# Continental X-King 2.4 RaceSport, 4 samples



## mechBgon (Jan 28, 2007)

For those interested in this tire as a high-volume tubeless-ready tire:

582 grams average, but a bit of a spread.


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## facelessfools (Aug 30, 2008)

my 2.2 xking has been the biggest pain i've ever had setting up tubeless...

good tire otherwise!


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## bholwell (Oct 17, 2007)

facelessfools said:


> my 2.2 xking has been the biggest pain i've ever had setting up tubeless...
> 
> good tire otherwise!


But the RaceSport versions are supposed to be tubeless ready, correct? http://www.conti-online.com/generat.../bicycle/general/innovation/racesport_en.html


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## rockyuphill (Nov 28, 2004)

The Racesport versions do have a bigger skirt on the bead (a bit like WTB's tubeless compatible construction but not as snug to install on a rim), they mount up fairly easily on a UST rim like the XTR. I'm using the Eclipse tubes so I haven't tried them tubeless yet.


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## mechBgon (Jan 28, 2007)

I'm going to be putting the heaviest pair onto my Shimano XT 775 training/all-round wheelset with Stan's sealant, hope it goes OK for me too. The lighter pair will be stashed for racing season, although I may pick up the RaceKing 2.2 RaceSport for racing in the end (supposed to be ~60 grams lighter per tire).


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## culturesponge (Aug 15, 2007)

mounted 4 of the Protection version X-King. 2.4 recently - 1 set was on DT rims with the Eclipse tubeless system, the other DT rims with 21mm yellow tape

i used innertubes & inflated the tires to approx 50psi for a few days before breaking the bead on one side & replacing the tubes with approx 80 -100ml of Slime Pro - et voilla!

all 4 tires hold air without loss once they had been for a spin around the block, but seeped air without being ridden

best XC tires on the market - imho


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## BlownCivic (Sep 12, 2006)

They need to release a Supersonic version of this tire in 2.4!


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## jochribs (Nov 12, 2009)

I have the racesports in 2.4 and they mounted really easily. They didn't seal up great with Caffe Latex, so after a day or so of goofing with that I cleaned it out, remounted and put in Stan's. Been fine since. This was my first foray at tubeless and I'd say it was pretty painless.


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## facelessfools (Aug 30, 2008)

bholwell said:


> But the RaceSport versions are supposed to be tubeless ready, correct? http://www.conti-online.com/generat.../bicycle/general/innovation/racesport_en.html


this is true but mine has a bunch of pin holes in the sidewall between the tread compound and sidewall where the two compounds meet. had around 4 rides and gets low on everyone. hopefully ill get it set soon..


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## culturesponge (Aug 15, 2007)

facelessfools said:


> this is true but mine has a bunch of pin holes in the sidewall between the tread compound and sidewall where the two compounds meet. had around 4 rides and gets low on everyone. hopefully ill get it set soon..


argh - not good

this *might* help: 
wipe the sidewalls with a clean cloth & stick small squares of electrical tape (for example) over the holes then rest the wheel so the sealant pools over the holes, flip and shake the wheel a few times + add air if/when ness

...what sealant are you using?

good luck


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## facelessfools (Aug 30, 2008)

just one tire. i have a raceking SS in the rear and the racesport xking front. ill keep working at it, should be pretty damn close by now to sealing


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## culturesponge (Aug 15, 2007)

should be a great combo

if no luck - i'll take it off your hands


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## facelessfools (Aug 30, 2008)

the tire grips well! both do, the race king gives similar grip to the racing ralph for less money and weight! 
went with the xking for extra confidence in the loose for the fontana winter series


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## mechBgon (Jan 28, 2007)

What are the pros and cons of Slime Pro versus Stan's? Is one slower to evaporate than the other?


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## ayjay69 (Mar 9, 2008)

Slime Pro is weak, I used it whole season... It simply does not work... Stan sealant is the best from all, trust me.


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## turbogrover (Dec 4, 2005)

Can I buy the X-King 2.4 tires from a US distributor or shop somewhere?


