Dexys Midnight Runner?

[DannyC]

In a true (disgraced Antipodean Star) moment......
"Can you tell what it is yet kids?"

Now this was only because my plethora of drum hubs is just sitting there begging to be played with and I wanted to see if (with proper attention to jigging & set-up) I could get some wheels pretty straight and paralytic parallel.

It appears (so far) that yes I can, as they look pretty straight & true to me.

The track "as above" is just a shade <30cm (1ft in old money).
Will it get turned into a trike? Who knows?

There's a million miles between this "afternoon's" activity and something rideable and enjoyable of course(there always is).

For instance:

• Most trikes with rear-wheels arranged like this are Python front-ends but I didn't get on too well with my Python adventure. It worked but it felt alien.
• The only other option I can think of is a twisted chain FWD and that's not an easy task to get right, but that's an acceptable challenge.
• Maybe it would be ok as a "racing machine"..... if, I was fit enough to go racing (currently I am certainly not).
• MBB & this sort of rear end was done as a prototype by Cruzbike but they decided there were not enough benefits to bother to make it an option.

I have in my possession both a pair of 20" Drum hubbed wheels (as above) AND a set of 24" ones too.

I wonder if a front-end that accepted both a 20" fork or a 24" fork would be a good ploy?

Biggest issue for a short-stack like me is that my legs (with a 29" inseam) probably cannot straddle a 24" wheel.

But hey, that's why we make stuff and try it and if it doesn't suit us we chop it up and make something else.

Anyway, sorry to bore you with my load of old nonsense. Take care you lot. Be well, be happy.

 

[Dale Rider]

You little tilter...

 

[stormbird]

I would take it down add straight edges [ long ] to wheels and run a tape over it .....

Not sure you REALLY want a 2 wheeled recumbent ?

Paul

 

[undertoad]

"Can you tell what it is yet kids?"

I dunno', but it looks dangerous, already ......

 

[stormbird]

He thinks he is building a trike ?

Paul

 

[DannyC]

I would take it down add straight edges [ long ] to wheels and run a tape over it .....

Not sure you REALLY want a 2 wheeled recumbent ?

Paul

Possibly not, but there may be points for trying, and my anti-fallover device may work.
As for the parallelism, I'm not sure it has to be "bang-on" and some toe-in/out may be acceptable across the 12" of track.

 

[Radical Brad]

This is an interesting design. It solves a lot of issues with complexity, linkage and even stability. The only downside is that non symmetrical look, which would only be an issue to us autistic folks. Yeah... I could never live with that, I am insane about symmetry and matching patterns.

 

[stormbird]

The guy in the video now uses 75mm cranks so the asymmetry looks much less , it also goes someway towards reducing tyre scrub. One with 170mm cranks can chatter badly if asked to corner sharply , even when being pushed !

Paul

 

[Popshot]

The only downside is that non symmetrical look, which would only be an issue to us autistic folks. Yeah... I could never live with that, I am insane about symmetry and matching patterns.

I know exactly what you mean, me too. It would grate at me enough to put some linkages in and much more building to get some symmetry.

 

[DannyC]

All valid points, and there is nothing to prevent the shortening of cranks at any point in the future; it's just cutting through welds and then re-doing the alignment exercise I have already done on shortened cranks.

The Citroen DS range of cars used an expensive hydraulic suspension system and this gave the cars a "magic carpet" ride, but it was at a cost.
Renault achieved a similarly softer ride on the less than perfect roads of France by offsetting the rear wheels and having a torsion bar between them on the Renault 16. Just like the i-lean the offsetting reduced the height changes by 50% as felt inside the passenger cabin. It was highly thought of at the time for its ability to smooth out the rough French roads. This won't have a torsion bar of course.

Its not at all new of course, and many people have already trodden this path (including Paul); so as he says above he knows it behaves like a 2-wheeled recumbent even though its a trike.

I may not actually progress it; so far it has been 1 afternoon's dabbling to see how hard/easy setting up the alignment would be with just simple tools (it went just as easy as I thought it would be). I already have trikes I struggle to ride with any vigour so adding another trike I don't ride enough may be sheer folly.

 

[stormbird]

If you make the rear end wide enough [ think cargo trike ] then you don't notice the asymmetry...

Oh the riders not in the middle now , DOH

Paul

 

[DannyC]

My current idea (may not work of course) is to have a variable resistance to the movement of the cranks.
I believe that when you brake at a stop the wheels are locked and the tilting is disabled. BUT, you are on a 12" track so it's easy to topple?
When you want to set off you don't want the thing just falling on its side when you release the brakes, so a resistance to static "fall-over" is applied.
When you are moving at a reasonable rate it ought to behave ok?

 

[stormbird]

I read on someone's thread [about tilters ] that if it has a tilt lock and it is applied then the steering behaves differently to when it is free to tilt and this can cause crashes ?

