Anybody know the time difference or watt difference between 5.6 & 7.8 for a 70.3?
Backstory…
So I have both the ENVE 5.6 & 7.8 wheelsets (disc brake), and am looking to sell one set but I can’t decide which.
I am done with full ironman distance, and will probably only do 1-2 70.3s per year going forward. The rest of my year will be mainly MTB racing & xterra with some local sprint/olympic traditional tris thrown in. I do the majority of my training on my road bike with big tires on the 5.6s (32c). I want to sell a set of the SESs to buy some ENVE M525 for my MTB.
I know from a purely performance perspective I should keep the 7.8s and use them everyday as they can do everything the 5.6s can, but it’ll just look silly rolling around with super deep wheels all the time. So I’d really rather keep the 5.6, but I’m just wondering if I did how much it would be costing me.
I don’t think it’ll cost you anything at all. Benefits of a slightly shallower front wheel: better handling of course, but you also zigzag less and need less core strength during cross winds. Which can easy make up for any slight aero loss. As zigzagging increases race distance and you can save that core stability to hold your run form better.
when I was rim brake only bike rider I had the same setup… I sold the 7.8s… riding around on 7.8s on my normal road bike was a bit much and I live in an area that can get a little windy at times. It made since then.
I know this is the right answer, but I’m an aero weenie at heart so knowing I’m giving up “free” speed is hard for me! But I’m trying to take this whole sport less seriously and more for fun so I just need to get over it.
ENVE here. Based on your dilemma, We can make the decision pretty simple for you. Sell the 7.8 and keep the 5.6. The 7.8 is the fastest open spoke wheel out there, but there are some tradeoffs. Namely weight and for some, cross wind stability (stability will vary for riders based on the bike they are riding, experience level, type of terrain and the wind it produces) but generally, people find the 7.8 to be the most stable “deep” wheel they’ve ever ridden.
As for the numbers, here are a few that engineering pulled together from our aero database.
Difference between 5.6 and 7.8 as a weighted average across yaw angles of 0-15 degrees is 2.4 watts or roughly 30 seconds over 56 miles, this is only calculating aero drag. This does not take into consideration watts lost if you’re less confident on the 7.8 and have to come out of your aero position (cross wind stability), or say you choose a less efficient tire, run tubes vs tubeless. In other words, there are ways to make up the 2-3 watt loss possibly.
Another note, I’d recommend at some future date considering the 4.5 AR or 3.4 AR if you’re really committed to high volume road tires. The SES AR wheels are aerodynamically optimized for a 28mm tire, but if you’re running 32mm the “ice cream cone” shape you’ll achieve w/ a 32mm tire on a 5.6 will be reduced making you more efficient. Also, the width of the AR rims will support the 32mm tires better allowing you to reduce your tire pressure (possibly) and improve cornering support and confidence. For what it is worth, nearly everyone at ENVE who isn’t doing TT or Triathlon is riding and racing AR wheelsets w/ 28mm tires.
Finally, stoked to hear you’re looking to spend more time in the dirt and the M525 is second to none as lightweight XC wheels are concerned. If I had one piece of advice to triathletes looking to have more fun on the bike, I’d say get a bike you can ride in the dirt.
Anybody know the time difference or watt difference between 5.6 & 7.8 for a 70.3?
Backstory…
So I have both the ENVE 5.6 & 7.8 wheelsets (disc brake), and am looking to sell one set but I can’t decide which.
I am done with full ironman distance, and will probably only do 1-2 70.3s per year going forward. The rest of my year will be mainly MTB racing & xterra with some local sprint/olympic traditional tris thrown in. I do the majority of my training on my road bike with big tires on the 5.6s (32c). I want to sell a set of the SESs to buy some ENVE M525 for my MTB.
I know from a purely performance perspective I should keep the 7.8s and use them everyday as they can do everything the 5.6s can, but it’ll just look silly rolling around with super deep wheels all the time. So I’d really rather keep the 5.6, but I’m just wondering if I did how much it would be costing me.
Thoughts?
HTFU. Seriously, why do you care about looking “silly”.
ENVE thinks discs are bad, so maybe take their advice with a pound of salt.
ENVE here. Based on your dilemma, We can make the decision pretty simple for you. Sell the 7.8 and keep the 5.6. The 7.8 is the fastest open spoke wheel out there, but there are some tradeoffs. Namely weight and for some, cross wind stability (stability will vary for riders based on the bike they are riding, experience level, type of terrain and the wind it produces) but generally, people find the 7.8 to be the most stable “deep” wheel they’ve ever ridden.
As for the numbers, here are a few that engineering pulled together from our aero database.
Difference between 5.6 and 7.8 as a weighted average across yaw angles of 0-15 degrees is 2.4 watts or roughly 30 seconds over 56 miles, this is only calculating aero drag. This does not take into consideration watts lost if you’re less confident on the 7.8 and have to come out of your aero position (cross wind stability), or say you choose a less efficient tire, run tubes vs tubeless. In other words, there are ways to make up the 2-3 watt loss possibly.
Another note, I’d recommend at some future date considering the 4.5 AR or 3.4 AR if you’re really committed to high volume road tires. The SES AR wheels are aerodynamically optimized for a 28mm tire, but if you’re running 32mm the “ice cream cone” shape you’ll achieve w/ a 32mm tire on a 5.6 will be reduced making you more efficient. Also, the width of the AR rims will support the 32mm tires better allowing you to reduce your tire pressure (possibly) and improve cornering support and confidence. For what it is worth, nearly everyone at ENVE who isn’t doing TT or Triathlon is riding and racing AR wheelsets w/ 28mm tires.
Finally, stoked to hear you’re looking to spend more time in the dirt and the M525 is second to none as lightweight XC wheels are concerned. If I had one piece of advice to triathletes looking to have more fun on the bike, I’d say get a bike you can ride in the dirt.
Let us know if you have any further questions.
Thanks for the info. I think I can live with giving up 30 seconds. Also gives me a #triexcuse if I need one 😂
Yes I’m aware of the ice cream cone effect of the 32s on the 5.6 but those are just on there during training for comfort. I’ll put some 25s on when I want to go fast.
I’m not Sean, but thanks for the input on this thread. Since we have you, do you mind if I ask if you have any plans for a 7.8 AR wheelset and disc wheel?