Head and neck restraints, what are the choices?
#101
Lives on the Forum
Just to be certain we need to be sure our readers know gsbaker is the inventor of ISAAC. I have a couple curiosities I hope Mr. Baker can indulge. As the inventor of the ISAAC device and with my understanding that everyone uses the same tests to market their own product as superior, I'd be interested to hear your comments on a couple things:
I've heard the often repeated claim that SFI 38.1 was written by Hubbard and purposely excludes ISAAC. Why would SFI 38.1 purposefully exclude ISAAC but allow other types of HNR devices that aren't made by HANS? Wouldn't HANS eliminate all their competition if they were in charge of the spec? Somehow a person or group of HANS supporters is in control of SFI and allowing other HNR devices to play but black balling ISAAC specifically with SFI 38.1?
The ISSAC Link system uses webbing (as HANS does) rather than dampers. You've stated elsewhere your refusal to compromise ISAAC's design in order to get an SFI stamp of approval, so why compromise ISSAC by substituting straps for the dampers? A quick search finds many talks you've given lambasting "pushing on a rope" etc as a reason why HANS is so inferior and yet your Link system uses straps as well. What differentiates Link from HANS? Have you changed your mind on straps?
I've heard the often repeated claim that SFI 38.1 was written by Hubbard and purposely excludes ISAAC. Why would SFI 38.1 purposefully exclude ISAAC but allow other types of HNR devices that aren't made by HANS? Wouldn't HANS eliminate all their competition if they were in charge of the spec? Somehow a person or group of HANS supporters is in control of SFI and allowing other HNR devices to play but black balling ISAAC specifically with SFI 38.1?
The ISSAC Link system uses webbing (as HANS does) rather than dampers. You've stated elsewhere your refusal to compromise ISAAC's design in order to get an SFI stamp of approval, so why compromise ISSAC by substituting straps for the dampers? A quick search finds many talks you've given lambasting "pushing on a rope" etc as a reason why HANS is so inferior and yet your Link system uses straps as well. What differentiates Link from HANS? Have you changed your mind on straps?
#103
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Originally Posted by DamonB
Just to be certain we need to be sure our readers know gsbaker is the inventor of ISAAC.
Wouldn't HANS eliminate all their competition if they were in charge of the spec?
More importantly, no one associated with ISAAC, LLC has ever clamed any kind of conscious conspiracy. These folks are just looking out for their own best interest. For the conspiracy stuff you need to hear Trevor Ashline's rant about the "hans mafia".
The ISSAC Link system uses webbing (as HANS does) rather than dampers. You've stated elsewhere your refusal to compromise ISAAC's design in order to get an SFI stamp of approval, so why compromise ISSAC by substituting straps for the dampers? A quick search finds many talks you've given lambasting "pushing on a rope" etc as a reason why HANS is so inferior and yet your Link system uses straps as well. Have you changed your mind on straps?
We realized that we can only save lives if the driver uses the product. If they can afford a $295 ISAAC, but not a $895 ISAAC we are not doing them any good if our least expensive product is $895.
What differentiates Link from HANS?
#104
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Thanks for the Info Gregg..Like I said, I respect what you do and how you do it..Keep it up...There is enough room in the Head and Neck Restraint market for Several Quality companies...
Don't even get me started on Trevor Ashline...It seems both you and I know the content of his Character...I had some fun with him at PRI last year...It was pretty funny (PM me if you want to know)...
I know first hand that several people that looked at early Isaac devices were worried about the complexity of the dashpot system and the proximity of rods and metal parts so close to soft tissue areas...Also, the early devices were too connected to the chassis (and it's direct movements)...Those are the main hurdles that you have to overcome...I know your system works, and nobody doubts that...
I have seen some pretty good sled tests that would open some eyes...My favorite is of the 45 degree sled test where on the rebound, the G-Force SRS 1 actually Speared the helmet off of the dummy!..
Like I said, I have been a longtime HANS believer, and user...But I am not blind to the alternatives..
Don't even get me started on Trevor Ashline...It seems both you and I know the content of his Character...I had some fun with him at PRI last year...It was pretty funny (PM me if you want to know)...
I know first hand that several people that looked at early Isaac devices were worried about the complexity of the dashpot system and the proximity of rods and metal parts so close to soft tissue areas...Also, the early devices were too connected to the chassis (and it's direct movements)...Those are the main hurdles that you have to overcome...I know your system works, and nobody doubts that...