When you are moving at a reasonable rate it ought to behave ok?

What do you mean by that ?

Just trying to avert a catastrophe and save you going down a dead end.....

Paul

 

[DannyC]

I read on someone's thread [about tilters ] that if it has a tilt lock and it is applied then the steering behaves differently to when it is free to tilt and this can cause crashes ?

Tilt lock is at a stop only and a sub-function of both rear wheels being locked by braking. as soon as the brakes are off, it's free to tilt.

What do you mean by that ?

I am referring to those mysterious forces that try to make a rider and machine lean over on turns etc. The faster the turn the more the tilting forces take effect. What I am postulating is that a certain level of "resistive" force that tries to prevent tilting freely happening can be overcome by the application of these forces.

Imagine if you will the rider on an empty road that freely steers an "S" shaped path as he rides along whistling a merry tune through his broken teeth. He tilts left and right automatically, it just happens. So too I am anticipating this will try to "freely tilt" but it can only do so IF the tilting forces are sufficient to overcome any resistance to tilting that has been applied. Not a "lock" just a reluctance to Freely-tilt.

Not saying it will work (I don't know if it will).....yet, and we are a long way from any life-threatening activities.

 

[Popshot]

A tilt lock can be a brake disc attached to the crank pivot and caliper attached to the chassis. Right hand does regular brakes and left does the tilt lock. With practise the tilt lock and be used progressively in both coming one and being let off.

 

[DannyC]

A tilt lock can be a brake disc attached to the crank pivot and caliper attached to the chassis. Right hand does regular brakes and left does the tilt lock. With practise the tilt lock and be used progressively in both coming one and being let off.

Yes I have seen that used before and I am sure it works well as a system once you have the "moves" embedded in your head and hands.
Yes, having a separate tilt-lock/brake might be excellent for R/L turns at junctions where you don't want to risk flopping over in the road at low-speed.

The thing is that locking the wheels at a stop is also a tilt-lock all by itself, so you should be able to just sit there with the brakes on and your feet still up and ready on the pedals.

What I have arranged in addition to this naturally occurring tilt-lock is a very simple addition to:

• Keep the trike in a mid/vertical-position on level ground without a rider on it or any form of lock applied.
• Gently resist the tilting action and always try to remain in a neutral position if possible (not a preventer, a damper with a return to home position).

Testing it with just a luggage scale and a strap shows a force of 10Kg or more is required to get significant deflection of the crank-arm, so like I say it isn't a lock or a brake its a damper only. The next test will be to see how much force is required to get it to tip-over.
For this I intend to put both wheels on the deck and the end of the spine in the cup of an axle stand and see how easy it is to tip while I am sitting on the keel.

Now it might all be a waste of time, but it's my time to waste.
Update:
OK scrap that test, you NEED the 3rd corner also firmly planted properly in order to test effectively.
But, as expected it stands up on its own. without slipping off to one side or the other in a major way even without any tilt-lock/brake.
Looking at the effective footprint of this rear section it has a track of c.30cm and also the axles are displaced from each other by about 30cm.

More work & investigation needed.

 

[DannyC]

This is an interesting design. It solves a lot of issues with complexity, linkage and even stability. The only downside is that non symmetrical look, which would only be an issue to us autistic folks. Yeah... I could never live with that, I am insane about symmetry and matching patterns.

Yes but it will match the doors I have planned for it.

 

[stormbird]

There is a fundamental problem with a separate tilt lock ?
When locked it behaves like a 2 wheeler requiring you to counter steer to start the thing leaning before you turn.
When unlocked it doesn't

You would need a more agile brain than I have to switch between modes at will ?

There was a Canadian I think his Blog was ' The Adventures of Greg ' his tilter had a sort of automatic lock where if he was going straight it was locked , any steering input unlocked it and it was free to tilt.
IIRC he abandoned it when it took to just dumping him on the floor for no apparent reason.

Paul

 

[Popshot]

There is a fundamental problem with a separate tilt lock ?
When locked it behaves like a 2 wheeler requiring you to counter steer to start the thing leaning before you turn.

If you turn when locked it won't tilt at all. If it does then it can't have been locked. A tilt lock on an ilean is only any use for keeping the trike upright when stationary. It doesn't have enough width to use as a regular trike with a tilt lock on and in motion.

 

[Popshot]

Just wondering Danny at what angle does an ilean run out of function and default to the inside wheel only? I suspect it's well over any realistic angle you will ever get to and if that is the case you could widen the track with some bending and strengthening of the arms. A wider track will lower the angle at which it takes to the inner wheel but there may be enough leeway to go a bit wider to help stay upright easier at traffic lights etc.

A wheel brake anti-tilt mechanism will be more effective the wider you go too as you'd get more wheel movement for the same tilt. I'm only talking of adding an inch or two to each side.