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## mechBgon (Jan 28, 2007)

turbogrover said:


> Can I buy the X-King 2.4 tires from a US distributor or shop somewhere?


The US distributor Highway 2 said they had about a hundred of them when I ordered mine about a week ago.

I'm having trouble getting mine to seal up. I installed them and gave them 60ml of Stan's each, aired them up, swirled them, and rode them a little in our basement (it's pretty large). The next day, they were empty.

Ok, maybe they need more sealant, more riding, more swirling or some sort of ritual sacrifice. So I added more sealant, swirled, rode a little, parked it, and they were soft by lunchtime. Maybe turkey sandwiches will count toward the ritual sacrifice requirement...

So at lunch, I painted a 1:4 mixture of dish detergent & water on the sidewalls. Whoa, the air is just coming right through the sidewalls EVERYWHERE. Grrr...

Suggestions? Does this type of thing cure itself with time? I thought the miraculous Stan's micro-sealing particles would've done their thing by now.


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## Trevorken (Jul 2, 2007)

Lay them for 30 minutes on a bucket on one side, and turn them then to the other side.
The sealant just can not reach the sidewalls enough.


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## culturesponge (Aug 15, 2007)

mechBgon said:


> What are the pros and cons of Slime Pro versus Stan's? Is one slower to evaporate than the other?


2 of my last 8 rides have been interrupted by small punctures that Stans couldn't seal - an almost impossible to measure puncture between the tread knobs of a rear Rocket Rons & a cocktail stick in the sidewall of a Racing Ralph this sunday (argh happy new year!) - there was plenty of fresh Stans in both wheelsets that should have worked as advertised

for Stans to perform like it does in their website videos i think you have to use a bottle in each tire, in the real world 100ml of Stans boogers-up into useless blobs in about 6-8 weeks here - abit pathetic really

been trying out Slime Pro since September, was famililar with the old (cheaper) formula which did a great job sealing 40-50 goatheads that were sticking into both tires more than 20 miles from home back in '05 & seemed to keep fresh in the tires for longer than it took for the tires to wear out. "new" Slim Pro was on sale at my local Performance $25.66 for 32 fl oz inc tax (about the same as Stans) so gave it a chance

Pro sealed up beads on our Conti X-Kings massively easier than Stans (which had actually failed to do so & i ended up wasting 1/2 a bottle) 1/3 less Pro sealant was needed in each tire compared with amount of Stans needed for 2.25 Rocket Rons - so less rotational weight + Pro apparently dries out much more slowly than Stans but not had a chance to confirm that yet - but so far no rides have been interrupted by punctures :thumbsup:

now thinking the best tubeless formula is one that you brew yourself at a fraction of the price of off-the-shelf sealant - so no expense to refresh every few months 

best


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## tmc71 (Oct 6, 2009)

turbogrover said:


> Can I buy the X-King 2.4 tires from a US distributor or shop somewhere?


I just recieved confirmation that my 2.4's shipped today (ordered today!) Price was pretty good as well. $46.75 each with the 15% discount they are currently offering. Hopefully I can get them to seal up...

http://www.biketiresdirect.com/product/continental-x-king-racesport-mtb-tire


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## scuver (Nov 5, 2009)

facelessfools said:


> just one tire. i have a raceking SS in the rear and the racesport xking front. ill keep working at it, should be pretty damn close by now to sealing


I'm leaning towards this set-up. I'm using RK 2.2 SS front and back right now. Is the XK 2.4 more volume than The RK 2.2 if mounted on the same rim?


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## bquinn (Mar 12, 2007)

culturesponge said:


> 2 of my last 8 rides have been interrupted by small punctures that Stans couldn't seal - an almost impossible to measure puncture between the tread knobs of a rear Rocket Rons & a cocktail stick in the sidewall of a Racing Ralph this sunday (argh happy new year!) - there was plenty of fresh Stans in both wheelsets that should have worked as advertised
> 
> for Stans to perform like it does in their website videos i think you have to use a bottle in each tire, in the real world 100ml of Stans boogers-up into useless blobs in about 6-8 weeks here - abit pathetic really
> 
> ...


