transforming bikes

http://i.gizmodo.com/5161263/rebirth-of-the-big-wheel-matias-contis-transformable-spin-vehicle

http://www.youtube.com/watch?v=jCxSUg12RLc

D: a trike with built-in baby carriage. The baby is up front to cushion any impacts you have with cars, LOL.

D: I saw a vid last year of an upright bike that could transform into a semi-'bent.

I wonder if that inspired me to consider a variable seat height. The height of the seat means it must be on its own boom.

Also, I am pondering a dual-mode front and mid-steerer.
This would require re-arranging some pins in the frame.
It would reuse the steering grips for either under or over seat steering.

Regarding the variable height seat on a recumbent - this was my way of
1) having a low drag fast bike but
2) a good visibility option for commuting in traffic.
I will never use a lowrider in traffic!
Even the short wheelbase recumbent 'highrider' seemed very low.
That is part of why I settled on a Cruzbike.

The highracers would be brutal on the pot-holes around here.
Our winter freeze-thaw cycle wreaks havoc on roads.
http://www.bicycleman.com/recumbents/bacchetta/bacchetta_aero_ti.htm

Aside- regarding my Mark I bike design contest offering, with the suspension built into the seat...
For intense cycling, one wants the suspension between wheel and frame.
Otherwise, the bike loses contact with the ground and doesn't hug the riding surface.
However, given the frame simplicity that results, I am willing to accept the trade-off.
Plus also recall that light wheels make for a light feeling bike frame.
It is less punitive for acceleration - imparting all that centrifugal force.
It gets wasted in braking as heat anyway.

mechanical and electronic gear shifters, hydraulic drive, bottom bracket dynamo

http://i.gizmodo.com/5153773/electronic-bicycle-gear-shifting-promises-aerodynamics-and-complications

The good and the bad and the prohibitively expensive.

http://www.nytimes.com/2009/02/14/sports/cycling/14gears.html?_r=2&pagewanted=2&ref=technology

Two earlier attempts at electronic gear changing by a French company, Mavic, often malfunctioned in rain. Another company, Campagnolo, has delayed bringing its version to market because of the economic downturn.

D: only 4000 bux (!!!) and reliant on a battery...

There was a nifty earlier attempt by Browning. The gear changing method is something else.

http://www2.bsn.de/Cycling/articles/browning.html (pic)

The critical feature that differentiates the Browning from standard derailleur systems is the continuous gear/chain engagement during shifting, there is no skipping or grinding even under the heaviest loads. The transmission will shift under any combination of speed, cadence and pedaling force. Shifts are smooth, fast and nearly silent. The chain stays fully in contact with the gear teeth during either up or down shifts. In contrast, even with the best standard derailleurs, on upshifts, the chain loses contact with the smaller sprocket before it is fully engaged on the large sprocket which often leads to grinding or skipping under heavy loads.

Another unique feature of the Browning transmission is that it is ideally suited for complete electric operation including computer controlled automatic shifting. This eliminates derailleur cables and cable adjustment.

D: I had pondered the idea of computer control after studying the efficiency analysis of the Rohloff gear hub.
http://www.ihpva.org/HParchive/PDF/hp52-2001.pdf
Love these guys!
As you can see, the Rohloff's efficiency varies by 4%, depending on the gear.
That is because the number of internal gears engaged varies.
I think between 1 and 4 at a time.
Obviously direct drive is always preferable.
http://en.wikipedia.org/wiki/Rohloff_Speedhub

D: yet another lament by me. I asked about the I-motion 9 internal gears.
Not like I couldn't crack one open to find out.
I got the third degree and then no answer to my question anyway.

OK - back to the Rohloff. A computer would be able to accommodate the gear efficiency versus optimal cadence equation. For example, let us a say that a certain cyclist spins at 80rpm best. In a good gear - one with fewer internal gears engaged - maybe we want him/her/it/them (sigh) to expand the cadence range by say 5 or 10 rpm prior to gear shifting.
Conversely, in an inefficient gear, we might wish to reduce the spread of cadence in that gear by a like amount. This is just the sort of equation a computer could do easily and well.

Frankly, the simpler solution is to use a NuVinci hub with a continuous variable gear. Then it's a simple matter of up and down.

A quick aside on drive efficiency.
1) a non gear-hub is likely ideally a bit more efficient. Dust, grit, rust et al makes me think is only true in theory.
2) a severe chain wrap around a small sprocket is inefficient
3) a taught chain is a must
4) oddly, lube seemed to serve no purpose here.

