BUT! Jan's hypothesis that skinny tires feel faster because they vibrate more seems to me to be very questionable. Doubtless when, after six months, I return to my slightly-sub-18-lb gofast fixie after riding the 30+ lb Fargo, the 30- trike and the 25lb errand Riv, and find it "fast," this is due to a myriad of factors that cannot, or only with more expertise and energy than is worth expending, be reduced to scientifically identified causes. But (1) it does *feel* faster; (2) it is no slower in concrete-like reality; and (3) all of this has absolutely nuthin', repeat nothing, to do with road buzz.
In fact, reducing the question to a crudely empirical estimate of crank rpm in the higher gear (75" comp to, respectively, 69", 70" and 72"), I *am* going faster. Again, no buzz factor. On Wed, Apr 18, 2012 at 11:09 AM, William <tapebu...@gmail.com> wrote: > agreed. Even Jan Heine admits that the perception of speed is far stronger > than any measurable speed difference in this hair-splitting area. He rides > quality fat tires because he knows empirically that they are no slower at > worst and slightly faster at best. He concedes that narrow tires feel > faster despite the measurable fact that they are not. I remember that every > time I see a post "I rode those tires for a while, but they were sluggish > and slow". 19 times out of 20, that's a qualitative judgement, not a > quantitative one. > > I've been tempted to ask Jan since going fast is fun (for the most part), > but since going slow is safe (for the most part), shouldn't he run skinny > tires, since they feel fast but are slow? I know, I'm a jerk, and a smart > aleck. > > > On Wednesday, April 18, 2012 10:03:07 AM UTC-7, Jim Thill - Hiawatha Cyclery > wrote: >> >> MichaelH illustrates how little difference it makes. Three minutes is his >> largest variation in his 18 mile ride on a variety of different tires with >> different bikes, and that variation wasn't even reproducible in a second >> trial. I spent seven years in grad school doing science, so I can see that >> there are confounding factors in Michael's research that muddy the waters. >> But his over all consistency from tire to tire and bike to bike suggests (if >> not proves) that tire differences play much less role than, say, the rider's >> day to day energy level and attitude, wind direction, and countless other >> factors. Comparing one lightweight 700x28 tire to another is really >> splitting hairs. >> >> On Tuesday, April 17, 2012 7:16:05 PM UTC-5, MichaelH wrote: >>> >>> Another single data point. >>> >>> Along with the post on where the Rambouillet fit in the Riv line up, I >>> rode an 18 mile loop from my home on my Ram with a pair of Continental GP4, >>> 23 mm tires. (A gift). The course has 900 feet of climbing and includes >>> 4-5 miles of dirt roads, with the rest equally divided among good pavement, >>> bad pavement, and atrocious pavement. After the ride I recorded my time & >>> subjective impressions (painful). I also discovered a cut in the sidewall >>> of the rear tire, so I decide to replicate the ride with a variety of bikes >>> and ties. I rode it twice on my Ebisu with Jack Browns. The first ride was >>> 3 minutes slower but the second was identical, although a lot more >>> comfortable. I rode it once with my Trek & T Serve (30mm actual). My time >>> was right between the faster and slower rides & the comfort just a nudge >>> below the JB. Now the wind has shifted around from the south to the west ( >>> it has been blowing at 20 -25 mph, making this very real world test) and the >>> dirt road has been graded, leaving it's surface full of rocks and loose >>> sand, so it's really hard going now. Hard to make comparisons. I'm in >>> Boston for the weekend and heavy rain forecasted for next week so this test >>> will be suspended for a while. >>> >>> I'm not sure where this leaves me. I'd like to put the Grand Bois Green >>> on my ram but am wondering if the perceived advantage is worth the added >>> flats. >>> >>> Michael >>> >>> On Tuesday, April 17, 2012 4:29:48 PM UTC-4, William wrote: >>>> >>>> I'm in the same boat with Pari-Motos. I flat almost every ride with >>>> Pari-Motos, and almost never with anything else. I've put them back on >>>> with >>>> Foss tubes to try again. I like the ride of them, but the flat record is >>>> pretty bad for me. For me it's been glass. >>>> >>>> On Tuesday, April 17, 2012 12:55:06 PM UTC-7, Mojo wrote: >>>>> >>>>> Prompted by this thread I changed out the Rolly Poly/Ruffy Tuffy >>>>> front/rear combo on my road bike wheels to the pair of (what I have >>>>> considered to be special event) Grand Bois Cerf 28mm tires. I rode them >>>>> for >>>>> 25 mountainy miles yesterday and enjoyed their feel immensely. Today I >>>>> got a >>>>> front goathead flat. This is the 3rd flat I have had on these tires in >>>>> about >>>>> a dozen rides. This is by far the worst flat record of any tire I have >>>>> used, >>>>> ever. I understand I cannot say this will be the flat record for me in the >>>>> future or for you in your environment, but my faith in the tire is shaken >>>>> and it affects the enjoyment of my ride. I am putting more effort into >>>>> scanning the road or trying to stay off the dirtier portions of the road >>>>> instead of enjoying the view or thinking my deep thoughts. {~; >>>>> . >>>>> When I got home I fixed the flat, pulled the GB Cerfs and replaced them >>>>> with the RP/RT combo. As I was changing them, I weighed them on my Park >>>>> digital spring scale. To the nearest ounce, the Cerf was 10oz, Rolly >>>>> Poly 11oz, Ruffy Tuffy 13oz, Jack Brown Green 33mm was 12-13oz. All of >>>>> these >>>>> tires are made by Panasonic. Now I believe Jan Heine's rollout tire >>>>> comparisons are valid. But for me to flat every second or third ride is >>>>> just >>>>> not worth the lower rolling resistance or an ounce or two of rotating >>>>> weight. >>>>> >>>>> > > -- > You received this message because you are subscribed to the Google Groups > "RBW Owners Bunch" group. > To view this discussion on the web visit > https://groups.google.com/d/msg/rbw-owners-bunch/-/OcFprdpgA48J. > > To post to this group, send email to rbw-owners-bunch@googlegroups.com. > To unsubscribe from this group, send email to > rbw-owners-bunch+unsubscr...@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/rbw-owners-bunch?hl=en. -- ------------------------- Patrick Moore, Albuquerque, NM For professional resumes, contact Patrick Moore, ACRW http://resumespecialties.com/index.html ------------------------- A billion stars go spinning through the night Blazing high above your head; But in you is the Presence that will be When all the stars are dead. 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