The Heist has been on the high-value list for a while now and, looking at the spec, the 2018 model is still right up there. Plus-size tyres give it a more forgiving ride, but it still has a passive rather than aggressive character on the trail.
The Boost spacing and componentry are bang up to date, but the 80mm stem and short frame reach not so muchRussell Burton
Diamondback has done a thorough job on the new chassis. The head tube is tapered, with sealed cartridge bearings top and bottom, at a price where you still find straight tubes with loose ball bearings.
External tapering and internal butting of the rectangular top and down tubes add strength where needed and saves weight elsewhere. You get a press-fit rather than screw-in bottom bracket, which should mean stiffer, if potentially shorter-lived, crank support. It’s rare to see the latest Boost spacing (148x12mm) on the back end of a sub-£1k bike.
The chainstays are relatively long for a hardtail, at 440mm, but that gives plenty of space for a knobblier 2.8in tyre than the WTB Rangers fitted, or a 3in with similar tread. It’ll take a 29×2.35in wheel/tyre combo too, if you want a faster-rolling set-up. There are bottle mounts on the down tube, but no rack fixtures.
Diamondback Heist 3.0+ kit
Considering Diamondback sells its bikes through ‘proper’ shops rather than direct from the distributor, the parts spec is impressive. The dropper post (even though it’s a basic, unbranded unit) is a definite control and confidence-boosting win. The RockShox Recon fork has steel legs, not alloy, which adds weight, but its 15mm through-axle and tapered steerer give it accurate steering.
An air rather than coil spring makes it easy to tune for different weights/tastes, and rebound and compression speed are adjustable too.
Shimano SLX shifters and an XT rear mech represent impressive value and give light gear changes. The web-backed cranks are stiff, and the SunRace cassette and KMC chain are proven pieces. Shimano’s M315 brakes are wooden in feel but reliable, and you can add more bite by fitting sintered pads.
Diamondback maximises the volume of the Heist’s 2.8in tyres by mounting them on extra-wide 40mm rims, which are easy to convert to tubeless, to reduce the chance of punctures.
Diamondback Heist 3.0+ ride
Even with tubes in, that extra tyre volume makes a significant difference to ride smoothness, compared to a conventional hardtail. That’s great from a comfort point of view, but also for holding speed over rougher sections.
The bigger, lower-pressure rubber squishes over rocks and roots that would kick smaller tyres around. That’s particularly noticeable at lower speeds, where the Heist carries on rolling over sequential jolts that would bring other hardtails to a standstill. While the tread is low-profile, climbing and cornering traction is surprisingly good for the same reason, and it only starts sliding around when things get really sloppy.
Diamondback maximises the volume of the 2.8in WTB tyres by sticking them onto super-wide 40mm WTB Scraper rimsRussell Burton
That extra tyre volume also flatters the ride of the already good fork. The through-axle and tapered top keep tracking accurate too, although plus-tyres inevitably feel more vague than smaller rubber. Their extra weight and softness dulls acceleration and gives a mushier feel under power on smoother sections, but if you’re riding in company you’ll be surprised by how well the Heist holds its own.
While the back end has been broadened to the latest standard, the handling hasn’t been updated. The 740mm bar width is acceptable for all-round trail use, but the short top-tube length is compensated for with a long 80mm stem.
Combined with the relatively stable 68-degree head angle, that makes the steering feel a little clumsy. The 120mm fork also tips the seat angle back, reducing front tyre grip slightly when you’re in the saddle.
All this means it’s not the most progressive-feeling bike on the trail. But if you want a smooth, well-specced hardtail that’ll look after you if trouble crops up, then it’s a proper bargain.