel by a captive chain-loop. So a triple with a shifter closest to the rider and a 2-speed chainwheel at the front with the chain-loop input and a final chain (fixed-links) to the N380 CVT hub (so not quite as shown in my diagram below, but I am sure you get the overall principle I am seeking to attain).



Secondly:
There is the option to make a flowroller, but to be honest It doesn't really appeal as the steering looks tome to be a total kludge and wheel-flop a definite feature.



So the jury is still out and no further steel has been cut.
 
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Dan

You possibly have the rings the wrong way around ?

What do you reckon will be the heights of the seat , BB and secondary ring ?
 
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Not overly dissimilar to your top drawing. Could easily have the drive taken to the front via a pulley.
Yes, I have looked at similar. The issue with pulleys is that they sap energy out of the drive train. With a FWD you want the power side of the train parallel with the forks and this means a tight-turn and a small pulley which is the worst combo. The twin chainrings will avoid this by and large.
 
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Dan

You possibly have the rings the wrong way around ?

What do you reckon will be the heights of the seat , BB and secondary ring ?
Yes, in the drawing they are the wrong way round. The seat looks to be around 16-17" the BB I will try to put at 22-23" and the secondary/final is going to have to be up above the head-tube height so 28-9" maybe?
 
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