The age old question is: which tires and what pressure should we be using here in our local Israel conditions (Loose over hardpack most of the year, and even looser late summer into the fall)?
Let's review the golden rules of tire selection:
Rear tire - get the power to the ground & get the bike moving with minimum resistance. Enough grip not to slip & to provide good braking. But you still may want to be able to drift when desired.
Front tire - get a grip on it. The front gives you all of your steering control & much of your braking power. The confidence for jumps & high-speed maneuvers comes from the front tire stability.
A 'round' tire profile gives better transition on the turns & faster rolling, but, generally less 'stable' on the gnarly stuff & jumps
A 'square' tire profile gives better grip & sometimes slower rolling. Much more stable on the gnarly stuff & jumps. More All Mountain / DH rated. The newer profiles (such as DHR-II, Highroller-II, etc. set out to solve the 'gap' problem and make the tires more stable in the transition)
Both tires:
The tire width must be less than the maximum stated by the frame mfgr. / fork mfgr. Using a wider tire, while it may appear to be OK is risky - insufficient mud clearance, high chance of rub if the rim is slightly out of true, etc. No reason to risk it...
The tire width must match the rim width recommendations for it to sit properly & securely (there's charts of rim width vs. tire width rules of thumb). https://www.dtswiss.com/en/support/wheel-characteristics/rim-inner-width-mtb#:~:text=The%20popular%20mountain%20bike%20rims,between%2025%20and%2035%20mm
For our conditions the highest possible level of tire 'armor' & strength to avoid punctures & sidewall rips from the sharp rocks
Like most bike things, there's not necessarily a wrong answer, and it's mostly personal preference!
Well -- I did find a wrong answer. My previous favorite was a Ardent
rear & Highroller
on the front. The problem was that the Highroller is a square tire & a bit squirrrily if it's not really leaned hard on the turns. So I tried a Kenda Nevegal-X Pro
on the front which I really didn't like. very poor grip for our conditions & the round profile (which I used to like riding more XC) didn't give good support or stability with a more aggressive & small jump riding style.
[I'll take this opportunity to thank Nachum for challenging me & questioning my tire & bike choice which prodded me to finally run this tests which I've been thinking about for a few months]
So, I recently did a scientific study & I certainly did find a better answer...read through the study to find the answer
In order to do the most scientific study, I setup a test changing only 1 parameter - the tires.
Test setup:
Turner 5spot (rides just as good as any of the modern bikes 😜, and a perfect platform for this test)
Old tires swapped out at 50% tread, so old bald tires was not a problem
Constants:
Same bike
Same tire widths (2.3")
Same pressure (30psi)
Same rims (diameter & width)
Trails - adulam & kanim ridden on consecutive weeks, with new tires on worse trail conditions
Old tires:
Rear: Ardent
Front: nevegal-x pro (picture from internet, not my bike) - you can see the rounded profile
New tires...
Rear: Minion DHF (yes, the dhF)
Front: Minion DHR II (yes, the dhR)
In summary...
The Minions are AMAZING
Superior grip & cornering
No loss of speed vs. the Ardent
The DHR II solved the gap problem of losing grip in cornering - the front tire is much more secure giving a much more confident ride!
*I highly recommend the Minions!*
Postscript
I'm now riding a pair of 2.3" minions on a wider rim. This setup gives significantly better support & grip. The slightly wider rim allows the tire to open up a bit and flatten out at the top. This provides a significantly more stable contact patch as well as a better supported sidewall.
Tire pressure
A lower pressure is, in general, much better for MTB riding than a high pressure. The lower pressure allows the tire to conform and grip to the surface (rocks, dirt, trail, roots, etc) instead of bouncing & ricocheting off everything like a rubber-ball!
Tubes - if you're (still) running tubes, be sure not to go below 30psi (or the minimum pressure stamped on the tire sidewall if it's greater than 30psi) in order to minimize the risk of "pinch flats" / "snake bite" flats.
Tubeless - 25-30psi is a great minimum to start with. Remember, tubes & tires lose air at a rate of around 5psi a week - especially important if you're running on the low pressure range - check & top off your tire weekly!
For a 26" wheel, since the tire volume is smaller, you may want to stay around 30 as a minimum.
For a 29" wheel, with a much larger tire volume, 25 is a standard minimum
Of course, if you're a heavier or lighter rider you can adjust these recommendations.
I recommend playing around - but be careful, if you ride too low a pressure the tire can "burp" on a hard fast corner, or can even blow off due to lack of pressure holding it on. You also run the risk of damaging the rim if the pressure can't support the tire on hard corners or jumps or sharp rocks.
Tire "Goo"
Tire goo is what keeps us rolling out here in the desert. All those thorns (especially the goatsheads) are constantly putting small holes in our tires, and the goo plugs the tire on the fly & keeps us rolling.
Both tubes & tubeless need good, fresh "goo"...so here's a few thoughts...
Goo needs to be fresh - it our desert conditions, it'll last about 6 months (less, if you store your bike outside or in a hot shed)
Before putting in new goo, good practice to take out the old goo (use a syringe with tube, or take the tire off a bit & wipe/scoop out the old, watery stuff).
If there's goobers in the tire (dried goo) take off the tire & clean them out - they only make more of a mess & destroy the fresh goo
When putting in new goo, make sure it's compatible with the old stuff - if not, be sure to either clean out the tire very well or put on a new tire!
If you get a big puncture & need to use a "worm", the goo is critical to seal around the worm - so keep the goo fresh!
I happen to like Joe's goo, but YMMV - use whatever works for you!
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