I have seen some pretty good sled tests that would open some eyes...My favorite is of the 45 degree sled test where on the rebound, the G-Force SRS 1 actually Speared the helmet off of the dummy!..
Like I said, I have been a longtime HANS believer, and user...But I am not blind to the alternatives..
Last edited by Quicker10u; 01-14-07 at 11:16 PM.
#105
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Originally Posted by Quicker10u
Thanks for the Info Gregg..Like I said, I respect what you do and how you do it..Keep it up...There is enough room in the Head and Neck Restraint market for Several Quality companies...
Don't even get me started on Trevor Ashline...It seems both you and I know the content of his Character...I had some fun with him at PRI last year...It was pretty funny (PM me if you want to know)...
I know first hand that several people that looked at early Isaac devices were worried about the complexity of the dashpot system and the proximity of rods and metal parts so close to soft tissue areas...Also, the early devices were too connected to the chassis (and it's direct movements)...Those are the main hurdles that you have to overcome...I know your system works, and nobody doubts that...
I have seen some pretty good sled tests that would open some eyes...My favorite is of the 45 degree sled test where on the rebound, the G-Force SRS 1 actually Speared the helmet off of the dummy!..
#106
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Does anyone have info or experience with the Leatt neck braces?
leatt-brace.com
They seem to be making major inroads in the motocross community and have an auto version as well that is sanctioned by some road race groups, like Southern Midget Racing.
It seems like a good system which allows a fair bit of range of motion. The only place that sold the road - race version that I found on the net had it for $1200, a whole lot more than the less expensive motocross version which was about $400.
Mark
leatt-brace.com
They seem to be making major inroads in the motocross community and have an auto version as well that is sanctioned by some road race groups, like Southern Midget Racing.
It seems like a good system which allows a fair bit of range of motion. The only place that sold the road - race version that I found on the net had it for $1200, a whole lot more than the less expensive motocross version which was about $400.
Mark
#107
Lives on the Forum
There's new, cheaper versions of the HANS, the R3 and the Hutchens Hybrid out now, so if budget was a concern before, then now's the time to have another look.
#108
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I have seen the HANS and the R3 and Hutchens hybrid. I was just wondering about the Leatt since all are accepted by NASA as approved head and neck restraints. In addition, I believe that there are 2 versions of the Leatt for cars just as there are 2 versions for motocross. My assumption was that the $1200 version was the more expensive one, but I may be wrong. As opposed to the other systems, the Leatt does not use straps or pistons. It acts as an extra large collar which limits the range of motion of the helmet and therefor the head/neck, deforming slightly on impact to minimize the decelleration injury to the brain.
Mark
Mark
#110
OBEY YOUR MAZDA
I've been wanting to aquire an Isaac device, what's holding me back is the mounting to the helmet.
I spoke to a guy in the national sanctioning doodad, he basicly said that if the helmet wasnt prepared for the Isaac device from the factory, he wouldn't let anyone use it. Something to do with drilling holes in the helmet, structual integrity or some stuff like that.
This was a few years back, so things could have changed.
Does anyone know wher to buy an Isaac prepared FIA/SA2005 approved helmet, if at all ?
Thanks in advance
Kim K. - From across the globe
I spoke to a guy in the national sanctioning doodad, he basicly said that if the helmet wasnt prepared for the Isaac device from the factory, he wouldn't let anyone use it. Something to do with drilling holes in the helmet, structual integrity or some stuff like that.
This was a few years back, so things could have changed.
Does anyone know wher to buy an Isaac prepared FIA/SA2005 approved helmet, if at all ?
Thanks in advance
Kim K. - From across the globe
#111
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The newest product out is the new LEATT Moto-R.......it is SFI 38.1 certified, the looks excelent and feels great. It is not uncomfortable to wear at all and is very light. Easy to put on and take off the brace connects to the helmet straps so there is no drilling into the helmet needed on the web site they have tons of testing that has proven that this head and neck restraint system works extremely well, i would expect to start seeing more and more drivers using this rather then the other devices. Check it out @
www.Propartsusa.com
www.Propartsusa.com
#112
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From December '08 Fastrack, Page 9:
MEMBER ADVISORIES
4. Driver safety equipment – The CRB would like input from the membership about whether head and neck restraints should be made mandatory.
MEMBER ADVISORIES
4. Driver safety equipment – The CRB would like input from the membership about whether head and neck restraints should be made mandatory.
