What are the largest tires that you run on your 'cross bike for off road use? I have it narrowed down to 2 frames and the max tire size on one is 700x38 and the other is 700x45 (mfg. numbers with fenders). Of course the one with smaller tires is about half a pound lighter or it would be an easy choice... as it would be if I will never use tires between 38 and 45.

i've used 35c maxxis locust and 40c ritchey alpha bites for singletrack. turns out the locust is cushier than the ritchey.

I don't think there are that many between 38 & 45, and I have yet to find one that is worth the extra weight. There never seems to be a significant amount of extra cushiness or pinch protection.

Riding off-road on skinny tires is fun -- like you are getting away with something you shouldn't be able to do.

It all depends if you plan to play Mtb Bike w/ your new CX rig. If you do, you'll probably end up wanting the bigger tire, I run a 44c mutano raptor and it grips as well as any XC/trail tire i've used on a 26er. For more traditional uses, I'd say that there is no real need for it, as long as you can use a 35 or 38 you should be fine. some frames are confined to 32c which is a real pain for tire selection because some of the 32's are too big. If you like the lighter bike, go with it, you can always upgrade the fork to a nicer steel or carbon (uhhh) with more clearance. there is absolutely no need for a 44 or 45 on the rear, a 38 with a few nobs will give a ton of traction.

What are the largest tires that you run on your 'cross bike for off road use? I have it narrowed down to 2 frames and the max tire size on one is 700x38 and the other is 700x45 (mfg. numbers with fenders). Of course the one with smaller tires is about half a pound lighter or it would be an easy choice... as it would be if I will never use tires between 38 and 45.
I have a cross check set up SS and I have used 42c Irc mythos tires, they work well and offer some good cush, but especially running a SS they are too heavy- steel beaded-no folding bead availible and really slow me down compared to a 30c michelen mud tire for racing or even a 35c ritchey trial mix steel bead allaround tire. I don't know about the weight of the larger WTB cross tires but their probaly fairly heavy also. A 42-45 c tire up front with a 35 or 38 out back should be enough tracktion and cush for the craziest trails you dare ride a cyclocross bike on. I'd say go for the lighter frame-if it comes with a steel fork you can probably run a larger front tire, and that would be enough.
The cross check is a great and durable fun frame, but I would not suggest running gears on one since it is such a heavy frame, and fork combo.

I'd say go for the lighter frame-if it comes with a steel fork you can probably run a larger front tire, and that would be enough..

The Surly CrossCheck is the heavier one that takes larger tires. The Soma DoubleCross is the lighter one. Both are steel frame & fork. I am leaning towards the Soma because of the named steel and the lighter weight. I am about to say if I need larger tires than a 700x38 that I really should just get a mountain bike.

My screen name should point out the obvious bias. My Soma Double Cross is sitting about 3 feet from me right now. Just this week I put a set of IRC Mythos XC 42c tires (currently $6.95 at Nashbar) on them. I had to do some creative grinding on the outside knob to get them to fit on the derailler side(plus I replaced the standard cable fixing bolt with one that is flatter). I will be taking the first offroad ride on them tomorrow so I can't comment on the ride quality yet, but, they are noticably higher volume than the Kenda Kross Supreme (35c) they replaced. The Kenda's were just fine on the bumpy and rocky fire/logging roads I rode last weekend. My assumption is that the the IRC Mythos are at least slightly more cushy.

I can't comment on the Surly, other than it seems like a fine bike. But, I can say that the Kenda Kross Supreme at 35c were fine for this 6'2", 220lbs. guy. Hopefully, the bigger tires will be even better. I can post more tomorrow.

I can't comment on the Surly, other than it seems like a fine bike. But, I can say that the Kenda Kross Supreme at 35c were fine for this 6'2", 220lbs. guy. Hopefully, the bigger tires will be even better. I can post more tomorrow.

I look forward to hearing more. Especially since we are very close in height and weight.

I look forward to hearing more. Especially since we are very close in height and weight.

