Thoughts on going back to alloy from deep carbon rims

Zoomer37
Zoomer37 Posts: 725
edited June 2011 in Road buying advice
Rode 52mm Carbon Cosmics for a while now and love them and was just about to get a new set, however I've been checking out the 2011 Ksyrium SR's at my LBS and fallen for them.

Whilst the weight saving with the SR's would be nice on hills (especially as im not a small frame) im just wondering would I notice a possible drop in performance when riding/racing at the point where the deep sections aerodynamics really start coming into play?

Like to hear your opinions on this. Thinking maybe 'if its not broke don't try and fix it' ..

Comments

  • Bar Shaker
    Bar Shaker Posts: 2,313
    I suspect the SRs will be quicker up the hills (they are mega stiff) but slightly slower on long flats where you are riding at over 25mph.

    For a mixed route, you may even find the SRs to be quicker.
    Boardman Elite SLR 9.2S
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  • Bar Shaker
    Bar Shaker Posts: 2,313
    I suspect the SRs will be quicker up the hills (they are mega stiff) but slightly slower on long flats where you are riding at over 25mph.

    For a mixed terrain route, you may even find the SRs to be quicker.
    Boardman Elite SLR 9.2S
    Boardman FS Pro
  • turnerjohn
    turnerjohn Posts: 1,069
    kind of agree with Bar Shaker;
    I've Mavic R SYS (same as SR's but with carbon spokes on the rear as well) their super light and spin up like lightening and climbing, bu their not as fast as my Zipp 404s which are easier to keep up to speed with. Thing is as everyone here will say you need to be doing around 20 average to feel any "aero" effects so its really down to your riding style.
    If you do lots of hills your notice a little difference; my Zipps are far from heavy but about 200grms heavier then the RSYS.....its really down to your riding style ! Recon the SR's would be a better overal bet TBH
    Oh one point Ive noticed, the RSYS give a smooth comfortable ride where the Zipps are much stiffer vertically.
  • u05harrisb
    u05harrisb Posts: 531
    inless your averaging 27MPH+ on rides very often then i would give up on the deep carbon rims and just get the ally normal ones. youll be much faster on hills and will be faster overall if your tending to average sub 27mphish. id go for the SRs because i dont average 27mph+ and more often than not they are a compemise for normal riding anyway.
  • Zoomer37
    Zoomer37 Posts: 725
    I suppose its just a effort thing then really i.e. it will take more effort to hold the speed.

    Hmmmm.. tricky one.

    Those SR's would look the b*llocks on my new frame :)
  • northpole
    northpole Posts: 1,499
    I have the r-sys and fulcrum zero wheels. The r-sys are great for climbing and provide a more compliant ride quality, but my thoughts at the moment are that the zeros are the better all round wheel when you want to motor on a bit. Can't recommend them strongly enough (hopefully not just another passing fad!).

    Peter
  • fleshtuxedo
    fleshtuxedo Posts: 1,853
    u05harrisb wrote:
    inless your averaging 27MPH+ on rides very often then i would give up on the deep carbon rims and just get the ally normal ones. youll be much faster on hills and will be faster overall if your tending to average sub 27mphish. id go for the SRs because i dont average 27mph+ and more often than not they are a compemise for normal riding anyway.

    :lol:

    How many people on here, or indeed anywhere, do you think often average 27+ mph?
  • Paul RS
    Paul RS Posts: 107
    My thoughts exactly, maybe he means kph...
  • on-yer-bike
    on-yer-bike Posts: 2,974
    ^^^
    I wish! I'd be turning pro tomorrow.
    Pegoretti
    Colnago
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  • amaferanga
    amaferanga Posts: 6,789
    u05harrisb wrote:
    inless your averaging 27MPH+ on rides very often then i would give up on the deep carbon rims and just get the ally normal ones. youll be much faster on hills and will be faster overall if your tending to average sub 27mphish. id go for the SRs because i dont average 27mph+ and more often than not they are a compemise for normal riding anyway.

    So by your reckoning, a TT'er doing 23min 10's would be wasting their time using deep section rims?
    More problems but still living....
  • danowat
    danowat Posts: 2,877
    u05harrisb wrote:
    inless your averaging 27MPH+ on rides very often then i would give up on the deep carbon rims and just get the ally normal ones. youll be much faster on hills and will be faster overall if your tending to average sub 27mphish. id go for the SRs because i dont average 27mph+ and more often than not they are a compemise for normal riding anyway.

    Another indication that people quoting avg speeds are have no idea what they are talking about, a 27mph avg is a low 22 for a 10 mile TT, which is pretty damn quick.

    People doing that sort of speeds are generally running full aero kit, including deep rims and disc wheels :roll:
  • RowCycle
    RowCycle Posts: 367
    You can go a lot quicker if you increase the wheel size setting on your computer...
  • Bar Shaker
    Bar Shaker Posts: 2,313
    I knew exactly what I was saying. Most people can hold 25mph on the flat. DS wheels will let you hold more or make 25 feel easier.

    Averaging 25mph on a ride is a whole different kettle of fish.
    Boardman Elite SLR 9.2S
    Boardman FS Pro