xc weight weeenie table

Quite an interesting site…

mtb rolling resistance

I sorted the table by rolling resistance at 25psi, but resistance at all pressures seems faily linear. Supprisingly the nobby nick snakeskin, despite its weight and nobby-ness is middle of teh table.

Interesting idea, there’s nothing on there however that says what date these were recorded. Tyre types can change over time.

I always said SB8s were terrible on the road.

Always been a fan of Rons and Ralphs

I’d guess they were tested in 2015, most of the models are 2015, with a few 2014, unless thats purchsed date rather than tyre manufacture date.

Think I’ll stick with my rons and ralphs too, teh lighter, less resistive tyres have a scarily little ammount of tread on them.

Very interesting, thanks for sharing. I always thought the SB8’s were fast-rolling – will need to rethink my tire choice.

Needs columns for “sidewalks made out of tissue paper” and “lethal in wet”

Interesting idea, there’s nothing on there however that says what date these were recorded. Tyre types can change over time.

Umm, yes there is…. the ‘Date’ column.

I’d like to see this sort of data for fatbike tyres.

It would be interesting to see how a ‘normal’ Thunder Burt comes out. I suspect many people going for super fast rolling XC tyres don’t go for reinforced sidewall variants. SB8 performance is interesting. Be good to see a full spectrum too – how does a 2.4″ Maxxis High Roller ST fit in!? Or a 2″ Mud X even.

On the site they do say of teh kenda:

” the Small Block Eight isn’t available in a 29 x 2.25 size so I’ve gone for the 29 x 2.1. This does mean it has a small disadvantage against the other tires because of the smaller volume. This is especially true because I always use the same test procedure with rolling resistance measurements at 25, 35, 45 and 55 psi. “

Not sure how much difference it makes, but ive always gone for 2.1 tyres thinking 2.2 would be slower, maybe I need to have a rethink too!

@mattyfex: Smaller volume tyres will have higher rolling resistance compared to a large volume one when at the same pressure, as the smaller one will deform more under the same weight (there’s simply less air to support said weight). The smaller volume tyre thus needs to be at a higher pressure for a fair comparison. As far as I know smaller tyres do typically offer lower rolling resistance when set up properly.

They had this for road tyres recently over at velonews. Looks like the Conti tyres (and Spesh having poached some Conti engineers) have a really good compound for rolling resistance.

There’s a section for road and a section for touring tyres on the site I linked to in the first post.. Might be an interesting comparison to Mr blobbys link.

Also there’s an article on mtb tubeless vs latex vs butyl tubes, the conclusion being the rolling resistance of tubeless being significantly lower than standard butyl tubes.

I’ve shyed away from tubeless but the difference in watts seems significant to my untrained eye?

Here

I reckon the non snakeskin thunderburt running tubeless could be a bit naughty as a XC back tyre if you can put up with what I imagine would be really sketchy grip!

I’ve got Liteskin Thunder Burts set up tubeless and they sure are fast, the grip is fine for cornering as you’re lent over and the side knobs really dig in, the only trouble is braking when the bike is stood up and that semi slick centre not offering a lot of bite.

I have the puregrip version of the xking 2.2 front and rear have found them superb grip at around 30/35ps in all conditions and surfaces with very little rolling resistance compared to my mountain kings of previous that were shocking

Great

reckon the non snakeskin thunderburt running tubeless could be a bit naughty as a XC back tyre if you can put up with what I imagine would be really sketchy grip!

Exactly as Nixon said, they’re very capable, but do tend to break away under braking quite readily.

The difference between the ‘Burt and the Ralph is so small it doesn’t seem worth it given the braking performance

That was surprising. I ran a RaRa front, Burt rear this year, which seemed really fast on the hard pack stuff in Austria.

I might go back to my Ron/Ralph combo as it suits my local conditions on to IOM better, although I really do rate the Burt as a rear tyre. It works surprisingly well.

😆

I think they just look fast, and people are ignoring that there is a lot more to rolling resistance than the block pattern – Schwalbe have always been know to have fast carcasses and clearly Conti are up there as well.

I’m also a long time Ralph fan, switching to NNs when it gets more gloopy – not convinced it’s worth saving <1W to switch to anything else, though if I was still racing seriously I might consider the 5W advantage to the Race Kings worth considering.

