Geax Saguaro Tubular 29″er Tires: Mid-Term
July 25th, 2010 by Guitar TedEditor’s Note: Here is the next update on the tubular Geax Saguaros by our European contributor, “c_g”.
GEAX Saguaro Tubular 2.0 tires – mid term report (performance) by “c_g”
Hello out there – anyone of you already had the chance to ride a set of the GEAX 29er tubular tires yet? NO? Here comes the mid term report on these breakthrough yet somewhat controversial tires.
Judging by the responses triggered by my first “Out-of-the-box and Mounting” post (here), where you also find all the numbers and specs of both tires and wheel components, it looks like the tubular technology is perfectly accepted (and welcomed) by all with a roadie or cyclo cross background, while the MTB purists are seriously skeptical on their benefits.
* It is true, the tubulars require a specific rim to work with, are not as convenient as clinchers to mount (tubular experts might disagree) and trailside repair is limited to introducing sealant and air.
* On the other side we see claims like “superior grip, unrivaled comfort, proven reliability” (banner text by GEAX), “incredibly smooth and fast” (seconded by racers) drawing us the picture of the new wonder tire.
This post will exclusively deal with the riding characteristics and performance aspects of the GEAX Saguaro 2.0 tubular 29er tires. This post does not include a debate on sense or nonsense of the tubular concept for MTB in general or the GEAX tubular tire in specific. I will deal with this topic more in my final verdict later in the season.
Usually I am reviewing a tire as one unit but after having spend some time on the tubulars, I feel like I should try to distinguish between the performance aspects of the tubular concept (being pretty new to the MTB world) and the tread characteristics where possible.
So let´s get started:
How did the tubulars perform? (… not being used exclusively on buff XC courses but on “real trails”?) How was it riding these tires just about anywhere, under any weather and trail conditions – and more so on a trail bike (the informed readers know the GAS29 STAMBEK Classic)?
For this review the GEAX Tubulars have been exposed to most forms of riding I typically do – in no way restricted to XC-courses. I will continue using these wheels on a different bike for the later part of the season and will report on my experiences.
1. Intro: Starting to ride tubular tires
When first spinning on these tubulars you might feel ….. well, feel nothing particularly extraordinary – just a nice, smooth running tire. That is because you are likely running much too high pressures. By the extremely supple and flexible casing and the 2.0 section most riders are tempted to start out above far too high, maybe 2.5 bar if not more when pushing hard.
At that high a pressure (and if you are sensitive to things like this), you will sense that the subtle casing does adapt nicely to small obstacles like trail debris, minor roots and rocks but the differences to a decent high TPI racing tire set up tubeless (at the same pressure)are not too big. What you will notice is that the wheels feel very lively (some might call it springy) at high pressures – much like running ultralight wheel sets, which tend to transmit more mid-size vibrations due to the lack of mass.
1.1. Lower the pressure and the magic begins. Suddenly you will feel like riding …. well the best word I know to describe it would be “silky smooth”. When riding over your standard fire roads you will most likely feel nothing anymore – the ultra sensitive 290 tpi (!!!) casing and latex inner tube do an awesome job of cushioning out all the small trail shocks that usually are the tiresome ones on your body. Make the obstacles bigger and the tire does soak up roots and rocks in manner you might not have experienced before.
By reading this, some might want to think about the feeling when using a high volume trail tire but it is different – I will try to explain:
While the tubs will suspend you from a good portion of the trail chatter in an active, lively manner, the trail tires do this by damping out. Don´t get me wrong, I love riding 2.3 to 2.4 trail tires in the rough but the feeling you get from them differs from the tubs´ characteristics. It is hard to describe if you haven´t felt it yourself – maybe the best way to put it is how you can make a good suspension component feel plush yet dull (by putting in low pressure but high compression and rebound damping – this would be the trail tire) or how it can feel lively and springy, when taking out much of the damping and ride higher pressure (only that the tubulars´ under damped feel is lively in a very responsive manner, while undamped suspension components might leave a bike unrideable) … Anyone getting what I am trying to say?
Note: Lower the pressure too much and the tubular tires do become undefined in corners, starts squirming and deflecting – just like any air filled, flexible object – I found that the “sweet spot” pressure was slightly lower than with the Saguaro´s tubeless ready (called TNT) version, which has reinforced sidewalls. So comparing the pressure related behavior of the tires (that sentence just sounded weird) I was surprised how low pressures the GEAX Tubs could be ridden, given the suppleness of the tire compared to its pretty stiff sibling. I also attribute the positive bond of rim and tire to this. I found my preferred pressures running in the mid to lower 20s and I am not in the weight range of a XC racer (with riding gear and back pack I often account for +190 lbs). As a purely subjective sensation I felt that the “sweet spot” pressure of the tubulars was somewhat more narrow than with other tires, meaning that even smaller changes in pressure will change the riding characteristics in a detectable way
.The latex tube is more permeable to air and does require you to check the pressure and fill up more often than a butyl tube – nothing new but it should be noted.