Write your letters guys. Its YOUR club. They WILL mandate a 38.1 device on you. $700 SFI device, + $800 winged seat + $100 Right side net = $1600 out of your pocket.
(now before anyone flames me, I'm ALL for HNR's, just don't tell me which one I HAVE to buy)
http://rsicommunity.org/
http://www.isaacdirect.com/html/product.html
crb@scca.com
#113
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Ok..so it seems ive joined this party late. Im to the point of finally being seriously in the market for one of these systems. I do have a bit of a specific concern, as I drive my car with an FIA seat and harnesses and a cage set up correctly to mount the harnesses to etc...
I also however instruct HPDE with NASA and Chin motorsports, and more often than not am stuck in someones car with the stock seatbelts and no protection. I often feel that the investment is allmost not worth it, as the chances of getting in a crash while riding with a student who is on the track for the first time ever would probably be higher than with me driving (although my crash might be worse).
To offset my bad mathematical chances I would need a Head and Neck system that would work both with my racecar as well as outside of a harness system.
Is there ANYTHING on the market you guys know about that would do this. In my situation I feel that it would almost be better to invest in something inferior that would work both with or without harnesses than something 100% that only works half the time.
I also however instruct HPDE with NASA and Chin motorsports, and more often than not am stuck in someones car with the stock seatbelts and no protection. I often feel that the investment is allmost not worth it, as the chances of getting in a crash while riding with a student who is on the track for the first time ever would probably be higher than with me driving (although my crash might be worse).
To offset my bad mathematical chances I would need a Head and Neck system that would work both with my racecar as well as outside of a harness system.
Is there ANYTHING on the market you guys know about that would do this. In my situation I feel that it would almost be better to invest in something inferior that would work both with or without harnesses than something 100% that only works half the time.
#114
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For what it's worth:
May 1 I bought the Defender. They claim that one size fits 99% of the people, but it didn't fit me. I am 6'-2" tall. Because I have a long neck, the back part of defender kept trying to get under my helmet - Bad. If I slid the Defender back so that it wouldn't get under my helmet, then it stuck into the back head restraint on my car, AND it stuck way up off my chest, holding my shoulder belts up off my chest - Bad. The Defender seem to be more popular with the drivers of "Lay down" cars like Formula and Sports Racers. The Defender did not clear the head rest on the back of my aluminum seat.
Last weekend at VIR I traded the Defender back into the vendor I bought it from, and I upgraded to a Hans Pro with a slider tether. The Hans fit great, and was very comfortable to wear, I didn't even notice it on during the race. The downside is that the Hans Pro + slider + new quick release mounts cost almost twice as much as the Defender did. There goes my racing budget.
May 1 I bought the Defender. They claim that one size fits 99% of the people, but it didn't fit me. I am 6'-2" tall. Because I have a long neck, the back part of defender kept trying to get under my helmet - Bad. If I slid the Defender back so that it wouldn't get under my helmet, then it stuck into the back head restraint on my car, AND it stuck way up off my chest, holding my shoulder belts up off my chest - Bad. The Defender seem to be more popular with the drivers of "Lay down" cars like Formula and Sports Racers. The Defender did not clear the head rest on the back of my aluminum seat.
Last weekend at VIR I traded the Defender back into the vendor I bought it from, and I upgraded to a Hans Pro with a slider tether. The Hans fit great, and was very comfortable to wear, I didn't even notice it on during the race. The downside is that the Hans Pro + slider + new quick release mounts cost almost twice as much as the Defender did. There goes my racing budget.
#115
Licensed Zip Tie Mechanic
For what it's worth:
May 1 I bought the Defender. They claim that one size fits 99% of the people, but it didn't fit me. I am 6'-2" tall. Because I have a long neck, the back part of defender kept trying to get under my helmet - Bad. If I slid the Defender back so that it wouldn't get under my helmet, then it stuck into the back head restraint on my car, AND it stuck way up off my chest, holding my shoulder belts up off my chest - Bad. The Defender seem to be more popular with the drivers of "Lay down" cars like Formula and Sports Racers. The Defender did not clear the head rest on the back of my aluminum seat.
Last weekend at VIR I traded the Defender back into the vendor I bought it from, and I upgraded to a Hans Pro with a slider tether. The Hans fit great, and was very comfortable to wear, I didn't even notice it on during the race. The downside is that the Hans Pro + slider + new quick release mounts cost almost twice as much as the Defender did. There goes my racing budget.
