As anyone interested in Triathlon equipment knows, the P5 has finally been released. While we’re still waiting on some information (like the most important bit – windtunnel data) there has been enough revealed to draw some early conclusions.

The bike was released to Triathlon media (no cycling journalists invited) in the Canary Islands, with members of Team TBB on hand to pose with the bike for the photo shoot. Cycling sites were quick to put up articles based on the press release but it’s a clear indication that triathletes are  the target market for this bike.

The standout features at first glance are:

  • Hydraulic rim brakes
  • Pushing the limits of shaping the frame within UCI rules
  • The UCI illegal fork and brake covers
  • No cables visible at the front when using the specific bar and brake covers


Clearly Cervelo took to heart the criticisms of the power of the P4 rear brake and decided they would shut up the doubters by giving them the most powerful brakes on the road. The important element is that they’re able to offer a caliper that stays out of the wind but still gives good performance. So while I’m a fan of the simplicity of a standard brake caliper, I think the balance of stopping and aero-ness that the Magura caliper offers are quite appealing.

UCI Shaping
The side profile of the frame clearly shows the exacting interpretation that Cervelo have applied to the UCI fillet rules (see page 9 of this gripping document). Those extra triangles at the tube joins allow a clever manufacturer to make sections of the frame that far exceed the UCI 3:1 rule – most obvious at the seattube-toptube junction and head tube area on the P5.

There are two versions of the fork. The ‘vanilla’ model that is UCI legal with skinny legs and the brake caliper sitting in front. And the ‘exotic’ version that has a 6:1 ratio between depth and width (not legal for Time Trials by any stretch of the imagination) with associated shrouds for the front brake caliper.

Hidden Cables

Cervelo have partnered with a couple of other vendors for this project. As already mentioned, they worked with Magura to produce a new braking system. The other major partnership is with 3T (which has considerable precedent – Cervelo have aided the design of many 3T products) to produce the new Aduro bar. The Aduro consists of an integrated stem-basebar and a pad-extension assembly that can be lifted by a V-shaped tower.

The Aduro requires careful cutting of the fork steerer as the gear and brake cables pass over the steerer and down through a shroud into the frame without ever seeing the wind.

Cervelo have stated that there is no aero penalty for using the V-tower spacer – which is nice for those who need the bars a bit higher.

Other Features

Beyond those obvious features there are few more subtle elements.

One of the most interesting is that there is a mix of standard airfoils and truncated (Kamm) shapes (a la Speed Concept) depending on the location on the frame. The detailed shaping of the P4 has evidently been taken to a new level to eke out a few more precious watts in the pursuit of speed.

The seatpost is one of the newly Kamm shaped elements, possibly to aid integration with a forthcoming bag that will strap behind it. Notable too is the abandonment of the twin hole saddle clamp system in favour of a sliding rail.

It’s no surprise that they’ve adopted BBRight for this frame as they’ve done that with the last two road bike model releases. BBRight is an asymmetrical Bottom Bracket-Crank format that essentially allows the manufacturer to stiffen the non-driveside of the frame by using larger tubing on that side. You can learn more about the principles at the official BBRight site.

For those who favour Shimanos Di2 shifting the P5 has a hidden pocket in the seat tube to eliminate the drag caused by the battery (which has been one of my objections to Di2 for timed races). However, if you wish to use the Magura brakes you will not be able to use the Di2 brake/shift levers and would have to hack some satellite buttons to retain the basebar shifting function. So it’s a mixed bag for Di2 users.

Torhans design rendering for top tube box

As well as the big name partnerships they’ve also allowed aftermarket hydration/storage vendors to start work on compatible accessories. Torhans are working on a top tube box that hugs the back of the Aduro stem shroud.

And the already available DarkSpeedWorks 480D will fit on the top tube mounts.

While on the fuelling topic, the Aduro bar has mounts for a between the arms bottle. So the P5 is definitely going to be easier to load up than its predecessor.

My Opinion

Overall I’m excited about this bike. The weaknesses of the P4 have been addressed and the strengths have been further magnified. The BBRight system and the refined carbon layup should make it even nicer to ride than the P4 (which is very impressive itself). The aero claims have yet to be clarified but the 75g of drag saving will equate to 5-6w for a leading age grouper at IM pace.

I’m also keen on the bar system as it is far slicker than the previous UCI legal offerings. I still feel there is a paucity of good aerobars on the market and the Aduro is a step in the right direction. Except for the limitations it places on bike fit.

Fitting this Bike

Cervelo have taken a leaf from Treks book in trying to make it easy for people to work out whether they can fit on the P5 and provided a chart with instructions on how to measure your current position and match it to a configuration of the P5.

From which arises my first issue – they’ve used the centre of the elbow pad for the measurement, which is not a constant in fit terms. The back of the pad would make a lot more sense as that allows for the variance in pad length across different brands.

However, it appears that the pad is ~80mm long so I’m factoring in that 40mm to the centre of the pad when I compare to my back of the pad based system.

My next issue is that the Aduro is based on an effective stem length of 90mm with a maximum pad setback of ~70mm (the distance the back of the pad is behind the centre of the bar). If you compare to the ever popular Vision TT Clip On aerobars which have a setback of a touch under 60mm it’s clear that the Aduro is going to limit fit options for a lot of people. Most of the Tri bikes I set up have stem lengths of 50-80mm and the Aduros minimum is equivalent to 80mm.

I’ve plugged the numbers from several of my clients in and so far none can get on to a sensibly sized P5 without having to change from their current position. This is despite the P5 frame having less reach (shorter horizontally) than previous Cervelos.

That the Aduro is equipped with S-Bend extensions is merely piling insult on injury but at least that is easily changed.

So far the Aduro appears to be both one of the best and worst features of the P5 – it will be a big part of the speed benefit but also a potential hindrance to maintaining the position that you’re used to (could be a speed detriment).

But I’m still excited about the bike…

You can view photos at

2 thoughts on “Cervelo P5 – First Thoughts

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