Minnesota-based Surly bikes certainly does things differently, be it long-wheelbase haulage or singlespeed cyclocross bikes, fat-tyred tourers, or this tall and chunky gravel machine.
Surly only builds from steel, using tubesets of its own design, which makes it something of a connoisseur’s choice.
The Grappler takes the basic outline of a gravel bike, with drop bars and big tyre clearances, and switches things up to make a unique bike.
Surly Grappler frame and specifications
At the front, the Grappler is noticeably taller than pretty much every gravel bike on the market.
My large test bike frame has a stack of 641mm. That’s around 30mm taller than the Scott Addict Gravel 30 and the Orro Terra S I’ve tested recently. The reach is also long at 458mm.
I imagined this would create a weird Frankenstein-bike ride position. However, these numbers, combined with a relaxed 69.5-degree head angle and a short 80mm stem, result in an on-bike position that feels spot-on.
In short, you don’t feel overly cramped or stretched. It’s a ride position more akin to a mountain bike than a fast road bike. In this instance, it’s a good thing because of the Grappler’s intended gnarly purpose.
The Grappler’s back end is long, featuring 425mm chainstays. The 1,162mm wheelbase, too, is long even for a gravel bike.
I like that Surly has kept the seat angle steep at 73 degrees, because this is the key to how well the Grappler rides when the going gets rough.
The double-butted steel frame is made from Surly’s Natch tubeset, as is the accompanying ‘Dinner’ fork.
The frame and fork have huge clearances, and are designed to work with both 700c/29in and 650b/27.5in wheel sizes.
Tyre clearances are 2.8in for 650b or 2.2in for 700c at the fork, and 3in (650b) and 2.5in (700c) for the frame.
Surly has managed such large tyre sizes by adopting the mountain bike ‘Boost’ standard for hubs (that means 110mm hubs for the fork).
At the rear, it’s Surly’s ‘Gnot-Boost’ design. This means the stays are flexible enough to spring outwards to 148mm Boost spacing and be clamped up to 142mm.
The Grappler has a very versatile design with myriad fittings, triple mounts on the fork legs, triple bottle bosses on the top of the down tube and a further three on the underside.
There are further bottle bosses on the seat tube, internal routing for a dropper post, plus mudguard mount points and rack bosses. The Grappler can be run either with a single ring or 2x. It’s all finished off with a 73mm-wide threaded bottom bracket.
The frame is very tidy, with neat welds on all the major junctions. All of the fittings are straight and tidy, and the threads are cleaned and clear with no paint overspill.
Surly also coats the frame using the ED (electrophoretic deposition) process. This means fully submerging the frame and fork in a liquid with paint suspended within it.
It is then electrically charged, which causes the paint to adhere fully to the metal with a uniform thickness inside and out.
It’s said to help prevent corrosion and is claimed to be incredibly tough.
Left-field Microshift drivetrain
The Grappler’s build stands out because there’s not a glimpse of Shimano or SRAM in sight. Instead, it uses Microshift’s drivetrain.
The AdventX levers are dual-control, though it’s only the right-hand shifter that’s used to control the 10-speed Microshift rear derailleur over the massively wide 11-48t cassette.
The left-hand shifter is used to operate the TransX dropper post. The 32-tooth chainring looks minimal compared to the dinner-plate sized rear cassette, but the combination works perfectly for the Grappler.
Shifting is quick enough on the downshift, but upshifts are a little slower. Compared to Shimano GRX or SRAM’s 1x shifting, it’s just not as fast, slick or smooth.
That said, it did the job competently and it never let me down in testing.
The lighter gears do have some major jumps, rising from 36t to 40t and then to the 48t sprocket.
I really liked the 32/48t combination. On a few slimy, grimy singletrack climbs, it enabled me to keep seated to maintain traction while spinning the pedals.
However, on some less extreme climbs I was left hunting for a sweet-spot gear between the 36 and 48 that wasn’t quite there.
The WTB rims on Novatec Boost-spaced hubs are a fine combination. The smooth hubs and taut construction, wrapped with Teravail’s 2.5in tyres, opened up trails and tracks that skinnier-tyred gravel bikes just can’t cope with.
Surly Grappler geometry
Surly Grappler ride impressions
The Surly isn’t a sprinter’s weapon like the Scott Addict Gravel or a nimble mile-eater like the Orro Terra S, but it’s a brilliant bike to head out on and go exploring.
The big-volume tyres swallow up ruts, lumps, rocks and roots with ease. The Grappler’s ability to stay planted on long rutted climbs and track true on technical trails that had me zig-zagging on other bikes, easily offsets the Surly’s 13.77kg weight.
When you descend, the Grappler’s mass is more help than hindrance, keeping the bike on line and enabling the chunky gravel tyres to absorb the shocks.
It’s also where the addition of a dropper post comes into its own. Drop the saddle out of the way with a flick of the left-hand shift lever to make the most of the low-slung sloping frame design, and the Grappler becomes a demon descender that feels more like a mountain bike than an adapted road machine.
The wide Cowchipper bar adds to the Grappler’s confident handling when things get rough.
Even the cable-operated Tektro Mira brakes, which can’t hold a candle to the controlled power of most hydraulic brake systems, did little to dampen my enthusiasm for pushing the Grappler downhill.
That said, I think the bike would be improved a lot by stoppers with more feel. I had to put fistfuls of pressure into the brakes to arrest the Grappler in full flow.
The long wheelbase and the slack head angle, combined with big tyres and a 50mm fork offset, give the Grappler a leisurely 88mm trail.
That should make for a great load-carrying bikepacking bike, and it certainly results in an easy big-mile rider, alongside its stability when things get rapid and rough.
Surly Grappler bottom line
In all, I’ve enjoyed testing the Grappler.
It’s a gravel bike that gets you off the track and into the wild, its mountain-bike-esque trail proving very capable with lots of ride stability.
The Grappler is just as at home when used as a bike to trundle big miles on, making the most of the double whammy of big tyre cushioning and steel-chassis smoothness.
How we tested
In the highly competitive £2,000-£2,500 gravel bike world, there is a huge variety of designs available.
Here, we put to the test three distinct takes on gravel bikes on road, smooth hardpack, twisting forest fire roads, heavily used bridleways and more than a smattering of mountain bike singletrack trails.