Epic REACT Mods and Carbon Fiber experiments

[Four by Six]

I'm gonna take a road trip this weekend and try to find some cheap ER2s on sale.

I went to the Nike clearance store at lunch today and did not have any luck finding cheap ERs or Rise's. So, I won't be able to do any crazy shoe destroying experiments until I find a new supply of cheap ERs. I'll keep doing my nondestructive testing though. I might even risk a small hole in my IDs, as I really like the feel of the crazy hole.

 

[Four by Six]

Very informative as well.

Here's some great info from "Cookie" at Nike, a 26 year veteran who engineered Nike Vaporfly NEXT.

He says they added more ZoomX to 4% because the lab guys said if you want to store more energy, you need more foam, as the foam is what is storing the energy. But they were limited in how much they could add due to wanting to keep the shoe stable.

Also, while the shoe stores and returns 4.4% energy, the foot and achilles tendon complex of a human body is capable of storing and returning 50% of the energy. He says there is a tradeoff, as a lower (zero) offset shoe maximizes the 50% body energy return, but causes fatigue and injury, while the higher offset (10mm) Nike uses lowers the 50% body return but minimizes achilles fatigue.

I jump directly to the relevant part in video below:

 

[Four by Six]

I just picked these up to use as lightweight hiking/trail shoes.

I'm finally going to get to use these Rise for what I bought them for - lightweight hiking/trail shoes. I am headed to the Rockies for hiking and backpacking. I did make one modification to them. I took the "floaty" carbon fiber plates I made for use in my Rise shoes and added a layer of dense woven Kevlar on the bottom as a rock guard. The CF plate evenly distributes pointy loads across the bottom of my foot while the Kevlar layer makes sure nothing breaks through the bottom. I could stand on the sharp end of a nail now and be OK. I am a bit concerned about traction, given my last hiking experience with my triple black Rise, but the React foam should grab the jagged edges of the loose rocky trails OK.

 

[Four by Six]

So far so good... Enjoying the Rise as a lightweight hiking shoe. The React foam out/midsole is super soft over jagged rocks. The flared heel works great going downhill as it contacts the ground first and eases the transition into a braking foot motion.

 

[Four by Six]

Still luv'in the Rise as a trail shoe... Wore them today as watershoes for a rafting trip.

The water got too shallow and had to get out and drag the raft. All I did was remove my socks and the insoles, and submerged my feet. Hung them to dry from my bear line and they were dry by sundown.

 

[Four by Six]

Used Rise’s as boat shoes today for tubing on ice cold alpine lake... Brrr!

 

[Four by Six]

Last big hike of trip... 3000ft vertical climb along river, through Grizzly bear country, to Alpine lake. Rises’ did great today.

 

[Four by Six]

Glad to be back in my soft, comfy turbos, running on flat paved running paths... A week of vertical hikes on crumbly rock trails takes its toll on ankle/calves.

 

[Four by Six]

Today was VaporFly day in my shoe rotation. I keep VFs in my rotation so I can have enough data to compare to my modified ERs. VFs are the gold standard in running efficiency. While I prefer laceless ERs with my custom CF plates, I can't deny that the ZoomX (PEBAX) in the VF is vastly superior to the REACT (synthetic rubber) in the ER. I really wish Nike would make a "Turbo" version of the Epic Reacts with some ZoomX in the midsole.

 

[Four by Six]

Headed on global business trip with only Triple Black IDs with glued in CF plates. They will do triple duty as business, leisure, and running shoes.

 

[Four by Six]

So how did the Rise do as a lightweight hiking shoe? They did everything so well that I thought it would be easier to talk about two situations they did not do well in, rather than everything they did great.

First is what I call heel stability. No, this is not over/underpronation control. I'm talking about how much the lower calf has to work to keep the ankle aligned on uneven surfaces. The long distance from the ankle to the bottom of shoe, combined with the soft foam midsole made my ankles work very hard when on rounded or sharply shaped rocks. It was not a problem on most trail surfaces, just when I got to sections with irregular rocks.

The second issue was the shoe was not stiff enough for the toe area to hold the entire weight of the body when only the toe area could contact the trail on steep climbs. I used my most flexible carbon fiber plates in the shoe, which made them more comfortable, but in retrospect I should have used my most stiff plate, or maybe even made a special completely rigid plate. This was only an issue on the extremely steep hills with only small gaps in rock to wedge the toes into for traction.

