Hello again, and what else ... questions.

[Pavel]

As we speak (type I mean) the Nomad has 700cm wheels, shod with 37cm tires and room for fenders mounted on it...

Pavel, I can't begin to tell you how much I'd like to see a photo of your Nomad in this configuration. If you have the camera handy...? 

I'll bet stops are...exciting. I remember similar setups as a kid, and the toll they took on my shoe-sole brakes.

Best,

Dan.

your wish is my ......

The rear clearance is good with the 37cc 700. The brake reach is mildly problematic and I keep burning through shoes (Keds) trying to stop.

[Pavel]

the front has a bit less clearance. Will it fit a fender? 

But the Dyno is ready for that New Thorn Disk brake!

So, ok this ain't gonna werk - but it was a fine experiment, which made me quite positive about the idea of 650B future surgery.

[Danneaux]

Many thanks, I just wanted to see to say I've seen it.  It is gratifying to see Andy Blance left *such* generous bridge clearances.

Yeah...no. Not gonna work. Besides the brakes, the clearances at the crown bold are inadequate for a fender, marginal without.

Besides, the BB height is now unrealistically high, but you've certainly altered trail(!) but not quite in the way you are seeking wrt ultimate handing. 

Going back to an earlier statement of yours where you mentioned looking for more gyroscopic stability through larger wheels...nope. Not what you're seeking. You could get that greater gyroscopic effect at speed by mounting much heavier/larger 26in wheels (concrete-filled tubes?). The effect you are seeking is a change in trail and reduced wheel flop and less nervous handling at low speeds. In other words, you're likely looking for a bike with less trail to better suit your vision of ideal handling for your present needs.

Remember, going to 650B rims alone won't get you where you want to go. 26x2.0 Duremes virtually equal 650Bx30 (to within 1mm or so).  650Bx42 will get you a larger wheel diameter (and radius, used for calculating the more common measurement of "ground trail" -- as opposed to "mechanical trail"), but likely won't get you where you wish to go if fork offset remains constant. The maths say you'd really need to (also) change that to achieve your goals.

By the way, my tandem runs 26in wheels, but the frame was originally designed for 27in (630mm EWD). The factory (no longer in business) decided they could make a "MTB tandem" (an inherently Bad Idea except in rare cases due to limited keel tube clearance) by simply dropping the canti brake bosses lower for 26in/559mm EWD wheels. It...works(!) and handling is fine. I am running 26x1.5in tires and it handles like a dream, a fortunate outcome. Thankfully, it was designed with fairly high BBs to start, so it all works without pedal strike.

All the best,

Dan. (...who urges you to keep watch on the Flintstone brakes in the meantime)

[Pavel]

Thanks Dan.  Good info here to ponder and seek to experiment with.  Speaking of experimenting .... what's the best way to get concrete into those tiny Presta valve things before it hardens? Please respond in the next two minutes. I only had quickcrete.

It suspect a slightly harsher ride but just think of the weight savings afforded me - as I leave my puncture repair kit at home!

[Danneaux]

  !

All the best,

Dan (...who is still chuckling and apologizes for the delay in replying)

[mickeg]

... Speaking of experimenting .... what's the best way to get concrete into those tiny Presta valve things before it hardens? Please respond in the next two minutes. I only had quickcrete.
...

I am late, your concrete has already set.

But a kg or two of Slime in each tube might do it.  You will need some air in the tube since slime is an incompressable fluid, a tube full of slime and no air would be as hard as a rock so the air is your suspension.

Some tubes are sold with removable presta valves. 

But concrete has a much higher density than Slime, so it won't be as "gyroscopic".

Please confirm that you were in fact joking.

[Pavel]

Joking?? This is in the name of science! 

Yeah ... of course I am.

I actually disagree with Dan's assertion, which almost never happens.  Gyroscopic effect depends on moment, not just weight so there is no substitute for wheel size as far as self-righting is concerned, which of course is what I'm concerned with.

(unneeded aside: My major was "process piping design" and I had to study nauseating volumes of mechanics (mechanical physics - not nut wrenching ), stress analysis methodology and metallurgy. Oddly enough it taught me much about chains ( We even had a major research project on vibrations and harmonics as relating to speed of the system - companies, such as mining companies, pay a lot of money and heed to minimize maintenance suffered from things like harmonics) and I grimace at the internet wisdoms found in forums regarding chain drives - don't get me started! )

Now, Dan is right in the greatest part, I should add, as weight is of course a factor, but there are other forces at work as far as the centripetal effect with regards to wheels (what one prof used to call complications) which when summed up in a simple manner point to that there is no real substitute for moment (versus simple mass). Bicycles are used in with a very limited set of precepts. Wheels are of only a small useful set of range as are speed and other factors such as vectors and reasonable weight limits.  It is interesting that wheel are a special area and really complex.  As far as I know it is not yet fully understood by scientists, the interplay of all the forces at work, and why things feel and respond the way they do  But the short version of it is that a 120 lb three inch diameter will have little "self-righting" effect while a two pound six foot diameter wheel will have lots of it - though most of us don't have the leg span for that.

But in the end, all I want is a bike that is slow handling at slow speed - and I don't seem to know how to get there.

[mickeg]

...
But in the end, all I want is a bike that is slow handling at slow speed - and I don't seem to know how to get there.

Get a trike.  When I did the Glacier Waterton loop, one guy had a trike and pulled a two wheel trailer behind it.

I saw a very similar trike when I was in Iceland, took a photo of it.  But this one used panniers, not a trailer.

The one in the photo also used a Rohloff.

[Pavel]

You sir have no idea how much I've contemplated either a trike or a recumbent. I've ridden both and they suit my style (more masher than spinner - I have (had) strong legs)

What gets me is the cost, in part, but more so the idea that I walk up really steep inclines or when I want to change up the muscles.  I can't figgure out how that could be done with recumblents.  Also, around here, in the South East of the US, their idea of accommodating cyclists is to put up a lame "share the road" sign, once in a while, but never, it would seem, to widen the shoulder for dem cyclist weird-o's. Riding a recumbent makes me a bit nervous as it feels like they will hit me in the head first (rather than flip me into their windshield - the way polite drunk drivers do ) and with a trike I would probably cause road rage in too many gun toting, pick-up driving, road-owning, rednecks.

Other than that ... I really, really want a trike and am patiently holding my breath for Andy to see the light.

[Pavel]

Here is an interesting bit about bicycle steering. A bit over my head, and it i seems to sink some of my basic assertions on the subject.  Hmmm.

http://www.phys.lsu.edu/faculty/gonzalez/Teaching/Phys7221/vol59no9p51_56.pdf