I used Slime Pro all 2010 and had zero flats and no air loss in my tires. When I took the tires off at the end of the season there was still quite a bit of sealant and it was sloshing around like the day I dumped it in. Keep in mind that my season is April - end of Oct and put roughly 650miles on the bike in that time. I have never used Stan's sealant and with the success of the Slime Pro I don't intend to either :thumbsup:


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## mechBgon (Jan 28, 2007)

scuver said:


> I'm leaning towards this set-up. I'm using RK 2.2 SS front and back right now. Is the XK 2.4 more volume than The RK 2.2 if mounted on the same rim?


I think the XK2.4RS might be just slightly more volume than the RK2.2SS. At a reasonable pressure, my XKs were about 56.5mm wide across the casing. If you need a precise answer, I can mount one of my other XK's on another wheel with a tube, and then do the same with a brand-new RK2.2 Supersonic.



> Lay them for 30 minutes on a bucket on one side, and turn them then to the other side. The sealant just can not reach the sidewalls enough.


Thanks for the tip. I did that and periodically shook and swirled them too, and I think it's helping. We'll see how they are tomorrow. I'll probably experiment with the Slime Pro too.


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## scuver (Nov 5, 2009)

mechBgon said:


> I think the XK2.4RS might be just slightly more volume than the RK2.2SS. At a reasonable pressure, my XKs were about 56.5mm wide across the casing. If you need a precise answer, I can mount one of my other XK's on another wheel with a tube, and then do the same with a brand-new RK2.2 Supersonic.
> 
> That will be super if that's not too much trouble for you. Thanks.


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## mechBgon (Jan 28, 2007)

scuver said:


> mechBgon said:
> 
> 
> > I think the XK2.4RS might be just slightly more volume than the RK2.2SS. At a reasonable pressure, my XKs were about 56.5mm wide across the casing. If you need a precise answer, I can mount one of my other XK's on another wheel with a tube, and then do the same with a brand-new RK2.2 Supersonic.
> ...


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## Ausable (Jan 7, 2006)

What a disappointment in reading the posts above. I stopped using Supersonic tires for the infamous pinholes, and was going to order a couple of sets of the (supposedly airtight) Racesport version. Better stick to Schwalbe I'm afraid.


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## rockyuphill (Nov 28, 2004)

On a 17mm wide XTR rim the X-King 2.4RS carcass measured 56mm wide and my RK2.2SS measure 53.5mm wide across the carcass.


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## mechBgon (Jan 28, 2007)

On a Mavic x517 with a tube, at 30psi, here are the width and height of the RK 2.2 Supersonic and the XK 2.4 RaceSport, both brand-new:









RK 2.2 SS width









RK 2.2 SS height from rim to top of casing (not to top of knobs)









XK 2.4 RS width









XK 2.4 RS height from rim to top of casing (not to top of knobs)

This morning they were not completely flat, but were very soft. This tells me something... if I'm planning to use the lighter pair as raceday tires, I'd better start sealing them well in advance of raceday.


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## RecceDG (Sep 4, 2010)

Just as a note:

Anything made out of cast rubber over a woven fabric carcass is going to be subject to a wider tolerence range than something machined out of a forged billet. It's just the nature of the beast and doesn't represent a quality control issue.

Read up on measuring the circumference of bias-ply racing slicks for stock cars so that you can intentionally put the larger ones on the outboard side of the car (it's called "stagger")

I'll bet there's durometer drift batch-to-batch too, and that may or may not be intentional.

DG


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## cddaraa (Oct 19, 2009)

Anyone knows if the 2.4 X-king fits in the rear of the scott scale?


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## ayjay69 (Mar 9, 2008)

Yes, it will fit.


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## cddaraa (Oct 19, 2009)

That's great, 
thank you


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## mechBgon (Jan 28, 2007)

Tires are still losing air pretty fast, despite being periodically spun all day to keep the sealant coat distributed in the casing. For something different, I tried removing the Stan's from the rear tire and throwing in some Bontrager Super Juice, since we have one open. It still dropped from 40psi to maybe 15psi overnight. 



