Wednesday 16 March 2022

Testing Schwalbe's Super Race Thunder Burts

Schwalbe Thunder Burt Super Race versus Continental Race King Protection rolling resistance
A few months ago, Bicycle Rolling Resistance (BRR) tested the latest version of Schwalbe's Thunder Burt with the 2.25" Super Ground casing (see results here).  It performed really well, narrowly beating the previous best mountain bike tyre, the 2.2" Continental Race King Protection (see results here).

As BRR said in it's conclusion: "The current generation has moved to Schwalbe's Super casings with a Super Ground and Super Race version available in several sizes. As the name suggests, the Super Race should be a bit faster than the Super Ground, while the Super Ground offers a bit more protection"

"...It looks like the Super Race version of the Thunder Burt is racking up quite a few votes and has a good chance of being tested in the near future as well."

Sadly though, the Super Race version of the Thunder Burt never made it to the top of the voting list and it expired from the list last month.  I was a little disappointed by this, but I decided to buy a pair of those tyres anyway, particularly as I have an upcoming beach race in April that the Thunder Burt tread is perfect for.  However, I wanted to test them first, to check how they performed against the Continental Race King Protection that I already own and have installed on the back of my MTB.

Equipment and test setup

I used my roller method for this testing, which I've described recently in previous blog posts.

The testing wasn't particularly straight-forward though, because my mountain bike doesn't have a power meter.  I only have power meters on my road bike, my cyclocross/gravel bike and my time trial bike.  Those are all Shimano Stages left hand crank-based power meters.  My mountain bike has a SRAM GXP mountain bike chainset, so the chainset isn't at all compatible with those power meters.

Shimano 105 Stages power meter on a Shimano SLX mountain bike (MTB) crankset
My solution was to use my commuting bike instead, which has a Shimano crankset and bottom bracket, albeit a MTB chainset instead of a road chainset.  Road and MTB chainsets are not compatible though, having different axle lengths and Q-factors.

This meant the chainset axle was too long for the Stages 105 left-hand crank arm that I tried to fit on it.  It did fit on the hollowtech tech splined axle, both having the same diameter and splines, but it left a gap between the crank arm and the bottom bracket cups.  I needed a 5-6mm spacer or washer to fill the gap.  I found that a spare set of axle cartridge bearings filled the gap perfectly (see photo above).  This was a bodge, but it worked really well.  As a result, I got my Shimano 105 power meter successfully working on the left hand side of my Shimano SLX chainset.

A bit more faffing was required to do the testing though: I had to remove my SKS mudguards, which rubbed on the large knobbly mountain bike tyres, and I changed the pedals to my good clipless SPDs too.  All in all, it took a fair amount of time before I could get started.

I chose to do the testing with a lightweight (150g) butyl inner tube, just to save the time and mess associated with a tubeless set up.  Since I was interested in which tyre was fastest, this approach was fine, because both tyres would be subject to the same additional losses from having the inner tube installed.  Furthermore, doing the testing with an inner tube allowed a better comparison with the BRR data, which also used a butyl inner tube for their testing, albeit a heavier-weight inner tube.


The plot below show how the the two tyres compare.  I had enough time to repeat the testing for the Thunder Burts, after testing the Continental Race King, to confirm that Thunder Burts really does give lower CRR numbers.  Since the two blocks of testing with the Thunder Burts were before and after the testing with the Race King, then I can be fairly confident the Thunder Burts are a better tyre, despite the imperfect repeatability seen in the plot below. 

The differences aren't massive, and correspond to only 2-3 Watts at 25 kph, but it's a benefit worth having.  Something to be noted is that the Thunder Burts were slightly larger than the Race King, at 2.35" width versus 2.2".  In addition, the Thunder Burt was brand new, whereas the Race King was one or two years old and has some Stans sealant residue on the inside.  This latter point might be a source of additional losses, I'm not sure, but in any case, the purpose of this exercise was to compare these two tyres ahead of my upcoming race, so these old and used tyres are the ones I would have chosen from anyway.

Finally, it's worth noting that the agreement with Bicycle Rolling Resistance data is remarkably good at the interface of the two sets of data.  However, this might be a fluke.


  1. Also torn between these tires. What's your anecdotal experience been, especially off road?

  2. Hi Logan, They certainly feel fast off road, and feel faster than my old tyre combination. To be honest though, I don't really trust my perceptions as I think the rolling resistance margins are quite small. Also, I've been dropping pressures for my MTB, on the basis of the testing I've done, from around 25psi for my old tyres down to the 17-18psi, so it's a bit difficult to judge because I've changed two things at once. I've got a couple of KOMs with the Thunder Burt tyres, but that's also not a particularly reliable indicator of anything. The one thing I have been really pleased with though, is that the grip seems to be good, in view of the light tread on the Thunder Burts (albeit only tested in dry conditions). Until now I've always ran a slightly knobbier front tyre, to give me more confidence in the front end, but with hindsight, that might have been unnecessary.

  3. Appreciate the thoughts. Very tempting, especially as I'd prefer the 2.35" size vs. 2.2" on the Race Kings for bikepacking. Are they noticeably bigger, or is it negligible?

    Also assume pavement performance between them is similar, given the results in the post, but let me know if you notice a difference there, too.

  4. I think for pavement performance, testing like I did here using rollers, or drum testing like is done by guy, is a good indicator of performance on pavement. That is, assuming the pressures are lower than the so-called break-point pressure, above which suspension losses start to dominate. The Thunder Burts certainly feel fast on the road, and qualitatively feel faster (although I only every had a Race King on the back with my old tyre combo, and paired it with a Schwalbe Rocket Ron on the front. So, the switch to 2 x Thunder Burts should be noticeably faster and they do feel it.

    I did measure the width of both tyres, the Race King and the Thunder Burt. I've lost the measurements though unfortunately, but from what I remember the Thunder Burt was wider, and wider by an amount that was consistent the 2.2" versus 2.35" claimed width difference - which I know is not always a given, especially for tyres from two different brands. I'm the same, and prefer wider tyres around that width.

  5. You're a goldmine of knowledge. Thank you, sir!