# 2019 S5 Disc 58cm Di2 Build - Review



## Emilio700

*2019 Cervelo S5 Disc 58cm Di2 Build - Review*

Just got back from first ride. Love it! More details on that later.

16.9 lbs as pictured
Di2 group
180mm 52/36 R9100-P (power meter)
11-30T
140mm rotors
D/A Pedals
Spec Romin Evo S-Works seat
optional 42cm bars (44cm standard)
optional 12cm stem (13cm standard)
optional zero offset post (20mm offset standard)
Light Bicycle 45mm tubeless wheels
25c GP5000 tubeless

Speed








Making changes to Di2 cables after the bike is assembled is not fun, but possible. Making changes to hydro lines after it's assembled involves cutting and rerouting the lines. So make all your measurements carefully. Also recommend you test all Di2 functions before buttoning it up. Then check full left and full right steering lock to make sure you don't have cables binding in the head tube.

Unlike most ported bars, there isn't much room to stuff excess Di2 wire length in. I had to stuff a bit in the right side drop but unlike a round tube frame, it won't swallow up 200mm excess Di2 wires. Also there is no port in the top of the bars, just a groove underneath like old bars. There is a port near the end for the EW-RS910 bar end Di2 port. The frame has no provision for Di2 port or external junction box. That means running at least one Di2 wire through that port in the drop up to the shifter. It's under the tape so if you are OCD, it might bother you. Wire under you fingers under tape on one side but not on the other. Would have preferred Cervelo figured out a way to hide that wire internally.

I run an EW-WU111 wireless unit so I can see Di2 info on my Garmin 520. On my other Di2 bikes, I run that little thing as a junction between frame and bar under the stem. This allows me to unplug it for traveling which disables the shifters from activating the system. Not a big deal but that's impossible on this bike. So the wireless transmitter is in the right side bar. Di2 stuff bar is all serial data stream and daisy chained. This means you do not to complete any circuit. The EW-WU111 can be on a dead end for example.

So how does it ride? First off, I'm 6-3, 160 lb cat 2, fairly strong rider.
Previously rode a Gen 1 S5 (2011) then a 2017 S3 disc. Built the S5D with the same wheels I ran on the S3D.

The original gen1 S5 rode pretty damn stiff, yet was torsionally pretty soft. Classic first gen aero bike, wiggly and hard riding, the worst of both worlds. But it was aero! The S3 Disc was a marked improvement in ride quality and torsional stiffness, while perhaps not quite as aero as the original S5. The 2019 S5 goes a big step further, riding not just a little better than the S3D, but a lot better. I ran thick bar tape on the tops of the S3D and would still get some buzz. I wanted to leave the S5D bar center area bare because aero geek. But was concerned the bare bare would leave my hands numb from road buzz. It didn't. Like magic, the buzz is gone,with no bar tape.

Out of the saddle accelerations require a bit of an adjustment because the bike tracks so well. I'm used to compensating for the waggle of the bike a bit but the S5D just tracks wherever you point the bars even when you are wrenching on them an 800watts. The S3D had a tendency to fall into the turns and would waver a bit when turning hard, sometimes making it hard to hold a precise line. I should mention that I am a very good descender, not the least bit tentative or shy about bombing it. The S5D is neutral in comparison. Lean it in hard and it just tracks without needing to add force to the bars to hold the line. A nice by product of that front end stiffness is better road feel. You feel more of the little changes in self centering torque coming up the through the bars as the front end tracks over undulations. That's confidence inspiring.

I did notice a bit more toe overlap than any previous road bike of mine. Not something you usually see on such a big frame but I think the front center is short. I wear size 46 shoes and run my cleats far back, behind the ball of my foot. Anyway, not a huge concern for me.

So, those bars. I like them. I ran 3T Ergo Novas on all my other bikes so these are similar. The drop doesn't have the little flattened section, being more rounded there. The reach is very short, suited more for riders with small hands I think. The flattened- aero shape tops, as mentioned before, are quite comfortable and natural feeling.

