Where were you the last time you got a flat tire?

[mstone]

@hozn 54402 wrote:

I am fairly sure that I was basing this off of Leonar Zinn’s post on the topic: http://velonews.competitor.com/2012/03/bikes-and-tech/technical-faq/tech-faq-seriously-wider-tires-have-lower-rolling-resistance-than-their-narrower-brethren_209268 . Specifically “’Wider is faster’ holds for clincher and tubular tires under the condition of the same air pressure.” Although he later goes on in another thread to say that lower pressure means lower rolling resistance (but obviously that is only true to a point).[/quote]

Yes, that’s the widely quoted page. Note that it’s not one that includes numbers, and contradicts itself within a paragraph. The quote from the manufacturer specifies a drum test, which is the source of a lot of the misconceptions out there. Yes, a steel disk on a steel road is really fast–we call it a train. On a real road, a pneumatic tire is better, but the testing has traditionally been done with a steel drum… Dig around for some of bicycle quarterly’s roll-out tests for what I think give more realistic results.

Quote:

Naively filling out the form (leaving defaults) and entering a wind speed of 16mph head-on, I get a % forces due to rolling resistence of 2.5% and forces due to drag (totaled for both wheels) of 10.7%.

Note that it doesn’t even include tire width as a parameter; as I said, I’m not sure that tire width alone is a significant factor in aero resistance at commuting speeds.

Quote:

At the end of the day we’re talking about really small wattage numbers here either way (when apples to apples), so it does seem likely that the feel is due to spinning up quicker or different tread patterns as opposed to actual rolling speed.

Yup, the differences are probably not real significant either way. My main objective is to hopefully make people avoid considering wider tires outright because “skinny tires are faster”. It’s a lot more complicated than that, but it may be that you can be just as fast on a wider tire but get a lot less beat up.

[jnva]

All I know, is that if I don’t get a flat, I go faster.

Also, my tires have a nice smooth spot right down the middle where it contacts the road. When coasting, I really can’t tell a difference between thick heavy tires and light skinny tires. I can tell a difference when turning, and accelerating does seem faster. Overall, though I would always choose the thickest most flat resistant tire for commuting.

[Rod Smith]

@jopamora 54326 wrote:

Yesterday afternoon the Georgetown Branch claimed another tube. Ended up walking home since it would have taken me the same amount of time to patch the tube.

Yes but had you patched it you could have ridden that last mile and arrived home with a bicycle that was not in need of repair.

[Rod Smith]

I flatted about six times in May. I usually flat about that many times in six months (I have four tires). “About”. I don’t really keep track, but last month would have been off the chart if I kept a chart. My last flat was yesterday morning. I almost crashed when I made a move from road to sidewalk across uneven pavement approaching my first stop of the day with a front tire that unbeknownst to me was getting soft.

[PotomacCyclist]

An update and a comment about the color of tires:

– I posted on a different flat tire thread that I finally did get a flat tire, about a month ago. I was riding on a CaBi bike in Pentagon City, near the ongoing construction zone (sidewalks, upgraded median park). I thought I hit a small rock, which happens often but it usually doesn’t cause any problems. The rock or pebble goes shooting off to the side while my tire remains unscathed and I continue riding. But this time, something felt a bit off. I was still riding comfortably as I turned into the empty parking lot (next to Costco) but I started to hear a clicking noise on the bike. And then the tire finally started feeling wobbly, but I was in no danger of losing control. (I was riding at about 5 mph, so even if I had lost control, it wouldn’t have been a problem.)

I stopped to check out the tire. It was a slow leak. I spun the tire slowly to see what caused the problem. I couldn’t see anything, until I saw that an entire flat-head screw was embedded completely into the rear tire. Even with that large of a hole, the tire didn’t blow out or lose pressure immediately. It took about another minute before the tire became flat. CaBi bikes are so heavy and stable that the flat tire didn’t alter the handling or speed of the ride at first. But once most of the air had escaped, I was forced to walk the bike. Fortunately there’s a bike station about 100 ft. away. So I walked over there, dropped off the bike, pushed the red Repair button, turned the seat around (an informal signal to other riders that the bike needs repair) and checked out a different bike. No on-road tire repair needed with CaBi.

