Why do so many road bike wheelsets use a comparatively heavy semi-aero rim? From what I can tell, and evidence i've read, these semi aero rims offer little or no benefit, and they weigh a lot more than a classic rim like a Mavic open pro etc. Obviously I understand the benefits that the full deep section aero rims can bring, but why in the say £100-300 aftermarket wheelset bracket are so many wheels using heavy, 20-30mm deep, semi aero rims? Surely saving the weight from the rim at this price, and running something like an open pro on say shimano or even Hope hubs, would be more beneficial to the average rider? Or am I missing something somewhere (stiffness perhaps?)?
It's got me puzzled, cos whilst I can see how time trialists would want full on aero wheels, normal club riders and all day riders, a lighter, hand built wheel would be better?
Fashion, innit. Look nice.
If I can remember this properly, aero trumps lightweight until you hit 12% hills. A deeper rim will tend to build up stiffer too.
Plus you can't forget fashion!
An awful lot of it is to do with controlling the airflow on the wheel, which in turn reduces drag as the air is not turbulent when released.
IMHO a bit of it is when you buy a road bike (rather than build one up) this sort of wheel is what you get and at the cheaper end of the market they're easy to get hold of from places such as CRC and ribble so they sort of perpetuate because of this. Also ans open pro on a cheap hub is still going to be about £150ish. I prefer open pro's for general road use but still have managed to accumulate a number of the factory type wheels you describe.
If I can remember this properly, aero trumps lightweight until you hit 12% hills. A deeper rim will tend to build up stiffer too.
But we're talking rims that are perhaps only an inch deep here. Not full on aero, Zipp 404 style wheels. Mavic Aksiums, Shimano RS10's etc... Surely no benefit?
on the flat, you'll go quicker with a heavy semi-aero rim than a conventional low profile rim.
...as measured in studies, by precisely **** all
It's fashion - like suspension on cheap mtbs - 'aero' wheels look good and attract potential buyers.
Probably so that the maunfacturers have somewhere to display their logos - difficult to do on open pros.
It's fashion.
Semi-aeros like cxp33 have the same maximum recommended spoke tension as open pros, so they are no stronger or stiffer than low-profiles. While it's true that aerodynamics is important at higher speeds, the vast majority of drag is going to be from the rider's body, so the aero benefits are going to be negligible.
They look nice! Like expensive wheels!
I don't like the look of them. So I have a pair of handbulit Mavic Open Pro's, just a choice thing
There's no point having a 32 spoke medium deep section wheel - you want to be thinking about 16 spoke front and 21 spoke rear.
So if you were replacing some cheap, own brand hubs on mavic cxp22's, what would you go for? Bike is a giant Defy2, full tiagra groupset, mainly going to be used for fitness and occasional group rides, not planning on doing any competing. So bearing in mind I can build my own wheels, do I get some hubs of my choice and build em into open pro's, or buy an off the shelf wheelset such as shimano RS20's, fulcrum racing 5's, or mavic Aksiums?
I have a Defy 3 and have just put some Planet X model bs on and................What a change!!!!!!
For £125 you can't go wrong!!
as explained to me by a very clever sports scientist, who has a phd, and is paid to be clever and impartial about these things:
"the deeper the rim, the bigger the logo can be"
people with lots of money will find things to spend it on, and they like everyone else to know about it. aero wheels with massive logos that you can read from space are a perfect way to do this.
i could spend thousands on a pair of aero-wheels, and my roadie friend Kipling would be very jealous, but i still wouldn't be able to keep up with him.
Bike position is way more important than wheel depth to get aero. Get into a low tuck and you'll go quicker. If you are a TTer then a decent position and a pointy hat are more important than wheel depth. It's obvious really - just look at a bike coming towards you head on - what can you see big person - and tiny narrow tyre.
For road riding, when you are accelerating / decellerating most of the time. Light and stiff wheels is the way to go. Get on the drops to go quicker on the flat.
For racing aero wheels are good.. But light aero wheels sub 1400grams... Help save energy and reduce 15% of drag if you already have an efficient position.
And they don't come in the sub 300quid price bracket.. Try sub 2k.
Mark (mboy) can you email me regarding the pikes
cheers D