That’s what I found as well. At least with the Mezcal front and back. Once I dropped down to about 17-18, they felt a lot better.
Still think I may go ahead and put the Barzo on the front.
I’m also still holding on to my Ikons just in case these don’t give me the same feel.
Hump
Just to echo what y’all are saying, when I ran barzo/mezcal I was running 17/18 psi as a 180lb rider. They do not work well at all over 20. My current setup is 2020 FasTraks front and rear and run 20/21 psi for reference on how much lower you need to run the Vittorias. Love both setups. FT came on the epic…
Ended up changing over to Forekastor 2.35 front and rear and dropping pressure to 16 / 18 psi for latest race. Different course but similar conditions in places and the difference was night and day, managed to stay off the brakes a lot more and even managed to pass someone on the one main descent. Ultimately it was my legs that let me down a bit this time round.
Hi
Is moving from a 2.25 tyre with 21int to a 2.35 with 25int a big difference?
I’ll be partaking in a local club league (short track xc 30-45mins, but staggered start times) that features super rooty, generally wet, natural trails. The fastest times generally are 17kmh average.
I am new-ish to XC (4 months) and just want to minimise risk and increase confidence.
I have a decent engine (4.5wkg) but am just inexperienced at mtb and would to make my hardtail as capable as possible.
Currently running racing ray and Ralph on 21int rims. I like the schwalbes. but if you have any suggestions.
Clearence on the hardtail will be tight - There will be some clearance I will just need to protect the stays as best I can.
On what type of surface?
I’m racing 6hr dry UK dusty single track on the Barzo’s at the weekend and taking the Forkaster on a spare wheel. As I need a “lights on” stop, I might change the front wheel for the experience.
This has been mentioned earlier in thread, but thought I’d include my experiences here. Based on this thread, I put the 2.35" Vittoria Mezcals on my XC bike (28mm internal width) for Moab Rocks. Very rocky and dry race. They were awesome. Really didn’t feel like I was giving up any traction on slick rock on the descents at all. I do notice in loose corners they aren’t as good as my Minion DHF that I normally run on trail bike, but that’s to be expected.
On my home trails, which are tend to be on the dry side with frequent sharp limestone rocks, they have also been great. I know they are fast rolling because I routinely roll up to my faster descending buddies when nobody is pedaling. So much so that I was initially confused and thought something was wrong with their bikes. Nope - the Mezcals just roll that quick.
My only other reference point for XC tires comparison are the Bontrager XR3 and XR4. These tires are nice and light for the tread profile they offer - especially the XR4. I would lean towards running that tire in anything wet.
Question; I see alot of talk about the Barzo. Given how well the Mezcals work for me, I’d like to know where the Barzo sits relative to that tire. Based on the tread, I’m assuming it’s not as fast rolling, but offers for traction for braking/descending (maybe even wetter conditions?) Thanks for any tips.
Barzo in front would be good to tighten up the bike in turns if you feel it is needed. When I ran Vittorias, Barzo Front and Mezcal Rear worked well for both control and wet conditions if they came up. Otherwise it is was a killer setup on dry loose over hard and the rocks you talked about. Never tried Mezcal in front but have heard that it works well in dry conditions, but not so good on front in wet conditions.
I used to run Barzo front and rear and felt it lacked in loose over hard, but from the last few comments in this thread I probably had the pressures set too high. They were terrible in mud as well
Dry loose over hard was where i was struggling. Seem to have improved there. Not sure about rolling resistance increase, it’s hard to tell without direct comparison on the same course (this was the British XC National Round at Lochore). The main downhill was more rooty / rocky, straight-line and was fine, it was the more flat twisty sections i was noticing the grip on.
Another yes for continental casings seeping sealant. Mine seem to seep from small (invisible) nicks, cuts, scratches, abrasions. They hold air just fine, just a minor annoyance if I happen to grab a tire when loading/unloading. My hardtail has the crossking/mountain king combo and it is very good. I had race kings, but they were just not durable for rocky terrain. I punched a hole through the tread that I could put my index finger through.
I dropped the pressure on mine front and rear Mezcal and it changed the feel of the tire completely.
I’ve also found that you really need to get on those corner knobs. I think most tires have that drift feeling when your in the transition zone.
They’ve been rolling fast now!
Hump
I have a few XC racer friends mostly pro or expert level races switching over to the Forekaster in CO. Say they love how it hooks on flat loose over hard cornering.
I was going to go with the new Fastrak as it looks better than the previous gen or something like a mezcal or barzo,
Currently running 29x2.35 Barzo front / Mezcal rear on my XC bike (previously ran Aspen / Rekon Race) , but looking to optimize tire choice for 2 races I’m doing in the summer. Both are 100mi+, one primarily long tarmac/fire road climbing and slightly rocky/rooty descents and the other primarily flowy singletrack with shorter climbs, very few rocky sections. For optimization purposes, we’ll assume both are in dry conditions 
Most advice I read for those 2 races was for narrower tires (mostly 2.2, some even 2.1) and surprisingly beefy treads (Ikon / Ardent Race, Specialized Fast Track).
After reading this very helpful test, I’m not sure I see the benefits for a narrower tire. Instead, I was leaning more towards something like a Rekon Race.
Checking bicylerollingresistance.com, it seems Conti Race King or Schwalbe Thunder Burt / Racing Ralph might be good options with low RR (in an optimized environment like tarmac) and save 100-200g/tire against the tires I currently have (partially that’s because they’re narrower, to be fair).
Any thoughts what y’all would run in these cases?
Could also just swap my existing setups and do Mezcal front / Rekon Race rear and just live with the slightly higher weight from wider tires, hoping it’ll be faster/more comfortable.
I think it’s hard to go passed the Ray and Ralph combo for one size fits all speed and confidence.
I’d not be running a Ralph as a front unless the descents are very grippy or not very technical, or if you have a high level of skill/familiarity of riding at speed with that little grip on the front.
The XCO Pro’s race Ralph still as a front tyre, but I’d say they mostly all have above average technical skills.
I live in Front Range CO and it’s normally dry with loose over hard. I have mostly been riding Mezcals with other front tires (Forekaster, XR4) mixed in as needed for some events where I felt I needed more grip.
From your list I swapped to Conti Race King for LT100 last year based on a lot of positive feedback for that tire in that race. They are noticeably lighter and faster rolling to me than Mezcal, but also wash out a lot easier. Going into even wide corners at speed on loose over hard led to sliding, but I am bad at cornering on dirt so YMMV.
I’m always a proponent of sticking with what you are familiar with. If your used to how they feel, then run them.
I’ve been running Mezcal front and rear in South Carolina. It’s been dry on the trails, and so there some slight drifting, but I find when I run a bit lower pressure and also get that lean in, the side knobs bite plenty.
I do have a Barzo on standby if it gets to be a very technical root ridden course.
Hump
Usually use a Racing Ray Race and Ralph rear. Although, as it’s super dry at the moment I’ve got a Thunder Burt rear. Mega quick.
Vittoria Mezcal and Barzo are the same. Can’t tell a noticeable difference. It just happened that the schwalbes were in stock at the time.
2.35s running at 16.5psi front 18rear with 29mm internal rims - Roval control 6b (I’m 71kg) CanyonLux
Rocks and roots 
I did my first race - a 6hr - on a very dry, dusty Rooty singletrack at the Weekend with the F Barzo at 18psi (I’m 76kg) - it was much better on the loose stuff.
Gorrick?
It was indeed - 6hr solo GV - you?