tooth

...Well yes, if you're time trialling...

However for a rider of modest ability (say a typical avg speed of 19 mph on a flat to gently rolling route) who doesn't ride competitively, would replacing a set of relatively light box section wheels with heavier (by about 190 g.) semi-aero wheels (30mm rims) provide a significant/noticeable benefit?

I've got an opportunity to pick up a set of Campy Sciroccos fairly cheap, but don't know if it will be a worthwhile investment.

Kev

I can notice the difference, basicaly the weight is rotational weight so it is more noticible to be honest. But the wheels are more aero so that makes up for the slight weight difference. You will feel crosswindws more also, but really is not bad unless you get extremely aero wheels like the Zip wheels.

Any chance you could take them for a test ride before buying them? What weels do you have now?

tooth

I might be able to to test ride the Sciroccos, Kev. Never hurts to ask anyway. Right now I've got a set of Protons that came with my bike when I bought it.

Jay H

Not all Zipp wheels are deep dish, only the 404s are but the 303s are a good compromise between weight and aero.

Probably around 15/16mph do you get an advantage of the aero wheels but they are also more fidgety in the winds, which is why in the Vuelta you see people with aero rear wheels with a straight box front.

Jay

AndrewP

If you are overweight like me the aero rims will give you the benefit of extra stiffness and will survive potholes better

karesz3

I don't think you will notice any difference unless you really start hammering around 27-31 Mph. Then, you can hold that speed longer with more efficient pedaling action. If you ride mainly recreationally on rolling hills, keep the lighter wheels you have now. However, if you want the light weight and additional aero benefits as you get stronger, look no further than the American Classic CR 420 wheelset. Those things are lighter and stronger than Ksyrium SLs and provide some great aero advantage.

Cheers

Ajay213

Aero anything starts to benefit you at around 15mph (it's an exponential scale), if you are riding at an average of around 19mph you should see a nice improvement. It's hard to say exactly what you would save (without knowing exactly how aero the wheels are), but you should pick up an additional 1mph without to much of a problem, maybe even closer to 2mph. Over a 40k TT at your speed (rough wattage) you should save around 1:40-2 minutes.

Weight? Well you will pick up .4 lbs of additional weight. Not a huge amount, but it is still rotational. You will still be faster even with the additional weight, unless you are climbing some big stuff.

Andrew

shokhead

It sounds like nobody really knows but for they are stronger.Bottom like,they look really cool so you need to have them.

BikeInMN

I don't think you'll notice any difference with a 30mm rim. That just isn't deep enough for any real aero benefit. From what I recall, 38mm is where the rim depth will start to make a difference but even that depends on the shape/profile of the rim.

They will most likely be stiffer but not any faster. If they hold speed better, it would be from the additional weight at the rim compared to what you have now and not due to an aero advantage.