Calling all engineering and geek types - bike design input?
I've been reading a lot about the new bike designs coming out and am curious what an objective, but technically sounds assessment would yield.
As I read the marketing documents, they all seem to be intuitive (isn't that the point??)!.
So...let's start with double triangle. This one is a bit simpler as it's essentially the standard. The P5 seems to be among the fastest from an aerodynamic perspective and happens to be the bike I ride.
So...on to the new designs.
Beam Bikes (Dimond, Falco, etc). They claim that by eliminating the seat tube it is not only more comfortable but also more aero as there is less frame to disrupt airflow after it hits the downtube and rider.
Lotus Design (Ventum) they claim that the downtube interaction with the turbulent air after it hits the front wheel creates the most drag. They also make some bold claims that it's 20% faster than bikes like the P5 and Shiv.
Real world testing is limited....only a couple pros race on these, but there are a number of examples for each. Rapp just set the course record at IMMT on a Dimond. Kyle Buckingham rode his Ventum to the best bike split at IM Canada, and Matt Trautman won IM South Africa 70.3 with the fastest bike split on a Falco.
So...thoughts?
Comments
In the late 90s and 00s, nine out of ten years running, the women's race @ Kona was won on a Cheetah, an "X" shaped frame without a true top tube. And Softride was popular 20 years ago. What goes around comes around... as Paul says, it's 90% marketing, maybe 10% value.
FWIW, Ventrum did have a rider on their wind tunnel tests per their data.
I made a point of looking for beam deflection when I'm ridden around Dimonds and don't see any. I've heard good things about how they handle and I really, really don't want proprietary head tube, stem systems, handlebars, brakes, etc. I want front and rear caliper brakes easy to access, a traditional steer tube on which I can use a tradition stem and source my own bars. Dimond offers this and I plan to talk to them sometime after IMWI.
I'd also like to see how the Scott Plasma test's up again the P5 etc?
The Dimon/Ventum ar both very interesting... Would love to see those graph's compared to the other superbike's.... DIMON is much nicer looking though IMO...
The rider will always be the biggest factor. I'm always reminded of this when some super stud 60 year old dude on a steel bike with downtube shifters and 30 year old Shimano components passes me and without losing a breath says something, "like nice day for a race" to me or something along those lines while I'm struggling for air.
You could put me on the latest Felt IA wunderbike and stick a dope free tour rider on a bike from the turn of the century and I'm going to lose.
I think they are claiming that the bike (sans rider) is 20% faster than another bike sans rider. I.e., a 20% drag reduction of the bike alone. Suppose that were sufficient to increase your average pace from 20mph to 20.5mph using the same effort over the course of an IM ... that would be around 8.4 mins time saved--an enormous amount. That alone would be a heroic improvement, kind of like when Crowie dumped his old Orbea for a proven superbike. With diminishing marginal returns it seems that making such a huge leap forward technologically would be getting tougher and tougher.
On a related noted, I notice that with 11 speed drive trains, more pro's are dropping the front derailleur and small ring for a 1-11 drivetrain and using an 11-30 or 11-32 cassette on the back. That is cutting weight and wind resistance of the FDR and one ring...what is that worth?. To ensure the chain doesn't come off, they are using an alternating wide/narrow chain that works with an asynchronous big ring up front (must be an even number of teeth). That means a mech build at this point but with only 1 derailleur it doesn't seem to be an issue. I'm thinking of doing the same to my older TT bike when I wear out the next crank and reserve it for flat to moderately rolling hilly courses.
Ala women with a shirt saying "You've just been chicked" on the back, I'm thinking of getting a shirt which says "You've just been geezered". But my bike is only 17 years old, and has round titanium tubes, so maybe I don't really qualify?
The real cure for bike drag is more power which is why I get chiced and geezered more than I'd like. I'm pretty certain that when it comes to bicycle drag technology is rapidly approaching the point of diminishing returns especially dollar wise.
Look at the history of the one hour TT. Some deceased greats are almost as fast as the new heroes on their new wonder bikes. Maybe it isn't all about the bike.... Or is it?