Another aside- a hydraulic drive was designed but never seemed to reach the market.
It would have the potential to allow dual-drive on a bike.
Pretty terrific for snow and up hills/gravel on a front wheel drive 'bent.
http://www.newadventure.ca/welcome/technology.php
Their site doesn't even seem to up any more.

Yet another unrelated aside. Shimano has the patent on a bottom bracket internal dynamo generator. I think this is to suppress it, so they can promote their wheel hub dynamos.

http://www.patentstorm.us/patents/7059989/claims.html

D: I like the idea of all the expensive components embedded within the frame itself.
This way, the wheels are 'naked'. They can be stolen but won't be worth much.
Or they can be used for other options.

Since my partial fairing closing-clamshell design (and the later pure-design 'lobster') covers the frame when closed and locked shut, the frame ought to be pretty safe.
Embedding some police anti-theft devices like RFIDs could also help.
With carbon composites hiding some RFIDs during construction is a snap.
There would be no way to remove them without causing catastrophic failure in the frame.

bus bike rack dictates basic geometry for commuter

http://www.toronto.ca/ttc/bike_racks.htm

D: Waterloo has a similar rack.
That was not something I considered when I settled on a front-boom SWB Cruzbike.
The triangular boom prevents the swing arm from rising.
With care, I might be able to put the bike on backwards, if I leave the (old front ) rear tire bare.

I had considered whether a SWB non-boom bike could have the pedal tube on a pivot mount. It could swing up and out of the way.
Alternatively, enough clearance and careful tube geometry could help.

Has anybody successfully mounted their SWB 'bent bike on a bus bike rack?

It certainly precludes a LWB or even MWB.

Lament: with a DVD and more care in the parts/instructions list, a Cruzbike would be very simple to build at home, as opposed to highly challenging like it is.
They could expand their customer base with a training DVD that costs one dollar...

A few more asides on Cruzbike construction:
1) bike shops don't use the same terms from threaded/threadless front fork bits
Simply including this bit, since all the cheap Y-frames will need it anyway would be nice.
2) NO bike shops in town sold the tool I needed to open the bottom bracket
3) you need TWO sets of Allen hex wrenches.
4) psychologically, I just had to drill more holes to mount the seat. No good reason.

Update: my bud Ryan found a talented cheap welder. My pal Fern is a whiz with stainless but is not as close.
We're gonna use scrap to make the first clunky version of my 'bike contest' SWB.
See an earlier entry- it is the one inspired by the GreenMachine.

my shot at bike design contest.

http://bicycledesign.blogspot.com/2008/10/commuter-bike-for-masses-design.html

http://www.treehugger.com/files/2008/11/bicycle-design-competition.php

D: the bike must be
1) easy
2) comfy
3) efficient
4) fun.

D: this reminds me of the old mechanic joke. You can have 2 out of 3 of the following. Cheap, fast, good. You can have good and cheap but not fast. And so on....

1) easy. I assume this means easy to operate for the end-user. No fancy controls. No complex technical aspects
2) comfy. Ergonomics. Feels good.
3) efficient. This one is trickier. This sounds like 'light' to me, with good gearing.
4) fun. I imagine 123 would make it fun. Not dealing with technical stuff is also fun.

Well, the above bike is just a 26" wheel DIY version of the Greenmachine I want to build.
The Gm is great - and about 5000 bux, with no support in North America.

I thought about dual suspension and whatnot. But that makes it heavier, more expensive, less efficient and complicated.
I wanted to make the frame very light.
Well just by isolating the rider, who weighs say 150 or so pounds from a bike that weights 20-30? pounds, on makes it both light (efficient) and fun (particularly with the seat).
I thought two parallel parallelogram thudbuster setups with a few inches of wiggle room by the frame on each side would suffice. Elastomer is adequate for non-winter cycling.
This does mean the seat must be free-floating. I.e. it is not leaning on the rear wheel assembly.

The square tube frame just makes my life easier. No concern that the seat can fall sideways!
A few holes or indents and the seat mounted on a sliding mount and the thing can adjust for rider height.
Of course (see the Optima Condor) below 5' 10" or so, 26" wheels become problematic.
There are 24 and 20" wheels about.

The chain is completely enclosed. No grease on yer work clothes. Pretty quiet.

The NuVinci drive is cheaper though heavier than an I-motion 9.
I suppose efficient favours the IM9, but I disliked the technical support.
The NVd is also easier in that it is a variable drive lacking discrete gears.

The SWB recumbent layout is amenable to a partial fairing and a motor assist if desired.
A backpack mount is a must! I'd like a Y-shaped shoulder mount on the back of the seat.
I don't like the idea of strapping a backpack to the luggage rack area. I always worry about those straps getting caught in the tires.

