Home Tech WTB Nano SG2 gravel tyre review

WTB Nano SG2 gravel tyre review

Go back just over twenty years and WTB’s Nanoraptor XC race tyre was one of the first designs ever to be upsized to 29in from 26in as part of Gary Fisher’s crusade for bigger diameter MTB wheels. It was also there in a 700 x 40mm format at the birth of his bigger tyre ‘Dual Sport’ hybrids a couple of years later. WTB were also super early with the whole ‘Tubeless Ready’ thing too. As a result, it was grabbed as the easy go-to option when gravel erupted as a scene and before other tyre manufacturers raced to get their own rubber options designed, moulded and ready to sell. And it worked great, as the same-spaced ‘V’ outer tread and almost continual centre rib of forked ‘tree branch’ lugs for fast-rolling is quick in a straight line but tolerably grippy in turns on most surfaces. 

WTB Nano gravel tyres

(Image credit: Guy Kesteven)

The trouble was that everyone – including WTB – now had a new range of specific gravel tyres to sell so Nano got largely forgotten. Plus, compared to more modern tyres the big bulbous carcass that provided its float tended to last less time than bit-part actors in a slasher movie when the terrain got nasty.


That’s where the new Nano comes in. It uses basically the same distinctive dual personality tread, ‘tree branch and wake of lugs’ pattern in a dual-compound rubber mix. 

Crucially it now gets the option of a 120-TPI (that’s twice the thread count of previous Nanos) carcass, reinforced with a flat fibre nylon SG2 bead-to-bead protection layer. A few months into all the abuse we can give it, that’s still not been breached despite regular rim-on-rock pinches and silly low pressures to cope with snow. It only adds 25g over the standard version (50g over the tan wall) too and while 557g is pretty heavy, it’s not far off the ballpark for a reinforced tyre that still blows up slightly over its stated size on a 24mm internal rim.

The generous volume means the extra protection doesn’t obviously affect ride quality so it still bowls along nicely with no buzz or rumble. You’ll still have to grit your teeth to keep up with a slick tyre on the road, but your jaw will be a lot more relaxed as soon as you hit the dirt. It’s not very directional so you need to stay loose and ready to drift, but ride it appropriately and it holds speed and control fine on sand, loose grit and woodsy singletrack wet or dry. It’ll even have a decent go at paddling through slop if it has to and it’s a lot more predictable when leaned than the cosmetically grippier-looking WTB Resolute. You can change speed and grip vectors significantly by raising pressure to get that centre ridge pert or dropping it low to get all the knobs engaged. Either way it holds pressure really well (the SG2 skin also helps stop air leaks/percolation) and the Dual DNA tread is tough in terms of wear too. 

Be aware that the tan version is still distinctly fragile and porous though, and that there’s no SG2 option in the 29×2.1 option that fits big clearance adventure bikes.


WTB has given Nano the confident protection it previously lacked and put this OG gravel tyre right back at the top of our fit-and-forget gravel tyre rankings for riders who default to dirt as often as possible. It would be good to see the 29er version get the same SG2 too though, and the extra protection costs a lot.

Tech specs: WTB Nano SG2 gravel tyre

  • Weight: 557g (SG2)
  • Versions: SG2 (tested), Black, Tan, Race (lightweight tubed), Comp (cheap tubed).
  • Size: 700 x 40mm


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