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View Full Version : help! added 6" seat pad to older airchair, now it rides bad.



kc5swi
05-27-2012, 10:41 PM
i had an old air chair, the plastic seat post one. i upgraded the seat pad to a nice 6 inch one. now to ride neutral you have to lean way back.

i tried shimming the rear of the front blade with a quarter, but the ski still wants to dive. what should i do to correct this?
could the new seat pad cause this?? seems weird the pad could cause this????

skyskiguy
05-27-2012, 11:30 PM
Shim the front of the rear wing - not the rear of the front wing.

kc5swi
05-28-2012, 12:32 PM
Shim the front of the rear wing - not the rear of the front wing.


ok, ill do as directed and post back- still would like to hear if others updated the seat and had this issue?

i have i a quarter for a shim!

thanks!

DRGergler
05-28-2012, 12:55 PM
I make shims, and currently have them in stock; here is a link to my FF post about reversible shims:

http://www.foilforum.com/forums/showthread.php?3915-Reversible-Shims

I also have a greater range of sizes in non-reversible shims, positive and negative. What you are describing is positive shimming. Here is a link to the post with the positive and negative shims:

http://www.foilforum.com/forums/showthread.php?2252-Shims-%E2%80%93-up-to-2.0-degrees&highlight=shims

My guess is that your quarter is equivalent to about .75 degree positive shim, maybe more. If I can answer any questions or if you would like to order shims, e-mail me at DRGergler@aol.com.

Don

kc5swi
05-29-2012, 01:35 PM
The quarter helped but even with 2 quarters I still have problems. Last year I rode this airchair, and if you thought about leaning back you shot upward. Ok, dumbass me disasembled the foil t bar part to get it into a small trunk. After I put it back togeather, it dives like mad! So, how could I possible screw up with only 3 parts? The bigger foil is to the front, rounded part foward. The little foil wing thing is in back, its twinn fins pointing down.
Bolts recess into foil. Please help the stupid ones as this is nuts.

Skidude
05-29-2012, 02:35 PM
If you raised yourself a full 6", then leveraging that much mass can definitely cause a "lack of lift". However, you may have also put the ski back together wrong? Can you post some pictures.

If it is simply a matter of compensating lift for the raised body mass, then you can keep adding shims to the front of the rear wing until the ski rides well again.

I have raised my seat by 2' and felt the lift of the ski change. 6" is extreme. You may want to put the other seat pad back on for a test run and see if that was the varible that made the change.

kc5swi
05-29-2012, 03:12 PM
Ok, I rechecked and I exaggerated a little bit. Not the part about me being a dumbass :). I removed the stock 1/2" seat pad and replaced it with a skyski 3" seat pad. I put new bindings on the board in the exact same locations, replaced the seatbelt strap. I did take the tbar apart and reassemble it.

The ski had no shims before. To get the ski out of the water now I had to lean way, way, way back. I got up, straightened up on the seat and boom, went down like i tried to land a jump with straight legs! 2 others in the boat tried . Leaning way back they could level out the dive, but nothing left to climb with. Hard to ride about to fall off the back. We hung our entire butt off the seat back to get more weight back. We shimmed the foil (wrong at first), that helped a tiny bit. We peeled my $47 dollar new seat pad off and it helped a lot(way more than the shim). We added another shim, 2 quarters total,(no seat) and it was better still. But it was still way negative. We moved around on the seat, tried different weight skiers, thought positive thoughts, but none of these raised the board....still way negative. Something has happened and I'm sure I did it....

I left the ski in storage, cant photograph it for a week at least. Could I have the big foil where the little one goes, and have the entire t bar facing the wrong way? It has to be something obvious like that. Last year I would have to go superman to keep the board down at times it had so much lift; now it feels like I'm dragging buckets of water.

XtremeFoils
05-29-2012, 03:16 PM
We once had a friend who had his foil in backwards (front big wing was pointed towards the back of the ski with the back small wing pointed forward). We were kind enough to not tell him when he got on it to ride. Did that exact thing - dove like crazy - he could only ride it 50 feet before letting go. And yes, there was a great deal of laughter involved. So having the foil in backwards could be the problem. Putting on the rear wing upside down will also cause the foil to dive like crazy (heard that from someone to remain nameless) :)

One more thing - you didn't remove the seat tower from the board did you? Putting the seat tower on backwards will also do this.

KO1
05-29-2012, 03:22 PM
Putting on the rear wing upside down will also cause the foil to dive like crazy (heard that from someone to remain nameless) :)

Beejay who??? :laughing:

kc5swi
05-29-2012, 03:26 PM
Thank god I didnt remove the tower from the seat!

I know the larger foil with the rounded front is facing the front of the board, little wing on back. I dont know if the bar they mount to is the same distance from the t bar part. If they can both mount in the same locations on the bar, then maybe I flipped the t bar part around and have the tbar backwards and the foils reversed. The rear foil cant mount upside down due to the little fins that face down. The front foil could be upside down, but the screw holes are countersunk, and I cant imagine they are that way on both sides.

