CX Tyres for XC/Enduro Racing?

IShaggy

I'm new to MTBing, so forgive me if this is a stupid question...

I'm participating in a long'ish race in June. The course is not particularly technical, with a bit of single-track, a bit of grass, some climbs, some downhills, a bit of gravel, and the odd root thrown in for good measure. I will be racing on a 29er and given that the course will most likely be dry (although you can never be sure with our British summers) I want to use some fast rolling tyres. I also have a cyclo-cross bike, so for the race I'm considering transferring across the tyres to my 29er.

So my questions are -

1) Are you typically allowed to use CX tyres on a 29er for XC and enduro races? Or are there tyre width restrictions which preclude CX tyres?
2) If allowed is it advisable to do so. I'm assuming they will be faster rolling but add in few technical sections and they might lose out by having less grip? Anyone got experience of using CX tyres versus fast rolling MTB tyres. Is there a noticeable difference?

cooldad

1 - no
2 - Will they fit your rims, might be a bit narrow. .

IShaggy

cooldad wrote:

1 - no
2 - Will they fit your rims, might be a bit narrow. .

Is that no - they're not allowed, or no to tyre width restrictions.

I've got Shimano XT wheels, which have a relatively narrow rim width, so I believe they will fit - but I guess that's irrelevant if they're not allowed.

cooldad

Sorry no restrictions.

IShaggy

cooldad wrote:

Sorry no restrictions.

Interesting - have you seen anyone use narrow (CX) tyres in races?

njee20

There used to be restrictions, but they seem to have gone, so yes, go nuts!

I've seen people use 'cross tyres at Thetford and Sherwood. There are very few courses I'd want to use them, if any. I'd go for a semi-slick MTB tyre, like a Furious Fred first, which will be far more comfortable and if you believe the research someone did, faster rolling than a narrower tyre.

IShaggy

njee20 wrote:

There used to be restrictions, but they seem to have gone, so yes, go nuts!

I've seen people use 'cross tyres at Thetford and Sherwood. There are very few courses I'd want to use them, if any. I'd go for a semi-slick MTB tyre, like a Furious Fred first, which will be far more comfortable and if you believe the research someone did, faster rolling than a narrower tyre.

You think there wouldn't be much difference in rolling resistance then - I guess that's a how long is a piece of string question as it's all dependent on terrain? Comfort may well be a factor. The race I'm targeting is a mix of MTBing and running over 8 hours. The Furious Freds certainly look quick. And I like Schwalbe tyres - use them on my road bike and CX bike.

Chinley Churner

I'm guessing it's the HellRider you're talking about...if so, see you there.. you solo or in a team?

It's the Chilterns so, any rain, and it'll be a slide fest... wouldn't want anything too narrow. Comfort's an issue too especially if you're running off the bike.. I'm going for Racing Ralphs.

ddraver

I'd be more concerned that 700 x 32c CX tyres are too narrow for your rims. But Unless you re hunting for victory I'd get a good, lightweight XC tyre instead, as you ll be able to use them more often. I use the (26 x 1.9) Maxxis Ultralight tyres when I'm racing here (Netherlands) because the courses are so smooth (they re all in sand dunes) and...well...easy...

I ve not got a 29er though so I'm no expert...

IShaggy

Chinley Churner wrote:

I'm guessing it's the HellRider you're talking about...if so, see you there.. you solo or in a team?

It's the Chilterns so, any rain, and it'll be a slide fest... wouldn't want anything too narrow. Comfort's an issue too especially if you're running off the bike.. I'm going for Racing Ralphs.

Bang on the money there - it is the Hellrider. I'm doing the solo event which I guess will be 8 hours of getting overtaken - like I'm standing still - by the teams What about yourself? Have you done the event before?

IShaggy

ddraver wrote:

I'd be more concerned that 700 x 32c CX tyres are too narrow for your rims. But Unless you re hunting for victory I'd get a good, lightweight XC tyre instead, as you ll be able to use them more often. I use the (26 x 1.9) Maxxis Ultralight tyres when I'm racing here (Netherlands) because the courses are so smooth (they re all in sand dunes) and...well...easy...

I ve not got a 29er though so I'm no expert...

I think I'm coming round to the idea that a fast MTB XC tyre is not too much slower than a CX tyre - as long as there's a few lumps and bumps on the course. I'll check out the Maxxis tyres. I need something that's fast and puncture proof. I know that there's usually a trade-off between the 2, but there's no point saving 2 minutes with a quick tyre if you spend 5 minutes fixing a puncture.

njee20

Rocket Ron or Racing Ralph if you want some grip or Furious Fred if not. FF Snakeskin will be tough, light, and very fast.

Chinley Churner

I Shaggy wrote:

Bang on the money there - it is the Hellrider. I'm doing the solo event which I guess will be 8 hours of getting overtaken - like I'm standing still - by the teams What about yourself? Have you done the event before?

No, but done quite a few MTB enduros and loads of off road duathlons... I also know the race organisers and, although the bike course isn't massively technical, there's enough to make it a mountain bike rather than a cross course.. that said, I'm probably going to take the cross bike as a spare in case of a major mechanical. Am doing a "Half-HellRider" training session this weekend on my local Peak District trails ...distances for loops are same as race (5km run / 8km bike) but quite a lot more climbing and more technical... should be a good test of where I am.

Chinley Churner

@I Shaggy

"Half HellRider" this weekend went well... I reckon my loops, which each contain 900ft of climb, are tougher than the race loops will be and my bike loop is probably more technical. In just over four hours I managed X4 run loops and X3 bikes including transitions... planning to do 5-6 hours in a couple of weeks time.

Chinley Churner

pic of me and my super helpful transition support team at the end of the session

IShaggy

Chinley Churner wrote:

@I Shaggy

"Half HellRider" this weekend went well... I reckon my loops, which each contain 900ft of climb, are tougher than the race loops will be and my bike loop is probably more technical. In just over four hours I managed X4 run loops and X3 bikes including transitions... planning to do 5-6 hours in a couple of weeks time.

Nice one - sounds like a great session, but it's a shame you can't practice the last few hours of the race as that'll be where the prizes are earn't

I'm not doing anything specific to the race in my training - just lots of run and bike miles. Most of my biking is on my road bike as I find I get a better training session that way - particularly in the Surrey Hills - as it's less stop-start on the road. I suspect my biking will let me down on the day, but hopefully my running will make up for that. I'm really intrigued to see how my legs hold out on the runs with the bike intervals potentially giving the muscles regular variation. I'm suspecting it'll mean less muscle stiffness but more cramping - it's going to be fun

IShaggy

I think I jinxed the weather - might be starting a thread about mud tyres soon

mobilekat

Think the weather is our fault, just put the 'summer tyres' on mine and OH's bike....

And it hasn't stopped raining since

Knew there was a reason I had left the mud flap on!