Stan’s NoTubes Crow tires, first of an era?
July 16th, 2006 by CloxxkiI just got in my pair of Stan’s NoTubes The Crow 29×2.0 tires, I’m stoked.
On my older NoTubes ZTR rims they’re around 48mm at 30psi, pre stretching, I expect them to get really close to their 2.0 designation in a day or two.
Being a weightweenie I lucked out getting 2 copies under the claimed weight of 470-510g : 931 or 933g depending on which scale I use.
Second lightest set I own : Kenda Karma’s with somewhat similar tread and casing, 1070g for the pair. And those already felt way light and snappy, plus fast rolling. These just might be better on all accounts.
The Crows are unique in oh so many ways :
* 20-40psi recommended pressure (typically you see 30-60)
* 26″ and 29″ models developped simultaniously
* 6 rows of side knobs for every 7 rows of centre knobs
* Way lighter than any other 29″ tires, but not super narrow like many 26″ race tires
* No-Tubes specific : easier to live with if you were already using tubeless, a big added performance boost otherwise
* Reinforced beads to make this possible on the 29″ version
* First new high-end tire brand to hit the market in years
Till recently, especially before the Kenda Karma came, 29″ tires really didn’t roll faster than 26″ race tires, by lack of fast 29″ treads. The Crow might bring us speed of a new level, that takes away the last technical advantage that 26″ers were holding.
And weight…which 470g 26″ tire really ofers a lot of grip and rolls fast? Very subjective, but there aren’t many.
I’ve not been able to ride my Crows yet, but everywhere on the web we hear that they seem to grip more than one would expect after looking at the low-profile tread, and roll faster than the low recommended pressures.
It’s really a new philosophy in tire making, and yet again it took Stan and his crew to make it happen. A huge 5-figure investment to order 2 tire molds in Taiwan, some 12 months beore the first $40 tires can be sold. Super coll that stan committed to immediately make a 29″ version, at a time when there’s so much controversy around using 29″ tires without tubes.
If even half my expectations about these tires hold true (the signs are all still there), they will change the way outsiders look at 29″ bikes. Faster rolling : more than ever. Slow accelerating : due to which added weight? Grip : still comes naturally.
I’ll be trying to carry out some scientific rolling tests using gravity as the perfect referee. To be continued.
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Well, if the reports of usage around my neck of the woods is consistent at all with usage anywhere else, I’d say we have a winner on our hands here. I will be curious to see what you think after running them on some of your XC courses over there in the Netherlands. I’ve seen pics posted by yourself before and it would appear that being able to accelerate back up to speed after slowing for a corner would be of prime importance. Now with the Crow tire, it would seem that the grip is still there, if the reports are to be believed. So you shouldn’t have to scrub of much speed into the corner, and with the lighter weight, you should be able to build up speed much easier and quicker than before.
Well, it’s all theory, of course, until you put it on the start line to find out for real. I’ll be interested to read your report!
I don’t buy the theory that lots of accelerating would be bad for a 29″er. It’s bad for any bike with high-rolling resistance tires. Or the math has been explained to me incorrectly. Larger wheels are supposed to roll faster, and especially offroad that should more than compensate for their proportionately increased rotational weight.
If you take all top-20 finishers in a national pro race, and determin the rotional weight on their bikes, I bet the variation is much greater than between 26″ and 29″. Around me I see riders with tubeless-mounted Flyweight 330’s (sub-330g) battling riders with tubed Racing Ralph 2.4’s (600g). It’s really not like the one with the half-weight tires is pulling away in each corner, let alone being catapulted by. The difference to the next corner is probably to be expressed in inches rather than seconds. MM’s on tight singletrack. But rolling resistance and grip…a whole lot to win tere!
On an XL 29″er with 1350g in mediocre tires I found myself being faster on winding singletrack than S and M riders with 900g Michelin race tires. I know this rider to be technically capable, I once ripped a jacket trying to follow his lines through trees.
