Features that get most XC racers’ heart rates elevated

Product Overview

Overall rating:

Score 8

Cannondale Scalpel-Si Carbon 3


  • Stiff and efficient frame


  • Unbalanced suspension


Cannondale Scalpel-Si Carbon 3 (2018) review


Price as reviewed:


There’s no mistaking the Cannondale Scalpel-Si. Thanks to the unique single-sided Lefty fork and the unmistakeable, bean can sized headtube.

cannondale scalpel-si

Cannondale Scalpel-Si Carbon 3 review

Like most of the other bikes here, the Scalpel has been Cannondale’s cross country platform for decades. Now on its fifth generation, the frame has been tweaked to reflect current XC trends. One of the first brands to incorporate flex in the stays rather than pivots, this Scalpel-Si sticks to that formula.

The ‘Si’ in the name stands for System Integration and whether you like it or not, Cannondale ploughs its own furrow when it comes to a lot of the technology found on the Scalpel. Take the rear end for example; it uses Cannondale’s proprietary asymmetric spacing to shift the hub and chainring position a few millimetres towards the driveside. Why? It allow for a dishless rear wheel, effectively bringing Boost-like stiffness without needing to increase the width of the rear end and compromise heel clearance.

cannondale scalpel-si

RockShox Monarch XX shock with 100m travel


The most obvious example of Cannondale’s ability to take matters into its own hands is the 100mm travel Lefty suspension fork. Unlike normal telescopic suspension forks, the Lefty is an inverted design that stacks everything into the single left leg. And even though it’s a square peg in a round hole running on needle bearings, it’s stiffer than more traditional twin-legged designs. It’s not quite as sensitive though, and it’s also a bit harder to live with especially if you take the font wheel out regularly. That’s because wheel removal requires the brake caliper to also be removed, plus you can’t just rest the bike upright on the dropouts like normal.

cannondale scalpel-si

100mm Lefty fork with remote lockout lever

At the rear the Scalpel pumps out 100mm of travel and business is a little more as expected. A neat carbon upper link drives the RockShox Monarch XX shock, eclipsing the performance of the front end with its superior, supple stroke. Both are linked to a handlebar mounted hydraulic lockout providing a simple on/off approach to the suspension.

cannondale scalpel-si

Hollowgram Si chainring has custom offset


Cannondale is renowned for making some of the lightest cranksets on the market and the Scalpel comes with the stiff and distinctive Hollowgram Si version. Due to the asymmetric back end the chainring has a custom offset so this is something to take into account if you ever look to change drivetrain components.

Similar to Giant, Cannondale has taken the slightly bold step in speccing a wide bar. In this case an own-brand 760mm flat, carbon bar. It’s incredible how a few extra milimetres can have a positive impact on the handling.

Stan’s Crest rims used to be the ‘only’ choice for XC racers, and the new Mk3 version sees an increase in internal width to 25mm for better tyre support. Laced onto Cannondale’s own C-Zero hubs makes for a super light setup. It’s easy to twist them into shapes though so heavier or more powerful riders might find them a little too flexible.


The Scalpel often gave the impression that it was battling with itself. It should provide a much more congruent ride but, just as can happen with a national sports team, sometimes all the main players just don’t gel. The frame gives you power and stiffness in spades and with the short wheelbase and stays, makes it a pleasure to slam through the turns. But this is juxtaposed by harshness that makes it all too easily for the bike to get defected off line by roots and rocks, making it difficult to maintain any flow you might have built up.

The high bottom bracket and steep angles also rein it in on the descents and we really struggled to balance the feel of the fork and shock. The rear shock’s supple action gives the bike great traction and small bump sensitivity. It does limit the support really required for race situations however, and gives the impression that the bike has something of a split personality. And because the basic lockout lacks any form of threshold adjustment, you often feel that the bike that is either too soft or too firm for properly efficient riding.

Cannondale Scalpel-Si


On paper the Scalpel seemed like the real deal, with the sort of build kit and features that get most racers’ heart rates elevated. Riding it however, leaves you feeling a little confused and wondering what could have been. Fundamentally, the frame sizing and geometry feels a little dated, making the Scalpel handle well enough but nowhere near as good as some of its competitors. Add in the miss matched suspension response, where the front end feels too separated from the trail and the rear feels like it needs a little more support. As such, the Scalpel-Si Carbon 3 hits just wide of the mark.


Frame:Scalpel-Si BallisTec carbon, 100mm travel
Shock:RockShox Monarch XX, Full Sprint remote
Fork:Cannondale Lefty 2.0 2Spring, Full Sprint remote, 100mm travel
Wheels:C-Zero hubs Lefty F/12X142mm R, Stan’s NoTubes Crest Mk3 rims, Schwalbe Racing Ralph EVO 29x2.25in tyres
Drivetrain:Cannondale HollowGram Si chainset 32t, Shimano XTR 11 speed rear mech, Shimano XT shifter
Brakes:Shimano XT M8000, 160mm rotors
Components:Cannondale C1 760mm flat bar, Cannondale C1 90mm stem, Cannondale C2 carbon seatpost, Prologo Zero II STN saddle
Sizes:S (27.5in), M, L, XL (29in)
Weight:11.55kg (25.46lb)
Size tested:Large
Head angle:69.9°
Seat angle:69.7°
BB height:328mm
Front centre:705mm
Down tube:692mm
Top tube:595mm