Thorn Cycles Forum

Community => Non-Thorn Related => Topic started by: Andre Jute on March 20, 2015, 11:18:29 am

Title: Kiffy, genuinely innovative leaning tadpole utility tricycle
Post by: Andre Jute on March 20, 2015, 11:18:29 am
Clever utility/urban trike design with tilting suspension to feel just like a bike, and versatile splitting/anti-theft options. Usefully narrow at only 22in, narrower than the 600mm handlebars on my bike. Could easily be redesigned into a fully self-supporting circumnavigator by using 26in wheels and adding appropriate bracketry — it has the bare bones of an extraordinary touring bike already.

More photos at http://www.bbc.com/autos/story/20141210-kiffy-trike-goes-where-cars-dare-not-tread

(http://ichef.bbci.co.uk/wwfeatures/976_549/images/live/p0/2d/tn/p02dtnqf.jpg)
Title: Re: Kifty, genuinely innovative leaning tadpole utility tricycle
Post by: John Saxby on March 20, 2015, 01:59:42 pm
Thanks, Andre -- interesting device! Your suggestion for 26"-wheel upgrades seems to make sense, too. With just a single- or two-speed hub, can a Rohloff be far behind?  Its compactness makes it attractive for longer journeys on plane or train. Bike Friday has earned a sizeable following for that very reason. The Trike is nice & narrow, too, though the Beeb's story has a misleading reference (a pickable nit, so to speak) to its '22" wheelbase': I'd guess that the wheelbase is in the 45" range, with the track being 22".

You may know that Piaggio make a tilting tadpole scooter, though I find it weird to look at--rather too short-coupled for my taste. (In the same corporate stable as Gilera--sacre bleu!)

On other ways of getting around, there have been some good stories in the press here about the recently completed Iditarod, so near to your heart if not your home, I know.
Title: Re: Kiffy, genuinely innovative leaning tadpole utility tricycle
Post by: Andre Jute on March 20, 2015, 06:37:22 pm
According to the Beeb, the Kiffy is 57in long, which is impressive. That's over 20in shorter than my Kranich. Of course, once you redesign it with 26in or even 700c wheels and balloons, you'll need to increase the wheelbase a little -- or perhaps not, depending on how tight you want it to turn; the cyclist's toes may be inside the wheels without interference arising if the tread (the spacing between the pedals) isn't too wide.

I'm intrigued by the "reverse gear".

My guess is that this tricycle was designed by someone who either doesn't cycle, or doesn't care a damn for cycling traditions. That's not a bad thing at all, as in my opinion roadies are the biggest block (next to dangerous roads, real or perceived) to the spread of cycling as an everyday activity. (Among my best friends are people who say things like, "If he can't keep up 25mph in traffic, I don't want him to cycle." And they're 40-year bicycle commuters...) In addition, the problem with many bicycle designers is that they have roadie backgrounds and adhere to the outworn traditions in which the next generation of cyclist not only have no investment but no interest.

But the narrow track (how can a BBC motoring programme get such simple terminology wrong?), the leaning suspension (essential for dynamic balance with so narrow a track and so tall a bike), and other details of the concept can be carried upward into a grown-up bike, possibly even a touring bike. I'd certainly be interested.
Title: Re: Kiffy, genuinely innovative leaning tadpole utility tricycle
Post by: Danneaux on March 20, 2015, 07:51:17 pm
Andre,

What a clever machine! And from the region of St. Etienne France, a veritable hotbed of framebuilding for ages.

This is an intriguing design as are all "leaners" (or "carvers", as they tend to be called in Germany, where much development on these designs has been done. Most carvers are delta trikes rather than tadpoles). I've had the good fortune to ride several tilting prototypes and they are a wonder at duplicating the lean-turn experience of a normal bicycle -- compared to most trikes. However, they do introduce another factor steering in tight turns, with or without Ackermann steering geometry. The tracking just isn't the same as on a conventional two-wheeled bike.

They are also not fall-proof as most non-leaning tricycles (tadpole or delta) are -- to a point. Much of a non-leaning trike's stability depends on ride height, center of gravity, and road crown. A couple leaners I tried had compensating spring to keep the bike upright while mounted at stops, but these interfered with the ease of tilting.

It seems ideal for its primary purpose as urban cargo transporter, complete with dolly. What do you see as the net advantages of such a design over a conventional touring bike with panniers?

I think leaners are generally great compared to conventional trikes of delta or tadpole design, but don't have it all over a conventional bicycle.