It’s much more about flow and timing than weight. In my opinion at least.
Over a ride, a lot of your energy goes towards rolling resistance. In you’re ride is flat and with little elevation, even more. Few turns to brake for, even more. Soft, loose or wet soil, even more still. I can run up to 70%+ of your energy. Even in the typical race, where it would be say 40%, shaving 10% off that will be huge, 4% (or 10-12W) less power required to manage the same laptimes.
A super-fast tire is worthless if you come to a halt in hard corners though, heaps of time are lost that way. Carrying a full Camelbag as an extra handicap will make it noticably harder to stay with your own level riders, but that penalty is a huge multifold of what 29″ adds by design. When I rode my 29″er with a rear tube filled with 3.5kg of water (see MTBR thread on that), it was annoying for sure, but not to a point that people would notice something to be “wrong” with my performance.
Weightweenies (I’m one myself) tend to over-think the influence of weight, and especially the rotating kind.
If Crows were to be established as rolling just as fast as the very fastest 26″ tire (whichever that would be), they could weigh 700g for what I care. They’d be a safe bet to round a lap quickly. I am totally psyched by the sub-500g weight though. I’ve been hoping for 510g for almost a year, and getting 466g.
Lightest 26″ tires I raced with some frequency: Maxxis Monotaur 380g (real skinny, grippy on grass and wet mud), Schwalbe Fast Fred 2.0 (370g), 2.35″ (495g) and Jimmy 2.1 (495g).
Interesting about the Crows and possibly what makes them work well, is the main knobs that are similar to the Kenda Karma’s, but lower and turned 45º. Also, the sides have a band of micro-knob surface between the actual knobs. I’ve not seen that a lot, looks grippy.
One of my racers is using Crows. At 150lbs soaking wet, he can actually get away with running 17 psi, where he has found the sweet spot for optimum grip. While running higher pressure, the grip was not quite there in our variable and mostly wet conditions, and slipped and spun out on just about every pedal stroke.
When we first mounted them on the rims, we noticed that it took less effort to get the wheel rolling. Weights were all over the place, from 460g to 504g.
My opinion is that this is a great race only tire for light guys. Running lower pressure is key.
What is the controversy around using 29? tires without tubes? Also, how much does your Stans wheelset weigh?
Thanks!
Many 700c rims seem to be at the lower limit of the standard, while most 29″ tires where made on the other opposite, making for a loose fit.
As 29″ tires have a longer bead (by 11%), it will also stretch more. Furthermore, as the nominal difference between bead hook size (622mm) and other rim diameter (635) is the same 13mm as weith 26″ (559/572), tires will be looser around the rim to be begin with.
All the above have resulted in many broken beads on tires, blow-offs with tubeless and even tubed. The larger the rim, the harder it will be getting tolerances correctly.
Stan’s rims are on the tall side of the standard, making for snugly fitting tires.
I have some very light (stupid) rear hubs in my Stan’s wheels. If I finish the rear wheel it will be a 1335g set. With good parts (Tune or DT hubs and flat spokes), 1450g IMO is very realistic and decently ridable for riders under 180lb.
cloxxki, 1450 is a little wishful. my AC wheels are 1515. AC hubs are
lighter than dt swiss, i have sapim cx ray spokes, and AC rims are lighter
than stans. AC’s rims are roughly 80 grams lighter than stans for the pair
so what hubs are you using that are gonna get you to 1335? with stans
rims. my AC wheels with stans rims would be close to 1600 grams. do hubs exist that will be 265 grams lighter than AC’s for the pair?
Non-disc, they exist. 52/175g.
What’s the actual weight for 2 AC rims? Mine are older ZTR’s, 389/390g.
right around 365 grams, what hubs are those? 52 grams doesnt sound
safe!
Don’t buy them, they suck. Front I never tried but trust, rears suck. Soul-Kozak. Better pay more and buy Tune.
If the AC’s came in 36-h…maybe I’d want them.