General Discussion Triathlon Talk » Wheels, help me understand this please Rss Feed  
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2010-07-08 4:55 PM

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Subject: Wheels, help me understand this please
Ok, the Bontrager SSR wheels on my road bike are a little over 3000 in weight.  I can get a set a Bontrager Race Lite alloy for a little over $400 and they are about 1700 in weight. I wanted carbon fiber and a set of Reynolds Assault wheels, but are $1400 and weigh around 1500. So what makes a wheel that is only 200g lighter be $1000 better? I am confused, and info will help. Thanks.


2010-07-08 6:02 PM
in reply to: #2969369

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Subject: RE: Wheels, help me understand this please
Weight savings will help you go faster, particularly on climbs and quick accelerations, but the big difference between the boontrager race lite wheels and the reynolds wheels you're talking about is aerodynamics.  The reynolds wheels are much deeper which will make you faster because you'll slip through the wind a bit easier, not so much because of the reduction in weight.

Are you looking at these wheels for everyday use or for race day only?

Also, you're planning on using them for tris I'm assuming?
2010-07-08 6:10 PM
in reply to: #2969369

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Subject: RE: Wheels, help me understand this please
also foggy on wheels...what is deeper?  i see measurements in ads from 30-70+mm.  What do these measurments refer to?  when you by tires and tubes for "deep clinchers" are they different?  what are disadvantages of going too "deep"?  (besides price goes up with depth).  what about lifespan of the wheels...is that related?  if deeper is always better, why make shallow rims at all? 
2010-07-08 6:26 PM
in reply to: #2969369

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Subject: RE: Wheels, help me understand this please
They are round in generally are beneath the bike. If they are above the bike, you are in the middle of a crash.
2010-07-08 6:34 PM
in reply to: #2969493

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Subject: RE: Wheels, help me understand this please
brycoy - 2010-07-08 4:10 PM also foggy on wheels...what is deeper?  i see measurements in ads from 30-70+mm.  What do these measurments refer to?  when you by tires and tubes for "deep clinchers" are they different?  what are disadvantages of going too "deep"?  (besides price goes up with depth).  what about lifespan of the wheels...is that related?  if deeper is always better, why make shallow rims at all? 


what is deeper?


"Deep"  refers to the material in the wheel between where the tire ends and the center of the wheel.  The deepest wheel you can buy is called a disc, which is one solid piece of material with no spokes at all.

when you by tires and tubes for "deep clinchers" are they different?


Generally, no the tires and the tubes would be the same, there is a different kind of wheel called a tubular that has a different system of tubes and tires though, many of your most expensive wheels are tubulars.

what are disadvantages of going too "deep"?


As you stated, price is a concern, Deeper wheels also tend to be a bit heavier which isn't an issue for most triathlons, but lighter wheels are better for steep long climbs, and quick sprint efforts.  Lastly, really deep rims have a sail effect while riding, so if you're riding in conditions with stiff crosswinds you do risk getting blown off the bike.  For this reason, some races like the Ironman word championships in Kona, HI don't allow disc wheels because the course is so windy.

In general, the advantages of deep section wheels outweigh the disadvantages, so most triathletes who can afford them ride a very deep front wheel, and a disc wheel in the back if they're able.

what about lifespan of the wheels...is that related?  if deeper is always better, why make shallow rims at all?


Deeper all carbon wheels aren't nearly as durable as regular aluminum box rims.  The carbon wheels are also more difficult to repair if they get knocked out of whack.  Because of this, most people train on regular wheels and use the expensive carbon ones only on race day.  There are other reasons someone might choose shallow rims where triathlon isn't really concerned, but I don't want to further muddy the water.

And, because a picture can be worth 1000 words:  Deep rims, vs shallow ones:











(boxrims.jpg)



(corvos_fabian-cancellara.jpg)



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2010-07-08 8:04 PM
in reply to: #2969527

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Subject: RE: Wheels, help me understand this please
thanks, sorry i had so many questions...i appreciate your patience with me, lol  one more question?  let's say I had $1500 or so too blow on wheels, (i don't yet).  all things being the same, what kind of speed/time gains can you expect? a full mph? more/less?  i have been focusing on sprints, but next summer i'm stepping up to OLYs Baby! 
off topic, I just put a down payment at my LBS on a JAMIS Trilogy....i'm so excited, i've been riding a gmc denali (walmart) it weighs like 40 pounds, lol


2010-07-09 12:26 AM
in reply to: #2969651

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Subject: RE: Wheels, help me understand this please
You might want to talk to a shop about renting a set of race wheels for your event.  That'll let you answer a lot of these questions for yourself without dropping a lot of money.  Also many shops that rent out race wheels will credit the rental price towards your purchase if you decide to buy them.  Ask around.
2010-07-09 4:08 AM
in reply to: #2969651


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Subject: RE: Wheels, help me understand this please

I cut and pasted this from race day wheels, who I'm pretty sure got it from zipp.

404 front + 404 rear =    58-60 seconds/hour, i.e. savings of almost a minute
404 front + 808 rear =    68 seconds/hour
808 front + 808 rear =    80 seconds/hour
808 front + rear 900 disc =  92 seconds/hour
808 front + sub9 rear =     120 seconds/hour
808 front + 1080 rear =     128 seconds/hour
1080 front + 1080 rear =   144 seconds/hour

The most economical combo is to get a disc cover for your rear and get something in the 60mm range off Ebay.  For $1500, you could get Hed Jet 60's, or Sram S80's.

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