Got some Slime Pro in the cart, maybe it'll be the magic bullet I'm looking for. Otherwise, what's the closest competing model from Schwalbe?


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## Ausable (Jan 7, 2006)

mechBgon said:


> Got some Slime Pro in the cart, maybe it'll be the magic bullet I'm looking for. Otherwise, what's the closest competing model from Schwalbe?


Rocket Ron (front)
For the rear, the Racing Ralph is Race King's nemesis


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## BlownCivic (Sep 12, 2006)

mechBgon said:


> Otherwise, what's the closest competing model from Schwalbe?


A proper 1-2 hour ride will seal that puppy right up. I have had the same issues in the past sealing up the Race King Supersonics using Stans, and after the requisite ride they were always perfectly sealed.


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## mechBgon (Jan 28, 2007)

BlownCivic said:


> A proper 1-2 hour ride will seal that puppy right up. I have had the same issues in the past sealing up the Race King Supersonics using Stans, and after the requisite ride they were always perfectly sealed.


We got a dump of snow a couple days ago, but now it's going to rain and stay above freezing for 4-5 days, so I'll watch for rideable conditions this weekend and try your advice if possible.


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## mmmaaaiiikkk (Aug 10, 2009)

cddaraa said:


> Anyone knows if the 2.4 X-king fits in the rear of the scott scale?


It will depend to some extent on what rims you run as these affect tyre width.

I had problems with rear RK2.2SS on Stan's Podium rims on my '09 Scale LTD (but many others seem to run them on their Scales). There was so little clearance that the side walls rubbed at times and I could see the wear on the walls from the rubbing.

In the end I changed to RK2.0SS and these fit much better, and unlike some on this forum, I think that the 2.0 version is every bit as good as the 2.2 in terms of ride and grip (I weigh 66kg).

Anyway ... given that the 2.4 X-King is wider than a 2.2 RK, I would be worried about the lack of clearance on my Scale (but I haven't tried them!).

Anyone got any pictures of the 2.4 X-King on a Scale (bike that is not the weighing instrument).


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## MarcoL (Jun 3, 2007)

mechBgon said:


> Tires are still losing air pretty fast, despite being periodically spun all day to keep the sealant coat distributed in the casing. For something different, I tried removing the Stan's from the rear tire and throwing in some Bontrager Super Juice, since we have one open. It still dropped from 40psi to maybe 15psi overnight.
> 
> 
> 
> Got some Slime Pro in the cart, maybe it'll be the magic bullet I'm looking for. Otherwise, what's the closest competing model from Schwalbe?


Just take the stans off the tire, clean it very well, then wash it with detergent (the one you use for dishes) and rub the inside well, until you remove the thin silicone layer inside the tire, and put new Stans and that´s it!! always work!!!


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## BlownCivic (Sep 12, 2006)

I got one of these today. Man, it's huge. I have the RK SS 2.2s on my Stans Race7000 and Race MMX rims, and this is noticeably bigger mounted on one of my spare wheels with a ZTR355 rim (19mm inner width). I can't wait to mount it up on my Race 7000 front wheel (21 or 22mm, can't remember). And I managed to match your average weight at 580g right on the money. I was hoping for a miracle tire in the 550-560 range,and actually asked if they could weigh some for me. They said no. =(


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## scuver (Nov 5, 2009)

mechBgon said:


> On a Mavic x517 with a tube, at 30psi, here are the width and height of the RK 2.2 Supersonic and the XK 2.4 RaceSport, both brand-new:
> 
> 
> 
> ...


Thanks mechBgon, greatly appreciate your help.


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## cddaraa (Oct 19, 2009)

mmmaaaiiikkk said:


> It will depend to some extent on what rims you run as these affect tyre width.
> 
> I had problems with rear RK2.2SS on Stan's Podium rims on my '09 Scale LTD (but many others seem to run them on their Scales). There was so little clearance that the side walls rubbed at times and I could see the wear on the walls from the rubbing.
> 
> ...


