XC Race Tire Thread

Interestingly I just remembered this triple bike check with 3 Cannondale’s and the Schwalbe’s for Nove Mesto. It was pretty sloppy conditions.

  • Fumic: 69kg, Ray 2.35 both front and rear, Superground 16/19psi F/R no inserts!
  • Marotte: 62kg (short track winner): Ralph 2.35 front and rear, Superrace 19/20psi, insert unknown but probably no given his weight
  • Avancini (XCO winner): 67kg, Ray front and rear (assuming 2.35), Superground, 18/19psi, insert unknown, could be either
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what is ya’lls’ go-to setup combo for wet conditions? Not necessarily deep, deep mud but wet, some mud?

Maxxis Forecasters

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New Tyre day! … and no I haven’t got a tricycle!

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What do they weigh? I heard the new compounds were heavy.

I thought I’d try something a little different - I’m running the Vee Tire Co Rail Escape front and rear generally, or the Rail Tracker when it eventually dries out here in the UK.

They are all slightly heavier than advertised. RR + RR are supposed to be 705g and TB 700g.

tyre 1

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I guses it all depends on where you ride but on the trails i’m on most frequently, traction trumps weight, if you have to choose only one

Forecasters are the best winter/wet tires for me. Not race fast, but don’t feel like they slow down the XC bike. Have incredible grip in almost every condition, if you have really hardpacked trails you can feel the knobs roll a bit and that is the only negative I’ve seen with the tire.

Kenda Regolith seems remarkably similar after a quick test ride.

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These came stock on my Norco and I really like them.

What rationale is there for pros running different casings front and rear?

I’ve noticed this several times, mostly on pros running Vittoria because the different casings are different colors so it’s immediately noticeable. I’m sure other teams are doing the same if available.

For instance, PfP has been running a Mezcal TLR front and TNT rear since she’s unveiled her Fourstroke. Got me wondering if she was just testing casings, but then I noticed that several riders ran world cups like this. So then I thought, well maybe there is an argument for having a beefier casing in the rear for impacts, etc. that are usually easier to avoid in the front. But then nope, found evidence of them running the TNT front and the TLR rear.

What is going on here? Are tire casings really this case by case (pun partially intended)? For gear nerds like XC riders I guess I’m not surprised, but then you’ve got ScottSram that runs a 2.4 Aspen all day every day :man_shrugging:

Maybe they have an insert in the rear only so feel they can get away with a lighter casing tire there? For example, on my trail bike I run Exo with insert in the rear, Exo+ without insert in front. In general it’s a lot more common to run a heavier casing in the rear than in the front, of course.

For us mortals, I’d always err on the side of heavier casing. I’m sure I’ll never lose a place because my tires weigh 50g more than my competitors, but I will certainly lose lots of places when I flat.

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Yes, but specifically speaking to Vittoria, there is a huge difference in the sidewalls between the TNT and TLR, with the latter being significantly more flimsy.

I’m guessing the TNT in the rear is to avoid the extra punctures and it comes out a bit lighter than TLR+insert.

There seems to be a bit of a debate right now about 25mm internal with insert versus 30mm internal without insert in terms of rolling resistance and puncture protection. Scott/Sram are in the camp of 30mm no insert, although there are some general reports of that combo still producing pinch flats for trail riding and above.

Then there is Cannondale where they are running 25mm internal with no insert and very low pressures…

On mine too but preferred the Schwalbe mix for my terrain.

Another vote for the Forecasters on an XC bike.

Is there any data on rolling resistance with inserts?

I have just ridden with them and they feel so slow, especially on the road.

But descending they feel so good! Like I never want to descend without them.

Maybe there’s an optimal tire pressure?

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Assuming pressure is kept equal I can’t see how inserts would change anything with regards to rolling resistance. Are you running equal pressure now that you have inserts and still feeling slower?

Of course one of the reasons to run inserts is so that we can drop pressure, usually about 10-15%? So we’re back to high vs low pressure and how it affects rolling resistance. On a smooth road lower pressure is slower. Over rough terrain it’s faster. I’m sure you know all this; just talking it out.

The optimal pressure is going to widely vary based on your weight, tire size, internal rim width, and course condition unfortunately. Unless you were running the exact same pressure, I don’t think the insert is contributing to rolling resistance, just the lower pressure?

Silca has a good blog with the concepts for road that is also applicable for mtb although you might have seen it so far.

https://blog.silca.cc/part-4b-rolling-resistance-and-impedance

The takeaways are pretty telling (quoting):

  • Tire Pressure is NOT a Maximize or Minimize Variable, but Can be Optimized for your weight, tire size and course conditions
  • Better to set your pressure a few psi below the BreakPoint Pressure than to have it a few PSI above the BreakPoint Pressure
  • Rough and/or Soft surfaces have steeper Impedance Lines making total rolling resistance higher and Optimal Pressure Lower
  • Tires with More Supple Casings Have Lower Rolling Resistance Everywhere and are More Forgiving of Over/Under Pressure
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I saw a pink bike article where Nino S. said he’s no longer using inserts with a 30mm rim and 2.4” tire.

Yeah - possible to pinch flat pretty much no matter what you are riding if you hit something hard enough. I pinch flatted a 2.4” rear tire on a practice ride in Leadville when I was messing around trying to pump features on the powerline descent. Which is hardly a technical ride, but I weighted the rear at the wrong time.

Other than that however, I’ve not pinch flatted - and I ride on some pretty gnarly terrain (and my current setup is 2.3”s on 25mm). So I’d say riding 2.4”s on 30mm rims is pretty safe.

Ok Nate, here’s what you need to run for Cape Epic. Roval SL wheels with 29mm internal width and Fast Trak Control 2.3 front and Renegade Control 2.3 rear. If those tires don’t float your boat, then Maxxis Aspen 2.4 front/rear. With those wide rims and appropriate pressure in the rear you don’t need the added weight of inserts for the rear. Inserts are really for the enduro bro boys like Jonathan who are trying to run flimsy tires.

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