Heres a run down of some of my favorites; Vittoria Barzo’s are great all around race xc tires. They have grip and speed. Also, they’ve got good puncture resistance. For dry hardpack the schwalbe thunderburts are some of the fastest tires ever, about ten percent faster watt per watt on hardpack than a set of kenda regoliths. Another One of my favorite tires of all time are the kenda kozmik 2 pro sct tires, hard to find but fast as heck on hardpack/pavement and still have enough traction for faster trails. Good puncture resistance too.
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The Continental Race King Protection is faster rolling than the Schwalbe Thunderburt.
Please tell me what the E-25 stands for then from Schwalbe website when talking about the compound of the tire: * Super Ground, E-25 ?
Maybe 25% slower and heavier?
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Has anyone used the Conti Race Kings on here, if so, what did you think? I’m wondering how they stand up to puncture protection??
E-25 and E-50 tires are Schwalbes indication that a tire is recommended for 25 and 50kph travel on an ebike.
I can’t find a reference on the Schwalbe website to E-25 compound for (as an example) the Racing Ray tire.
The website does indicate other MTB tires are suitable for e-bikes, but not the ones most of us here are looking at 
I’ve used the earlier gen of the Race Kings for Long marathon events where traction is not really a concern - e.g. Leadville, gravel rides, White Rim.
No problems with flats, and they roll very well.
I wouldn’t recommend them for traditional XC style riding with a lot of turns, braking, though. Traction not sufficient.
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Back in the day Jobst Brandt did a number of pretty thorough explainers on rolling resistance and argued that most of the losses weren’t from tread pattern but rather factors internal to the tire and rim/tire interface. A lot of his stuff is still kicking around ( Rolling resistance (Jobst Brandt)):
<<<The center ridge tire by Specialized was made under the belief that rolling resistance was kcaused mainly by tread scrubbing on the road and that reducing the contact patch would reduce rolling losses. In fact losses are mainly caused by rubber deformation in the tread, tube and the inter-ply rubber matrix, not by road contact. The raised center ridge increased all of these losses besides decreasing road contact, and therefore, traction when cornering or braking.>>>
Bottom line: casing flexing and tread “squirm” are major culprits—it’d be surprising if a tire insert didn’t have a similar negative impact.
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It’s fascinating to go back into some of the rec.bikes.tech archive and see JB calling out stuff that’s just now being “discovered” by the mainstream cycling community. For example, this from 22 years ago on lower tire pressure and rolling resistance:
This constant offset was caused by rim glue losses that depend on load alone and are not affected by inflation pressure. Therefore, tires
with low rolling resistance don’t get much better the harder they are inflated and have a flatter characteristic over the range of inflation pressures while high rolling resistance tires have a steeper slope, getting better the less they flex but never as good as a low RR tire except toward infinite pressure where none would have any flex or RR. Of course these tires all had smooth or nearly smooth tread patterns.
I like the racekings too, they definitely haul on the hardpack. however, they are a pain to seal and are heavier than the burts. Havent tried the new version of them though they might have fixed the screendoor sidewalls?
I’m not saying you are wrong, but what makes you think inserts would cause more casing flex/tread squirm?
From JB:
Rolling resistance is caused by rubber deformation losses in the tread, the tube and the casing. The tube is firmly attached to the casing by inflation pressure so it is like a tread inside the tire. The whole tire flexes in three dimensional space, X, Y and Z. You can verify this typically by laying a standard business card between tire and tube. It will shred to fine confetti when ridden. It is this motion that causes hysteretic loss in the elastomer in the casing, the tread and the tube.
I read this to mean that since a good portion of RR comes from flexing and fretting between tread, tube, and casing then adding an additional interface (the insert) would yield even greater losses depending on volume, etc…
(Anyway, I’m by no means an expert—just wanted to point out that it’s not super-intuitive where exactly RR losses come from. At least to me. 
)
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Just knowing where the internal losses come from would make you evaluate these different types of liners differently:
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Fair enough thought. Though I’d say there is only a small amount of interface at the rim bead/side wall.
I’m also no expert, and that explanation does make sense with regards extra friction adding rr. It just doesn’t feel like my tyres roll slower with my insert in, and when visualising what you were talking about I was just thinking about the huge air gap between tread casing and insert. The sidewall definitely has some contact though.
Interesting stuff anyway.
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Yes, I exclusively use Cushcore XC which is rim/lower sidewall contact, and a bunch of air gap.
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I run Forekaster 2.35 in front and Aspen 2.25 in rear. I’m not known for my bike handling skills and the Aspen in the bike doesn’t give me much cornering confidence.
Has anyone compared a Rekon Race to the Aspen in the rear?
This may or may not help, but a mate of mine (who is an excellent handler/very fast mountain biker) trialled the Aspen in 2.4 recently and found them too sketchy. He’s going to try Rekon Race 2.4 I believe.
It’s obviously a little condition dependant, they are probably fine in some of the dry climates (like where the TR crew are). Pretty sure Jonathan had Aspen’s on the Epic on the IG video.
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It’s interesting to hear Jonathan talk about the characteristics he likes in a tire. He likes the tire to break traction sooner, because when it’s sliding he knows it’s sliding and can then control the slide. He’s said this about gravel tires also.
So maybe the Aspen breaks traction sooner than other tires, and the slide is controllable. Whereas other tires break traction later, but the slide is harder to control because by then you’re in a more extreme cornering situation?
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That makes some sense. Though my experience with some very low tread tyres (I haven’t run them for ten years so they may be better now than they were) was that the break free moment happened too quickly to be regather-able (on the front).
I can definitely see someone like Jonathan with his skill level being able to control them better. I think it would be hugely conditions/course dependant and I would never go back to something like that.
I have a really hard time trusting the data from that website. I am not a measured instrument of efficiency, but some of his findings directly conflict with what I feel.
Part of this comes down to his testing protocols not being real-world tests, I believe.
I might try Schwalbes this year, but previous experience with them has been truly bad in every way. I want four primary things out of a tire:
- Predictability
- Traction
- Rolling Resistance
- Puncture Protection
I’ve ridden Burts all the way up to Nobby Nicks (sp?) and they only check one of those boxes, depending on the tire.
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