Cable Science! Should you worry about wasted watts from your messy bike cables? 

Now try cable drag calculator here: fft.tips/bars (and pls join us on strava bit.ly/fftstrava) #happytraining

u came here for 12:58

As someone with a PHD in Aerodynamics. If someone came into my office and expressed drag in "Grams" I would seriously question their aerodynamic proficiency. It's like someone measuring the distance from London to Paris in Lightyears.

Summary: the new gen aero bikes that completely hide the cables in the front save anout 3 watts @ 25 mph in this regard compared to traditional/light/climbing frames that have exposed cables in the front. Does not seem anywhere near worth the much higher cost and much more difficult maintenance of these new fully integrated aero bikes for 3 watts.

I would tidy the cables on my bikes for years, every single bike I ever owned. I just never liked the look of sloppy cables, never really thought of any aero benefits, just did it to satisfy my OCD..

Superb effort Alex. Clear, specific, evidence-based, multi-source comparison/validation with a confident commentary and many helpful graphics and visuals. 👏👏👏

i like having some cable showing, i have white housing against a flat red frame.. nice contrast, easy to work on since i dont have a team of mechanics on the dole

Firstly respect to Your works. All Your videos are awesome as an always. Every parts, all air drags are important. Cable drag is little. Low handlebars(without spacer) with aero position is so important than cable and aerodynamic of bicycle parts. Human body is big than bicycles. Note: Grey S-Works is low and long, good aero position.

Always remember Chris Boardman saying cables are like hanging a trout fish from your handlebars for every cable!

“Most of us don’t have one of those fancy super bikes” so true😂

Now a "how to" integrate cables without a $$$ I integrated bar and stem...I simply wrapped the handlebars AND the stem to conceal cables all the way to behind the stem cap where it cleanly enters the frame. I only have one front brake cable exposed which I plan to his inline with head tube by upgrading to an aero caliper like tri rig x

Internal cabling ONLY make a difference to competitive racers! They will make it considerably more difficult to maintain shift and brake quality. Especially if you replace cables less than once a year. The housings take tight bends through the h bar, stem and frame increasing friction. Increased length of housing also adds to friction. Internally routed hydro hoses are plain and simply a PIA! My old school, 33 year old downtube shifted Dura Ace 7400 7 speed still shifts just as fast and more solidly than DI2 because theres just 8”of cable housing! But DI2 is perfectly suited to internal routing. Traditional External cables with short sections of housing can be made to last longer and are much easier to maintain than internal cables. I have heavily used MTBs where external cabling lasted over 10 years! The newest internally routed designs with tunnels are an improvement. Im a bike mechanic. We’re usually grumpy, so if you bring your bike to me, none of this really matters except when you get the bill AND WHEN you get your bike back. You will pay more for internal routing, one way or another. We charge $20 to replace 1 external cable,$30 for internal OR $1 per minute for exotic PITA aero bikes. I can replace simple cables and housing in less than 5 minutes on the spot, while you wait. Internally routed bikes will normally be put into our schedule 2-3 weeks out. It Might seem dumb, but we’re extremely busy all year. I have customers who travel over 40 miles to have me repair their bikes!

I was wondering about this yesterday.. FastFitness Tips again provides me with helpfull insight, Thanks!

Odd that cervelo go to such lengths to make the bike aero then spec the massive they axel leaver. Would’ve thought the watt cost of that would be greater than the drag produced by the cables.

I think these videos are very informative. 2 watts saving is nothing; but if you total up the watt savings from all the other videos they've uploaded, 5 watts here, 10 watts there, another couple watts here also, then it all adds up to something significant. A difference of hitting a wall at 40kph on a flat or breaking through it and reaching beyond 45kph. Marginal gains could become massive gains.

Digging deeper about now arrowDynamic epic! The rider is the biggest air dragger. This is where the fucos must be! The clothing must be spearhead designed too.... or the helmet itself! Will..just giving an idea yo!

I optimized my exposed exterior routed cable routing so they all are "in line" with the steerer tube, not sticking out to the sides. If it saves me a few thousand dollars and a watt or 2.

Wow didn’t realise I got a shout-out😵

if that win-tunnel video of a specialized roubaix is the one they tested on, which has a ridiculous amount of cables hanging out (also near vertical against the oncoming wind) is 2.4 watts then it's safe to say that it's only affecting me for about 0.5 watts or less which I could easily make up by doing something else to my bike at a very cheap cost.

Don't care about watt savings but love the clean look of no cables.

Idea: holder for all the cables together in form of airfoil

Very interestig video, thanks. I feel the signficance of marginal gains could be directly proportional to the level of cyclist you are, and matters very little for a club cyclist in a group who cannot sustain riding in the drops or low on the hoods. Many cannot do this. And yet bike progress in the last 8 years suggests the gains are worth pursuing.

how about disc brakes? how much drag are they costing? they are giant circles directed to wind.and also shift levers?

Great stuff, interesting as always. Thanks Alex.

loving the science. shared. sub. kudos.

What happens with the rider on bike?

Well I have to see if the pelleton of the Tour de France or the Giro will go fully internal cables in a few years. There a also a lot of disadvantages and the gains are marginal. For the time-trail it's a nobrainer but for the regular road bikes i'm not so sure what will happen.

