Hello folks,  
 Forget 700c fixed-wheels. The high-wheelers are the ultimate city bike;  view traffic hazards from a trucker's perspective—eye to eye.  It is  very intimidating to them and they give your wide berth, which is a good  thing, as cars don't see you at all and turn rather impulsively in front  of you.  The High-wheeler has a fixed-wheel drive, which is all  the rage with the ladies; especially the Gothic bike-gang types we like  to swoon over in our fair city.  
 No real brakes, of course, are a FEATURE that adds to the danger in  traffic and the possibility of certain death from this, the ultimate  two-wheel high wire act. It's only a matter of time before Ford tools  up their old bike production line and we see one like the new-old  mustang production.  
 On wheels noted earlier and below:  
 Triathletes often have bikes equipped with smaller than ATB (ATB are  nominally 26x1.5-2.125 559mm ISO) 650 C (nominally 26 inch wheel 571  mm  ISO) wheels.  The 650 B  size (demi Balloon nominally 26x1-1/2  inch 584 mm ISO) is actually an older  French touring standard size  that sits between the modern ATB (thorn 26 noted below) and the common  700c (622 mm ISO) road diameter. The Triathlon racing wheel noted is  actually a 650c (nominally 26x1 inches  571 mm ISO) which is an old  Schwinn Balloon Cruiser 26x1-3/4 nice narrowed up for race use.  I hope  I got this correct?   
 On rolling resistance that latest wisdom that some people have claimed  is that wider tires have less rolling resistance.  this goes against  the intuitive reasoning that says that the 700x18 mm tire is faster than a  700x25.  "The wider the better," some say, "and we have testing to prove it."  Continental did some original testing on their equipment and found that  their 700x25 tires had lower rolling resistance than their 700x23 tires  a few years back. They attributed this to the larger tire having a  smaller, but perpendicular, contact patch (compared to the longer, parallel  contact patch of the narrower tire). Seems reasonable.  
 Thorn claims that their 26 inch (ATB size tires) have lower rolling  resistance than larger wheels.  While I have not seen this, I do not  doubt this statement, but I will say that in bicycles, as in all things, this  "DEPENDS." If wider is truly better, the Triathletes would certainly  gravitate away from their skinny 650c x20-23 tires (nominally 26x1  inches  571 mm ISO)  to the faster  Schwinn Balloon Cruiser tire  26x1-3/4 (571 x47 size  571 mm ISO) and watch the records be broken!  This will not happen for many reasons, chief among them it would be  impossible.  Between these similar diameter tires (wider tires are  taller tires too!)  the wider tire has so much more rolling resistance  that the narrow one might have lower rolling resistance riding on the  rim uninflated.  I personally set a personal best in a Time Trial years  ago placing second riding 23-miles on a flat front tire in a 25-mile  event.  Very tricky and I would have never attempted it but a fellow in  New Jersey placed first or second in the national championship 8-9  months earlier doing essentially the same thing; not by choice of  course.  
 There are so many variables: tread, tread compound, casing fabric,  thread count, width of rim, air pressure, diameter, weights of various  components and the biggest are the limits of testing equipment, time  and budget.  The old skinny tired high wheelers had very low rolling  resistance. This could be as much because of the hard (high pressure  before it was cool) solid tires as the large wheels compliance to  irregular pavement (sort of a suspension system of the day).  
 The Alex Moulton small wheel bikes we sell have been tested many times  on rolling resistance and always test very well ( tops in many tests)  regardless of testing style even though many claimed tests for rolling  resistance did not account for other variables, An older version of  this  bike holds the world land speed record for upright bikes and many  older HPV records were set with the newer (at the time) high  performance, high pressure 17 inch wheel (most Moultons use 20-inch  wheels these days). The absolute world land speed records set behind  automobiles on the Bonneville salt flats are over 160 mph and they have  been set with 20-inch (nominal) wheels.  While I don't feel that  smaller  17-20-24-26 inch wheels are necessarily faster than 700c or  larger wheels my experience is they are not slower either and similar  setups can vary quite a bit for a number or reasons. I was recently at a  gathering of small wheel bikes in Philadelphia where, after climbing  nearly 400 vertical feet in a mile, I was treated to a long steep  downhill in company.  After a slow start down I realized a downhill  race was formulating ( my specialty).  A fellow on a late model Bike  Friday had about a 200 foot head-start before I realized the game was  on.  He was loaded with a hefty belt/backpack for the weekend and was  sailing.  Even though I had a very unaerodynamic handlebar bag,  mudguards and rear rack and small bag I not only caught but passed him  going about 4 mph faster than his 43 mph  top speed all the time  coasting. We had similar wheels, tires (20-inch 120 psi) and overall  weight.  His body, luggage and bike were probably more aerodynamic than  my setup. What was the variable?  I suspect it was that the Moulton has  a full front and rear road tuned suspension and this may have lowered  the rolling resistance but who is to know.  
