Surfriding Why shorten a hull?

[Dustin Mustangs]

The transom on my blaster is blown out big time so I am going to have to redo the whole rear end of the ski. This is obviously a good time to change things around back there and I’ve got a bunch of ideas floating around in my head. I see a lot of you pole ski guys (and even some blaster guys) are shortening your hull in the back. What is the purpose of this? Is it a flatwater only mod?? Are there any downsides??? Tell me why I should or shouldn’t consider this. I did a search and was surprised I didn't find much on the subject of why...

 

[Matt_E]

On a Superjet, it makes the ski much more responsive to rider input. It becomes very flickable and playful.
It can ride more nose-high, depending on ride plate, pole length, and foothold position.
This makes flips easier.
The shorter length also reduces pearling somewhat.

 

[chriselmore_1]

hack it! I rode a blaster chopped -3 or 4 and it rode completely different. Turns way better and breaks loose effortlessly! So much easier to get the nose up when you want to. But because you ride with your weight forward on a fixed steer anyways you can barely tell a difference when just cruising.

 

[munki63]

Matt, How much did you shorten your hull?

 

[Matt_E]

2 inches. It made a huge difference. Easily the best handling mod to my old Roundnose in six riding seasons.

 

[munki63]

Is there a write-up "How too" thread?

 

[Matt_E]

There are several build threads that feature good instructions.
My own build thread has decent pictures on it, so does SJBrits. There was another one posted just yesterday.

 

[Roo]

The shorter length also reduces pearling somewhat.

i know what a pearl necklace is... :doh:

what does pearling mean in jetski terms?

you mean "porpoising" where the front end of the ski wants to jump up and down when trying to go in a straight line?

 

[Matt_E]

Pearling refers to subbing the nose (and the subsequent spectacular wipe-out) when coming down the face of a wave.

 

[chriselmore_1]

pretty much the oppisite

 

[Roo]

Pearling refers to subbing the nose (and the subsequent spectacular wipe-out) when coming down the face of a wave.

thanks Matt!

i know nothing of riding down a wave living on a inland lake! heh

 

[munki63]

So shortening your hull makes it easier to backflip, what about rolls, stabs and rippenkroeger tricks?

 

[Matt_E]

That depends on the rider and their preferences.
I think certain tricks are easier because of how much quicker the hull responds.

 

[227]

There are down sides to shortening a hull. Every one I've tried seemed like it rode to nose high and it affected the straight line stability. I'm still of the opinion that Yamaha got it right from the beginning

 

[Matt_E]

You're right about riding nose-high. I switched to a -4 pole at the same time, though, so that helped quite a bit (pole, steering, and bracket made for -7.5 over stock)
I did keep a longer, dedicated ride plate around just for surf.

I never noticed any straight line stability problems. I took mine to the low 50's without issues.

 

[Waternut]

I noticed some high speed stability when shortening my old SN but I went -3" and did a 90° cut instead of a nice smooth taper like most people do. The hull begins to walk a little more above around 40mph but that never bothered me much since I rarely ever go that fast.

It's totally rider preference but for lightweight riders, I think it's a must. I'm only 165lbs and I just don't have the ability to sink the back end and manipulate a stock length ski like I want. So when I give it a handful of throttle up a wave with a stock hull, I go a little up and a lot forward. When I can sink the back end just prior to jumping a wave, I am able to go a lot up and a little forward because I'm able to change the angle at which the ski is moving. I've found that I'm able to make low speed turns much tighter on a shortened hull. The back end is usually a little looser on a shortened hull but when it catches, it digs in hard.

 

[Berky]

It makes the ski slash turns a bit more vs carving them .

 

[DK-Freestyle]

So shortening your hull makes it easier to backflip, what about rolls, stabs and rippenkroeger tricks?

My rolls feel a lot more tweaked out on shorter hulls as opposed to on a super jet or when I was doing them on my REV.

 

[wydopen]

It makes the ski slash turns a bit more vs carving them .

dosnt matter how long your ski is...you can do either kind of turn..its all about throttle control and weight distribution..id imagine if anything u cant carve a shortened ski as well as a full length..

 

[Matt_E]

That's true. It will slide out sooner.