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50mm wheels vs 90mm wheels
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Whats the time savings advantage of a 24mm wide 90mm wheel (flo) over a 23mm wide 50mm wheel (superteam) over the course of an ironman?

Really just a front as the rear will have a disc cover anyway

Yellowfin Endurance Coaching and Bike Fits
USAT Level 1, USAC Level 3
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Re: 50mm wheels vs 90mm wheels [surfNJmatt] [ In reply to ]
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Front or back wheel? Elevation profile of the course? Type of spokes and hub?

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Re: 50mm wheels vs 90mm wheels [surfNJmatt] [ In reply to ]
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I would look no further than FLO's performance table. There are so many variables, and they did this modeling taking multiple factors into account. Based on their work, a 90mm is just 7 sec. faster than a 60mm. A 50mm is not going to be hugely different than a 60.

Based on this, I decided to buy a 60/90 FLO wheelset. However, after riding a year, and liking the looks of the 90 up front, I regretted it. I now ride on a 90mm/Disc.


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Re: 50mm wheels vs 90mm wheels [exxxviii] [ In reply to ]
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Try going down hill with a front 90 at high speed in cross winds. LOL
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Re: 50mm wheels vs 90mm wheels [rhudson] [ In reply to ]
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100 x better than a HED 3...the only wheel that I have ever been airborne on...contrary to a full front disc or conventional deep wheel with zero negligible effect.
FYI...the speed was in excess of 90kmh when it happened.
Last edited by: Bernoullitrial: Mar 21, 18 20:09
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Re: 50mm wheels vs 90mm wheels [exxxviii] [ In reply to ]
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I think the Flo data neglects watts to spin. A taller rim has a shorter spoke and the speed of the spoke at the top of the wheel is lower. Aerocoach has some recent data that probably puts the difference in the 4-5 watts range at zero yaw and Swiss Side did some watts-to-spin tresting as well (an extra watt for exposed spoke nipples).

A watt is worth about 3-4 seconds in a 40k/25 mile TT, so 12-20 seconds going from a 50 to 90. Multiply by 4-4.5 for an IM ballpark estimate. Let's call it a minute. It isn't a lot, but it isn't 7 seconds either.
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Re: 50mm wheels vs 90mm wheels [grumpier.mike] [ In reply to ]
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grumpier.mike wrote:
I think the Flo data neglects watts to spin. A taller rim has a shorter spoke and the speed of the spoke at the top of the wheel is lower. Aerocoach has some recent data that probably puts the difference in the 4-5 watts range at zero yaw and Swiss Side did some watts-to-spin tresting as well (an extra watt for exposed spoke nipples).

A watt is worth about 3-4 seconds in a 40k/25 mile TT, so 12-20 seconds going from a 50 to 90. Multiply by 4-4.5 for an IM ballpark estimate. Let's call it a minute. It isn't a lot, but it isn't 7 seconds either.


That should be it.
Unless the Threadowner is planning for Lanzarote (It will not be Kona because he plans a disk behind), I would advise a 90 in front.

And always train with it. One or the other day you will get some wind blasts from the side and you get used to the feeling.
Last edited by: longtrousers: Mar 22, 18 0:11
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Re: 50mm wheels vs 90mm wheels [longtrousers] [ In reply to ]
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longtrousers wrote:
grumpier.mike wrote:
I think the Flo data neglects watts to spin. A taller rim has a shorter spoke and the speed of the spoke at the top of the wheel is lower. Aerocoach has some recent data that probably puts the difference in the 4-5 watts range at zero yaw and Swiss Side did some watts-to-spin tresting as well (an extra watt for exposed spoke nipples).

A watt is worth about 3-4 seconds in a 40k/25 mile TT, so 12-20 seconds going from a 50 to 90. Multiply by 4-4.5 for an IM ballpark estimate. Let's call it a minute. It isn't a lot, but it isn't 7 seconds either.


That should be it.
Unless the Threadowner is planning for Lanzarote (It will not be Kona because he plans a disk behind), I would advise a 90 in front.

And always train with it. One or the other day you will get some wind blasts from the side and you get used to the feeling.
I don't train on my race wheels and nor do I want to be dealing with strong winds on windy training days. I like to enjoy my training in a more relaxed manor. Maybe if you lack skills train constantly on deep training wheels if you want to gain a minute???
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