I decided to flip the included Garmin mount behind the stem. My reasoning being the 520 isn't as aero as the bar itself so stick it behind. I run a Bontrager Ion 100 /Flare RT light set at all times. Very small and not to disruptive to aero IMO.

Edit 1/25/2019: Ordered the "aero axles". Cervelo doesn't yet have the fork nut to accommodate a threaded axle. The rear dropout from the previous gen S3 and S5 is threaded and fits the S5D. I swiped the dropout from my S3D so I could use a bolt on axle, because aero. Since no front nut exists yet, I'm going to either 3D print or CNC my own to replace the 1/4 turn RAT system nut.

More slickery
















The Di2 wire is a spare I left there for diagnostics with the SM-PCE1 linkage device. This allows me to connect to the full system. An alternate metthod is plugging into a spare port in one of the STi's.








The 25C GP5000's measured at 27mm wide on my wheels. Plenty of room for 30mm of tire, just measure yours if you have modern wide wheels. Sorry about the dirt wheels..


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## natedg200202

Great to hear your ride impressions. I really like this model. 


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## RStoR

Thanks for the info! Very helpful. I have a 58 frameset on order and will be doing many of the exact same swaps as you, ex. 42s, 120, & 0 offset. 

Are you willing to detail your e-tube cable set-up? Knowing what lengths work will be very helpful. 

What diameter internal seatpost battery holder is required? Cervelo provides so little info on the frameset.


PS: Just sold my ND Club for a CTR. Thanks for supporting the Miata gang as you do.


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## Emilio700

RStoR said:


> Thanks for the info! Very helpful. I have a 58 frameset on order and will be doing many of the exact same swaps as you, ex. 42s, 120, & 0 offset.
> 
> Are you willing to detail your e-tube cable set-up? Knowing what lengths work will be very helpful.
> 
> What diameter internal seatpost battery holder is required? Cervelo provides so little info on the frameset.
> 
> 
> PS: Just sold my ND Club for a CTR. Thanks for supporting the Miata gang as you do.


Unfortunately, I did not document the wire lengths like I did for the S3. Sorry. You can map it out ahead of time if you have a frameset at the dealers to measure though. Tricky part was definitely the bars. One gripe I do have is that there is no port in groove up top that lets you run the cable from outside to in for the EW-RS910 bar end Di2 port. For some reason they located the port under the drop. So you need to run the Di2 wire from the groove up top, under the bar tape around the curve of the drop and into the port there. 

It's also generally easier to run the Di2 wires in a traditional bar. I definitely wrestled with the wires a bit on mine. My EW-WU111 transmitter is in the right drop too. Crammed in there but it works.

Take great care laying the Di2 wires in the stem when you bolt it onto the fork. Easy to pinch. Ask me how I know.

The frameset did not ship with any hose or wire guides or insulation. My rear brake hose rattled just behind the head tube. Had to stuff a few light weight sheets of closed cell foam in there to stop it. I'd recommend wrapping the rear brake hose in the upper DT area up to the HT in something to prevent the rattle.

Battery tray comes with bike. Mounts in DT just above BB. Design of this tray and fasteners that hold it in are ah, not ideal. When you get to that part of the install, put a drop of super glue on nuts to hold them in tray. I won't explain further, you'll see.

Pressed in BB. Red loctite. Blue loctite if it is immaculately clean and you use a lot.. a lot. Some use superglue but that's really hard to get out for servicing. Blue in mine now (slathered).

Inner ring might be close to chainstay guard. Just check it after setting things up.

D/A 9100 power meter cranks on mine which require magnet. Didn't trust provided double sticky tape so I superglued it to chainstay.

All of the fork, bar and stem fasteners need to be torqued, ah, generously. Torqued to spec and I would get pops and clunks when hitting sharp edges or dropping of a curb. Torqued "all the way" and the noises are gone.

