Hi Rob,
There have been at least a couple of Nike Free threads on this forum which I have commented on. I should note that I have no affiliation with Nike... I just like the Free concept (& the
Bowerman series). However, if someone from Nike is willing to offer me a job as a shoe designer & tester, whilst supporting a heavy training schedule (thus you get Podiatrist, designer, tester & runner... that's 4 for the price of 1) with accommodation close to Nike HQ in the Oregon forest... I will be willing to listen

.
There are now three types of Nike Frees... the 7.0, the 5.0 & the 3.0. There is even a
Nike Free Wikipedia on them. The
Nike Free website may also be of interest.
Basically the shoe was designed with the intentions of somewhat mimicking barefoot running via reducing the heel height & reducing the restriction of the natural movement of the feet, thus why the sole is very flexible with very little 'upper' support i.e. very little heel counter support. These characteristics are also proposed to strengthen the lower limb muscles. The different numbering refers to the differing heel to forefoot gradients i.e. 7.0 has a higher heel than the 3.0. As you would have picked up on with the above links; Nike classify a 'normal' structured shoe as a '10.0' down to a bare foot as '0'... however, I find this classification a bit misleading as 'normal' structured shoes can have varying heel heights & support, but I understand why the context of the concept is used.
I feel the majority of running shoe heel heights are too high & are a contributing factor for the development of adverse foot & lower limb kinetics (movement) & subsequently adverse forces which contribute to injury.
When Nike Free first came out there was only the 5.0. I started training in them when they first came into the country (about 2004) as I had heard rumours of their development a couple of years before. I have been training in a Nike Free ever since. From the 5.0 I next went into a 4.0, which Nike does not make anymore (which disappointed me at the time). I did a lot of miles in the 4.0 - virtually all my training was done in the shoe... long runs (up to 45km), tempo runs, road interval work, hill reps, recovery runs & trail runs. I got up to 185km a week in the 4.0 without any problems. I thought it was the perfect shoe for me, thus disappointed when the 4.0 was ceased.
When the 3.0 came out I thought it would be a bit on the flimsy side for the amount of training I was doing.

Now that I have been training in the 3.0 for well over a year I have found it to be the best shoe for me... it feels natural & comfortable.
I am personally not familiar with the feel of the 7.0 as I have never thought it appropriate for me at the stage when it first came out. The 7.0 came out later & I think it was designed to give runners a slighter transitional option in the Free range from a 'normal' structured shoe.
RobHall, on Jun 12 2009, 10:34 AM, said:
So I thought I would just do a short half marathon in them rather than a long half marathon.
This sounds interesting.
RobHall, on Jun 12 2009, 10:34 AM, said:
...a niggling knee ligament twanged and slowed me down for a bit, but otherwise all the usual problems went away.
When I first started running in a Free (5.0) I developed some knee pain but it gradually went away. I think the best thing to do is to gradually adapt to the new shoe (as Nike suggests). Everyone is going to be different to some degree... some may take longer to adapt than others. In my line of work I see all types of foot structures & biomechanics. Some people I feel would find it difficult to adapt to a Free due to its reduced support because their lower limb structure & alignment are too unstable thus excess movement & forces will not be controlled & subsequent soft tissues &/or joints will be stressed out too much thus causing them to meet their injury threshold too soon.
RobHall, on Jun 12 2009, 10:34 AM, said:
So for the first time in ages I had no sore right ankle, left heel, both planta fascia, both soleus, right 5th metatarsal. I would also point out that I normally run like crap in the morning as I am usually pretty stiff from the run the night before.
It sounds to me that the shoes are having some benefits to your biomechanics & subsequent injury threshold already.
RobHall, on Jun 12 2009, 10:34 AM, said:
Am I going to root my feet/legs long term by doing this? Should I be mixing it up with my other shoes?
Not knowing your biomechanics, but as per above... providing you adapt appropriately to the shoes... you should be fine. You need to play it by ear & listen to your body. Some may need to initially mix the wearing of other shoes whilst they adapt to a Free, but once you have adapted you should be fine to just wearing the Free in most cases.
RobHall, on Jun 12 2009, 10:34 AM, said:
I did get bright red ones so they should make me go faster
They say that red can do that to you.
Roffy, on Jun 14 2009, 09:52 AM, said:
Quote
So yesterday, I ran home from work (21km conveniently,) in them aided by my trusty super socks and all went well. So I thought I would run back to work this morning and felt fantastic so I started to push and a niggling knee ligament twanged and slowed me down for a bit, but otherwise all the usual problems went away. So for the first time in ages I had no sore right ankle, left heel, both planta fascia, both soleus, right 5th metatarsal. I would also point out that I normally run like crap in the morning as I am usually pretty stiff from the run the night before.
Am I going to root my feet/legs long term by doing this? Should I be mixing it up with my other shoes? I only have a short amount of time before Youyangs and I want the best shot possible at beating maggot
Hi Rob, I had to laugh when I read this. Not at you, but at human nature and runners alike (myself included). You wonder if you are buggering yourself up by feeling good in the nike frees?!?!? Let's look at it in reverse. Ok,When you run in your other shoes you get a sore right ankle,sore left heel, bilateral plantar fascitis,sore calves and right foot. Does that sound good? Me thinks not, it aint rocket science, run in the frees. cheers
Good point Roffy.
Maggot, on Jun 14 2009, 01:06 PM, said:
Rob, I think you should train in the Vibrams, preferably on cement, or at least in the Nike Free 3.0s. And then on race-day, slip into a pair of trusty Brooks Beasts with full-length sorbothane in-soles. I think they're only a tiny bit heavier

. And most ultra runners carry a couple of spare sets of shoes around in their pack during races too.
Maggot
Not wanting to get in between the duel between Maggot & yourself... I suggest you analyse to above post very carefully

.
All the best!