13 Intuition Alpha carbon review

Does more aero always mean more performance?

Our rating 
3.0 out of 5 star rating 3.0
GBP £1,000.00 RRP

Our review

Lacks punch, power and precise control but it’s a smooth and efficient distance machine
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It doesn’t take long to get the measure of 13’s Intuition Alpha Carbon in terms of its design cues and the pros and cons of its performance. In fact it’s all summed up pretty neatly in the front wheel, fork, cockpit and head tube.

  • Highs: Very smooth cruiser with an efficient performance position and reduced drag
  • Lows: Soft tracking, flexy under power and spongy brakes on slippery tyres undermine power transfer, precision and confidence
  • Buy If: You’re a sit-down-and-spin, not a stand-up-and- stomp rider who wants fatigue-free long-haul speed

Right through the bike, 13 has used its own componentry where possible rather than going off the shelf. With the wheels that means you’re getting a semi-aero rim that’s subtly colour coded to match the frame and even gets coloured marker spokes for finding your valve quickly if you puncture.

Adding colour are 13’s semi-aero rims: adding colour are 13’s semi-aero rims

Adding colour are 13’s semi-aero rims

The semi-aero fork mounts the Tektro brake behind the fork crown rather than in front. This is a drag-reducing trick that’s normally reserved for pure time trial bikes or premium aero road frames, and shows how serious 13’s designers are about their wind cheating.

The side-pull brakes are noticeably softer than conventional dual-pivot models, and while the power comes on strong eventually it takes a while to get confident with the feel. The mushy action is even more pronounced with the longer internal cable run needed to get to the rear brake under the chainstays too.

While it houses a tapered steerer fork, the slim head tube and neck of the frame are soft in terms of steering precision, as is the front wheel thanks to its skinny hub. And though they run fast and last well, the Vittoria Zaffiro tyres also have limited traction, particularly in the wet.

Add that to the brake issues and you’ve got handling that creates a back-foot rather than balls-out attitude to technical descents. Despite an oversized BB30 crank the 13 also feels soft under power, especially if you’re trying to add bar-heaving effort into the equation. So, while it’s it’s competitively light, it definitely lacks punch on steep or sudden climbs.

The long-reach bar and low front end also promote a stretched position: the long-reach bar and low front end also promote a stretched position

The long-reach bar and low front end promote a stretched position

Where the Intuition Alpha does make big gains is in terms of smooth comfort. Deep-tubed aero road bikes designed for the pro peloton’s sprinters and breakaway strong men typically create a rough ride. However, 13 has reflected its largely recreational audience in skinny top and seat tubes plus slim stays that don’t have to handle rear brake stress either.

Factor in a narrow 27.2mm seatpost (with barely more drag than a significantly less comfortable aero fin, according to 13’s tunnel testing) and life in the curvy Fizik-style saddle is a very smooth, buzz-free experience. There’s very little vibration getting to your gloves through the fork and bar, even with 23mm rather than 25mm rubber.

While it might not have the muscle to put every watt straight into the road at full gas, if you spin rather than stomp, the low wheel and overall weight gives an easy and progressive speed increase. Exact aerodynamic benefits are hard to categorically quantify outside the wind tunnel but it maintains momentum well once you’ve spun it up to speed.


The long-reach bar and low front end also promote a stretched rather than sit-up-and-beg ride position that’s naturally more aero efficient. The further you ride, the more the fatigue-reducing benefits of the smooth ride are on your side, so if you prefer playing the subtle long game rather than smashing out a lunchtime power hour, 13’s Intuition Alpha Carbon is an astute choice.

Product Specifications


Name Intuition Alpha carbon (15)
Brand 13 Bikes

Available Sizes 51cm 54cm 56cm 58cm
Saddle 13RS
Wheelbase (cm) 98.5
Top Tube (cm) 54
Seat Tube (cm) 54
Chainstays (cm) 40.5
Wheelset 13RS Aero
Weight (kg) 8.49
Stem 13RS
Shifters Shimano Tiagra
Seatpost 13RS Alloy
Seat Angle 73
Rear Tyre 23mm Vittoria Zaffiro III
Bottom Bracket FSA PF6000
Rear Derailleur Shimano Tiagra
Head Angle 73
Front Tyre 23mm Vittoria Zaffiro III
Front Derailleur Shimano Tiagra
Frame Material Aero UD carbon
Fork Aero UD carbon
Cranks FSA PF30 50/34
Chain KMC X10
Cassette Shimano Tiagra 12-28T
Brakes TRP T822/820
Frame size tested 54cm