May 1 I bought the Defender. They claim that one size fits 99% of the people, but it didn't fit me. I am 6'-2" tall. Because I have a long neck, the back part of defender kept trying to get under my helmet - Bad. If I slid the Defender back so that it wouldn't get under my helmet, then it stuck into the back head restraint on my car, AND it stuck way up off my chest, holding my shoulder belts up off my chest - Bad. The Defender seem to be more popular with the drivers of "Lay down" cars like Formula and Sports Racers. The Defender did not clear the head rest on the back of my aluminum seat.
Last weekend at VIR I traded the Defender back into the vendor I bought it from, and I upgraded to a Hans Pro with a slider tether. The Hans fit great, and was very comfortable to wear, I didn't even notice it on during the race. The downside is that the Hans Pro + slider + new quick release mounts cost almost twice as much as the Defender did. There goes my racing budget.
Canadian distributor is Track Mart (www.trackmart.com).
#116
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I have the Defender as well. Three of us used it at the LeMons South in September and once we got it fitted, it worked very well for all of us, as in disappeared once racing. The tallest person was 6'1". I have recommended it to everyone but I will let taller people know your experiences.
Mark
Mark
#117
needs more track time
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http://www.defnderneckbrace.com/
DefNDer here too. Comfier than the Hans IMO. Cheaper too when you add sliding tethers and such.
DefNDer here too. Comfier than the Hans IMO. Cheaper too when you add sliding tethers and such.
#118
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This is my cage that Afgmoto1978 and I have put together for myself.
Just need to finish the bars that will go through the firewall to the front strut towers and the cage its self will be complete.
please delete, sorry
Just need to finish the bars that will go through the firewall to the front strut towers and the cage its self will be complete.
please delete, sorry
Last edited by Daniel_Leed; 12-03-09 at 01:53 AM. Reason: Messed up, Ment to post this in different thread. Sorry..
#119
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FIA Certification?
Any other restraints have the FIA certification? Where I race (In western Canada) we need an FIA certified restraint system for 2010 competition. I'm liking the DefNDer, but it says FIA certification will be announced. I'm planning to wait a few months and then purchase. Hopefully the range of choices gets better than just Hans.
-Trent
-Trent
#120
Any other restraints have the FIA certification? Where I race (In western Canada) we need an FIA certified restraint system for 2010 competition. I'm liking the DefNDer, but it says FIA certification will be announced. I'm planning to wait a few months and then purchase. Hopefully the range of choices gets better than just Hans.
#122
...Serf of Taxifornia...
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^ No longer in production but available for purchase at two dealers: one in Canada, and one in New Zealand. I just spoke to the DefNder people and they said they will continue to support the HNR devices, with helmet hardware, tethers, fittings available for purchase directly from them. The same people also operate another business that manufactures go-karts, but they will continue HNR support as a service to existing DefNDer customers.
#123
...Serf of Taxifornia...
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DJ Safety
One more to add to the list: the DJ Safety HNR:
http://www.djsafety.com/
http://www.djsafety.com/DJ_2011_JO_V...tWebSized2.pdf , page 26
SFI 38.1 approval "pending."
I like the fact that it's built around a foam neck brace, which would make it relatively comfortable, IMHO. I have been using an anatomical foam collar for many years, but am being forced to select an HNR device by NASA rules.
I'm in the process of test fitting a Hans Pro 20*, Pro 30*, Sport II 20*, and a Hybrid Pro Rage. All the Hans devices have the same problem -- the back of the Hans needs quite a bit of clearance (1" to 2" depending on the angle of the model) between the helmet and seatback. If this spacing requirement is not met, the position of the head is forced significantly forward, in relation to the torso. I have an OMP Big seat, but I would expect a similar problem with other fiberglass or tubeframe seats, since the upper part (above the level of the harness guides) of a typical seat is curved upright slightly in relation to the rest of the seatback. IMHO, that curvature is a hindrance to being with, since the bulk of the helmet prevents you from leaning back much, which also forces the head forward.
http://www.djsafety.com/
http://www.djsafety.com/DJ_2011_JO_V...tWebSized2.pdf , page 26
SFI 38.1 approval "pending."
I like the fact that it's built around a foam neck brace, which would make it relatively comfortable, IMHO. I have been using an anatomical foam collar for many years, but am being forced to select an HNR device by NASA rules.
