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We see how the Blue AC1 SL holds up against our Four Ride review.


Our test bike came with SRAM Red, TRP R970SL magnesium brakes, a Fizik Arione VS saddle and an Aerus cockpit with a carbon handlebar and an alloy stem. The Zipp 404 carbon clinchers are aerodynamic and practical but we were surprised at how much they’re tugged about by crosswinds. The cable routing into the top tube behind the stem is neat but the rear brake cable sticks out where it exits and it touches your leg with every pedal stroke.


Blue make no claims for the AC1 SL’s aero credentials nor reference any wind-tunnel test data but all the tubes use airfoil shapes. The down tube meets the head tube lower to reduce its frontal area to the wind and features a cut-out to tuck it over the wheel. On two fast one-hour rides the Blue didn’t feel extra fast and when we repeated the rides on a non-aero bike of the same weight with similar wheels we went quicker by 1mph. Surprising as the Zipp 404s are top drawer.


The AC1 SL weighs 6.76kg but feels heavier as there’s a lot of flex around the bottom bracket. Hard efforts seem to be absorbed by the frame and the rear triangle flexes so the Zipps rub the brakes when you’re out of the saddle. Fast descents, even in a straight line, can feel scary as the wheels don’t agree on a direction of travel. Cornering is inaccurate and we encountered some shimmy while tucked in and freewheeling once above about 40mph.


The AC1 SL is a comfortable ride. Both vibrations and bigger hits are absorbed well. The Fizik saddle is accommodating to perch on and a zero-offset seatpost is available to get a better tri position with clip-on aero extensions bolted to the stiff-yet-compliant Aerus handlebar. These attributes save it as a potential Ironman bike, so long as the route isn’t hilly. However, the flexy frame means the Blue AC1 SL isn’t one of our favourites.

Price £5,999.99 (as tested) £2,299.99 (frameset)
Weight 6.76kg (14.9lb)
Sizes 48, 51, 54, 56, 58, 61cm
Frame and Fork Blue AC1SL; Aerus C4SFT2
Seatpost Aerus C4 Aero Carbon Pro
Stem Aerus 7050 AL Pro Ti
Transmission SRAM Red
Brakes TRP R970SL
Chainset SRAM Red 53/39
Saddle Fizik Arione VS
Wheels Zipp 404 carbon clinchers
Tyres Schwalbe Ultremo
Cockpit Aerus C4 carbonbar, Aerus 7050 AL Pro Ti stem

This review was originally published in Triathlon Plus magazine. Save time and money by having every issue delivered to your door or digital device by subscribing to the print edition or buying digitally through Zinio or Apple Newsstand.

You’ll find loads more triathlon gear and kit reviews in’s Gear section