2. XC Style
The first part will try to emphasize on the riding characteristics of the GEAX Saguaro Tubulars under XC conditions – meaning rides predominately at easy to moderately technical trails and at higher speeds.
2.1. Speed: This above mentioned uncommon smoothness of the tubs (when ridden at the right pressure) will make you feel super fast.
The wheels I have built for this test are light but nowhere near “weight weenie light” – but the ride quality still makes you believe differently. But beware:The tubular technology is giving a complete new push to ultra light wheels – I have seen a sub-1100g 29er wheel set for tubs and see more and more sub 300 g rims popping up in tubular specific design!! So expect to have the ultralight sensation to be emphasized even more with actually ultralight wheels.
This surreal smoothness and liveliness when riding at the right pressure and the sensation of speed is THE thing mostly commented on by riding tubular road tires. I am not a PRO racer and don´t clock my rides but the simple fact that many times I found myself riding a gear higher than usual makes me agree. (What I have heard from PRO riders is that the tubulars do not only feel fast but that they REALLY ARE – or they wouldn’t use them.)
1.4. Cornering: The tubulars´ perfectly round diameter is something that road riders greatly appreciate in cornering for there are no transition zones when leaning into corners – secure grip at any angle. Interestingly the exact opposite is the case with many MTB tread designs that purposely design a transition-gap into the tire to make it corner more aggressively by leaning into the corner.
Cornering on the GEAX Saguaro tubulars on hard surfaces and pavement has definitely shown that the positive characteristic of tubulars is there. It was plain fun to take high speed corners but when the surface became loose (which it often is on MTB trail conditions) this became subdued. I could tell that the supple casing would hold the line better, by creating a better interlocking with the irregular trail surface but only marginally. In my opinion it was the Saguaro tread limiting the cornering qualities of the tires – more on that later.
As it is cornering was pretty good (very good on hardpack surfaces) and definitely on par with many other good racing tires. I could imagine that with a more aggressive tread pattern cornering could be spectacular.
XC-Impressions:
Overall the GEAX 29er tubulars are fast and superbly smooth under XC riding conditions. Pure fun that could only be beaten by shaving some more grams from the wheels (easily possible by some of the new generation of sub-300 g tub-rims.)
I am not holding my breath to see the tubulars lighten up too much because GEAX is putting the emphasize on riding characteristics more than weight saving (Besides the 740 g for a tubular tire includes the sewn-in Latex tube – so the weight isn´t bad at all).
2. Into the rough – TRAIL and All Mountain riding:
Though the technology certainly is directed primarily at XC-racing applications – I just wouldn´t feel right not doing the rough stuff on these as well – well no bike park riding or enduro but some seriously technical Trail riding.
And this is another area where the GEAX Saguaro 2.0 tubulars can surprise you. The GEAX Saguaro tubulars ride like they were at least the size of their bigger brother the 2.2 Saguaros (where the tread design is bigger also leading to a more aggressive and more open tread there). Traction is great, so is braking grip, things I attribute both to the softer compound and the supple casing. Only aggressive cornering is limited but always controlled in loose over hardpack – but that again is a trait I mostly attribute to the Saguaro tread.
2.1. Learning to “hit your rim” without feeling bad: In the rough the ride does equally benefit from the lively feel and boosted grip described above, but there is one thing I learnt:
The subtle casing does resist flexing very little by its own; this supple, lively riding characteristic creating the superb ride feeling with smaller obstacles, can be a bit unnerving when the going gets too rough because the tire will blow through its “travel” and then hit the rim. The tubular tires simply lack the progressive suspension action that other tires with thicker and stiffer sidewalls have.
Initially I felt this was degrading the tubulars´ ride qualities, having an uneasy feeling every time when hearing the occasional “twang” and I was kind of expecting a flat to happen sooner or later. But over the time – despite me pushing hard on the wheels and inducing multiple hits on the rims – I had not had a single pinch flat, puncture or snake bite on the tubulars.
I talked to GEAX about this and have been told that this “bang” (within reasonable limits) is something more mental (and emotional) than real. The rounded shape of the rims does take these hits so much better (and mostly without any damage) and do that with very little risk of pinch flatting or snake bites. When asking several riders with road racing and cyclocross racing background the confirmed that those hits were a common thing for them and no one is overly concerned with it – one more thing we MTB riders might have to learn from the roadies using tubulars.
What does this mean?
* If you are able to simply ignore the occasional “bang”, then it does have no implication. (In my test I have really taken the “occasional hit” very literally, trying to find the tubular´s flat proof limits – inducing multiple hard blows– all without any negative effects.