I still haven’t had a flat on my own bikes even though I’ve ridden over many small rocks and pebbles, and occasionally pieces of broken glass.

– Tire colors normally don’t matter, except for the Continental GP4000 tires, I believe. I’ve read several online comments that the Black Chili compound is only found in the black version of the GP4000s, not in the other colors. The Black Chili is supposed to improve the rolling resistance of the tires, although I have no idea if that’s true. If you accept that the Black Chili tires are better than the non-BC tires, then you would want to stick to the black GP4000 and other Continental tires with BC. If you don’t think that the compound really helps, then the color doesn’t matter. Except aesthetically.

[mstone]

@PotomacCyclist 54515 wrote:

– Tire colors normally don’t matter, except for the Continental GP4000 tires, I believe. I’ve read several online comments that the Black Chili compound is only found in the black version of the GP4000s, not in the other colors. The Black Chili is supposed to improve the rolling resistance of the tires, although I have no idea if that’s true. If you accept that the Black Chili tires are better than the non-BC tires, then you would want to stick to the black GP4000 and other Continental tires with BC. If you don’t think that the compound really helps, then the color doesn’t matter. Except aesthetically.

More specifically, the “black chili” (boy is that stupid name) is only in the GP4000S (schwarz), the color versions are just GP4000.

[Bilsko]

@mstone 54522 wrote:

More specifically, the “black chili” (boy is that stupid name)…

*sadface*

[PotomacCyclist]

If you order from Amazon.com, the product listings can be confusing. All of the GP4000 tires are combined on a single page. Then you have to choose the color you want, but there is no indication that only the black color is the GP4000s with Black Chili. Some of the reviewers point this out, but if you don’t look at the reviews, you won’t know about this.

[hozn]

@PotomacCyclist 54528 wrote:

If you order from Amazon.com, the product listings can be confusing. All of the GP4000 tires are combined on a single page. Then you have to choose the color you want, but there is no indication that only the black color is the GP4000s with Black Chili. Some of the reviewers point this out, but if you don’t look at the reviews, you won’t know about this.

I was wondering about the GP4000S tires; are these good general-purpose road tires? As I posted in my earlier Hutchinson-hate note, I switched my road bike back to Gatorskins, but if there are better rolling tires that aren’t race tires I’d be open to trying them out too.

(I actually ordered a set of Vittoria Open Corsa Evo Cx tires last time I was placing a direct-from-France order since I remembered reading that they had fantastically low rolling resistance and they were like $35. Then I realized when I got them that I had just purchased racing tires and ordered Gatorskins to use as my everyday tires.)

[mstone]

@PotomacCyclist 54528 wrote:

If you order from Amazon.com, the product listings can be confusing. All of the GP4000 tires are combined on a single page. Then you have to choose the color you want, but there is no indication that only the black color is the GP4000s with Black Chili. Some of the reviewers point this out, but if you don’t look at the reviews, you won’t know about this.

Using amazon for education purposes seems backward. Suggest checking conti-online.com

edit to add: that’s a general problem–at least half the people on this board probably know more about any given bike product than the person selling it, or at least has the motivation to learn more. and reviews these days are too often clueless or astroturfed.

[PotomacCyclist]

No, I use Amazon for ordering. I try to shop locally but many stores don’t seem to carry 650C tires these days. The last time I checked, I couldn’t find anything. Now I don’t even bother since I don’t have the time to travel to 3 bike stores each time I want to get new tires.

[mstone]

@PotomacCyclist 54539 wrote:

No, I use Amazon for ordering. I try to shop locally but many stores don’t seem to carry 650C tires these days. The last time I checked, I couldn’t find anything. Now I don’t even bother since I don’t have the time to travel to 3 bike stores each time I want to get new tires.

I didn’t say anything about where to buy something, just not to blindly trust any seller to provide accurate information.

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