Interesting. I’d like to see the difference between exactly the same tyre in different widths. Currently got a 2.25 RoRo on the back (had a spare in the garage) and my overly analytic mind is in agony that it’s too wide, but I’m not really sure it makes much difference this time of rear

id like to see 2.1’s tested

I thought higher pressure = lower rolling resistance was a myth?

Not on a hard surface or a drum used to make those measurements – in that case higher pressure really does equate to less RR. It’s only on less smooth surfaces where lower pressure rolls better because of less losses due to the bumps.

Clearly a consistent test can’t be done off road due to variety of surface even when choosing a different line down the same route but how much do the rolling resistance measurements of an off road tyre on the road translate to when those same tyres are off road?

My semi slick Mezcal’s are noticeably quicker on the road than my X King or my Race King but as soon as they are off road the differences are difficult to notice but the Mescals are probably still a bit quicker.
That is on terrain where grip is not a priority (hardpack gravel) but as soon as I need any grip (up hill, fast corners etc,.) then I am slower on the Mezcals.

Again difficult to do anything scientific but a better test may be testing the tyres around a mixed off road loop

But doesn’t higher rolling resistance generally mean more grip? All well and good saying tyre X is faster rolling than Y, but if X throws you off or can’t carry speed through the corner then it’s a moot point…

No. Because as I wrote above, a lot of the RR comes from the carcass rather than the blocks. A low rolling resistance tyre is one which doesn’t use much energy deforming – ie one which deforms easily, which also makes for good grip. Just to pick two tyres from that table, I’d expect to have better grip with a NN than a SB8, yet the NN is much lower rolling resistance.

Everything being equal, the more grippy tyre is likely to have higher rolling resistance – see results for Ralph and NN above which is what I’d expect, though the difference isn’t huge (it’s small enough I might rethink whether to just use NNs all the time). But everything isn’t equal if you’re looking at different branded tyres.

I’m dubious about that – see where Race Kings and AKAs are in that table above, and I can’t see any obvious reason why a Mezcal is likely to be a huge amount better than an AKA – the weights are very similar, which suggests a similar carcass. I suspect like the SB8s people rave about, they look quick, hence they “feel” quick.

Though you’re right that the difference in RR is likely to be masked when riding rougher off-road where there are other bigger sources of resistance. It’s likely that the absolute power difference is even larger though, as the carcass which doesn’t use much energy deforming will have an even bigger advantage when there’s a lot of deforming happening.

jam bo – Member
I thought higher pressure = lower rolling resistance was a myth?

On run down tests I’ve done on the rough roads around here too much pressure is slower. High pressure just feels faster.

I was amazed at just how low I could drop pressures without loss of speed.

After years of running higher pressures in my tyres I completely changed my thinking. Part of that is because tyre construction for ordinary has improved quite dramatically over the last 10 years IMO.

aracer – I see what you’re saying but I don’t understand how that works. If a carcass is supple and deforms easily for low rolling resistance, how can it then provide a solid base for the blocks to give grip? The force on the blocks would force the carcass to deform rather than resisting the force on the block to push it into the ground. What am I missing?

Hmm. I see there’s no column for how good the tread sounds on smooth tarmac.

Clear win for the SB8 there. Tie fighter tastic.

Well, I’ve been on SB8’s for the Tour Divide (popular choice for this race for lighter racers) and all my South Downs Way training and the x4 event itself. I rarely puncture (tubeless system).

When you see what something like the Thunder Bert’s can offer in terms of less effort used, better puncture resistance, the only thing is to shove a pair on for a couple of months.

There is more to riding than RR, but if these T Bert things grip, brake and hold together, then I will report back.

They are only £50ish for a pair – whats the worst thing that can happen?

That’s a useful website so thanks

Slightly surprised how little difference doubling the pressure makes

There is more to riding than RR, but if these T Bert things grip, brake and hold together, then I will report back.

They grip, their braking isn’t great and they’re a little fragile (exactly the same carcass as a Ron/Fred/Dan). I opted to use Bontrager XR1s for the SDW as I decided Burts would be a bit fragile. Snakeskin may be wise choice for durability.

Great tyres though.

see where Race Kings and AKAs are in that table above, and I can’t see any obvious reason why a Mezcal is likely to be a huge amount better than an AKA

A Mezcal is clearly going to roll better than an AKA. An AKA has loads of knobs whereas a Mescal is semi slick.

I do not use low pressures through as ride on very hard pack surfaces most of the year and around 40% of my ride is on the road so not a good test case for off road tyres as such.