infestedguy1

no, i'm not talking about what happens when you give an armadillo speed, i'm talking about the tires and how fast you go. i was wondering if any of you have noticed what i've noticed with armadillos. i put those on my new wheelset, and the tires feel really sluggish. my steamroller is geared 49 - 16, the spicer is geared 47 -16 (with armadillos) and with all other things being equal (tire pressure, tire size, etc.) its harder to maintain speed and acceleration than the higher geared bike. have any of you that use these tires noticed this? just curious.

auroch

yup

jeff

absntr

I don't run Armadillos but I do run Gatorskins which seem to be equivalent for the most part. I suppose it goes that the more casing you have, or rather, the more puncture resistance, the more rolling resistance.

When I switched from Vredestein Fortezza's, which I loved, I noticed it imemdiately. However, I've gotten used to them and I have to use them - I got three flats in the space of two weeks when I used the Fortezza's, damn these debris-scattered Chicago streets.

infestedguy1

that makes sense, i guess i would'nt have thought i would feel THAT much difference. but, like you said, i guess it is something that you get used to.

timmhaan

they may be a bit slower, but the armadillos are nice. especially in the middle of winter when you don't want to be walking your bike home or changing a flat on the side of the road.

fixedfiend

you definitely have more weight on that tire which would cause the rolling resistance.
just take a regular road tire and an armadillo and you can see the difference. I run them with mr. tuffys so my tires are pretty heavy. ...but, I need the protection with the metal and glass strewn all over the streets these days. I say run them for about a week and see if you get used to them.

jimv

My understanding is that alot of the 'feel' (and rolling resistance) of a given tire is determined by the side-wall. If you feel the sidewall of an unmounted gatorskin versus that of an armadillo the difference is striking.....The gatorskin is very supple and I think that's reflected in the ride. As for me, I've had great luck with the Vredesteins for the past 1+ years...Guess I've been lucky.

Take care..

Jim

RainmanP

I very much like the wider 32 and 35 mm Infinity Armadillos that I have on my heavy commuter. However, I have tried and do NOT like the narrower, slick road type Turbo Armadillos. These tires seem extremely wide for their nominal size. For instance, the 26mm seems significantly wider than, say, 28mm Continentals. Additionally the tire cross section is not nice and round. It is very flat across the "tread" area. Between the extra width and the flat tread, these tires seem to have a lot more contact area and a LOT more rolling resistance than Continentals.

infestedguy1

yeah, i'm not sure how the gatorskin's sidewall feels, but the armadillo's have one of the hardest sidewalls i've ever felt. i almost couldn't get them on the wheel (alex r390) because they are so hard. hopefully, i'll get used to them cause they aren't the cheapest tires around, you pay for that flat protection. otherwise, some slightly used armadillos may be coming up for sale soon :-)

bostontrevor

It's a funny thing, not a lot is really known about rolling resistance. There's a lot of theory (sidewall plasticity, temperature variance, other stuff) but not much is actually known other than it's related to wheel deformation and surface flatness. It's just never been carefully studied.

absntr

Definitely - stickerguy runs 25mm Armadillos and when you look at them, they look like 28mm or more. They're huge tires and he even had some clearance issues when he was picking out a new carbon fork. They feel insanely tough, which like jimv said there's a difference - the Gatorskins defnitely seem much more supple on the sidewall and seem actually normal - the actually tread is thicker but not the sidewall. If you get the 23mm's they look more like 25's at least heightwise.

Which is why I picked up the Gatorskins over the Armadillos, the difference in density was noticeable.

ostro

I have ridden both gatorskins and am currently riding armadillos. I felt the gator skins were a much weaker tire then the armadillos. I had several flats on the gatorskins and a cut (by a piece of glass) which destroyed the tire. (cut from the side wall into the center of the tread) The sidewalls on the gatorskins feel really flimsy and weak when compared to the aramdillos.

I feel my ride is actually faster from the hardness of the armadillo. Maybe its just me.

keevohn

How about mixing n' matching?

Run an Armadillo/Gatorskin in the rear for flat protection and durability, and a more supple/better rolling tire up front for ride quality. I find that most of my punctures occur in the rear tire, and flat-prone tires that I've run in the rear fair much better up front.

Just a thought.

jimv

For anyone interested in rolling resistence, I would recommend reading Jobst Brandt's posts on the subject when he was working with Avocet. In fact this entire bicycle related page is worth a look if you're not familiar with it. Lot's of good insight from the Sheldon Browne/Jobst Brandt camps. Brandt seems to know alot about bikes especially with regard to wheels (he wrote 'The Bicycle Wheel') but boy is he ever a cranky guy (no pun ... really).

Here's an excerpt from one of the discussions.


Rolling resistance is caused by rubber deformation losses in the
tread, the tube and the casing. The tube is firmly attached to the
casing by inflation pressure so it is like a tread inside the tire.
The whole tire flexes in three dimensional space, X, Y and Z. You can
verify this typically by laying a stadard business card between tire
and tube. It will shred to fine confetti when ridden. It is this
motion that causes hysteretic loss in the elastomer in the casing, the
tread and the tube. If the tire has patterned tread, such as a knobby
tire has in the extreme, deformation of the tread into the voids will
cause additional loss. That is why knobby tires roill so poorly.


