shallow profile rims stiffer / less stiff

[Allen254]

I remember an old GCN video where they were comparing aero bikes and light weight ones, and Dan said something along the lines of:
"These aero wheels, when you look at them you think 'wow they look mega stiff' but when you actually get out the saddle, they're quite flexy. I'm even getting a bit of brake rub"
Can anyone explain this? I think they were zipp wheels and Boardman frames. I'll try to find the video tomorrow.

ive ridden my firends old zipp 303's and they were very flexy.

[Kurets]

I remember an old GCN video where they were comparing aero bikes and light weight ones, and Dan said something along the lines of:
"These aero wheels, when you look at them you think 'wow they look mega stiff' but when you actually get out the saddle, they're quite flexy. I'm even getting a bit of brake rub"
Can anyone explain this? I think they were zipp wheels and Boardman frames. I'll try to find the video tomorrow.

It's quite simple really. The question of lateral wheel stiffness has two sides, either the rim will bend or the rim will "pivot" around the hub. If the rim is soft compared to the spokes, the wheel will bend when exposed to large lateral force which will not cause break rub (as the wheel bends where it contacts the road). If the rim is stiffer than the spokes, the rim will pivot around the hub causing it to deflect both where it contact the road, and in the brake caliper.

This will make it seem like a deep rim profile is softer than what it actually is, as the problem is really down to too weak spokes for the chosen rim. While it would be assumed that a stiff carbon rim requires less spokes for stiffness, thats not the case outside of radial stiffness concerns. Both lateral and torsional stiffness are both primarily spoke driven still.

[grahus]

ive ridden my firends old zipp 303's and they were very flexy.

I am always curious when I read comments like this...

Was your friend happy/oblivious that his wheels were flexy?
Did he equate flex with comfort, therefore it suited him?
If you had bought these expensive wheels, would you be happy they felt so flexy?

I ask this, as a self-confessed cheapskate-weightweenie, the idea of spending > £2000 on a set of wheels only to be disappointed in them seems crazy!

And that leads on to my next questions. I read on here that some Zipp hubs have a poor reputation, yet they are laced to high end wheelsets, so what is the attraction to Zipp? Are they worlds above the 'next best' option?
Do people just like owing them for the name?
Are they really worth the cost? (it's ok, I know the answer to that..., and the answer is, it depends.)

I just like to hear other opinions about why 'we' spend so much on products we still complain about.

[Allen254]

ive ridden my firends old zipp 303's and they were very flexy.

I am always curious when I read comments like this...

Was your friend happy/oblivious that his wheels were flexy?
Did he equate flex with comfort, therefore it suited him?
If you had bought these expensive wheels, would you be happy they felt so flexy?

I ask this, as a self-confessed cheapskate-weightweenie, the idea of spending > £2000 on a set of wheels only to be disappointed in them seems crazy!

And that leads on to my next questions. I read on here that some Zipp hubs have a poor reputation, yet they are laced to high end wheelsets, so what is the attraction to Zipp? Are they worlds above the 'next best' option?
Do people just like owing them for the name?
Are they really worth the cost? (it's ok, I know the answer to that..., and the answer is, it depends.)

I just like to hear other opinions about why 'we' spend so much on products we still complain about.

iagree with you on somethings but zipps arent really known for stiffness rather they are known more aero, now how much more aero they are in real life compared to other cheaper alternatives IDK, and for the price shouldnt they also be stiff? yes. After that he sold the zipps, i dont think he liked them very much> He then bought some Fulcrum speed 40 tubulars, let me tell you something about the fulcrums speed 40's, they are stiff light weight and smooth to point were im purchasing a pair next week. Fulcrum speed 40s are were its at, as well as the bora ultras which ive ridden as well very stiff and light wheels.