 Conclusions and Observations:  
 Most rolling resistance tests rely heavily on downhill coasting  contests that test ease of pedaling more than actual rolling  resistance.  I have seen some that tested coasting UPHILL,  A small  wheel bike with lighter wheels and less wheel momentum will be  handicapped in this test but a heavy larger wheel wheel will often have  an advantage.  
 IS wider better? 
Perhaps, but only to a point. On a very wide tire the contact patch can grow and the aerodynamic handicap increases, tire  pressure generally decreases, and the weight increases, all affecting  performance and test results in a negative way.  
 Most tests have shown conclusively that higher air pressure tires do  lower rolling resistance, but a rough surface can makes this figure go  the other way unless road-tuned suspension is added.  
 Smaller wheels are stronger, lighter, more aerodynamic (bigger  advantage than most people realize, even at touring speeds) and more  compact than similar performing large wheels, which has advantages for  touring and transport.  In the proper frame, tires from a 20-inch wheel  rim can accept 28-52 mm width tires on the same rim, offering much more  versatility than is typically available with 26-700c wheels and frames.  
 The smaller the wheels used, the more road shock is transmitted to the  rider. This may raise rolling resistance and certainly will fatigue the  rider.  Mountain bike suspension used on the road is styled a little  like landing gear on aircraft and is designed to take sudden, very hard  impacts. It does increase potential comfort, but tends to absorb  pedaling effort in many designs and may actually slow the bike down  rolling resistance wise on rougher roads as it tends to overcompensate   small bumps.  A suspension system used on the road should be  designed for the road and can decrease rider fatigue and lower rolling  resistance, which can be very beneficial for touring.  
 Continental tire tests compared several tires, but results might vary  with different brands as well.  I have found that Continental tires  feature very stiff side-walls which, on anything but the smoothest roads, seem to increase rolling resistance in my own simple tests.  A flexible  side-wall tire might have different results with wide verses narrow,  
 Few tire tests take into account road surface variation, bumpy verses  smooth and grades in between.  Certain low ranking tires might out-perform high ranking ones, if the surface is changed.  
 Disc Brakes are hard on spokes, frames and forks. Disc brakes on small  wheels may or may not exacerbate this problem.  
 With tires, like most things bikes, I believe I can construct tests that  will make winners out of almost anything and give conflicting  conclusions.  
 Ideal Touring Wheel and Tire: 
- Tough enough to carry the loaded bike and rider
 - Large enough cross section to protect the rim.
 - High enough rim weight and spoke count for the job at hand, without being overly heavy
 - Small enough for easy transport
 - Easy to patch, boot, install and remove
 - Self-healing from cuts (this is not advertised, but varies a lot from tire to tire.)
 - Heavy enough to do the job,  Light enough to accelerate easily
 - Low aerodynamic profile (Small narrow wheels are the best; choose smilie short- if not narrow if you have to choose one).
 - Long wear between replacements
 - Accepts a high enough pressure to protect the rim and offer low rolling resistance.
 
   and for 
Off the beaten path add— 
- Ease of finding local replacement
 - Small enough for economical shipping or carrying (folding models are a plus, 20-inch folders are now available.)
 - Very long wear between replacements
 - Tough enough to survive minor falls while loaded.
 - Wide enough for some off road capability (may also be needed above)
 
  Small wheel to high wheel, it's not only the size that matters. They all  can work well.  
 I hope my experience has been of value.   
 Yours in Cycling,
Gilbert Anderson 
North Road Bicycle Imports
P.O. Box 840
166 Courthouse Square
Yanceyville, NC 27379  USA
toll free: 800-321-5511
local: 919-828-8999
e-mail: cyclestore@aol.com