For my use, the triple track would be a decided disadvantage over my single-track bicycle. My homemade 2-wheel trailers are offset so one wheel follows inline with my bicycle's wheels so there is only a double-track. Even so, it is hard to avoid potholes and such compared to running my Extrawheel single-wheel trailer. Even so, it finds more than a few, just as my back tire finds things I miss with the front wheel.

A Dutch friend just splashed out EUR 6350 on a new tadpole velomobile (Velomobile Quest), and is learning he can "find" every bit of glass and pothole in the road as well as catching the odd Heineken can rolling in the wind. I had the same experience trying a variant of the Vector back in 1982? outside Early Winters in Seattle: http://home.comcast.net/~jeff_wills/vector/vector.htm ...this one: http://lh3.ggpht.com/-zGawrEZoItM/S8A8zpcs2fI/AAAAAAAAHJQ/Ljf0cEW7dwU/s288/Early-Winters-Vector-Recumbent-1983.jpg

Thinking back to the Eastern European portions of my tour last summer, I was hard-pressed at times to find room for my two inline tires on the nibbled edge of many very rough roads. I think an offset front wheel would have made passage a bit more difficult. It would also rule out using the train as an option, given how the hanging racks are currently configured and spaced.

This looks like a great option for short-haul cargo-hauling in urban use, in the same way a "Long Jan" or bakfeits is but with some limitations inherent to the design.

Oh! Ever tried one of these? Lots of fun...: http://www.trikke.com/

All the best,

Dan. (...who loves "carvers" and cargo bikes, just as he loves all bikes)
Title: Re: Kiffy, genuinely innovative leaning tadpole utility tricycle
Post by: Danneaux on March 20, 2015, 07:52:21 pm
...On the other hand, this fellow isn't having any trouble with a double-track vehicle out in the woods: http://mpora.com/articles/says-need-working-legs-go-mountain-biking-stacy-kohut-kills#IMogimjTuP7HfFWF.97

Nice to see what is possible.

Best,

Dan.
Title: Re: Kiffy, genuinely innovative leaning tadpole utility tricycle
Post by: Andre Jute on March 21, 2015, 10:44:10 am
Wow! That Stacy Kohut really has what it takes, legs or not.

[The Kiffy] seems ideal for its primary purpose as urban cargo transporter, complete with dolly. What do you see as the net advantages of such a design over a conventional touring bike with panniers?

My main interest in tricycles is as geribikes (TM, a word I created for "bicycle suitable for a geriatric"). If you just ask older people without a lot of cycling experience, often without any experience, taking up cyling for the first time, what they want from a bicycle, you'd design a crank-forward, feet-flat-on-the-road bike like the RANS http://www.ransbikes.com every time. And every time you'd do your dough, because, when you actually put them on the bike, psychologically they feel vulnerable below the waistlines of the carelessly driven SUVs. Reclining trikes and bikes are out even before then; too low to get into, worse psychology, undignified. So, a tall tricycle. But, unless you want to force your new cycling pals to commit to the horrors of vehicular cycling, to taking the lane and keeping it regardless of the tailback of impatient motorists and truckers, the tall trike can't be as wide as it needs to be to counter the tendency of the upright inside wheel to dig in and flip trike and cyclist over it. Hence tilting suspension to civilize a narrow trike.

Those 18in wheels on the Kiffy (why not the more common 20in wheels?) are probably good enough for town utility riding. The dolly is a brilliant labour-saving idea: put your groceries straight onto your bike right at the checkout!

Turning now to your question about the Kiffy concept, developed of course, as a touring trike with bigger wheels, mudguards, a Rohloff (perhaps even with a reverse gear!), a rear rack for hanging panniers. With 60mm balloons I see it as not only stable but more comfortable than a single-track bike. Since the bike is no wider than the handlebars, I see no problems that don't also arise for bicycles and quite a few advantages once you overcome attitudinal resistance built into the cycling community. For a start, you can lose the trailers because the tilter with big wheels and fat tyres can be built to handle at least 240kg/352 pounds. It is therefore likely to be a lot less awkward for loaded touring than an equivalent bicycle. And when you want to stop, no messing around trying to find a kickstand under all the luggage or fiddling with a telescoping pole because your bike designer let you put a kickstand on your touring bike (!); you just n'lock the steering (with or without one of the optional cables) — and walk away.

Sounds like many added conveniences to me, and very little downside.
Title: Re: Kiffy, genuinely innovative leaning tadpole utility tricycle
Post by: Andre Jute on March 22, 2015, 01:22:50 pm
PS. Might add that a tricycle solves a non-problem that new cyclist worry about, the tendency of two-wheelers to weave.
Title: Re: Kiffy, genuinely innovative leaning tadpole utility tricycle
Post by: Evilc on January 15, 2021, 07:34:47 am
I know this topic is old but I am a disabled person and am seriously considering a kiffy but it looks just about impossible to test ride, and I am not clear if it is possible to import one currently.