XtremeFoils
05-29-2012, 04:04 PM
Sure sounds like everything is right. No, the front/rear wings cannot be interchanged - hole spacing is different on them. Plus there are 2 bolts for the rear and 3 for the front on your setup. If the rear wing has the winglets facing down, there really isn't much else I can think of.

And yes, I'm sure you would notice if the front wing were upside down since the bolts would stick way above the wing without the countersunk holes.

Pictures would be good. I can't imagine what else it could be.

skyskiguy
05-29-2012, 04:08 PM
Didn't he say it is the old style, plastic Air Chair seat tower? If that is the case, there is no front or rear and you can't possibly install it backwards.

Hangtime
05-29-2012, 04:10 PM
Thank god I didnt remove the tower from the seat!

I know the larger foil with the rounded front is facing the front of the board, little wing on back. I dont know if the bar they mount to is the same distance from the t bar part. If they can both mount in the same locations on the bar, then maybe I flipped the t bar part around and have the tbar backwards and the foils reversed. The rear foil cant mount upside down due to the little fins that face down. The front foil could be upside down, but the screw holes are countersunk, and I cant imagine they are that way on both sides.

There is a plastic shim that is supposed to be on the back wing that moves forward and backward if you dont have one order one from airchair put the fat side all the way to the front edge of back wing if still no lift push it back from there

YJim
05-29-2012, 04:43 PM
Is that the Airchair that had that crazy dihedral rear wing that curved upwards? It swept back for "advanced" riders and swept forward for "Pro" riders? If that's the case, your rear wing is upside down...

kc5swi
05-29-2012, 04:57 PM
It is a 1990s era air chair with the plastic tower, wing nut on top, anodized black t-bar, flat front and rear wing. 3 bolts in front wing, 2 in back.
Bought is "very" used to see if the kids and i would dig it. I havent seen any plastic shim on the back. The bolts all sit flush to the wing top and shimming them doesnt make it look very efficient. Maybe we hit something and it bent a small amount.

Its so weird. I would have thought the thicker seat would raise the molment arm and made it more responsive.

The wings appear to sit flush to the bar, at least before I added the 2 quarters to the front of the rear wing. I just shimmed the front, directly infront of the bolt.

Why does it seem having an air chair is like having a dial telephone these days compared to the sky ski?

skyskiguy
05-29-2012, 05:35 PM
It is impossible to install the seat backwards and there are no shims with the original Air Chairs. A taller seat pad would indeed increase the moment arm above the rotational axis which actually decreases lift - but not by enough to cause the issue you are describing. Just increasing the pad thickness a few inches shouldn't be causing your problem. It's not possible to install the wings in the wrong location - backwards or upside down, perhaps, but not in the wrong location. It sounds as if you have it put together correctly. I'm stumped. Post photos when you can.

kc5swi
05-29-2012, 09:56 PM
It's crazy but i have a photo of the board. I'll have to get 8178the foil and photo it also.

Drossiter
05-29-2012, 10:22 PM
Why does it seem having an air chair is like having a dial telephone these days compared to the sky ski?[/QUOTE]

It has more to do with the age of your hydrofoil than a comparison of the two brands, your riding one of the first generation Air Chairs and compared to the newer products it will not have nearly the performance. The newer Air Chair and Sky Ski products are both high performance and you will see that many of the riders on this forum have combined different parts from several companies to make up their hydrofoil set up.

kc5swi
05-30-2012, 08:53 AM
Ok, if this is a shimming issue, where is the proper place to have the board ride? Should I shim until it's neutral or slightly positive? Can you overshim? Do you ever shim the front foil? Do they make replacement front and rear foils that improve performance? Is it cost effective to alter this one or start over? I looked at the Sky SKi Pro SS. While it is lighter, it appears very similiar to the old one I'm using. Since I'm really just riding the foil, they look really similiar. $1845 seems like a lot to get a shiny foil and an aluminum tower. I think they look great, but its hard to see the $1845 differance in value from purely a performance perspective. It may be something I would have to ride to see, i suppose. I realize one is several pounds lighter, which could be my differance in weight before and after lunch for me....what am i missing?

XtremeFoils
05-30-2012, 10:36 AM
Read this when you get time:

http://www.foilforum.com/forums/showthread.php?252-X-Wing-Setup-Lift-Quickness

There's some other sticky stuff at the top of this list there you may want to learn about as you get more into this sport:
http://www.foilforum.com/forums/forumdisplay.php?8-XTREME-Foils


Basically you are riding the 1st generation of foils. Although they work, we have learned a great deal since then. If all you are looking for is a foil to ride around on, then you are fine. If you are ever planning on jumping/inverting... you will be moving up at some point. The equipment out these days is so much easier to ride. What everyone says is never test ride something you can't afford - most likely you will be buying it. Very true in this case. What you would notice from the new equipment is much less drag, much more responsive and controllable, more air on your tricks, etc. The weight of the foil is a factor, but not as big of one as the other benifits you would see.