In my current setup I run RoRo 2.1 front and rear. I wanted to add some more comfort so I thought that those big volume conti tyres will do the job. My first option was Xking 2.4 front and RKing 2.0 rear. Since the racesport edition of the RK is not out yet and my rear is completely worn I made an order for 2 XK 2.4. I will see if I can cancel it. I have no grip issues with the scwalbes but I would like to try something new and add more cushion


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## BlownCivic (Sep 12, 2006)

I mounted mine up on my Stan's Race 7000 front wheel. It easily aired right up after having spent the night on a spare rim with a tube in it. I dumped about 2 ozs of Stan's sealant into it, aired it back up. Gave it some shakes. Threw it on the bike and rode it around my cul de sac for about 10 minutes. The only place it was leaking initially was around the bead between the tire and the rim. It's holding air nicely right now. I'll check again in the morning, but I suspect it'll still be good.

Now for the amazing news. That tire on that rim is 59.6mm wide. same measurement as the pics above - carcass width - yes - 59.6mm. Crap that's wide. I think it's going to be a blast. Oh, and that's with 23 psi in it. Going around in my cul de sac, it seemed very stable, and it feels firm on the bike, not wiggly or squirmy.


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## tmc71 (Oct 6, 2009)

Just mounted my 2.4 race sports on crank bros cobalts. Weights were 585 and 571.

This was my first time setting up tubeless and so far it has been fairly pleasant. Added 2 scoops of stans per wheel, aired up w/ a floor pump and they are holding great. Dunked them in the tub and no leaks whatsoever.

Didn't take any measurements, but 2.4's look plump. Just eyeballing them I'd say slightly more volume than the RK's 2.2's. Almost wish I had ordered a 2.2 for the rear.


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## wannabeRacer (Feb 9, 2004)

this tire better be good as I've been waiting for mine since mid December of last Christmas. Hows the tire perform everyone?


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## rockyuphill (Nov 28, 2004)

Big, grippy on wet surfaces, weirdly quiet on pavement and hardpack, rolls extremely fast for a huge tire. No substitute for a MK 2.4 when the mud gets really deep or squidgy, but much better directional control than the RK2.2 SS in mud. Better cornering grip than the RK 2.2 in loose or muddy conditions.


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## wannabeRacer (Feb 9, 2004)

thanks for the rap rockyuphill, I hate to make another complained everyone but I been told my tire will be at my door around mid Feb.....urghhh!


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## GlazedHam (Jan 14, 2004)

I mounted the X-King, RaceSport 2.4 on the front Mavic 819 rim. I absolutely love the tire --I'm not sure I would use it as a race tire but it does make a nice XC/AM tire at 581gms.

I've mounted three RaceKing SuperSonices and had less trouble with those than this RaceSport. The SSes had tons of microholes, but the RaceSport has some freakin' huge holes in the sidewalls. There aren't any real pinholes just a half dozen gussers. Even a sold two hour ride in warm weather with full half cup (the cookie measurement) of Stans did not seal them up. ....and I had to stop a couple times to put more air (shooting for 22 PI but started higher) in and finished the ride with about 15psi of pressure.


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## BlownCivic (Sep 12, 2006)

Well mine is leaking slowly as well, but there's no issue holding enough air for a 2-3 hour ride. It'll drop from 23psi to about 12psi after 3-4 days of sitting. On the other hand, I don't honestly see a performance improvement for the trails I ride. There is never much mud or loose dirt, and for the most part I'm dealing with slippery wet rocks, roots, logs and moist damp loam/mulch. 

What I did notice was the increased weight of the tire. Call me weird, but the first thing I noticed when riding the bike was the increased gyroscopic effect of the tire being 140g heavier than the RK SS 2.2 that was on the front before (440g vs. 580g). I honestly thought there was something amiss in the front of my bike. Then I realised what it was. Sure enough after riding around on the Junk Yard Dog Race course for 5 minutes, the feeling went away, but it was there right in my face at 1st.

For me, the increased size and potentially better traction does not outweigh (pun intended) the increased weight on the front. I'm going back to the RK SS 2.2.


