Most new TT bikes have moved to behind the head tube cable entry into the frame. More aero. Certainly looks a whole lot cleaner / tidier.
The two main exceptions now being the Look 596 and Cervelo P3C. Especially on the Look, when viewed from a front on view the cables really hang out! Quite untidy.
So, who has an estimate of the gain or loss in aero terms for these two cabling options? Is it worth worrying about for us age groupers or more cosmetic?
Aside from looking cleaner it will make no appreciable difference
I mean its great to be more aero and in theory it works and you’ll be faster, but in the real world the benefits seem to be far lower than people around here make them out to me
I mean in 93 Mark Allen put up a 4:29 bike split in Kona, this year Stadler did the same… and Stadler had what in theory should be a way lighter and more aero bike.
Yeah it looks awesome on both bikes and always looked god on the felt bikes
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Aside from looking cleaner it will make no appreciable difference
Agreed. On a bike with aerobars depending on the cable routing, it can make the bike look cleaner. However, on a road bike, I don’t like the look of this. It tends to clutter up an area of the bike, the stem area, that was previously nice and clean. I like to look down and just see the stem - not the cables looping and curving over top of it. Also if you use a stem mounted computer, HRM or GPS unit - those cables are now going to be directly in the line of site.
I mean in 93 Mark Allen put up a 4:29 bike split in Kona, this year Stadler did the same… and Stadler had what in theory should be a way lighter and more aero bike.
I believe the bike split times from those early years, included both transitions!! More current race timing separates out actual discipline times and transition times.
I mean in 93 Mark Allen put up a 4:29 bike split in Kona, this year Stadler did the same… and Stadler had what in theory should be a way lighter and more aero bike.
I believe the bike split times from those early years, included both transitions!! More current race timing separates out actual discipline times and transition times.
So… how did they do it?
Bikes are better, faster, more aero, athletes are more focused, train “better” “smarter”, … how do they do it?
Housing perpendicular to the wind comes in at 8 grams of drag per inch.
Housing perpendicular to the wind comes in at 8 grams of drag per inch.
I’ve seen figures anywhere from 8 grams/inch to 8 grams/foot given as estimates of cable housing drag force. Based on my calculations using the frontal area of 4-5mm housing and Cd of 1.2 for a cylinder, I estimate cable housing drag at more like 18 to 30 grams per foot (1.5 to 2.5 grams/inch) at 30 mph (love that mix of metric and imperial!). This of course ignores downstream effects, but is probably in the ballpark.
Based on that, I’m thinking that the difference in cable drag between a bike where the derailleur cable housing goes into the downtube, and some more recent designs where the cable housing goes into ports in the top tube, is very very minimal and probably not worth worrying about. And this is coming from someone who tends to worry about these sort of things.
I could be mistaken
Rik
No one else has any speculation/data?
Rik
Bikes are better, faster, more aero, athletes are more focused, train “better” “smarter”, … how do they do it?
Some bikes are better.
Some of them train better/smarter.
Athletes are more focussed than Mark Allen? Most of them don’t put out consistently good seasons of racing like he did.
Problem with looking at bike times is it’s a race - not a TT. Race means tactics, which often means slower.