I'm in the process of test fitting a Hans Pro 20*, Pro 30*, Sport II 20*, and a Hybrid Pro Rage. All the Hans devices have the same problem -- the back of the Hans needs quite a bit of clearance (1" to 2" depending on the angle of the model) between the helmet and seatback. If this spacing requirement is not met, the position of the head is forced significantly forward, in relation to the torso. I have an OMP Big seat, but I would expect a similar problem with other fiberglass or tubeframe seats, since the upper part (above the level of the harness guides) of a typical seat is curved upright slightly in relation to the rest of the seatback. IMHO, that curvature is a hindrance to being with, since the bulk of the helmet prevents you from leaning back much, which also forces the head forward.
#124
...Serf of Taxifornia...
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Hans Pro/Sport vs. Sport II
I called Wine Country Motorsports and talked about my Hans fitment problem. Apparently, drag racers complain about the same clearance issue. Hans developed the Sport II device to: (1) address this problem, with a shorter rear "bill", (2) rounded edges to help prevent the Hans from catching on something as a driver exists the vehicle, (3) reduce the weight.
Some measurements show that the differences may not be as substantial as claimed.
Dimensionally, the Pro and the Sport are nearly identical and have essentially the same shape. Wine Country claimed that the bill is about 1.5" shorter on the Sport II. I found the difference to be much less.
As measured from edge to edge (red line in pics), the bill on the Sport is 5 3/4" tall and 4 7/8" on the Sport II. But this measurement is deceptive because the overall shapes of the bills differ substantially among the two models. The Sport II has a wider and taller "gap" between the shoulder rests. So I measured the distance from where the Hans rests on the shoulders to the top edge of the bill. On the Sport, it's 6 3/8" and on the Sport II, it's 5 3/4". These measurements are approximate, since I estimated where the shoulders would rest, but the effective difference between the two models is much less than 1".
On the Hybrid Pro Rage, the strap collar bill is just over 2" in height, slightly taller than my OMP anatomical neck collar.
In terms of weight, the Hans Sport, Sport II, and Hybrid Pro Rage all came in at 2.6 lbs, including the gel pads (Hans) and all straps (Hybrid). I don't have the exact weight of the Hans Pro, but it was about a pound lighter. The Hybrid is substantially thicker in places and possibly made of a denser material.
Sitting in the car strapped in with the devices, I didn't really notice much difference in terms of weight sensation / distribution. The sensation of the harness belts pressing the device into the shoulders (Hans and Hybrid) and chest (Hans) overshadowed any sensation from weight resting on the shoulders.
Wearing the device outside the car, the Hans Pro felt noticeably lighter on the shoulders.
Some measurements show that the differences may not be as substantial as claimed.
Dimensionally, the Pro and the Sport are nearly identical and have essentially the same shape. Wine Country claimed that the bill is about 1.5" shorter on the Sport II. I found the difference to be much less.
As measured from edge to edge (red line in pics), the bill on the Sport is 5 3/4" tall and 4 7/8" on the Sport II. But this measurement is deceptive because the overall shapes of the bills differ substantially among the two models. The Sport II has a wider and taller "gap" between the shoulder rests. So I measured the distance from where the Hans rests on the shoulders to the top edge of the bill. On the Sport, it's 6 3/8" and on the Sport II, it's 5 3/4". These measurements are approximate, since I estimated where the shoulders would rest, but the effective difference between the two models is much less than 1".
On the Hybrid Pro Rage, the strap collar bill is just over 2" in height, slightly taller than my OMP anatomical neck collar.
In terms of weight, the Hans Sport, Sport II, and Hybrid Pro Rage all came in at 2.6 lbs, including the gel pads (Hans) and all straps (Hybrid). I don't have the exact weight of the Hans Pro, but it was about a pound lighter. The Hybrid is substantially thicker in places and possibly made of a denser material.
Sitting in the car strapped in with the devices, I didn't really notice much difference in terms of weight sensation / distribution. The sensation of the harness belts pressing the device into the shoulders (Hans and Hybrid) and chest (Hans) overshadowed any sensation from weight resting on the shoulders.
Wearing the device outside the car, the Hans Pro felt noticeably lighter on the shoulders.
#125
...Serf of Taxifornia...
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20* vs. 30* Hans
Shown here is the difference between the 30* (Model 30) and 20* (Model 20) versions. The Model 30 Sport is in the foreground, with the Model 20 Sport II behind it.