This is not a dig or complaint against the Rise, as all athletic shoes used for hiking will have these two issues. It is more of a rigid heavy hiking boot vs flexible lightweight boot issue. Only a very stiff, rigid, high rise boot will not have these two issues, and then, well, you are stuck with a hot, heavy, uncomfortable boot that traps foot heat and sweat.

In summary, the Rise is the best lightweight trail shoe I've ever used (especially with my carbon fiber plate added), but it will not replace dedicated stiff mountain boots for more extreme climbs.

 

[Four by Six]

My triple black laceless ERs doing duty in central China. My most versatile shoes. Love the reflective black swoosh.

 

[Four by Six]

Not sure if I ever mentioned it, but the laceless ERs with CF plate make a pretty good skateboarding shoe. I tried the ERs without a plate, and they were OK for boarding, but a little too flexible and unstable. With the CF plate added, they provide a very stable platform for everything but extreme tricks (which I can't do anyway). The REACT foam really isolates the board vibrations from the foot.

Here is a pic from today, longboarding on cobblestone in Sweden. The cobbles are tough to board on, and the ER midsole really soak up the bumps.

 

[Four by Six]

Jamie recently did a video comparing carbon fiber plate shoes. Like I said before, they may all have a CF plate, but only Nike improves running efficiency. The foam stores the energy and the plate returns that energy to the running stride. Only the Nike VF does that (and my modified ERs).

 

[Four by Six]

For those who PM'd me, yeah I'm still here. I'm back from my month abroad. I planned on several more shoe experiments this week/weekend, but my supplies got lost in shipping. I did get a full refund from shipper, but it bummed me out a bit and I haven't reordered yet. So, I've just been enjoying my Nike shoes, both with and without mods.

After a month in just my triple black laceless Epics, it felt good to get back into my shoe rotation. I've now run 3 times in Turbos, 2 times in VFs, and twice in ERs with hole in sole.

Yesterday, I spent the whole day in my blue laceless ERs and was amazed at their versatility. I began the morning with a 8 mile run. I usually do a half marathon on Sat mornings but I'm a bit out of shape after all my recent travel.

I then took my socks off and used them as summer shoes and drove to a nearby beach.

I then took my insoles out and used them as sand/beach shoes.

I then put the insoles back in and used them to hike the nearby waterfront trails.

I don't know of any other shoe that can be used for such a wide variety of uses on the same day.

 

[Four by Six]

Today I used my black ERs with the hole in the sole and stiff carbon fiber plate insert to climb a nearby trail. It is a 5K long, 2000ft climb on uneven packed dirt. The ERs were perfect for the conditions. I realize Nike has lots of trail shoes, and some with REACT in them, but I still prefer ERs for trails.

 

[Four by Six]

Awesome video on Stoll, the company that makes the upper knitting machines for shoe companies, on how one piece flyknit uppers are made:

 

[Four by Six]

I've been very happy with my "hole in sole" modification to my Epic REACT shoes. The foam no longer feels like it is bunching up under my foot during transition to toe off. Also, it feels like throughout the entire foot transition, there is more of the outsole contacting at all times. And the most recent wear pattern agrees.

If I look at the wear pattern, even after so few miles added to the shoes, it clearly shows more even wear across the entire forefoot.

Before the hole was added, the wear appeared at strike pad and rolloff locations on edges of outsole. Now it seems more uniformly distributed. Here is another light angle... it is hard to capture in a picture:

I do not have that many new running miles on the shoes and yet they are showing a lot of additional wear. The hole mod has caused the shoe to wear much faster. However, I look at that as a good thing, as it shows much more of the REACT foam is now making contact with the ground, grabbing, gripping, and actually doing something. I would estimate the wear as more than twice as fast, but the shoe should still be good for 300 miles.

 

[Four by Six]

Of course if one hole is good, two must be better, right?

If I look at the bottom of the outsole, there is another area where Nike put deeper grooves in the foam to let it flex. Again, it roughly forms a diamond shape.

Again, Nike has put a hole in the felt near this location.

However, in this case, the hole and the deeper grooves do not align. In the pic below, the bronze metal pin is located inline with the hole in the felt. Note the hole and desired cutout do not align.

I had a choice of either centering a relief cut on the hole or the center of deep grooves. I decided to try the later.