I have extremely poor balance and have an e assist Christiania, which obviously is large and heavy.

I am not clear from the discussion here how self balancing this is, the stability of the Christiania is fundamental for me.

Why has it only three gears and not the eight internal with internal brakes the Christiania has?

Is there anyone in London area able to service them?

Are there Marathon Pluses that will fit that wheel size?

I assume it can easily be treated as large luggage for trains and planes, does it have a bag for Eurostar?

Thanks?
Title: Re: Kiffy, genuinely innovative leaning tadpole utility tricycle
Post by: Evilc on January 15, 2021, 07:40:09 am
I forgot to say I use toe clips as my legs will go walking off by themselves and not stay on the pedals. Putting my feet down when stopped does not happen
Title: Re: Kiffy, genuinely innovative leaning tadpole utility tricycle
Post by: Andre Jute on January 15, 2021, 09:46:37 pm
I wouldn't spend my money if I were you, Evilc, unless you can first, at a minimum, see video, preferably extended, of the Kiffy operating in traffic.

You did the right thing by telling us about your legs and the toeclips in your addendum. The problem with all these tilters is particularly relevant to you: Unless the designer makes provision for keeping it upright without forward motion plus the pilote's sense of balance, at standstill they fold over until the earth stops them. The device for keeping them upright can be mechanical, as in a disc brake on one of the cross bike connectors of the suspension, or electro-mechanical to keep it light and programmable and even automatic, in which case the stiffening could be made inversely proportionate to speed, cutting in at say 9kph and increasing with lower speed until it is 100 per cent at around 2-5kph. So the first question you want to ask is, "What keeps the leaning trike upright at very slow speed and at standstill?"

On a trike with only one wheel at the back, you can have whatever gears are available for two-wheel bikes. It's another reason to choose a tadpole rather than a delta trike.
Title: Re: Kiffy, genuinely innovative leaning tadpole utility tricycle
Post by: Evilc on January 16, 2021, 11:52:57 am
Thank you :-) you have highlighted a couple of issues that have been buzzing around incoherently in my brain.

I googled folding trikes and was sent to really boring sites showing the classic old biddy deltas.

I already knew about kiffy but as you have correctly commented i was unclear if the tilting mechanism meant the basic principles of a trike- stable when stationary unstable when moving - the opposite of a bicycle- were lost.

Your term geribike is where I am coming from. I am involved in Wheels for Wellbeing and recently wrote this. https://clivedurdle.wordpress.com/2021/01/09/enabling-a-disabled-persons-mobility-service-%E2%80%8B/

Are designers aware of the design compromises they make? If there were explicitly detailed publicly available decision trees design compromises would be obvious and people would be continually looking for and making available solutions. The Kiffy feels like it could solve a huge range of issues with some tweaks.
Title: Re: Kiffy, genuinely innovative leaning tadpole utility tricycle
Post by: Andre Jute on January 17, 2021, 01:37:58 am
Well met, Clive.

I understand your desire for stability in a tilting tricycle at slow speeds and stops. But that needn't be the decisive factor even if you can't put your feet down.

You can put tilt-limiting stops somewhere on the suspension arms, probably near the pivots. They needn't be very sophisticated. I once made a jury-rigged stop in a Porsche suspension and forgot all about it for thousands of miles until my girlfriend asked one of the mechanics why the car, retired to road use for her, was so harsh: the two plumber's ratchet pipe clamps per side with their screw heads facing as bump stops had lasted all that time!

Or you can easily add a manually operated dynamic retard/detent to an existing tilter whose designers expect the cyclist to put down a foot to stabilise the tricycle at stops.

Abstracting for the moment from the Kiffy's complicating detachability, and considering a generic tilter: The ideal suspension for a tilter is parallel equal length arms pivoting on the centreline of the tricycle. A longer pivot bolt can be fitted and to this a small disc brake can be attached, connected by cable to a grip on the handlebars -- perhaps in the place of the rear brake grip. As you slow down to stop, you simply grip the lever and hold it until you've demounted, tilting for an easier dismount only if desired by relaxing and tightening your grip on the lever. A lock on the grip (a piece of inner tube on the handlebars to slide over it) would hold the bike upright when you're away from it, or a fancy prop-stick such as some Thorn owners carry because rear-triangle-fitted stands are strictly verboten on Thorns -- you've really lucked out in arriving here!

***
Don't get me started on the shortcomings of bicycle designers! I'm here because I think Andy Blance, the Thorn designer, should be beatified immediately for his common sense and functional approach.