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## mechBgon (Jan 28, 2007)

BlownCivic said:


> Well mine is leaking slowly as well, but there's no issue holding enough air for a 2-3 hour ride. It'll drop from 23psi to about 12psi after 3-4 days of sitting. On the other hand, I don't honestly see a performance improvement for the trails I ride. There is never much mud or loose dirt, and for the most part I'm dealing with slippery wet rocks, roots, logs and moist damp loam/mulch.
> 
> What I did notice was the increased weight of the tire. Call me weird, but the first thing I noticed when riding the bike was the increased gyroscopic effect of the tire being 140g heavier than the RK SS 2.2 that was on the front before (440g vs. 580g). I honestly thought there was something amiss in the front of my bike. Then I realised what it was. Sure enough after riding around on the Junk Yard Dog Race course for 5 minutes, the feeling went away, but it was there right in my face at 1st.
> 
> For me, the increased size and potentially better traction does not outweigh (pun intended) the increased weight on the front. I'm going back to the RK SS 2.2.


For me, the attraction was partly a tubeless-ready tire, which is now debatable given the amount of weird science involved in getting them to seal.

I was hoping that the higher tire weight (versus my RK 2.2 Supersonics) would be mostly offset by dropping from 120-gram tubes to 60 grams of sealant per tire, with a traction bonus, tougher sidewalls and the impossibility of a pinch flat. But the tires are heavier than expected, and it takes more sealant than expected, so like you said, it amounts to a weight penalty right where you don't want one: at the edge of the wheel.

I see there'll be a RaceSport version of the RK 2.2, but if it's equally tough to seal and weighs more than they claim, that might be throwing good money after bad. Seriously considering Rocket Ron 2.25 Pacestars next.


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## BlownCivic (Sep 12, 2006)

My RKs were tubeless to begin with, so none of those fears, other than the thin sidewalls were an issue for me. I have suffered a sidewall cut that destroyed a 10 minute old World Cup version, but otherwise have had good performance and good luck for the last couple years.


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## rockyuphill (Nov 28, 2004)

I just tried the X-King 2.2 RS today on the hardtail that I normally run RK 2.2 SS on. Very quiet, fast rolling, certainly worked better for lateral grip in the wet mud, but I really miss the extra 4mm of carcass size. The X-king 2.2 only measures 50mm versus the 54mm RK 2.2 on the DT rims. 

Not a big weight penalty to change to X-King RS 2.2, only 15-20gms each over the RK 2.2, but it will take some tinkering with air pressure to get the X-King dialed in for use on my hardtail. I'm thinking the X-King may be better suited to my new 4x4 FS bike and I'll stick with the RK 2.2 SS on the hardtail.

The other thing I found, the X-King 2.2 is a better sized carcass for the Eclipse tubes, it is possible to run them at a pressure that doesn't stretch the tube to its elastic limit so they aren't twangy. The X-King 2.4 is just too big to use with an Eclipse tube.


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## GlazedHam (Jan 14, 2004)

mechBgon said:


> For me, the attraction was partly a tubeless-ready tire, which is now debatable given the amount of weird science involved in getting them to seal.
> 
> I was hoping that the higher tire weight (versus my RK 2.2 Supersonics) would be mostly offset by dropping from 120-gram tubes to 60 grams of sealant per tire, with a traction bonus, tougher sidewalls and the impossibility of a pinch flat. But the tires are heavier than expected, and it takes more sealant than expected, so like you said, it amounts to a weight penalty right where you don't want one: at the edge of the wheel.
> 
> I see there'll be a RaceSport version of the RK 2.2, but if it's equally tough to seal and weighs more than they claim, that might be throwing good money after bad. Seriously considering Rocket Ron 2.25 Pacestars next.


I'm thinking of trying the RR Pacestars as well so let us know. I've got an 8 day biking vacation which should have plenty of all day riding in mountainous and sometime sandy terrain so I was really hoping this RaceSport would be my tire.

...but it is FAR from tubeless ready and I don't plan to be the moron who has to stop every hour to add air to his tire. It does work well in the Rocks and hardpack under scrabble though.


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