Take care

Jim

bostontrevor

Yes, but what's not known is the quantities of rolling resistance. We at least some of the inputs, the things that qualitatively affect it, but we don't know exactly to what degree and how those inputs change under different conditions.

Another authoritative work, Bicycling Science says as much. Of course it's impossible to prove a negative, but it's a well-regarded work on it's third revision. I'd expect that if it were egregiously false that would have been edited out by now.

There is a lot of theory and little measurement.

TimArchy

I run an armadillo on the back and a lighter race tire on the front. I love the durability of them and I haven't felt too much difference in rolling resistance, so long as I keep them aroud 120psi. I don't have many problems with flats so I get them mostly b/c they last three times as long as any other tire when I'm skipping/skidding.

infestedguy: if you don't get used to them, I'll take them off your hands.

tim

sbeatonNJ

I have armadillos on my fixed gear right now (23c) and while the puncture resistance is great I really do not like them. They just seem to ride rather harsh in my opninion but they were free from a customer who didn't want them anymore when he got new tires. I don't know what I am going to try next, probaly just the plain old cheapo Avenir/Cyclepro tires. They aren't the fanciest things but they have a kevlar belt that I have had no flats with on my other bikes I use them on; plus they cost like 11 dollars.

2manybikes

Yes I have noticed too.

noumena9

Mine seem slow when I am at 120psi or less. I pump them up to 140psi and they feel really crisp. I weigh 230lbs, though, so I don't know how much that factors.

The thing to consider is how much is your overall average speed improved by not having flats? I used some faster tires for three months here in NYC and I got a flat every other week. I switched back to Armadillos in September and have not had a flat since.

Ira in Chi

If you want a very tough yet round tire, try the Continental Top Touring 2000. Yes it is heavy and yes it has a little tread, but it virtually puncture proof and has a really good shape. I've noticed that after riding through dust with wet tires, only a 23-25mm strip on the center of my huge(37mm) tires is marked with dust. This means the tire is massive enough to ride down stairs, but has similar rolling resistance to a racing tire. Granted, these things are HEAVY and I would not reccommend them to any weaklings but they last a long time and are 100% worth the money.

luckycat

I've used both armadillos and gatorskins, and thought the gatorskins ride quality was much better.

jimv

I guess I'm not sure what you mean here. Rolling resistance is a measurable thing (in the lab). If you mean the effect of the combined rolling resistance of tire, tube, road quality, temperature, etc in a 'real world' ride, then yes, there is much that isn't understood. But the fact that the tire's RR is dominated by the deformation of the tire material over a hard road surface (or of a soft road under a hard tire ... it's the same thing) is pretty well accepted. Once again, how that actually affects a particular ride, well I agree there are many other factors. It is believable to me that a person riding the same roads everyday with the same setup would notice more resistance with Armadillos over some low RR tire.

I have Bicycing Science as well. It's a great book. I didn't see anything in there that was in disagreement with Brandt. This is an interesting discussion and I certainly wouldn't recommend anyone buying one tire over another simply based on some lab measured/calculated rolling resistance figure. As noumena9 and others have pointed out, there are more important things to consider ... like flat resistance.

Sorry if I completely missed the point of your post.

Take care

Jim

bostontrevor

Bingo. There isn't much known about how to predict rolling resistance which is to say that there aren't any good models of it. It can be measured but it's not understood except in a loose qualitative way.

What happens 2 minutes into my ride as my tire heats up? 10 minutes? On a 90 degree day? What if I'm running tire liners? Asphalt versus concrete? And so on.

bostontrevor

Starting on pg. 130 in Bicycling Science, 3rd ed. there is a brief discussion of rolling resistance. It's full of phrases like "whereas slope resistance is rooted in basic physical laws and can be calculated precisely, rolling resistance is founded on empirical observations...", "tire rolling resistance is more mystifying", "There is no particular reason to think that the force of rolling resistance should be exactly proportional to weight, nor that it should be independent of velocity, as this expression implies. Unfortunately this is an area in which too few careful measurements have been made", and so on.

Even Brandt cites measurements made of specific products operating under specific circumstances. No effort is made to claim that those circumstances represent anything like the actual operating environment.

Much more is known about things like aerodynamics, human power output, frame strength, etc. In those cases performance under a given set of conditions can be largely predicted, even a rider's performance.

edit: by the way, this isn't to imply that the concept of rolling resistance is worthless or that one cannot talk about a tire having higher RR than another. I was merely making an observation that a lot is said about RR for something that's so poorly understood.

Tony Arms

I run 700 X 23c Armadillo All Condition tires on one of my fixed. Havn't had a flay in over 1000 miles.
On my other fixed I run 700 X 23 Michelin Race pro. The pros are faster but not as much flat protection.
The response of the Armadillo tires are a bit slugish but I am willing to cope with it for the flat protection.

Tony