For further proof, read the report by Sam of SINGULAR cycles on the GEAX tubs to back up my statement here (http://singularcycles.posterous.com/finale-24-hour-saguaro-tubs-and-carbon-rims).
* Another way of reduce the number of those “mental blows” when riding tubulars hard might also be to feel your ride more, apply more finesse and sensitivity to your riding, than you might have before – racers do this anyway and it probably doesn´t hurt the trail riders as well. In other words riding tubulars might even assist in making you a better rider.
2.2. REBOUND at slow speeds: One thing was peculiar with the tubulars: When riding them at XC speeds and a good cadence they would gip like mad, but when riding at maximum output and low cadence, I found the rear spinning out over roots and rocks more often than I usually do with the same SAGUARO tread in the NON-Tubular version. This was especially happening during the beginning of the test.
Why? I am convinced it has something to do with the low damping characteristic of the casing. When riding over obstacles the tubular would deflect quickly and rebound immediately after, something you will either not feel at all when going fast or sense positively like a tiny push from behind but when working your way up slowly the tire will soak up the obstacle but rebound while you are still not fully over it – thus you might spin out more often.
The fact that this sensation vanished after a few rides on the tubulars indicates to me that there is a learning curve I needed to go through – adapting my riding style.
Again, “feeling” your way more over the terrain will compensate for this.
TRAIL impressions: Overall the trail worthiness of the GEAX Saguaro 2.0 29er tubulars is much better than the somewhat skinny looks and fine tread would make you think. It might require you to adjust your riding style a bit (to reduce the number of hits and take full advantage of the grip even at slower speed) to take full advantage of it but if this is the only price to pay for the superb ride quality, then I am more than willing to accept it.
(That is: As long as I have no defects to report on during the continuing test period – more to come)

3. A word on the tread pattern: The GEAX Saguaro tubulars do share the well known Saguaro tread, only in a softer 50 ShoreA compound. Those who have ridden the Saguaro tread, know that it definitely is a fast and smooth rolling profile with good potential for varying conditions. It might not seem to be the most fancy tread but it does handle almost anything but too wet or too soft.
How does the tread compliment the tubular technology? I have already mentioned the extraordinary smoothness of the tire and the tread has its share in this. On the other hand the suppleness of the casing does boost the tread´s capacity. It definitely is noticeable how well the tubulars grip the terrain, both in traction and cornering control – despite the fast and smooth tread. But like hinted before – under wet & soft conditions the tires do find their limits – when the ground is soft, then the supple casing cannot add any benefit and the tread is too minimal and closely spaced to “dig” in.
I personally would love to see a more aggressive tread for the front (GATO maybe … and while you are at it: maybe you can make it a bit wider, too: 2.2 or so J)
Why choose this one? I talked to the product manager and designer of GEAX Samuele Bressan about it and it is just as it was with the 26 inch tubulars: GEAX opted for the most versatile and widely accepted tread pattern of their XC range – the SAGUARO.
(It was not denied that others might follow – it simply was a matter of acceptance and production numbers)
Mid term evaluation:
Let´s summarize how well the GEAX SAGUARO tubulars fulfill their claims:
1, “UNRIVALED COMFORT” Yes – once you have set them up correctly and don´t mind hitting the rims occasionally.
2, PROVEN RELIABILITY- FULL CHECK (so far) – no issues, no matter how hard I push on them.
3, SUPERIOR GRIP- A definite: IT DEPENDS – You will be amazed how aggressively the GEAX SAGUARO 2.0 29er tubulars can be ridden as long as the trail stays on the dry side of things. (I think it is the tread pattern to blame, more than the construction of the tire).
So far the GEAX Saguaro tubulars do fulfill their claims as a racing tire nicely by being fast, reliable and smooth. Even under trail riding they perform much better than you´d expect a racing tire to do, the only weaknesses is at very wet or very soft conditions. Compared to other super smooth riding racing tires it is on the grippier side.












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Thank you c-g, full credit for trying to explain a tyres ride characteristics, can’t be an easy thing to do.
I know you said you will summize the validity of tubular in your final report but can I ask some questions in advance?
Given the cost of a new wheelset and low availability of options does anyone see this being more mainstream? I have only ever seen tubular dugast mtb tyres on world cup and elite racer’s bikes.
What happens if you get a sidewall cut? Can it be repaied on the trail? And
Why the soft compound. These tyres probably cost a bomb anyway and with 50a rubber might only last a thousand K or so of riding (like bontragers XR1 team editions!)
Thanks
@professed: “c_g” has reported to me that the tubular mtb tire category will be expanding with some more 29″er choices. To my knowledge, sidewall cuts are not trailside repairable, but then again, the tubulars construction and purpose must be considered whenever you decide to use a tubular mtb tire. In other words- “Horses for courses”. Tubular mtb tires are aimed squarely at the racer. While “c_g” will be using his as anyone would use a clincher tire, and Geax and others will be pursuing more uses for such tires, the initial charm is going to be for racing.
