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Existentialism-- Just a bloody good excuse to go riding...

Monday, June 21, 2010

Tire Time

I hate changing tires. As far as possible, its an avoided chore though as anyone who rides with me knows that I religiously carry a pressure gauge and tune me rubbers according to trails and conditions.

I'm a firm believer that the first suspension in any bike is not in the fork or shock but the tires.
Therefore setting them up in sync with your suspension settings together with fluid flow in the limbs can only then complete the picture of total suspension. Traction is primary. Comfort is secondary but a side effect of being dialed in with all the "suspensions" of riding is usually one that will afford better comfort.


I've been chanting the mantra of bigger tires for awhile. IMO a good bigger tire outweighs the weight penalty. Still it would be silly to lug a 1.5 kg DH carcass on trail rides. It all boils down to what your ride, bike type and yes, in part bodily strength if u aren't simply keeping both wheels to the ground. Rocking a bike or airing can be physically demanding and excess weight especially up in the front wheel just makes for a few more sloppy moves when tired.

Price is always a factor and not all expensive tires are good. On the main 6x6 rig, I have more or less come to a conclusion on the tire types it needs for my kind of riding around here; lots of hardpack and square edges during short steep climbs. The downs are nothing to talk about in our local trails, most bigger tire will give the extra confidence and aggressiveness to chomp down most stuff that can be found. Big aggressive squarish profile in front tends to push dirt rather than roll over it in general. But a rounded profile at the back is too skittish. rear works best for me with a squarish tire but low center rolling knobs.

Having steadfastly hugged 2.35 Fat Albert up front, I wasn't too keen to change to other tires. The notable exception was the love-hate affair with a Rubber Queen 2.4 once..........until now. With only 1 more new spare Albert in the storeroom, this cheapo non folding model I have been using is discontinued with the launch of the new Albert range. No doubt lots of marketing bullshit for more expensive tires to suck the consumers' dollar. Not too convinced from all the reviews available on the new Alberts, so it was time to rethink what could hopefully be the next new tire for the few years to come.

Firstly a little review... 2.35 Fat Albert (touring, non foldable) model has been up front since the Motolite to the present El Guapo. Grips just about anything despite the sparse looking knobs. Initially I had to overcome the feel of the rolling resistance as the last few tires had ramped center knobs like Nevegals and Panaracer Rampage 2.35 which made for much faster rolling. However after a few rides and getting a hang of things, the Albert performed much more predictably, notably from its huge carcass amd was rather confidence inspiring. Weight, is pretty light for a non-folding. Never really weighed but compared to other claimed 750gm tires, it probably felt like 680ish gm.

Molded over 30mm Spank Subrosa, they are pretty wide upfront. Rocking over 2 foot wide dips between roots is not a problem. Can't say the same for most skinnier tires.

As a non believer of UST tires, naturally pinch flatting was a concern. Till date after 3 Fat Alberts in as many years, I had believe it or not, only just as many pinch flats. 2 of them from landing stupidly off-cambered in jumps at low pressure.... and one from hitting a sharp rock seriously hard on a down.

Tire pressure. Every piece of rubber has more or less their own sweet spot. And it is pretty oxymoron to talk about tire pressure without taking into account rider's weight when trying to find the lowest that still runs best without too much flatting.

For me, its 19-21 psi at a geared weight of 75kg.
~21 psi when on the Motolite with a 140mm fork with a bike geometry that has considerably more weight pressed down in front.
~19 psi now on the El Guapo with a more laid back posture, due both to the bike geometry and the way its set up.

How low is too low? A few factors to consider, but my easy way out on days when I am feeling less profound is to size it up with my eye-ball-o-meter. When seated, if the rubber's height deflection is not significant and riding over a consecutive rough patch doesn't bounce like a ball, that's good enuf for me.

Have tried tons of pressure setting and the above always work out. On super wet pouring days where every millimeter of traction counts where I know I won't be taking a jump anyway, the pressure has gone as low as 13-16 psi without ill effect.

High side? Anything above 24-25 psi for me is only good for 1 thing. Riding Tarmac to get home quick after a day in the trails. Once pumped up high, the tire loses its good handling characteristics. On few occasions where trail condition was nice and dry higher pressure certainly made things feel a lot faster on the hardpack but the moment it came to getting controls at the bends over roots and rocks, I wished it would just deflate back to a hair under 20 psi.

On the height profile, it raises ~0.6 cm over the 2.35 Rampage (hence it is overall 1.2 cm bigger in diameter).
Without considering the extra girth, the height alone translates to a huge jump in air volume.


Durability? Sure as hell lasted for long time. Though 3 were changed in 3 years, the last one is still in use on another bike. The earliest was de-commisioned due to rubber hardening over time and not because knobs were too worn down to be thrown away.

Weight of non folding is usually the bane and that actually is where the cheapo Albert shines. You know they always say, "Light, Strong and Cheap, choose 2"-- this one u can have all three and eat it too.
But all good things comes to an end....so today I threw the 2.4 Rubber Queen back on that were used for a couple of months last year. Its bigger than the Albert and the height is a good ~1 cm higher and wider too.
My rant with it is the relatively weaker sidewall that tends to fold at lower pressure. Sure, all the marketing hype about Snakeskin and whatever compounds is stronger .....bottom line,  a folding tire is usually weaker when it comes to the tire buckling  in a corner compared to non-folding tires.

