FINAL VERDICT

We set up this test to check that all the hype, lust and extra cost associated with carbon fibre was justified, and it’s thrown up some interesting answers. Saracen’s Kili Flyer proves that a full-carbon chassis can save a serious amount of weight. Frame flex and sticky pivots mean it can’t capitalise fully on its modern shape and decent spec when things get techy though. Cannondale’s Jekyll 3 is definitely stiffer, but it’s still giddy rather than grounded-feeling. It’s also a lot heavier than the Saracen, and barely lighter than the burlier Jekyll 3.

The top bikes here are good for different riders. Specialized’s Stumpjumper Comp Carbon is possibly the safest-feeling bike we’ve ever ridden, in a good way. The semi-carbon frame is rock solid, the suspension is easy to set up and it combines with 2.6in tyres for a super-smooth, high-control ride. Santa Cruz’s full-carbon 5010 C R has a similarly stiff frame, plus punchy, interactive suspension that’ll appeal to those who want to play and pop, and only slight kit downgrades compared to the non-boutique bikes.

That put both Spesh and Santa Cruz on target for 4.5 scores, until we looked back at the sub-£3k alloy trail bike test in MBUK 346. There, the Trek Fuel EX 8 and Whyte T-130 S had 1x12 gearing and comparable or better kit to the 5010, Trigger and Stumpjumper, at the same sort of weight, and the Scott Spark 945 came in 500g lighter, with a similar spec. So, while carbon bikes can be great, don’t assume they’re better than alloy, especially when it comes to value for money.