Cervelo P5 – tech & gear on my new TT bike

Cervelo P5 - my new TT bike in reviewCervelo P5 – my new TT bike

There seems to be a bit of a Cervelo thing going on with me. I traded-in my speedy S3 for a lighter-weight Cervelo R5 climbing model and now I seem to have ended up trading in my Specialized TT bike for a Cervelo P5six, which I got at the back end of 2020. It’s a 2014/15 model so fairly old and still fairly expensive. On the plus side, this came with Dura-Ace, Di2 and lots of goodies and was one of those bikes where the previous owner seemed to only use it for races. It looks in showroom condition to me.


Buy Approved Used + New Cervelo bike and Fraesets
Buy Approved Used + New Cervelo bike and Fraesets

Overall Looks & Considerations

I like the frame design but am less keen on the retro colour scheme so I researched the price of a respray and was quoted about £500/$650….so I’ll give that a miss!

AFAIK, the later P5 series is a slightly superior, disc-only frame and even the cheaper Ultegra groupset variant of that comes in at $8,000. Ouch. Mine was less than half that price with trainer wheels, Di2, PM, a bit of Dura-Ace, travel carry bag and other goodies. I’m still sticking with rim brakes as they work with all my current Mavic Exalith/Carbon wheels, so the P5six was the model for me.

I have a 54cm road bike and 172.5mm cranks and was definitely keen to get more aero on a smaller TT frame. So, with a Cervelo that meant a 51cm frame.

Initial Concerns

I need a TT bike fit and getting one is proving tricky because of Covid. I got some advice from a wannabe bike-fitter-cum-friend that the 51cm frame was good for me. Basically, a smaller frame means the seat needs to be higher and then your front end can be lower and more aero. So long as the cranks are the right length and you have the flexibility, all should be good.

I guessed I needed smaller cranks to avoid whacking my knees into my chest but wasn’t quite sure of the optimal length for me…definitely less than 172.5. They can be easily changed so the precise choice was only a mild concern. I think I have 167.5mm ones, which might be a tad too short.

The Magura hydraulic rim brakes were also an unknown and of concern because of my zero knowledge about them and their efficacy. Are they going to be a faff to maintain? How well will they work? How can I get those sold-out bits that are only available directly from Germany, Brexit-permitting? That kind of worry.

The bike had only been cut down marginally at the front with 3x5mm spacers still left to be taken out. So plenty of wriggle-room there. I’m guessing I’ll need two of those taking out. Apparently, it takes 3 hours to cut the front forks down accounting for a complete bleed and refill of the hydraulics, so this will be a task not to be undertaken lightly. In fact, it will be a task that someone else will undertake lightly for me.

Finally, my current wheels are all 23/25 wide and so that is fine for this frame. Though I don’t think it will take anything wider as my current 25mm rear is a tight squeeze.

First Rides

My bike hygiene is poor and my bikes tend to get dirty, stay dirty and wear out quickly. The P5 shall have to be treated with a bit more respect and so I’ve only been using it on recent good days. Yes, we even have warm February days in England.

Some indoor turbo rides were good to get the seat height sorted out and all was cool there. I’ve used the Adamo Prologue before and my initial seat position left me reaching way too much for the bars. Eesh. I initially thought I was going to have problems here. Surprisingly just moving the saddle 15mm further forwards so that it was 5cm behind the BB centre line was perfect. That yawning chasm to the end of the bars simply went away. Those two simple saddle adjustments made the bike imminently rideable.

In the early 2010s, I trained a lot on my turbo with the TT bike, I preferred this at the time as that sort of training saved time, introduced better specificity and was safer. I did that training exclusively on TT bikes although in recent years I rarely use turbos and almost always go on the road! Despite that total about-face, I still find the TT position more comfortable than a road bike, perhaps my cycling grew into the TT position? So, not having ridden a TT bike for a year it is now a joy to be back and balanced precariously on my speed machine. On the road for the first time and 10 miles later all felt good. Really good.

There are not many TT bikes on the roads right now so, whilst completing pleasant laps around Richmond Park, there is still time to nod to fellow-TT riders going in the opposite direction. It’s like a club within a club.

