Australian Cycling Forums - Bicycles Network Australia

hello
this may seem like a really noob question but just wondering how much difference 6mm is on the rim? you get 24mm rims that don't have the word "aero" associated with them but 30mm rims do. just wondering how much difference half a centimeter could make (besides weight)

| | About that much.

Not a lot. 24mm going to 50mm would be more significant, but even that % difference is in single digit.

norbs wrote:| | About that much.

wow, i didn't know you peolpe knew so much about these things thanks for your help

ERD of 30mm rims makes finding replacements bothersome, I'd stick with 24mm so that you'll have a good range of readily available rims to choose from when replacement time comes around.

usernameforme wrote:hello
this may seem like a really noob question but just wondering how much difference 6mm is on the rim? you get 24mm rims that don't have the word "aero" associated with them but 30mm rims do. just wondering how much difference half a centimeter could make (besides weight)

Yep, noob question.

Reality is despite the marketing fluff, to all but racing types, difference is sweet fanny adams.

sogood wrote:Not a lot. 24mm going to 50mm would be more significant, but even that % difference is in single digit.

umm, not really percentage difference is 70% (percentage change is 108%)

tallywhacker wrote:

sogood wrote:Not a lot. 24mm going to 50mm would be more significant, but even that % difference is in single digit.

umm, not really percentage difference is 70% (percentage change is 108%)

Sorry, I should have been more specific in my reply. Given the context of aeroness, the percentage difference referred to power saving as a result of aerodynamic characteristic of the wheelset.

so i wouldn't notice the "aero" difference in a 30mm rim compared a 24mm rim? i take it that it is better to get a lighter rim then a aero rim

usernameforme wrote:so i wouldn't notice the "aero" difference in a 30mm rim compared a 24mm rim? i take it that it is better to get a lighter rim then a aero rim

Well, there are many variables to aero characteristics and power efficiency of a wheelset, not one that a lay person can figure out just by a quick look. Also bear in mind that aero performance is not an all or none phenomenon, it doesn't suddenly performs better by hitting 50mm, but it's a continuum of performance changes. Further, aero performance isn't just about rim depth. Spokes and hub also play a part. In any case, the general understanding is that aero will always trump weight. But even that depends on how much more weight. The statement stays true though for wheels in the same class.

The other aspect to consider is the quality of bearings and rigidity. They also play a role in power efficiency. Selection criteria shouldn't be based on a single criteria.

I have just built a set of 30mm wheels (plenty of these rims around) and have been happy with them. I have been riding 24mm so far and have noticed a somewhat stiffer ride. The wheel is a little heavier, but I ride mostly on flats. It does look more aero, but haven't ridden it long enough to jugde if it rides more "aero" too.

igstar wrote:I have just built a set of 30mm wheels (plenty of these rims around) and have been happy with them. I have been riding 24mm so far and have noticed a somewhat stiffer ride.

Theoretically, deeper rims will give a harsher ride as they should be more rigid in the vertical plane. Lateral stiffness depends on rim, lacing, build and other factors.

norbs wrote:| | About that much.

You are an optimist norbs.
It is actually a little less than that. (Or did you apply the Coffee Shop Admiration Factor? That could boost the result significantly)

usernameforme wrote:so i wouldn't notice the "aero" difference in a 30mm rim compared a 24mm rim? i take it that it is better to get a lighter rim then a aero rim

Aero trumps weight.

jacks1071 wrote:

usernameforme wrote:so i wouldn't notice the "aero" difference in a 30mm rim compared a 24mm rim? i take it that it is better to get a lighter rim then a aero rim

Aero trumps weight.

Better engine trumps aero?

Pose value at the cafe trumps all!

sogood wrote:

igstar wrote:I have just built a set of 30mm wheels (plenty of these rims around) and have been happy with them. I have been riding 24mm so far and have noticed a somewhat stiffer ride.

Theoretically, deeper rims will give a harsher ride as they should be more rigid in the vertical plane. Lateral stiffness depends on rim, lacing, build and other factors.

Never noticed much difference between standard wheels, 50mm and 65mm which I have now in terms of the rigidity.

But I did notice a difference in the speed (running above 50km/h) with the 65mm versus the 50mm which surprised me. The 65mm seems quite a bit quicker. Or maybe it was the fact that the engine wasn't misfiring on that day.

The better thing is the hubs - the new wheels have very good hubs on them. The weight difference between the two is marginal, to the point of not being worth mentioning as it is so small.

usernameforme wrote:hello
this may seem like a really noob question but just wondering how much difference 6mm is on the rim? you get 24mm rims that don't have the word "aero" associated with them but 30mm rims do. just wondering how much difference half a centimeter could make (besides weight)

Probably very little. Upgrade the engine instead.

human909 wrote:Pose value at the cafe trumps all!

Very true! And to go with aero wheels, the super slippery skin-suit to give the ladies something to admire (or perhaps cover their eyes in horror).

bugger aero wheels.....get serious aerodynamics...

Get a Velomobile!!!!

..... now THERE'S your aero difference.... LOL

+1


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