unbelievably

enduring qualities of light weight wheels.

What are some attributes of light weight tires?

I currently roll on Conti. Gatorskins.
According to their website, they are listed at 230g.

It would seem to me that with the added puncture resistance,
there has been little in the way of "drag" compared to the Bont. Hard case.

What could I expect from "upgrading" to lighter weight tires?

What tires would you recommend that would have an advantage over Gatorskins?

Thanks

ElJamoquio

Michelin Pro2Race. Someone will post the chart, but they have very low rolling resistance, and what the testers graded 'very good' puncture resistance. If I recall correctly, they aren't too heavy, either.

Squint

Differences in rolling resistance will absolutely eclipse differences in tire mass. The former can be quite significant while the latter is negligible.

DMF 

Then why do people (not just weight weenies) lust after lighter wheels?



^^^ actual non-rhetorical question

slowandsteady

Because wheels have essentially nothing to do with rolling resistance.

DMF 

I'm not denying that, but how does it answer my question? The statement was "differences in tire mass ... is negligible." Yet the common wisdom is that rotating weight is the weight to save when you're saving weight. In other words, that polar moment is quite significant. Since the tire is farthest from the hub, then a difference in tire mass will make the greatest difference in polar moment.

So which is it? Is polar moment important or not?

To possibly answer my own question, polar moment would seem to have a greater influence on acceleration than the straight line inertia of the non-rotating mass. Is that it?

Squint

All the data is out there. I'm not going to do the work for you.

The wrong tire can cost you 40 watts and beyond. That's a lot, like the difference between a cat 2 and a cat 4.

I think analytic cycling may have a calculator that tells you how much less power you need given lighter wheels/tires. It's going to be something like 100 times less.

CastIron

I'll say this about lighter tires:
Last year I got a hold of some Veloflex Pave tires. The difference was noticeable in many ways. They were a bit faster to 'spin up' and were quite a bit nicer to ride being more supple. But light and comfy did not equate to being terribly durable, easy to mount, or cheap (assuming MSRP). Tires are always a trade off. Make your choices.

DMF 

Then do it for the other interested people here. What good are you if you're not willing to share your knowledge? If you don't care to explain it, the very least you could do is point us at the data.


"Wrong tire" how? Mass? Rolling resistance?

babydee

The Gatorskins actually do very well on the rolling resistance comparisons. Combined with their puncture resistance and good durability, I think they are great for all but racing.

MAK

Okay...I did a search and found a few charts and articles but noticed that the Specialized Armadillos are never mentioned with regard to rolling resistance, etc. I am very happy with their durability and although I don't do any racing (and never will), does anyone have any information so I can do comparisons. I'm relatively new to road biking and a shrinking clydsdale. I wonder if my Armadillos (2007 700/25's) are having an effect on my performance. Thank you for any info and/or opinions.

Squint

The coefficient of rolling resistance for Armadillos is about 0.01. For a bike + rider of 100 kg, it takes about 45W extra to ride 20 mph compared to Michelin Carbons (Krylions). I used to train on Armadillos all the time and you will definitely notice it.

MAK

Thank you Squint. In simple language that a "soft skill" person will understand, how does 45W translate into speed? For example, if I'm doing 15 MPH with the Armadillos, how much faster will I go with the Michelins with the same effort? It seems to me that a 45W difference would also make a big difference regarding hills. Is there a watt to speed formula?

pedex

not without knowing more variables, but at 15mph, 45 watts might get you another 4-5 mph give or take roughly

armadillos as far as bike tires go are like boat anchors, durable, but very heavy and ride quite harshly.......going from them to some race tires is a difference you will notice for sure

Squint

I've attached my Excel spreadsheet. I'm not 100% positive it's correct as I copied the formula from another cycling forum. For Crr, you can enter the Crr of a tire to find out how much power it takes to overcome its rolling resistance or the difference in Crr between two tires to find out the extra cost.

Quijibo187

4-5 mph gain from changing tires? I'm finding that a bit hard to believe.

maybe by the "wrong tire" they mean underinflated 35c touring tire.

pedex

no he asked about 45 watts, which IIRC is about what a pair of armadillos will cost you at like 30mph, and 45 watts isnt chump change, especially at 15mph LOL, I answered his question as asked, not what he should have asked

going from armadillos to race tires at 15mph, you wont gain much at all, not going fast enough to gain much, enough to notice but not enough to gain much

they are heavy stiff harsh riding tires, about as tough as ive ever been able to find so far though