# Aero wheels - 40mm v/s 60mm



## yetidude (Dec 18, 2007)

I'm thinking about getting the Flashpoint clinchers. But need your help deciding how deep I should get them. I'll be doing my first ironman (AZ) and some TTs so I need all the help I can get. What size will be more beneficial, 40 or 60 mm? What about wind factor? I read somewhere that 40 front and 60 in the back will also be a good combination. If it matters I'm 5'8 and 155 lbs.

Also are Flashpoint a good everyday wheel?

Thanks in advance for all your help!


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## rruff (Feb 28, 2006)

Go with the 60s... front and back... the 40s are really 38mm and you can get good 30mm aluminum rims. The FP60 rims have the same profile as the 404s and weigh about the same. Zipp rims get great scores for aerodynamics. The experiences that people have with wind seem to be all over the place, but I don't recall anyone complaining about Zipp rims being hard to handle.

They should be good everyday wheels so long as you can afford to replace them if you hit a pothole or rock... or crash. If you are going to be racing though, I'd have a dedicated set of race wheels with the best tires and tubes... ride something cheaper and more durable for everyday.


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## cpark (Oct 13, 2004)

Reynolds SDV66 C gets my vote if your budget allows...
They are lighter and deeper although pricier..


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## yetidude (Dec 18, 2007)

Thanks for the help. Very good advise, I appreciate it. I've also heard mix things about the wind. Is there a lot of difference between the FP40 and a good aluminum 30mm rim? Like the Easton Tempest II for example. I mean for half the price.

The Reynolds look awesome, but out of my budget. Thank you.


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## team_sheepshead (Jan 17, 2003)

If you are going to doing solo events (multisport, TTs), go with the FP60s. The deeper the better if you are riding solo. I have a set and I love them. I would have preferred the FP40s for a good all-around wheel, but I got the FP60s on eBay last winter for less than $700, so it was an offer I could not pass up. I used them as an everyday wheel for most of the summer, and they have held up very, very well. I've been impressed. Crosswinds are not an issue for me unless I'm on a bridge, totally exposed to wind from both sides. Then I have to fight the bike a little bit.

If you believe Dave at Speed Dream, you need a rim at least 50mm deep to produce lift. http://www.speeddream.com/wind.php Difference between FP40 and a good alum 30mm rim? You are going to have to worry about scratches and gouges in the carbon FP40. The carbon rim is lighter, but not by much: Flash-Point claims it is 497 grams. http://www.flash-pointracing.com/technology/carbonrims The alum rim like a Velocity Deep V is going to weigh at least 520 grams.

Finally, the alum rim is going to be V shaped, while the FP is toroidal. If you believe the guys at Zipp and Hed, toroidal is going to be a little bit more aero.


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## cwg_at_opc (Oct 20, 2005)

you can build up a FP 80r/60f for ~1100 with ultegra hubs
at prowheelbuilder.com, same price as a 60/60. the weight
difference is significant, 2153gms with the 80 rear, and
around 1840gms for a 60/60, but on a flat tt/tri you'd be
able to achieve slightly higher top speeds with the deeper
rear.


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## rruff (Feb 28, 2006)

team_sheepshead said:


> If you believe Dave at Speed Dream, you need a rim at least 50mm deep to produce lift.


There is no step function. If the rim is deep enough to produce an airfoil shape, you will see some crosswind benefit... it is obvious on 25mm rims compared to 20mm rims. The deeper rims will show better performance particularly at higher yaw angles... but yaw angles are rarely greater than 15 degrees... 5-10 is normal.


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## yetidude (Dec 18, 2007)

Thanks a lot for the help. 
Now is it only 10 - 15 second reduction in an hour long event? Is this for the diference of semi and full aero? I've heard that aero speed gains were anywhere from half to one mile faster per hour compared with a regular wheel, right?


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## rruff (Feb 28, 2006)

That's 0.3 to 0.4%, and that isn't very much. Based on all of Tour's aero tests, I'd expect a wheelset with FP60s to be ~1-2% (~.25-.50 mph) faster compared to something like a Nio30... which would be ~1-2% faster than a shallow rimmed wheel with lots of round spokes. The greater the crosswinds the more benefit you get with deep rims.


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## yetidude (Dec 18, 2007)

Thank you so much your everyone's input. It is a lot clearer for me now. 60's


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## allenpg (Sep 13, 2006)

Go with a 60 rim for the best aero/handling benefit. Going with an 80 upfront and disc in back could really help on a calm day; however, the 60s are good even in 20-30 MPH winds. You could always get a custom wheelcover from wheelbuilder.com for under $100 if you wanted a disc for when there was less wind (or leave it off when it's really windy) That's what I used with my Zipp PT. Good luck at the race!

-Pete


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## yetidude (Dec 18, 2007)

I agree. From what I've read the 60's seems like the better choice.
Thank you.


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## scubad (Jun 22, 2004)

So, here's question. I got a set of Reynolds MV32's for Christmas. I also planning on buying a deeper set. The front will be used on my TT bike. I race a bit, ride quite a few long rides. 

What depth should my next set be. They will probably be Reynolds since our shop sponsor is very good to our team. 

Is it the DV46 or SDV66?

I live in a mountainous region and fear descending on the SDV's. There is one descent that I will not do when it is windy with my old 404's. I feel the 404's are the best depth, but they had the aluminum rim and I want all carbon wheels so I don't have to swap out pads all the time.

Thoughts?

ScubaD


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## rruff (Feb 28, 2006)

If you want the most aero wheel go deep...


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