[see update at bottom of post]
As previously posted, my Santa Cruz Blur XC bike from earlier this year was custom-built with Continental “Rubber Queen” 2.2 UST tyres. I quite liked the non-UST versions of these tyres on my old bike but very soon realised that the UST versions are quite heavy and perhaps overkill for an XC-oriented bike. With summer approaching, it was always my intention to try the new “X-King” tyres (also from Continental) as the consensus seems to be that these tyres are quite good; light, fast rolling and with good grip. They sound almost too good to be true!
Anyway, allowing time for my knee to heal, plus some time spent on a trip into Iraq, it’s taken some time but I’ve now finally managed to replace the tyres. There was a problem, though, in removing the Rubber Queens from the rim. Try as I might, I just could not get the tyre bead to budge one iota from the rim. But my friendly bike shop, using a lot of brute strength, managed to remove the tyre and fitted the new X-Kings in the process. Hopefully the X-kings won’t be as difficult to remove as the Rubber Queens. Oh, the valves were also replaced with Stan’s Universal models so that I could remove the valve core to add sealant (I really don’t want to be removing the tyre beading from the rim!).
These X-Kings are the Race Sport (RS) versions which are tubeless-ready and not fully tubeless. What this means is that the beading will fit UST rims but that the tyre sidewalls are likely to be quite porous and let air out. But using Stan’s Tire Sealant and his “shaking the wheel and rest” method I was able to make the sidewalls pretty much non-porous. It’s still early days and I haven’t ridden on these tyres in earnest. But the good news is that I was able to reduce the weight of the bike from 25.3 pounds to 24 pounds. I used 90 ml of Stan’s Tire Sealant in each tyre which should be plenty (perhaps too much?).
Being the Race Sport (RS) versions, I realise that these tyres are not as well protected as most of the other X-King models. But it should be fun to find out how well they handle the rougher trails, and also how well they’re sealed. Late spring is here, my knee is healed and my bike is ready. Time to go cycling!
|Frame:||Blur XC Carbon (2011), medium size, gloss red|
|Shock:||Fox Float RP23 Boost valve:|
|Velocity Tune: L|
|Boost Valve Tune: 225|
|Rebound Tune: M|
|Fork:||Fox 32 F120 FIT RLC 120 mm Black (15 mm Through Axle):|
|Shifters:||Shimano M980 (XTR)|
|Front Derailleur:||Shimano M981-D (XTR)|
|Rear Derailleur:||Shimano M980 SGS (XTR)|
|Chainset:||Shimano M980 24/32/42 (XTR) 10spd|
|Bottom Bracket:||Included with crankset|
|Chain:||HG-X (XTR M980)|
|Cassette:||Shimano M980, 11-34 (XTR)|
|Brakes:||Formula R1 with 160 mm rotors|
|Bars:||Syncros FL carbon 31.8 mm|
|Stem:||Easton EA 90 31.8 mm|
|Grips:||ODI Ruffian Lock-On (130 mm)|
|Headsets:||Chris King 1″ 1/8|
|Seatpost:||RockShox Reverb 380 mm (30.9 mm dia)|
|Saddle:||WTB Silverado SLT|
|Wheels:||ZTR Crest rims laced to Hope Pro 2 hubs|
|Tyres:||X-King 2.2 Race Sport (RS) folding Black Chili|
|Tubes:||tubeless – 2 x 90 ml of Stan’s Tire Sealant|
|Valves||NoTubes Universal 35 mm valve stems|
|Pedals:||Point One Podium|
|Gear cables:||Gore Ride-On sealed low friction|
|Scratch shield:||SportsCover Bikeshield (fullpack)|
|Total weight:||24 lbs (10.9 kg)|
Just as I was about to post this article I found a video from professional mountain biker Oli Beckingsale on fitting a Continental tubeless-ready tyre (in this case the X-King):
The main differences here to what I did are that I didn’t clean the inside of the tyre (bummer!), and that I used Stan’s “shake the tyre and rest” method rather than spinning the tyre. I’ve now got a high-speed air compressor and a Prestafalor from Prestcycle to help with getting the tyres to sit properly onto the rim.
Update 16 July 2011: I did have a couple of pinholes in the rear tyre which appeared a day after installing the tyres. That was easily fixed by repeating Stan’s “shake the tyre and rest” method at 45 PSI a few times. However, soon after that I noticed that the rear tyre would lose significant pressure over a few days; I hadn’t actually ridden the bike with the new tyres so far. But after a couple or so proper rides the issue with the loss of pressure disappeared and the tyres are holding pressure well even if not ridden for a week. So I call this a success.