The meaning of the model # is that it is designed to fit a seat reclined the same number of degrees.
For example, the Model 30 is intended for drivers sitting in a 30* reclined seat. Since the head position is leaned back (as compared to a 20* seat), the Model 30 Hans has the bill reclined less than in the Model 20. In other words, the bill on the Model 30 is more upright than on the Model 20.
I thought the more upright stance of the Model 30 would help my clearance issue, but it still forced my head forward too much. (I may do a fitment with additional seatback foam and report later on if it works.)
The available seat incline fitments differ depending on the Hans version, with the Pro having 10*, 20*, 30*, 40* (special order) models. The Sport gets the 20* and 30* options and the Sport II only 20*.
There are also Super Small, Small, Medium, and Large sizes, which have to do with the spacing between the shoulder rests so you can slip your neck through it. With a 17" neck circumference, I was able to fit the Medium and Large sizes, with the Large being easier to slip on. The narrowest point of the Hans is about halfway down the harness rests, with the neck opening being substantially larger. Once the Hans was resting in its intended position, I didn't feel any difference between the Large and Medium sizes.
The Pro 20* model offers all four sizes. Other versions and models offer a smaller selection of sizes. With the Sport II, Hans has adopted a "one size fits most" strategy; there are no choices. It comes as Medium, for 20* reclined seat.
So with the Hans, model selection and fitment consists of considering:
Weight: Pro vs. Sport & Sport II
"Format/Shape": Sport II vs. Pro & Sport
Seatback recline
Shoulder rest spacing
Aside from selecting the lightweight vs. heavier version / cost consideration, it's difficult to tell which version / size / recline fits best unless you're sitting in your car, helmet on, strapped in (as I found out). It isn't necessary to attach the Hans to the helmet for a test fit because the tethers should be loose under normal driving conditions (i.e. not in the process of colliding with a barrier). However, attaching the tethers will enable you to experience any restrictions in range of motion (it will also make the anchor posts unreturnable).
The Sport II, despite its higher price tag and lack of sizing options, is currently popular and sold out at Wine Country Motorsports. Other than the "new is cool" factor and supposedly easier vehicle exit, I didn't see any perceptible fitment or performance improvements to justify the extra cost.
The meaning of the model # is that it is designed to fit a seat reclined the same number of degrees.
For example, the Model 30 is intended for drivers sitting in a 30* reclined seat. Since the head position is leaned back (as compared to a 20* seat), the Model 30 Hans has the bill reclined less than in the Model 20. In other words, the bill on the Model 30 is more upright than on the Model 20.
I thought the more upright stance of the Model 30 would help my clearance issue, but it still forced my head forward too much. (I may do a fitment with additional seatback foam and report later on if it works.)
The available seat incline fitments differ depending on the Hans version, with the Pro having 10*, 20*, 30*, 40* (special order) models. The Sport gets the 20* and 30* options and the Sport II only 20*.
There are also Super Small, Small, Medium, and Large sizes, which have to do with the spacing between the shoulder rests so you can slip your neck through it. With a 17" neck circumference, I was able to fit the Medium and Large sizes, with the Large being easier to slip on. The narrowest point of the Hans is about halfway down the harness rests, with the neck opening being substantially larger. Once the Hans was resting in its intended position, I didn't feel any difference between the Large and Medium sizes.
The Pro 20* model offers all four sizes. Other versions and models offer a smaller selection of sizes. With the Sport II, Hans has adopted a "one size fits most" strategy; there are no choices. It comes as Medium, for 20* reclined seat.
So with the Hans, model selection and fitment consists of considering:
Weight: Pro vs. Sport & Sport II
"Format/Shape": Sport II vs. Pro & Sport
Seatback recline
Shoulder rest spacing
Aside from selecting the lightweight vs. heavier version / cost consideration, it's difficult to tell which version / size / recline fits best unless you're sitting in your car, helmet on, strapped in (as I found out). It isn't necessary to attach the Hans to the helmet for a test fit because the tethers should be loose under normal driving conditions (i.e. not in the process of colliding with a barrier). However, attaching the tethers will enable you to experience any restrictions in range of motion (it will also make the anchor posts unreturnable).
The Sport II, despite its higher price tag and lack of sizing options, is currently popular and sold out at Wine Country Motorsports. Other than the "new is cool" factor and supposedly easier vehicle exit, I didn't see any perceptible fitment or performance improvements to justify the extra cost.