I got out for a short ride today on the Mythos. I have to say that they were more cushy than the Kenda Kross Supremes. And, I probably could have run them about 5 lbs softer and had an even better ride.

I was riding on old logging roads that are down to double track. The surface is about half dirt, half broken pieces of flat rocks. It rained some last night and the dirt was wet, but not muddy. Other than one slippery rock on a climb, I never lost traction. Going back down the hill, I felt like I had enough tire to maintain control. I mean, it was not like riding my old Sugar FS bike, but it definitely was cushy enough to maintain control.

All in all, I like the tires and I can recommend them.

Andy

35c kenda cross supreme up front
35c kenda kwick in the rear

good fast rolling combo. lots of road riding and the kwick rolls pretty fast (it's a semi-slick). at the same time, tke kwick give pretty good grip when climbing in dirt.

the cross supreme up front is ok. holds good and it hasn;t surprise me yet on a turn....it ain;t cushy though.

i am running 75 psi front and rear (so i don't have to deal with pinch flats, i weigh about 160).

The UCI limit on tire width is 35 mm. Again, your tires act as shock absorbers on a 'cross bike, so using 28 mm tires and pumping them up to 75lbs means you might be fast on the pavement, but you'll get knocked around anytime you're on the dirt. Using a wider 32-34 mm tire at a lower pressure, anywhere from 30-60lbs, means you'll have traction in the turns, float through sand, and you'll smooth out the bumps as you go.
If you run tubular, you can easily run the pressure as low as two bar

Thankfully, my Giant TCX has a lot of rear clearance (45mm). The Easton EC90X also has 55mm clearance up front.

So far, the Ritchey Zed 700x42 has fit front and rear although I'll likely shave the side knobs in the rear for better clearance.

I've ordered a Bontrager Jone XR 29x1.8 tire for the front.

I'm not worried about the UCI rules at all. And I am currently running 28s pumped to about 100psi (clydesdale here) for road use. I will be sticking with clincher tires though the tubular seems nice.

If 42c fit on the Soma that is a plus... was that with or without fenders? How much more room do you have without those?

I'm not worried about the UCI rules at all. And I am currently running 28s pumped to about 100psi (clydesdale here) for road use. I will be sticking with clincher tires though the tubular seems nice.

If 42c fit on the Soma that is a plus... was that with or without fenders? How much more room do you have without those?

C'mon, it's a cross bike for goodness sake, if it is wet out and you have fatty's on, you should be reveling in the slop, not trying to stay clean..besides you won't be able to...and you will thrash the fenders super quick if they don't end up in your spokes.

now that I think about it, you should get the Surly..yeah it is heavier, but it is WAY cooler, the Cross Check Cult is WAY bigger(and better) than the Soma one....is there a Soma cult?

I'm not worried about the UCI rules at all. And I am currently running 28s pumped to about 100psi (clydesdale here) for road use. I will be sticking with clincher tires though the tubular seems nice.

If 42c fit on the Soma that is a plus... was that with or without fenders? How much more room do you have without those?
If you're looking at 42c tires, you're actually looking for a MTB or a two niner.

What I'm looking for is 1 bike that can do it all. The reason for fenders would be for commute use mainly. If it was a cross race, you are right - the fenders would be gone. And I have heard of Surly owners putting 29er tires on their CrossCheck. Sounds like up to about 1.8 or 1.9 work.

Yeah - One bike that can do it all. Commute / comfort / centuries / cross (I would add touring, but that doesn't start with a C).

I have a Soma Double Cross. I'm not sure about 42C knobbies with fenders in the rear. I know that 44C Mutanorapters will fit w/o fenders, and you could go with a seatpost mounted fender. 2.1" 29er tires will fit in the stock fork, so I don't expect that a knobby 42C with a full fender would be a problem.

(I've heard that clearance has shrunk on later model Cross Checks -- I would look into it before buying with the intend of running 29er tires.)

If you want versatility with ultimate tire clearance, consider the Surly Karate Monkey 29er.