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

Monday, July 19, 2010

Tire Time 5

The wrist was bad this morning, both knees were bitching... guess that qualifies for another of my rare medical leaves in the last 10 years. 90% of which are contribution from biking related incidents. Can't remember when I last had a fever or other "normal" medical conditions that warrants resting at home.

While getting the paw all wrapped up, I was still pondering on the tire...
...was it more because of my bias after the washouts or is the tire design that's really the cause...With more time to reflect and good daylight, it was another round of photo taking and comparison.

This writeup is more focus on the knobs of various tires, performance related matters has been covered in the earlier writings of this "Tire Time" series.

To clarify, these few articles on tire thoughts may not apply to everyone. Most of my riding is with a bike setup that is gravitated towards pointing down. While it climbs and still maintain respectable speed on the straights but awards definitely aren't coming from those departments.

Tire testing and suitability on the bike means it has to be taken at speed over hard corners and no tire will be bitched or commended if it hasn't seen action in the wet or over slick surfaces. Personally, I think there is nothing much to test on the straights and dry jungle trails. Rolling resistance is mainly a function and design of the center knobs. If it rolls, it rolls. What hampers the rolling on the straight often compensates during climbing over loose steep soil.

The suitability of tires are mainly favored with respect to the usual terrains I ride in. Tropical jungle trails and many sections due to human invasion over time has become hard-pack or fireroads from torn down villages of years gone by. Lots of rolling terrain with a number of steep loose soil interspersed with slick rocky surfaces every now and then. Usually no huge ass boulders but root patches are common. Rain! With 2 monsoons annually and freaky years like this one which see flash floods in the dry season, mud is still not too big a problem but slick leave litter and roots can be really fun without the proper rubbers in place.

Hence some of the things described may not apply to quick and light nimble XC hardtails that will sacrifice some of the surefooted-ness of burly tires for speed or people riding in dry desert conditions etc.

Traction vs rolling resistance on the turns. Its hard to have both. Choose one.

After the recent spate of troubles, I'll now be even more inclined to choose traction. In a full set of side knob patterns on the RQ before the pattern starts repeating, it is a pair of forward facing followed by 3 "concave" knobs.

The green line would represent the bite when the tire turns. The red represents where the lack of knobs will give a no-bite zone until the tire rolls forward until the next pair of forward facing knobs.

The gap in between is significant compared to a few other tires below

The purple lines shows the lack of proper transition knobs. The trailing edge of the side knob (see smaller purple circle) interlocks with the transition knob but is too far inside to give a smooth transition.

The distance between 2 transition knobs are also significant. Although its sandwiching a center knob but the outer edge of which would be too far inside to be of much good during hard cornering.

Compare with the noted spacing of knobs described above with the 2.3 XT Prowler below

Paired side knobs with interlocking paired transition knobs.
Before the traction can break, tire would have rolled off to the next set of knobs.

When cornered hard enough, each of the staggered pairs are likely to "split" and afford more grip. Initially I had thoughts of how fast the knobs might strip but this was really not an issue. In fact with repeated hard cornerings, the signs of wear is evident only during tube changes where rubber from the rim-bead area gets flaked off and remains inside the rim.

This is the third Prowler in as many years as a rear tire. from the Motolite to the El Guapo. I'm pretty confident it works as a front as well....if only it weren't for my fetish of a bigger tire between the fork.

The Ardent 2.4. Inner to outer transition knobs look good and outer transitions interface closely with side knobs. No stupid big spaces in between. Though the knobs are outside relative to the sidewall but its only marginally so. Diving in hard might still be a case of side wall trying to grip the terrain rather than the knobs.

Center ramp knobs is a little too high for my liking but manageable. Therefore even in use as a rear but without flipping direction (ie following the direction as a front tire), rolling resistance is noticeable w.r.t. to it being a ramp knobbed design which should have less of such a feel. However as everything is holding well, I'm not really complaining too much. May experiment with cutting a step in the ramps like I did with some other tires....

The slanting inner transition knobs does slip a bit before the next set grips again but its predictable enough not to cause those "oh sh#t" moments.

Ok...let's dig the rest out for a comparison

Left to right:

2.35 Maxxis Dual ply High Roller DH- a tad small and heavy for this kind of volume..still pondering what to do with it

2.40 WTB Mutano Raptor (which part of it is 2.4???)

2.35 Schwalbe Fat Albert- my all time favorite as a front but this wire bead version is discontinued :(

Got it to try as a rear as Dylon swears by it and from watching behind as he rolls off those steep technical drop downs, it seems pretty good.

Got sent the wrong heavy DH version. Not worth the weight for the relatively small Maxxis sizing imo.

Now that I'm getting all anal about knob designs, just notice that it lacks clear transition knobs. But still given the solid row of side knob that protrudes far out, I'm leaning towards believing that its apt to grip well enough. The outside of the ramp edge should do nicely in transferring the grip over to the side knobs. Not too much empty space in between the area where transition knobs are supposed to be anyway

Since Dirty recently passed me a single ply version, looks like I will be trying it out soon probably on the hardtail.

Yup, cheap as ever, I only got this cos it was on sales.
But when it arrived.. WTF! Even dunking in hot boiling water to expand, doubt it would be anywhere near 2.4

Anyway since it was front specific, I threw it on the Pig for a couple of rides. Hadn't described it much back then. To summarize now, it was anything but confidence inspiring.

Though narrow, some volume was made up with the high tire height.

Now that I look at the tire again and thinking back, it does display similar characteristics to the Rubber Queen when banking into a corner. (Note the wide space between side knobs and a transition knob that is too far in). Also the sidewall was bulging out more than the side knobs for sure.

This, like many of the WTB front/ rear specific tires has knob patterns that arrows inwards leaving too much gaps and quite visually disturbing imo.

I don't look at my tires much when riding (you should always be looking ahead anyway) but with knob patterns like this, the eyes-to-tires syndrome becomes kind of an involuntary response. Rolling wise, it was pretty fast.

Ok, a close look at my all time favorite front rubber.
Cheapo wirebead 2.35 Fat Albert.

Certainly doesn't grip like the rear end Prowler then but not much slippage either. When it does, it finds grip again quickly. Countless time I thought it was going to washout during a turn over some roots but somehow it claws its way back. So much so that I got used to it and use it to my advantage....using the slight slips to force the leech-like Prowler from behind to drift out a little.

Edges of the side and transition knobs are cut to maximize contact with the soil or whatever it may be gripping even though the knobs aren't close-spaced. I'm not sure if the prominent siping on the side knobs are helping in any way.

oh and this tire last forever and ever. On the front, a change is never due to wear but because of rubber hardening over time

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