The last time I ran it, pressure was at ~25 psi, anything lower I would be looking at the wheel more than I like during a run. Yesterday I decided to go with ~21 psi and just not look at it but concentrate on the trail ahead. trail was dry, traction was good. Hit a couple of flights of stairs in between going both down and riding up, no unexpected bounce off.

Putting on the Rubber Queen took a little bit of bitch-yanking technique. Still I managed to do it without the aid of a tire lever. Which is a good thing cos u know sometimes on the trail when u need those little helpers, they somehow go mysteriously missing in your hydro bag.

Overall its 2 cm larger in diameter than when compared to the Rampage from before and almost 1cm higher than the Fat Albert (Carcass measurements, not including knobs).

With a road bike front wheel put side by side, an inflated 2.4 Rubber Queen is almost as large as a 700c wheel.
Maybe not a 29er yet, but sure is close to being like some of those 650 mountain hoops

More trail testing needed but the same feeling of added confidence came back like the first time I had used it. The slight rise up front due to the rubber height was noticeable but not in a negative way. I begin to compress my front and dunk harder on the trail, pumping the bike became easier and less scary. Compensating for a higher front, just have to un-weight a split second earlier into climbing position when going up steep rutted climbs interspersed with rocky square edges.


The back was still somehow mated to my trusty WTB Prowler XT Comp 2.3. Again another tire of choice that has stayed since discovering it 2.5 years ago. Not the widest or most voluminous that my stays could accommodate but the best performing piece for me.

I was changing the rear too after the front but somehow after putting on the WTB 2.55 LT Weirwolf Race, I simply can't fathom how I am gonna ride that piece. Took a look at a 2.35 High Roller, realized that I was sent the wrong model--it was the DH super heavy 2 ply model in my hand. Should have checked the package when it arrived two months ago.  Arrghhhhhhh....so I suck thumb and stuck the 1/2 worn down Prowler back on.

Tire Pressure. Initially the tire didnt look like it will grip but after all these while I got the sweet spot at ~21 to 22 psi and it grip like a leech. So if u are the type that likes a little more drifting, then this may not be such a good tire for you. Beyond 25 psi, the noticeable kick from going thru bigger roots is something that my butt can give you a good review on. I attribute part of the grippiness to the roughened surface i between the knobs and the split knobs themselves. When the tire breaks, it will quickly find grip again noticeably starting from the inner row of side knobs. Rolling resistance is something I wouldnt rate as being too low but not silly high and makes u feel sucked down either.




















On a side note, the new Prowler SS Race 2.3 with the additional center row of knobs seems to be WTB's answer to something faster rolling but retaining all the other traits of this tire. But how does the extra knob affect centerline traction now that the space in between knobs is filled up as compared to the XT?
All in, from magazine reviews to those of rider Joes, what's described has been similar to my own experience with the WTB Prowler XT, so next purchase? Yah, I'll probably end up with both the XT and the more expensive SS too...

At ~850gm its not light (as heavy as the non UST 2.4 Rubber Queen). For the performance, I wouldn't trade it for anything else now. Oh yes, it is a folding tire but with considerably thick sidewall, which probably explains the weight and also why it would fold in easily during hard cornering.

Durability. Center threads will start to wear a bit thin after a couple of hundred km. But tire will continue to hold.
My early concerns then was the bits of rubber found inside the rims as the side gets sheared off. But each time till I retired the XTs, none had their sidewall rubbed off enough to render them unsafe. The nylon threading on the sides will start coming off making the tire look all mangy but again its only superficial.

Flatting, yes when I start to go silly low on some days like 12-15 psi and insist on ripping thru every piece of tire devouring rock out to catch stupid bikers. Otherwise, again it is a relatively flat-proof tire.

Figured that once the useful life as a hardcore tire is over, could always find it a second life as "semi slicks" on my other bikes that see more gentle riding. No point throwing away perfectly good things. Do your part, save some rubbers.


So for now, my next stable combo looks set to be 2.4 RQ front and 2.3 Prowler XT Comp/ 2.3 SS Race in the rear



Time to sell off all other once tried but otherwise still new tires....


Measurement & Comparison of  tires from above
Height measurement is taken at highest flat point of carcass (without knobs)
Width measurement is taken at widest point which could be either at the knobs or carcass.
 
Tire Rim+Tire
Height
Tire Height
(inch)
Tire Height
(mm)
Width (mm) Width (inch)   Tire Height
(mm)
15% deflection
inclusive of rim height
15% deflection
rule not inclusive  of rim height
Tire Dimensions Relationship
Rubber Queen 2.4 with Rim 82.00 2.23 56.60 61 2.402   56.60 69.70 48.11
Fat Albert 2.35 + Rim 78.30 2.08 52.90 57 2.244   52.90 66.56 44.97
Rampage 2.35 + Rim 72.00 1.83 46.60 54 2.126   46.60 61.20 39.61
WTB Prowler XT 2.3+ Rim 75.30 1.96 49.90 53.3 2.098   49.90 64.01 42.42
Ardent 2.4 with Rim 81.00 2.19 81.00 58 2.283   55.60 68.85 47.26
Rim height used for all @ 25.40                























































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