Note the offset hole location in the inner heel area of shoe. I would be worried about this bothering my foot during heel strike, but remember I have a carbon fiber plate in these shoes, and yes it fully covers the heel too.

Here is a pic of the resulting REACT foam cores. Note the foam is much thicker in the heel location.

I will try these out during tomorrow's morning run. I'm a bit skeptical this will result in any improvement, but I couldn't resist at least trying the mod out.

 

[Four by Six]

I didn't expect to be able to feel any difference in the shoes with the added heel hole, as the heel is large and thick and the hole is relatively small, but I was wrong. I tried with no insole, with insole, and with insole and CF plate and in all 3 cases I could feel a difference. The heel feels more flexible and cushioned. I was surprised I could feel the hole against my heel even through my stiffest CF plate.

I ran 4 miles this morning in them. I didn't like the feeling of the hole on my heel at first but I got used to it. By the end of the run I liked the more flexible heel feeling.

My conclusion thus far is I will not put a heel hole in any other of my ERs, but I also will not throw these away. I'll keep these in my running rotation for now and see how the heel wears out with time.

 

[Four by Six]

Today I ran in just plain ole' laceless ERs. No CF plate, no holes. It felt like running in Free's as the laceless ER is so flexible without a plate. Very comfortable. But once I crossed the 10K mark I could feel the muscles in my feet fatiguing, especially my arch. Without the extra support and structure of the CF plate, my arch muscles gave out at mile 10 and I could not complete my intended half marathon distance.

And now that I am used to the hole in ERs, the feeling of the foam bunching up mid foot bugged me the whole run. I'm definitely going to add the forefoot hole to all my ERs now, though I'll probably try a smaller hole than I used on my TB ERs.

 

[Four by Six]

Did a climbing trail hike again this afternoon. I chose my Triple Black ERs with the two holes and stiff carbon fiber plate. They did amazing. The perfect shoe for the job.

The trail was very steep with sections of dust, sand, pebbles, rocks, loose big rocks. The ERs had plenty of traction. Whenever the trail was too steep for the REACT portion of the sole, then it was also steep enough that the front/back rubber outsole was in contact with the ground (uphill/downhill).

A very difficult challenge for the shoes, and other than being trashed with dust, they held up great. The only anomaly was halfway down the trail I developed a hot spot on the inside and outside of my big toe on both feet. For now, I am blaming this on my socks, as they got sweaty and started to grab my skin. I'll try different socks next time and see if the hotspot returns.

 

[Four by Six]

And now that I am used to the hole in ERs, the feeling of the foam bunching up mid foot bugged me the whole run. I'm definitely going to add the forefoot hole to all my ERs now, though I'll probably try a smaller hole than I used on my TB ERs.

I don't have many miles on my laceless blue IDs, but you can already see the bottom of the REACT foam is wearing first where I feel it bunch up under my foot - hence the reason for my experimenting with a relief cut.

Since I typically wear my blue pair for more casual use, with no plate or my most flexible CF plate, I wanted to use a smaller hole than my last pair. My last pair was 1", so after some thought, I decided to try a 0.75" hole.

Here are the resulting cores:

I think this might be the perfect size forefoot hole. Thus far it feels great. Much better than no hole and very comfy. I do not feel the hole under my foot even though I am currently wearing no CF plate with them.

It makes me a bit nervous to be wearing these with no protection from sharp objects though. I will probably glue a piece of kevlar mesh over the hole for safety purposes, like I did with my black pair.

However, since I wear these on the beach in sand without insoles, I need to find something with a finer weave that will stop sand. I also need to find something that will be comfortable with bare feet against it. Still thinking about what would work best over the hole.

 

[Four by Six]

Ran my 5K loop this morning in my newly holed blue IDs on pavement. No CF plate, just laceless ER with the 0.75 hole in forefoot. Very comfy. Very slow too. I've gotten used to the 4-8% gain my CF plates give me. However, I'm not racing and in the end it doesn't really matter what my time is. I want to put some more mileage on this shoe with hole and no plate, for data purposes.

The good news is my new CF supplies finally arrived this evening, so this weekend I'll probably be making some more CF plates, trying out some new designs.

 

[Four by Six]

4 mile run this morning at my 5K pace with HR held at 160. My VaporFly's were up in my shoe rotation. VFs are hard to beat for speed and efficiency. Set a new PR for HR kept below max.