Thus the softer compounds. Yes, they will wear out faster, just like any other high performance tire for any vehicle. Once again, the Geax Saguaro tubular is an all around tread pattern which Geax chose for its first tubular 29″er tire and is designed with racing in mind. (Slightly narrower casing, slightly different tread, compound is softer, etc.)
Finally, it is my opinion that the widespread use of mtb tubular tires is going to be limited by riders preconceived notions, intended use, and availability of rims and tires on a widespread basis. Racers will gravitate towards it, and perhaps some enthusiasts, but I think it will remain a small niche market.
It is time to do an updated test of the different available sealants.
It would be interesting for you to put together the lightest possible 29er hardtail, soft tail, full suspension and extral long travel bike and then compare them for climbing, loose track and mud with various tires such as tubed, tubeless and tubular.
I know that you have done some of the above at various times but a new summary comparison would be helpful.
It wold be helpful also to list a number of definitive conclusions about what specifications are best for various conditions when using a 29er. Such as what is the best set up for single track that is loose. What is the best set up for mud? What is the best set up for climbing steep technical trails. This could be done without singling out specific brands and looking more at factors such as fork travel, tire width, location of rear fork, length of tubes and etc.
TPI? Why all tubeless and tubulars are made of high tpi and ordinary tubed versions are like 60 tpi? What is the logic behind it?
@DC – $$$$$$ is my guess. And, a higher TPI probably doesn’t matter when you’ve got a tube messing up the ride quality.
Professed: I think you have given the answers yourself:
For now the technology can best be understood when comparing it to the Formula 1 technology in MTB tyres.
- whether they ever will turn mainstream is a question of acceptance and eventually an effect of trickling down from cutting edge to more mass production
- as such it is less a question of how fast a tread compound is wearing but how to optimize its performance – thus the softer compound.
- theoretically it could be possible to re-sow a cut in the sidewalls (if you don´t hurt the inner tube by this procedure) but I doubt it would work in practice .
DC & dman: Yes the high TPI (thread per inch) count makes for an extremely supple casing that conforms to any irregularities of the ground so well. 60 TPI is pretty common in budget and mid range (or AM, Freeride) applications, the better XC/Trail casings are often 120 TPI but the 290 TPI used in these tubs is close to the utmost possible TPI of 320 which only the most premium road tubulars feature.
By the TPI numbers alone it is hard to judge – you have to ride it to get the idea.
Have you tried a trailside puncture repair with a can of Vittoria’s PitStop sealant/inflator?
I wonder what pressure that can get’s the Saguaro 29′er up to, 2.5 bar?
The future has arrived! GREAT REPORT!!!!! Seems like it takes the tubeless advantages to the next level. The “only” drawback to 29′rs is the greater rolling mass to accelerate, problem solved!!!
290 tpi, I wonder what a normal tubeless tire might ride like is it had 290 tpi. 120 tpi is the highest that I have seen.
If you program yourself to fell that you are not really pushing hard if you do not get the bottom-out bang, you have a great training aid….
Great Report!!!!!
Who’s making tubular specific 29″ rims? These make a lot more sense now that I see the potential for extremely low wheel weights. The elite racing crowd will embrace these if they’re light as a package. Not sure if they would for a wheel of the same or more weight.
jason: to my knowledge there are two versions of GEAX´s PIT STOP available:
1, PITSTOP (content 50 ml) which is recommended for tirés 26 x 1.1 to 2.0 (so I´d guess you will need to do some pumbing by hand to get to your desired pressure on any MTB tire).
2. PITSTOP MAGNUM (content 75 ml) which is recommended for tirés 26 x 2.1 to 2.7 (which sounds like the one I´d take out on the trail with me)
I will try to get some, do the pressure test on the tubs and report back – for now I can´t give you a more conclusive answer.
t0m: The 29er tub specific rims dedicated to MTB use that I know of are:
- EDGE composite (Carbon tubular, 32 mm heigth, 24 mm width, ~ 270 g)
- AX-Lightness (Carbon tubular, 28 mm height, 25.5 mm width, ~ 250 to 265 g)
- BOR/FRM (Scandium tubulars, 24 mm width, ~ 340 to 365 g)
- AMBROSIO (alloy tubulars, 24 mm width, 410 to 420 g – the ones on my test configuration)
There might be others around: will gather more details and post them in my final report.
RIDE ON!!
Has Geax indicated when these will be available? I have a set of Edge clinchers that I can’t get to seal for the life of me and I’m thinking of swapping them for the tubular rims. But I’m not going to do that unless there are tyres available other than the Dugast.
tim: If my information is correct they should already be available through your national distributor. I have no information on the price though, sorry.