I bet matt finish on a frame waste more watts compared to cables

Well only in zwift do aero gains get added together. Adding the other changes to the s5 plus new handlebar plus no cables is not the net sum of allure changes individually. So it could be 5 watts on its own but not when all added up

I'm interested in watt savings concerning light wheel weight rotation compared to a exact weight bike with the same rubber tread. In other words, I'm wanting to figure out the best value of a light weight wheel. Thought it might make a good video and you're the one that can pull it off. I love your vids.

Guys just spend 10 grand and you'll finish your ride up to 5 seconds quicker!

Remember that adding the water bottle will help with Whitcomb Area ruling to reduce drag when cycling at transonic speed especially if your handle bars aren't supercritical NACA airfoil cross section.

Thanks Prof.

The more videos I see of internal cable routing the better SRAM etap looks.

It is scientific. You save 100 watts with integrated cables just from the coolness factor...

I've been thinking. If cables cause so much drag, how much drag do cassettes cause? There are 11-12 gears just on the back, and I bet that thing is flopping around like a trout on a boat deck in the breeze.

How many watts in aero drag diffidence are those modern longer cage (by comparison) dérailleur and 11 speed wide cassettes to something like a Shimano Ultegra Rd-6400 and narrower 7 or 8 speed cassettes?

may be an placebo effect

I swear I could feel a difference when i put eTap on my supersix evo and deleted the external shifter cables, especially when going fast into a headwind

Can I take it from the graphic at 6:23 that these measurements were obtained on a riderless bike? If so they're complete BS.

I am more worried about my wallet health thank you kind sir

Did you test the cables at angles.

Wind tunnel time is a lot of what the consumer is paying for.

When bikes don't need riders this test might be meaningful. See that thing you "don't really doubt"? Doubt it.

we need aero shaped cables!:)

Marketing is everywhere and thats the sad thing.....

Where is cyclist in this wind and side wind etc in this wind tunnel tests?

12 seconds over 40kms = who cares!

Has anyone ever posed/explored the question(s) upon the wind tunnels themselves? i.e., are all wind tunnels truly alike/equivalent/EXACTLY THE SAME/etc.; (one could easily presume not) "Apple to apples" and all that. (would make for a good follow up video) *AND......* Are all, said wind tunnels in frequent need for calibration, updates, *OR* vulnerable/subject to manipulation of say "Volkswagen emission" type scandal/standards, per corporate interests ??? en.wikipedia.org/wiki/Volkswagen_emissions_scandal Inquiring minds would like to know ;-) Btw, love your hard work & time divested here, each & every vid you put out. Look fwd to them truly each week/month for obvious self interested reasons, shared by many, to improve one's knowledge &/or performance. Methinks you have a "corner-on-the-market." Cheers!!! +FastFitness Tips: Cycling Science!

My bike is tarmac sl6 has internal cabling on down tube and top tube, doesn’t have totally concealed cables on handlebars it’s not that high end. How many watts is basic internal cabling saving over no internal cabling like a caad 10 for example?

I looped my cables over so they cross on the downtube to avoid contact with the head tube, in other words the left shifter cable goes to the right side of the bike and vice versa. That probably adds a few inches of cable to each side. When you're caring panniers with cargo cables are the least of your issues.

Vanity over sanity. Leave bikes at the cheaper end with cables out front. Tape and conceal them on higher end bikes and charge silly money. Quite sad the way cycling is going.

Areo Cable housing a new market segment?

soon the budget road bikes will be a tough maintenance work for average joe who used to fix his own bike, now even with the small problem you will have to take your bike to the shop and leave it to the professionals, just like modern cars with all electric parts

Where did you get the video at minute 12:30 ? thanks !

Hello, would like to know if two small (50% of existing ones) (left & right side) front disk brakes would be or create less drag than one of the large/present/existing disk break arrangements.

How about Bluetooth operated brakes to do away with cables altogether ( etap sram) ?? Watch this space 👍

13.22 what is that bike??

So accepting in future all be rightly cable integrated we need see better mechanical designs

Remember that all this goes out the window if the rider is a bit porky/overweight!!

the real question is why are all the cables on one side on that bike??? 0:10

Yeah I’m not interested in buying a new bike without hidden cables... it just looks dated lol plus aero gains 👍👍👍

Do you guys have any wind tunnel test data for the new tt bikes?

Not really if you have strong legs

Taking marginal gains to the nth degree. 😏 Just get fitter ffs.

Im not interested about the watts saving. Im fan of how sleek and modest that is

its fun to geek out on the bike tech for sure, but wouldent shedding a few pounds and cycling a bit more makes any watts saved by super expensive upgrades. thats to the budgy middled men out there with too much disposable income=save the consumerism just bike more if you wanna get faster!

Riding with the mouth closed also saves watts but they will not tell you that. Something to pounder....

I dont like the handle design.i like only trinx bike handle truly and i like only cannondale bike handle truly

all this money for only 5 watts?

Spent 13 minutes to give 20 seconds of info.

And this entire exercise is just silly, when you put a bottle and cage or two on the frame

much talking for a second answer ..

Giving the cables a tail is all that they need to do.. make the shape of the cable like a drop of water and problem solved.. Let me know what else you need help with. How stupid are you people?