Here are some of my tech revelations


I have to say the Magura hydraulic brakes are brilliant with the RT8 TT levers. I’ve only ever ridden with MTB-hydraulics and this is a world apart when compared to all my previous TT bikes’ braking experiences. There is awesome stopping power as well as a progressive feel to how the stopping power can be applied. I love them, the one criticism is an initially slight sponginess when you first start to apply braking pressure.

All my front wheels have an Exalith rim and the rear discs/deep sections have carbon rims. Obviously, the front wheel with Exalith was always going to stop well, perhaps too well, but I had very low expectations of the rear. Again I’m surprised. The pads/wheel are identical to my old bike but the hydraulics just seem to make stopping work. Which is a good thing!

Definitely delighted here with the braking.



It’s electronic Di2 on the front and rear. Yay! The gears have been perfectly set up and shift beautifully.

Chainrings are 52:36T (oval) and the cassette is 28:11T on a medium hanger. So a 36T front and 28T rear combo is my spinniest gear which is fine for my normal uses but I’m not sure it will be spinny enough for my hilly A Race which, from memory, has almost 2000m of vertical climbing. The rear derailleur looks to have a medium cage (30T max?) and that might pose some gearing issues. Let’s see.

I finally managed to configure the Di2 to shift as S1 semi-synchro. This means that when I make any shift on the front ring the rear automatically shifts as well to a similar gear ratio…in my case, I have this set to shift two gears on the rear and that is fully configurable to however you want it. There are other Di2 shifting settings you can make and the only other I’ve done is to increase the shift speed up a notch from the middle setting.

My aerobars have the Di2 two-button bar-end shifters (SW-R671) which are pretty cool. Again this is the first time I’ve used Di2 on bars in earnest and it works super well so long as I press the right button 😉 On my previous bike, I had the cable Dura-Ace bar-end shifters and they were alright but the one moving the front mech needed a good tug sometimes. Di2 is a notable improvement here. Perhaps the one downside of Di2 shifters on the bar is that there is no extra button control for your head unit to add laps or scroll through screens (the later Dura-Ace/Ultegra road levers do have that eg on my R5).

Cervelo P5 - my new TT bike in review

Di2 Sprint Shifters should be mandatory on TT bikes

However, I’m saving the best til last. I also have two sprint shifters each installed near the brake levers. These are super-awesomely brilliant and make riding a TT bike in training a lot safer. The sprint shifters are NOT for sprinting but rather to help shift gears when accelerating or braking due to other events on the road. My one criticism of Shimano here would be that I would like to have the sprint shifter set to FULL synchro mode as, currently, the left and right buttons only change the rear gears, ie I can only change the front gears at the bar ends. I think I could perhaps set them as full synchro only if I had full synchro on the bar end shifters too…and I don’t want to do that.

What I would like is

  • Bar End – Semi synchro
  • Sprint Shifter – Full synchro

And apparently, that’s not possible.


Techy Di2 bit: the upgraded Di2 battery I think is located near the BB, if you take off the rear wheel, there is an access port to the battery and the cabling junctions.

Crankset Issues

I once had oval Q-Rings on every bike but vowed never to use Q-Rings again after I bade a fond farewell to them on my last bike. That said, Q-Rings feel like they are faster, the dodgy power readings say they are faster but if the chain keeps coming off then you’re not faster.

Years ago I used the Rotor tool to determine my OCA/OCP (Optimum Chainring Angle/Position) and found it best for me to be set to a highly ‘aggressive’ position, perhaps favoured by the far-forward seat position I favoured at the time. The OCA I currently have sets the ovals to a more chilled out position and I’m good with that for now. One thing I found was that even though I preferred an aggressive TT position when coupled with the extreme OCP, it seemed to restrict me from generating the same levels of power whenever I temporarily returned to a road bike…NOT what you would expect. You would normally expect to produce more power on a road bike. Anyway, the chain hasn’t come off yet so I’m happy enough to stick with Q-Rings for now.