Check torque on everything after a hundred miles or so. My bars settled a bit and needed a 1/4 turn on each torx. I'm using the max tilt spacer so that's certainly a factor. Bike shop should have a kit full of all the spacers and wedges.

RAT axles have to be pretty damn tight too. Otherwise they'll creak out of the saddle. Tighter than say a Shimano or Mavic cam type QR. The knurled nut is your preload. The axle nut from my old S3 allowed me to use a bolt on axle for the rear. No such nut exists for the new fork so I'm going to have my engineer scan and print a threaded one from POM (Delrin).

I have the zero offset post. Not a great design. Relies on a long unsupported length of 8.8 grade M4? bolt (zinc or ss), which will stretch. Takes quite a bit of torque to keep from popping over bumps. Again, torqued "all the way" and it's fine now. I plan to replace that with a 12.9 grade black oxide SHCS just to increase fatigue life on what is an over-stressed fastener IMO.

Don't fret. Once it's all dialed it's silent, comfy, bulletproof and dead sexy. It might also be the fastest road bike in the world  I have a few thousand miles on mine. I ride it Cat 1 hard, lots of 100 mile days.


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## goodboyr

Blue and Red loctite are thread lockers. Not for press fit BB's. 

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## Emilio700

goodboyr said:


> Blue and Red loctite are thread lockers. Not for press fit BB's.


Yup. I run a shop that builds race cars, familiar with thread vs cylindrical bonding, solvent resistance, dielectric, anaerobic, etc. Specifically chose it for it's modulus, weak bond and lack of reaction with carbon or aluminum. We have it in the shop, it works.

Superglue or green cylindrical bonding loctite form a much stronger bond but make service a bit more of a bear. It's up to each owner/mechanic of press fit BB's to decide what fits their needs.


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## goodboyr

Okey dokey. Just quoting what the manufacturer recommends. Please report back on whether you get the dreaded creaks. 

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## Emilio700

goodboyr said:


> Okey dokey. Just quoting what the manufacturer recommends. Please report back on whether you get the dreaded creaks.


Oh they will eventually creak after a year or so but it's then a simple 15 minute service to re loctite them. That last time I superglued, it lasted only a little longer but was a 2hr ordeal to get the old glue cleaned off without damaging the carbon. If you aren't careful, you'll take a layer of the carbon layup off when scraping the cyanoacrylate (superglue) off. The green cylindrical bonding loctite is an inbetween. Better bond than red loctite but way easier to clean off than superglue.

I'm OK servicing things, former bike factory race team head mechanic. Also why I use lube on the nipples of the wheels I build instead of spokeprep which lock the damn nipples on making them very hard to repair. I have found, if you build them right the first time, they never need truing anyway.


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## RStoR

Info added for others who may read this. 

Cervelo S5 Disc Assembly Manual


Factory recommended Di2 E-wire Cable Lengths
750mm E-wire: Connects Left and Right Di2 Levers 
300mm E-wire: Connects Right Di2 Lever to Junction A Bar-End 2-Port
1400mm E-wire: Connects Junction A Bar-End Port to Internal Junction B 4-Port 
600 mm E-wire: Connects Internal Junction B to Battery
300 mm E-wire: Connects Internal Junction B to Front Derailleur
600 mm E-wire: Connects Internal Junction B to Rear Derailleur

Think I'm going to use 2x 150mm cables for the Junct B-to-Battery which will allow me to attach the Inline Wireless Unit to the battery. This should avoid any potential for rattle as well as the need to stuff it in the bars. 

I've ordered one of the Hambini BBs in hopes the one piece shell and tighter tolerances avoid creaking better. He recommends use of Loctite activator 7649 and Loctite Medium Strength retaining compound 641 (Green) during install. 

_*The axle nut from my old S3 allowed me to use a bolt on axle for the rear.* _
Have you considered having one made with a direct mount hanger? I'd be interested in one. 

