My review of the ENVE 7.8's... Nope

[carbonLORD]

Built up a Canyon Aeroad over the winter and set it up with my 4+ year old ENVE 6.7's.

Entertained the idea of getting into a newer set of ENVE hoops, not that there is anything wrong with the 6.7's, even though ENVE discontinued the 6.7 a while back in favor of the "More Aero" 7.8 with its new brake surface and tubeless capability.

The other option was the 4.5 as the 5.6 is disc only which seemed too shallow for the build.

I contacted ENVE and was told it's an 8 week back order. 13 weeks later I finally received the new 7.8's.

My size Large (58cm) Aeroad weighs 6.8Kg with 6.7's. With the 7.8's I was up to 7.3Kg. This is in part due to the brake blocks weighing twice as much, the skewers being slightly heavier and of course the rim's which are also the widest I've used. On the subject of overly wide rims, impossible to change a tube quickly. I can change a rear tube on a 6.7 in under a minute and a half from start to finish by hand. Took me nearly 5 minutes to pry the same tire on and off the new rim bed. I understand the idea of a more "stable" wheel by making it wider but I weigh 90Kg and have bike handling skill. This wheelset is wide and heavy, difficult to change flats on and...

...the new braking surface... horrible. I do not ride in wet weather which I imagine is the best new feature from this braking surface but the noise it makes while braking is worse than Mavic's Exalith braking which is pretty tough to beat. So forget the Wednesday night ride on these hoops. They are heavy so have fun either pulling the whole time or surging and if you do hit the brakes you'll manage to scare everyone off with the siren-like-noise they produce.

I took a chance on what should just be marketed as a TT wheelset but at least I still have my beloved 6.7's.



I'll just leave it alone...

[mrgray]

i realise it has been a year since this review was posted however this is a review of the clincher right? i did see something else about them talking about great stability and speed but very heavy and so not much fun for bunch stuff what with all the surging.

i am really interested in the tubulars right now which is what prompted my attention. i want deep wheels but i don't want stability issues.

[TobinHatesYou]

Deep wheels and crosswind instability go hand-in-hand. I get blown around in 20mph winds even on 40mm deep rims. I couldn’t imagine running my 5.6s in the wind that has been hanging around the Bay Area peaks these past two weeks.

[spdntrxi]

7.8 are more stable then for example 808s or even 404s .. op complains about the braking surface but not performance because the actually brake nicely. Yes the sound can be annoying and lessened (but not eliminated) by toein. My 2.2s are pretty quiet .. 4.5/7.8 not so much

I pretty much keep my 7.8 on the TT rig.. somewhat dorky looking on my roadie.

Yes it has been windy in the BA.. 2.2s getting all the riding time

[wingguy]

There are also different kinds of stability, no?

A deeper wheel like a 7.8 is always going to have more total side force, but a lower frequency of airflow breakaway/reattachment can make it feel less grabby or squirrely than a much lower profile wheel. There's an interview with Enve engineers where they say a set of 7.8s can potentially feel easier to handle in crosswinds even than a set of 3.4s, where the 7.8s need more input to stay straight, but a more consistent input, while the 3.4s would need smaller but more rapid corrections.

You can easily imagine that some riders would prefer on or the other based on riding style, gustiness of the wind or simply rider weight.

[johnrho]

...the new braking surface... horrible. I do not ride in wet weather which I imagine is the best new feature from this braking surface but the noise it makes while braking is worse than Mavic's Exalith braking which is pretty tough to beat. So forget the Wednesday night ride on these hoops. They are heavy so have fun either pulling the whole time or surging and if you do hit the brakes you'll manage to scare everyone off with the siren-like-noise they produce.

The brake shoes need to be set up with a little toe in to stop the noise.


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[wingguy]

Similar to the Mavic surface - it'll still whine, but there's no reason for it to screech.

[eforce123]

how long is the screech? or is it vibration?

[kode54]

i have noise regardless of toe in. on colder days like 35 degrees...it makes noise. warmer...same degree of toe in...not much noise. its a bit annoying...although i have moved back to the gray brake pads as suggested by Enve and they are much more tolerable. more brake wear, but noise reduction is at least 50%.

[spdntrxi]

mine seem to make noise as they get warmer (from use)... for example decending Mt Diablo... by the time I'm half way down my brakes are making noise, but not so much when I start out. My 2.2 tubs are the best.. then 2.2(c) , 7.8.(c) then 4.5(c) being loudest.

[alcatraz]

If you have issues with crosswinds then try not to put wider tires than 25c's on your wide rims. Ideally stay on 23's in front so that you give the crosswind an easier path around the outside.

I think it's worth trying.

By wide I mean 28mm wide rims. If you have some funky new 30+ rims your optimal might be 25c tires.

/a

[izza]

If you have issues with crosswinds then try not to put wider tires than 25c's on your wide rims. Ideally stay on 23's in front so that you give the crosswind an easier path around the outside.

I think it's worth trying.

By wide I mean 28mm wide rims. If you have some funky new 30+ rims your optimal might be 25c tires.

/a

It depends on shape of inner edge of rim.

To reduce crosswind issues, the goal is to have the profile of the rim/tyre combo as symmetrical as possible when viewed cross sectionally from above.


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[Beaver]

Both factors are important. If the tire is wider than the rim at the brake track, the airflow will already loose contact there. The higher the rim the worse the effect.


https://silca.cc/blogs/journal/part-5-t ... rodynamics

Sharp V-shape rims like Reynolds (or older Mavic) are more stable than round V-shapes like Enve and far more than torodial shapes like Zipp or Roval.

Tour mag. tested 12Nm side force for Zipp 808, 1Nm for Ksyrium Pro and Reynolds 58 Aero...

The new Bontrager XXX wheels got "sharper" because of this. The new Campagnolo WTO got rounder, so they will be more effected by crosswinds than before (and have better aerodynamics in higher yaw angles).

[otoman]

Beaver that is very interesting. So we might have hit a limit if wide tires and will now be reverting to a bit of a narrower tire on pointy rims.... hmmmm

[Hexsense]

Beaver that is very interesting. So we might have hit a limit if wide tires and will now be reverting to a bit of a narrower tire on pointy rims.... hmmmm

No, not that way.
It's just that tire size are limited by brake track width which needs to be wider than the tire. Most current rims with few exceptions keep brake track relatively too narrow to keep compatibility with rim brakes. With wider internal width making all tires run oversize, it then end up being most optimal to run 23c (which is now 27mm+ wide) on current rims, at least in the front.

The trend forward is to make brake track (or that same area on disc specific rim) wider to support wide tire.
Rim shape, however, depend on what you want. Toroidal U-shape have lower drag at high yaw angle (read: faster in strong crosswind), while modern rounded V shape is more stable in crosswind and weight less.