Jay
05-30-2012, 10:38 AM
So you were able to ride and fly with no issues until you added the new seat pad?

kc5swi
05-30-2012, 01:29 PM
Last season I rode and flew with more issues with too much lift. I'de have to go superman to push the board down if I flew to high to avoid popping the foil out of the water and dropping suddenly due to a lack of lift. This season I bought an sky ski 3" seat pad, new bindings with heel straps, and a new sky ski belt. I also had disassembled the foil / tbar to move it in a trunk of a smaller car.


When I tried this year, the ski was diving so bad I had issues leaning back far enough to get up. Once up, I had to lean back at maybe a 30-40 degree angle to not submerge. After another two riders tried with the same results, we tried shimming with a quarter. (we were out of town at the lake) It helped maybe enough to tell it made a differance. I ripped the new 3" seat pad off next, that helped quite a bit. We then shimmed with a second quarter, and we could ride and fly maybe a tiny bit, but the drag felt incredible. It was hard to be stable because we were still leaning back a lot to ride neutral.

At this point we were stumped and gave up. Very frusterating...

skyskiguy
05-30-2012, 01:38 PM
Entire foil inserted backwards?

kc5swi
05-30-2012, 01:39 PM
No. rounded big part in front.

Skidude
05-30-2012, 02:02 PM
I'll go out on a limb and say the the rear foil is on backwards. Not upside down, but rather rotated 180 degrees. Just a guess...

kc5swi
05-30-2012, 02:17 PM
I hope so, sending my sister by to snap a photo of the foil this saturday.

Oldgroaner
05-30-2012, 04:36 PM
I have no advice, but i'm so intrigued that I can't wait to find out what the problem was. It's like a cliffhanger.

Arm
05-31-2012, 07:32 AM
Two things that will help solve the issue:

-Post a close up picture or two of the wings assembled on the t-bar? This may clear up what you have and if it's assembled correctly by eliminating the guessing game.

-How fast do you ride? At one point you mentioned that you had to ride in the Superman position (could be caused by going too fast), then something changed & now the ski is diving. Just want to take boat speed into the equation.

kc5swi
05-31-2012, 04:18 PM
I'm getting a picture of the foil soon and will post. We ride at 14-16 mph via gps. Tried up to 18mph. 15.5 felt best...

janked
05-31-2012, 06:40 PM
I may be way off here, but I have a friend with an SS pro that is a couple of years old. I was on his boat for the first day of boating last year and I rode his foil. It had so much drag that I could not get it to fly at all, no matter what I did. It was tarnished a bit, so he polished it up for the first time since it was purchased. Polishing resulted in a HUGE difference in how it rode. The polish job was pretty good, but not perfect. Still needed a little positive shimming, but rode great compared to the oxidized finish. I'm not sure if your setup is polished, anodized, powder coated or what. But maybe someone who reads this could benefit from my experience. Good luck with the troubleshooting.

Foil~N~Powell
05-31-2012, 08:20 PM
Sounds to me like the tbar may be kicked back in the tower. Where it may have been kicked forward before. Check and make sure the gap between the front of the tbar and the slot in the board is the same as the gap between the back of the tbar and the back of the slot. If it's not, loosen the wing nut, even out the gap, and retighten the wing nut. Keep us posted!

skyskiguy
05-31-2012, 10:28 PM
I may be way off here, but I have a friend with an SS pro that is a couple of years old. I was on his boat for the first day of boating last year and I rode his foil. It had so much drag that I could not get it to fly at all, no matter what I did. It was tarnished a bit, so he polished it up for the first time since it was purchased. Polishing resulted in a HUGE difference in how it rode. The polish job was pretty good, but not perfect. Still needed a little positive shimming, but rode great compared to the oxidized finish. I'm not sure if your setup is polished, anodized, powder coated or what. But maybe someone who reads this could benefit from my experience. Good luck with the troubleshooting.

1st generation Air Chair - powder coated. Lots of drag in the design anyway. Shouldn't matter - it still ought to fly. My money says it's something with the way the wings are installed.

Foil~N~Powell
06-07-2012, 11:51 PM
So... what's the verdict?

kc5swi
06-08-2012, 12:06 AM
The foil was on correctly . Ive got a photo to post tonight.

kc5swi
06-08-2012, 10:41 PM
8230

here is the rear fin, front fin normal also. Shim set came in so its time to start testing them out.

Arm
06-09-2012, 06:54 AM
Adding seat height has a similar affect as raising your arms. The additional leverage causes the ski to dive. Counter this my shimming the rear wing. Think of it like an airplane, if the rear/tail wing angles down it forces the front up. It may take a lot of positive shim to counter the extra inches of seat you added. On my old rear wing I had glued (3) guitar picks together, so it was a pretty good amount of shim to add the needed lift. Another analogy as think of it as a See-Saw. As the one side pushes down the other side will come up.

If you really enjoy the sport you may want to consider upgrading your equipment. Someone else posted how valuable seat time was, so spend a little money to really get the most pleasure out of it.