Offshoreonly.com - New shock absorbing seats built and designed by Two Cocks Racing

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- - New shock absorbing seats built and designed by Two Cocks Racing (https://www.offshoreonly.com/forums/general-boating-discussion/250921-new-shock-absorbing-seats-built-designed-two-cocks-racing.html)

The seats are incredible, a night and day difference between using them and not using them. especially in race situations.

We used fox racing shocks from a quad. We learned a lot this racing season so the design is changing to improve safety and to try and remove some weight also.

The coolest feeling in the world now is when i apply power the seats actually raise about an inch and a half under acceleration. Then, when i let out of the throttle the seats compress and absorb even the smallest disturbance in the water, making you feel weightless...

It's good to see that you use genuine racing seats with side supports for the head!

The seat is an important part of the safety system but often forgotten.

Seat belt geometry has already been mentioned in the thread. What does your regulations say? I would recommend you mount your belts horizontal for two reasons.

1. It's HANS compatible if you plan to use them in the future.
2. The belt geometry recommended by belt manufacturers are based on a horizontal impact. Since stuffs rarely are perfectly horizontal a downward routing of the shoulder belt will put unnecessary forces on the spine. The same goes for impacting the water up side down.

http://www.schroth.com/installation-.../image_032.gif

Since you are updating the design, have you thought about triangulating the upper seat belt mounts (green lines)? Any flex in the fixations will generate slack which is bad for the occupant.

https://lh3.googleusercontent.com/-6...s640/13312.jpg

You can easily test the strength of the belt fixations if you bolt the frame to the shop floor and pull them with a truck or similar. Some scales from a crane will keep track of the pulling force. Your regulation might use other forces though.

It is if utmost importance that the seat and belt fixations are strong enough to restrain the occupant. Especially in a race boat where you might have to evacuate quickly.

Just my 2 cents.

Those are awesome! It's great that you kept the design simple. I see you said they were quad shocks. They look close to the front torque arm shocks on a Polaris ProX.

here is a pic of how we solved the shoulder mount issue

http://i282.photobucket.com/albums/k...1/photo-12.jpg

This is really great. It is a large step in saftey. I bet it will take some impact of of a crash. I have thought about using motorhome airbags in a simlar fashion to cut down on hard impacts. Boats don't really have crumple zones to absrob impact like race cars. Thanks for sharing !

It's very difficult to focus on the seat with two massive engines in the picture. :p

The belt geometry looks good with your changes! But the upper fixation looks very weak IMHO.

Quote:

Originally Posted by Gripenland (Post 3572256)

It's very difficult to focus on the seat with two massive engines in the picture. :p

The belt geometry looks good with your changes! But the upper fixation looks very weak IMHO.

oh those little things... thought no one would notice.

thanks for taking the time to give your input and i do like the triangle design for added strength. The next version will probably incorporate a little of this but eliminating some weight has become part of the challenge also.

Quote:

Originally Posted by Gripenland (Post 3572256)

The belt geometry looks good with your changes! But the upper fixation looks very weak IMHO.

looks awesome, I agree I think the weakest point would be where the shock mounts and the weld to go up to the shoulder mount. maybe tie it in with a brace of some sort to the base where it pivots. In the event of a stuff with your weight being thrown forward I think it may have the tendency to bend there. Or if you did the uprights with cold rolled steel to achieve the proper angle instead of welded sections, it may save on weight too. have it like ( instead of the weld :)

[QUOTE]

Quote:

Originally Posted by [B

dreamer[/B];3370923]Wrong harness mounting

Proper mount should be behind the shoulder and at no more than 7 degrees deflection

How that would ever pass any sort of tech inspection is beyond me

Any impact or rapid decell would cause spinal compression....[/QUOTE]

Comment:
I agree with Dreamer here and think suspension seats are detrimental to your spine.

Here is why:

Quote:

This biggest problem with any suspension seat (factory car or performance) coupled with the use of a non retractable double shoulder harness is: When you pull the shoulder straps down thus forcing the occupant down into the seat... Now instead of just gravity in the down vector only (1G). The suspension seat actually has a force vector in the up direction too. This actually can put forces on the spine to almost 1.6Gs Just sitting there. So if you weigh 200lbs and are in a Tub or pan style seat your spine sees forces just over 1G at 1G. But just sitting still in a suspension seat your spine (mid mass is well over 1G) I've seen the results in the lab.

Bla Bla Bla

Simple man's terms.. Sit on a F-150 coil spring and use your butt to compress it 1 inch with your friend pushing down on your shoulders. Not only is gravity working against your spine... So is the spring.

You guys are pretty much spot on. It's the preload against the spine that kills your back not the bottoming out.

Tub seat 1G + 2 G landing = 2.0G to the spine

Suspension seat 1.6G + 2G landing = As high as 2.6 - 3.2G to the spine.

The rebound of the spring or suspension portion is always working against you when compressed. Uhhh No thanks. When your boat comes off a swell and impacts upon landing ie... similar to bottoming out your suspension and tires, there will be a rebound. If your suspension seat is compressing down while your boat is rebounding up, you are the only thing still going down but the chassis is going up. Kind of like a bat hitting a ball.

Another interesting thread can be found here when desert racers discuss this very same topic.

http://www.race-dezert.com/forum/showthread.php?t=58050

I once thought suspension seats would be great... but have changed my mind... rigid seats such as Sparcos, Corbeau, or Recaro's IMO are better. It makes a lot of sense all the desert racers, rally drivers have rigid shell type seats with minimal padding.

Do what you want... just offering another perspective for you to consider in the interest of safety.

KAP