24 May 2009

bikefix Initial Review: Specialized Purgatory 2Bliss tires

If you follow my tire reviews at all you will remember that I used to love Specialized's 2Bliss tires- until they stared to suck. This happened because the company decided to abandon the UST standard in favor of (lighter) tubeless ready tires. Doing this made the tires (particularly the sidewalls) too thin- and as a result they rolled over and burped air too often. Tubeless-ready tires often have this problem (when compared to UST) and I try not to have high hopes when I buy one. The current crop of Specialized tread designs seem to be pretty good, but I will only run UST tires as the current tubeless ready generation just hasn't been working for me.

Not too long ago though, Spez introduced the Purgatory tire. It is a trail/enduro type tire so I was vaguely interested but what caught my eye was that the 2Bliss version was offered with the company's Armadillo casing protection. It occurred to me that this protection system might bring back some of the side-wall integrity that had I been missing in recent Specialized tires, so I bought a pair.
The good news is that I haven’t burped these tires yet- the Armadillo casing seems to have made the difference. I still notice a bit more squirm underneath me than with most UST tires but it isn't too bad. I rarely cut my sidewalls (or get flats) though, so I don’t know how well the Armadillo feature works but I’m guessing life is better with than without it. These tires are light for their size at about 680 grams for a 2.2.

The bad news is that this tread design isn’t that great. I was surprised by this too, as Specialized usually turns out well-tested and effective tread patterns. In a straight line, these tires seem to work great- up there with the best trail-tires out there. Cornering is a different matter however. I first thought that I had put the front tire on backwards (these are directional tires) but when I looked, it was mounted correctly. These tires start cornering just fine, but just when you are feeling good and starting to really lean into the corners- they release their grip and start to wash out. This trait is very pronounced on the loose-over-hard packed trails where I spend most of my time. I made a point of riding other types of trail surfaces with the Purgatory to be sure it wasn’t a terrain specific trait and it isn't. The effect was much more subdued on other surfaces, but that is to be expected since most other surfaces offer a fair bit more traction than loose pebbles strewn over packed clay and rock. The point is that the tire still washes out- and it was nerve wracking at times. I ran them at pressures from 30psi to 35psi and never could get this trait to disappear. I should mention the dual compound rubber on this tire, but considering how this it corners, it doesn’t seem to be doing its job enough to overcome the design's shortcomings. The softer rubber (60a) on the shoulder of the tire is supposed to improve grip, while the harder center (70a) is supposed to help make the tire last longer. I usually find dual compound tires to be quite effective but still a bit fast wearing. I would hate to ride the Purgatory's with a harder rubber corner on the shoulders- yikes.

I think that my Holy Grail of trail tires is a 2.2–2.3 size tire with an all-around great tread pattern and a reasonably light weight (650-750g). The Purgatory has a chance to be this tire if Specialized re-design the cornering knobs (or something). Specialized also offers the Fast Trak and the Eskar in tubeless ready models with Armadillo protection, which should be worth a try since I know I like the tread-patterns on both of those tires- I just didn’t get along with the non-Armadillo versions. The Purgatory 2Bliss Armadillo sells for $65.


charlie

1 comment:

Anonymous said...

What is the internal width of your rim. Looks like a crossmax ST. If your running 2.2 + try an SX. That should help stability issues considerably. I had no such cornering issues with the Purgs with a wider rim. XC rim = XC tires in 2.1 and under. More than 2.2 on a 18-19mm internal width I don't expect great stability or traction as you have to over compensate with more pressure to prevent roll.