I could ride a 'bent the first weekend I tried it, so there is not much learning curve.
(Unlike a front-boom style - I still don't trust myself in traffic! ).

Well that is what I think a commuter bike should look like.
Other than the seat-suspension, the whole thing should be pretty simple to make.

bike pics from car free day at UW

D: graciously provided by Bicycle Forest.

leaning trikes.

http://www.jetrike.com/prior-art.html (pic)

D: thoughts....
- the 2 -wheels forward design, the delta (v.s. tadpole) is more stable.
- a full width trike generally does not play well with traffic
- a narrower leaning trike addresses this.

D: I bike to work on Waterloo Westmount-Northfield.
For c. 500 feet past University, it is as narrow as 1' before becoming a bike lane.
By placing a white line on the road edge, despite a clear curb and whatnot, it implies to traffic that
- that is where bikes go
- maybe it is wide enough for bikes
- just staying on the other side of the white lines will avoid me.
Nope. This road would be much better off with NO white line until it reaches a full bike lane width.

Why such a wide bike lane?
No surprise at all.
With a car, the mirrors stick out. Allowing another 6" of wander on both sides, that amounts to an additional 2' lane width v.s. the actual car width.
Bikes are much the same.
If I ride the curb,
- I risk the tire catching on the curb lip.
- I risk the pedal hitting the curb.
I ride a decadent (sarcasm) 1' away from the curb itself.
Deal with it.

primer on bike handling, geometry

http://tripatlas.com/Bicycle_and_motorcycle_dynamics

Center steering

Between classical front-wheel steering, and strictly rear-wheel steering, is a class of bikes with a pivot point somewhere between these two extremes and referred to as 'center-steering'. These design allow for simple front-wheel drive and appear to be quite stable, even ridable no-hands, as many photographs attest.^[24][25]
These designs usually have very lax head angles (40° to 65°) and positive or even negative trail. The builder of a bike with negative trail states that steering the bike from straight ahead forces the seat (and thus the rider) to rise slightly and this offsets the destabilizing effect of the negative trail.^[26]

http://surfin_dude.tripod.com/cycling/python/Project_Python.html (pic)

http://www.python-lowracer.de/

D: compare to the disastrous handling of the original Flevobike.
http://www.pedersenbicycles.com/chinkara.htm

AND THEN…

No one who was present that day would consent to demonstrating the machine, but several people volunteered that they had seen a rider earlier in the day who displayed extended no-hands riding! I couldn’t believe it. I didn’t think it was possible to ride a recumbent without hands. At least my experience to that point hadn’t convinced me that it was possible.

So I spent half the day trying to learn to ride it, and it certainly exhibited some strange behaviors. To begin with, it just wouldn’t stay upright. The front half wants to fall over, and fall over fast. It isn’t the kind of bike that you can push along gracefully while holding the back of the seat. In fact, holding the back of the seat is a sure way to let the front half fall over and of course, that happens rather quickly. And to make matters worse, just like more conventional underseat-steering recumbents, the handlebars are a little low to be comfortably used to direct the bike when standing to the side. But in the case of the Chinkara, the handlebars don’t even provide enough leverage to counteract the front half of the bike, which seems to have a mind of its own. Such behavior made it hard to handle the bike. It wouldn’t stand up on its own. It seemed impossible to control, and this was before even trying to get on...

D: of course, there are lots of online vids of folks scuffing their hands on the Python too.

I thought something like the Triton Trike for steering would be desirable.
I'd be curious about a steering system with some gears to amplify the effect near the far range of motion. By that I mean:
- handles normally for minor movements
- when turned, say 45 degrees, amplifies the turn on front wheel by 1.5x
- at much more, by 2x.
I hear under-seat-steering has problems turning the wheel severely.

In a bike very sensitive to steering, maybe even reducing the wheel-turning below 1:1 in the middle would be desirable.
Steering which is speed-sensitive would be nice, but the mechanical details would be a nightmare.

D: latest Cruzbike thought.
I think an even more severe oval that exists commercially *might* be desirable.
I do wish the company website had warned against the combo of short wheelbase AND high seat height.
Like I said, I wouldn't trust the stability of mine at faster than 30kph.
I suppose that is fine for a commuter.
I finally figured out the aluminum sleeve included is to serve as a gap-filler on a stem adapter.
The spare parts for use in other kits were confusing.

Aside: I found a 135 degree angle for seat/pedal combo. It looks ideal for future models, with the pedals below seat height and a modest seat back angle.
I am also intrigued by laying in all electric lo/hi power wiring and shifter/brake cables internally on the internal-chain version.