Monday, July 13, 2015

My P5: Now it is truly simply faster

Whenever you buy a "superbike" you always buy "complications." What makes a super bike a super bike (kind of like a super car or a hyper car) is a "no compromise" attitude towards its design context.  So for a triathlon superbike, that function is aerodynamics and integration. The P5 was introduced way back when in January of 2012.  In bike terms, that's a pretty long time ago.  It, in many ways, revolutionized the aero bike segment. Well, it borrowed certain ideas and perfected some others, let's say. It wasn't the FIRST bike with an integrated front end (but it certainly had the best one, so far). It wasn't the first bike with integrated storage solutions.  It wasn't the first bike with completely hidden cabling (except for RD loop/wire, which no one has yet hidden completely on an externally geared bike).  BUT, it did all of those with a level of aerodynamic superiority that was new to the game.

Well, aerodynamic superiority insofar as it concerned "fast" riders.  If you study all of the data out there and sift out the bad testing from the good testing and the testing with acceptable context (and actual "x" and "y" graph labeling) you can discern a few "facts:"

The P5 is still the fastest bike from about -7 to +7 degrees of yaw (give or take) among factory produced bikes. Certain other bikes (IA, SC, PR, etc) are a bit better out at higher relative yaw angles.



I could find more, I am sure.  My point is not to talk about how aero or not aero one bike is vs. another (but if you want me to I am happy to blast away for a while but be prepared to get bored).  My point is that the P5 is a super bike and - like other super bikes - comes with a few interesting things that make you want to learn more about bikes...maybe.

1) Hydraulic rim brakes (Magura RT6 or RT8)

You might have heard stories of bad stuff and wondered how all that works and know someone who has said bad stuff but at the end of the day anybody that says anything negative about the Magura brakes on a P5 just probably doesn't like going fast and maybe doesn't really know what they are doing... I've had this bike for 3 years and have never, ever had a problem with these brakes. The same couldn't be said for having a certain other popular aero brake that I had for a month... (hint hint).

To route a cabled brake line on a bike like the P5 + Aduro aero bar (read: hidden and integrated) would require very tight bends that would dramatically affect the brake power and modulation at the rim.  Magura has designed a brake that gets around all of that, is easy to work on, is light, is incredible aerodynamic, and looks great too!

2) Hidden battery

The "external" Shimano Di2 battery has been placed in the seat tube cutout to remain hidden.

3) Hidden junction box/top cap

The junction box is housed under the 4 bolt stem cover which is under the bottle cage mount which is under the arm pads. So to adjust or check battery I had to remove bottle cage mount, remove arm pad cups, remove stem cover. Adjust and check, re-install.

Now I am perfectly fine with doing all of those things because I got what I paid for: the fastest bike money can buy. I want each of those little seconds. I agonize over my front tire choice for certain races because a GP4000s II may save me 20 grams of drag at 23-25mph vs. a Conti Supersonic 700x20 may save me an extra 10-15g drag at ~30 mph but I lose a little comfort/confidence. Etc. I make choices like that. Do you? Then maybe the P5 isn't for you...

(just kidding, it's definitely for you; go buy one)

I've been wanting to do a project on mine for quite some time now and finally got around to doing it last week once I had all the parts I needed:

1) Install updated Shimano Di2 "internal" battery
2) Install Junction A in the saddle area
3) Convert to "true" 1 x 11 drive train
4) Adjust front water bottle carrier to allow for tall bottles

All of those may seem rather innocuous, but when added together they make a bike that's ABOUT 100x easier to deal with in many ways and it's just plain fun to tinker.

So, step 1:

Figure out where to put battery.

Since I don't need a front derailleur anymore, I figured the easiest and most secure place to put the new internal battery was in the left aerobar extension.

The perfect fit!
Now the left shifter is simply a placeholder.  The e-tube runs out the back of the extension and into the Aduro's rat's nest area of cables, wires, hoses, maybe a bird egg or two...etc. Who knows what you may find in there:


But this is much, MUCH cleaner than it was before. Prior to this update I had the older front "harness" stuffed in there as well. Lots of e-tube was visible.

An internal junction box (Junction B) then sends one e-tube down into the bottom bracket area of the bike to another junction B.  That then sends e-tubes to the rear derailleur and the Junction A.

To house the junction A where I did (on top of the seat post) you have to do something that voids the warranty (on your seat post): drill a hole.

Now, did I have to do it this way? No. I probably could have fit Junction A somewhere else (maybe under the BB) and been fine, but this is the way I wanted to do it.


Now the e-tube runs cleanly all the way down to the BB and I can adjust and charge my bike without touching anything other than an easily accessible junction box zip-tied to my saddle rail. Sweeeeeet!


Moving on, I also addressed a huge annoyance for me when trying to combine hydration and computer placement. This is a difficult question for EVERYBODY (and I mean everybody, this is probably the most common question I hear related to bike purchase and setup) and I am not immune from the issues. The integrated bottle mount is great but when you want a computer out where you can actually see it (i.e. by your hands) you cannot fit a taller bottle or one of those stupid deer park water bottles they give you on course.

Simple solution: X Lab aero cage optimizer.  Bolts right onto the integrated bosses of the P5 and slides the bolts right back to where you need them to be.  As an added bonus, it increases the "stack height" of thebottle cage so it nestles a little bit more cleanly in between my forearms. NICE.


Last but certainly not least, I updated the drivetrain.  I was originally running a 2 x 10 system featuring SRAM Red Quarq (10 speed) 130 bcd 53/39 chainrings + a 10 speed Ultegra 6770 RD/FD with an 11-25 setup for training and racing.

I figured: why not go with a 1x setup? One of the unique things about the P series bikes from Cervelo is that you can remove the FD mount itself, which really cleans up the profile if you're going to take off the front derailleur.

Unfortunately, until recently parts to do this RIGHT weren't easily available. But now they are, and so the time had come to swap that stuff to what I really wanted.

Up front we have a SRAM X Sync 52t 130bcd single ring (this features "narrow/wide" teeth technology which basically means the chain doesn't fall off without a front derailleur).  In the rear we have (11spd) Ultegra 6870 "GS" RD (gs = longer cage) which can accommodate up to 32t on the cassette.  So for the most part I have a 52t + 11-32t as my gearing options.  It's way, WAY cleaner looking, has a wide range, may lighten the bike, and looks sweet. Wait, I said that already.  It may be slightly more aerodynamic, although various testing has been inconclusive so far.  But, it looks awesome.  Did I say that already? I did, yea.


So fresh and so clean!!

Tools required for charge check plus RD adjustment...

Simple? Yes. 

Anyway, was all of this necessary? No. But it sure was fun. In some ways. The P5 offers limited "tinkering" abilities as it relates to fit and such so this was the next best thing I could do.

1 comment:

Eugene Diefenbach said...

Cool! Thanks for sharing. I just converted to 1x and am just about to post a similar "what I just did to my bike" update. I'm happy for you that the FD hanger actually comes off! What made you decide on that RD as opposed to going with a clutched? I didn't get a clutched RD either my logic was that even the rougher roads of tri training and racing aren't the sort of abuse that bikes take in CX or MTB, where it would really be necessary. I've put it through its paces on a stretch of boardwalk and crummy road near me and have had no problem, so right now I can say I'm glad I didn't bother with the clutch.

Happy racing.
Eugene