We originally had the 26in wheeled Dakar XCT Race pencilled in for this test, but delivery dates kept getting pushed back so we made a last minute switch to the Dakar 650b Comp.
Both models in the Dakar platform share the same frame configuration and MP4 suspension layout where the main pivot is above the BB and in line with the 24t chainring. The 650b bike delivers 130mm of travel front and rear — which is 10mm shy of the 26in wheeled XCT Race.
Frame features include a tall, tapered ‘zero stack’ head tube (140mm + 15mm headset cover, and that’s before factoring in the taller wheel and fork); it also gets a high, humpback top tube that will damage more than your family jewels if you come a cropper, as the shifter pods smash into it when the bar spins round.
At 448mm, the asymmetric chainstays are almost as long those on as most 29ers… so much for 650b offering the advantages of 29 but none of the disadvantages! The bike is also 1.5kg heavier than the lightest bike in test.
Confusingly, the 19in bike actually measures 18in from the centre of the BB to the top of the seat collar. Still, the length of the 19in is in line with a well-proportioned medium, even if the head tube and standover height are more akin to an XXL.
Sealed bearing pivots throughout guarantee a smooth running, stiction-free suspension linkage, so the constant knocking we experienced in the rear suspension must have been coming from the RockShox Monarch rear shock.
Up front, the X-Fusion Velvet fork lived up to its name with a smooth, controlled action. It’s super-easy to set up and adjust and the lockout feature will prove handy for any ashpalt sections.
Shod with the stock Kenda Nevegal tyres, the wheelset on the Jamis is 0.5kg heavier than the heaviest 26in wheels in this test and almost 1kg heavier than the lightest. Plain-gauge spokes don’t do the wheels any favours on the scales either, but at least the 2.35in dual-compound front tyre provides stacks of grip.
Next to the Rose and Canyon the spec on the Jamis pales in comparison. To be fair to Jamis, it’s all decent mid-range Shimano kit (bar the non-hollow forged chainset) and the 650b Comp wouldn’t seem so under-gunned if it were up against the likes of Giant, Specialized or Trek.
Jamis fits size-specific stems to all of the Dakars: 6° rise, 90mm on the 15in; 100mm on the 17in; 110mm on the 19in and a 120mm on the 21in. Basically, you get a nice paperweight with every bike. The handlebar profile and ‘ergo grips’ mean both of those will be joining the stem on your desk. In fact the WTB Volt saddle is the only one of the contact points worth keeping, but there’s no seatpost QR for raising or lowering it.
All that said, the Jamis rode better than we thought it would. The super-high front end, relatively long front centre and beefy dual-compound tyres made for a pretty good wheels-on-the-ground DH bomber. OK, so it’s not the most manoeuvrable bike and the knocking in the rear suspension was really annoying, but we were pleasantly surprised how fast we could get down Mountain Ash on the Jamis.
Getting it to the top was a very different story. The weight of the bike is really noticeable and when the gradient pitches up steeply, the rear suspension tend to squat under harder pedalling efforts in the middle ring, robbing precious energy.
Ultimately it is the shape of the Dakar 650b Comp — or more specifically the height of bike — that makes it something of a one-trick pony. For all-day riding the position feels more akin to a big fella’s commuter hack than a 130mm travel trail bike.
If Jamis were to shave 30mm of the height of the front triangle, it would improve the riding position and save some weight. In many ways the 650b Comp proves it takes more than just a bigger wheel size to make a truly engaging bike, and Jamis has some way to go before the Dakar 650b Comp surpasses any of the 26ers in this test.
Mbr rating: 6
The Jamis Dakar 650b Comp was tested head-to-head against the Canyon Nerve AM 8.0X, Rose Granite Chief 6 and Stevens Glide SX in the July 2012 issue of MBR.