Then we come to the power2max Type S power meter that came with the bike. That seems to have absolutely zero means of updating the firmware and p2m told me I was good to go forever on what I had and that no maintenance was required.  #Shrug. Seems fine. I’ll whack some pedal PMs on and compare them at some point but I suspect that the pedals won’t calculate the power properly with the ovals despite what the manufacturer says. My other means of comparison, the Wahoo Kickr, is playing up too and sorting all these things out just takes up so much time.

Pedals? It came with Dura-Ace pedals, which was very exciting. I’ve never had DuraAce pedals before and so I immediately had to swap them onto my R5 to make it imperceptibly lighter and save 2 or 3 grams …or whatever it is. Of course, it made zero noticeable difference, especially when carrying two full bottles of water!

There are rumours that Favero will introduce a Shimano cleat compatible version of the Assioma this year (2021) so I may well end up using those. My experience with them in the past was that they overstated power on ovals.

Cervelo P5 - my new TT bike in review

Seat & Hydration

For HIM/IM, the best place for fluids is inside the frame, lower down, in sufficient quantity to eliminate or minimise refuelling stops.

For a sprint tri you probably don’t need hydration and for an Oly, 500ml from a bar-based delivery mechanism is probably best if  you need hydration/liquid fuel.

I’m targeting HIM distances and so with this frame, I will have to compromise. If I assume 3 fuelling stops then I could adopt a decelerate, grab, go and transfer the fuel/water strategy. I’m not going to use that tactic as I’ve found that (warranted) anti-littering rules reduce its time-effectiveness. So I will carry all I need for the bike from the start. Probably I will have 2 water bottles stored behind the saddle BUT the bracket I have for that doesn’t fit the Adamo. Grrr. So I’ll end up putting my favourite Specialized Toupe saddle back on just so I can use the water bottle storage bracket I have for it and I’ll likely combine that with a third bottle in the regular place, I can’t see me getting a special aero-bottle of any sort.

Handlebars, Aerobars

The 3T Arduro integrated stem/cockpit combination seems great to me.

Cervelo P5 - my new TT bike in review

I have the original 3T ‘ski’ type bars but have swapped them out to ‘something else’ which point up a fairway at the ends. I used to use the ski bar design many years ago until they became unfashionable. Now they are back in fashion due to some imagined or rediscovered aero benefit. Whatever the benefit, I simply find them more comfortable to use and I’m glad that no-one will ‘tut’ at me when I use them.

I’m probably going to end up with a Wahoo Bolt mounted to the horizontal part of the bars with a cheap Wahoo plastic mount. If I’m honest I’d have to say that, right now, I’m simply wearing my tri watch on the inside of my arm when I ride. I’m doing a lot of bike+run sessions so that is easy to work with. There’s plenty of space to add some sort of mount as I’m not going to have any hydration on the bars. Maybe I’ll stick my Wahoo ROAM on there instead of the Bolt (currently ‘on loan’)

Cervelo P5 - my new TT bike in review


I’ve got a TorHans Bento X and will almost certainly use that to store gels. Handily the P5 has holes in the top tube for it to be secured to.


What would you change?


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My P5
  • Price - 85%
  • Build Quality & Design - 85%
  • Features, Including App - 85%
  • Openness & Compatability - 70%

Cervelo P5 Six – The Ride

P5 six gives a solid, controllable ride. It feels quick but probably no quicker than my previous TT bikes unless I can get a better aero position. It steers well, it turns heads.

Cervelo P5 - my new TT bike in reviewI get a bit of internal cable rattle on bumpier roads and the wind blows it about a bit – but that’s the deep section wheels. Without the speedy wheels, it doesn’t look as good yet can easily handle a >15mph wind and can stop on a sixpence with the lovely Magura hydraulics.

I’m happy though, it feels fast, looks fast and above all is comfortable even before I lower the front end.






  • It’s mine and I have a big smile on my face. 🙂
  • Apparently good aerodynamics
  • Good rider position & comfort


  • Feels a bit heavy
  • The original spec was probably a bit lacking…I have some rather nice extras on board to compensate.
  • RT8 levers really could have better-considered satellite/sprint shifters
  • Ugly Di2 charging port strapped under the bars.
  • Shimano could think about satellite/sprint shifter functionality a bit more.