_*No such nut exists for the new fork so I'm going to have my engineer scan and print a threaded one from POM (Delrin).*_
Will delrin threads hold up in this application? I saw the Robert Axle Project group is developing a frt fork thru-axle solution for Cervelo.


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## Emilio700

I already have a front bolt axle from my S3 disc so I'll still make my own nut. Interested to see what Robert Axle come sup with though. I was mistaken in the earlier post, the OEM "nut" fork insert is indeed aluminum. We'll see if POM works. 

Personally, I don't feel a need for direct mount RD. The bike shifts flawlessly under all conditions and the S3 nut works so I'll consider that end solved.

Hambini's loctite rec is spot on. Medium green is ideal. Strong enough to avoid creaks but can still be serviced. My BB is a old Rotor OEM press in, not made any longer. Two independent press fit cups. That design is intrinsically more prone to creaking than a slightly heavier combined design like the Hambini. My engineer uses a threaded two piece Wheels Mfg in his Specialized Venge to avoid creaks. This one here: https://wheelsmfg.com/bbrighttm-outboard-abec-3-bb-for-24mm-shimano-cranks-black.html That solution also works but is heavy. 

Putting the wireless unit in the DT by the battery is a better solution than mine. I was repurposing the wires that were on my gen 1 S5 then swapped to the S3 disc then again to the new S5. Too cheap/impatient to go buy new wires


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## RStoR

Thought I'd let you know that The Robert Axle Project has their RAT front fork replacement thru-axle set available now. Got mine today...but still don't have a frameset yet! I also ordered their rear axle with derailleur hanger.


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## Emilio700

RStoR said:


> Thought I'd let you know that The Robert Axle Project has their RAT front fork replacement thru-axle set available now. Got mine today...but still don't have a frameset yet! I also ordered their rear axle with derailleur hanger.



Woot! Thank you for posting this. Just ordered the front.

On a side note, I have noticed the occasional rotor drag or pop from the front wheel. It's the alloy nut insert not fitting tight enough in the round carbon fork dropout. No matter how I scare myself by cranking on the poor RAT Q/R lever, it still shifts back and forth.

I can install the wheel, no rotor drag and high, firm brake lever. Thump the wheel hard to the side with my hand, spin the wheel and presto, rotor drag. This is a production tolerance issue with the dropout and nut insert. I have sent an email off to Cervelo about this.


On a related note, I have found that all the fasteners in the fork/ bar/ headset need to be ah, _slightly _over torqued to keep from creaking and popping. If you are a gentle rider on smooth roads, you may not have an issue. I race my bike, not afraid of rough roads and generally pound on the thing.


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## RStoR

Emilio700 said:


> On a related note, I have found that all the fasteners in the fork/ bar/ headset need to be ah, _slightly _over torqued to keep from creaking and popping.


My local dealer worked with Cervelo on the first "excess hbar/stem flex" case to be reported. No clear item was found to be defective but Cervelo authorized replacement of the stem and the fork retention parts anyway. The tech communicated a similar message to yours in that it took a few torque cycles to get everything settled correctly with the system. 

Picked up my frameset on Wednesday so I'll start my build soon.


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## Emilio700

Have had several creaks and pops to chase down on it so far. One was the seat, not related to the frameset. Used carbon paste (Park) on post and aluminum binder wedge thingy. Still developed a creak. Took seat mast and wedge apart after about 3,000 miles. Cleaned everything again, reapplied carbon paste quite liberally this time. Silent now.

The bar/stem/headset, as mentioned above, took several tries to get quiet. That's taking it completely apart (not fun), re-routing cables, hoses, cleaning mating surfaces, cleaning threads and threaded holes. Re assembling and re-torquing everything to within an inch of its life.

I will say though, it is sublimely quiet, damped and smooth. A regular 12 mile section of bike path I ride has multiple bridge underpasses that are wavy brushed concrete. Hit those at 25-30mph and it just floats.


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